Nr1en2020

Revista Minelor Mining Revue AN INTERNATIONAL JOURNAL OF MINING AND ENVIRONMENT Vol. 26 No. 1 / 2020 ISSN-L 1220 – 2053 / ISSN 2247 -8590

Published by: University of Petroşani

REVISTA MINELOR - MINING REVUE EDITORIAL BOARD Editor in chief: Prof. Ilie ONICA Associate editors: Lect. Paul Dacian MARIAN Lect. Lavinia HULEA Senior editors: Prof. Dumitru FODOR Prof. Nicolae ILIAŞ Prof. Mircea GEORGESCU Scientific committee: Prof. Iosif ANDRAS - University of Petroșani, Romania Ph.D eng. Marwan AL HEIB - Ecole des Mines de Nancy, INERIS, France Prof. Victor ARAD - University of Petroșani, Romania Ph.D eng. Horea BENDEA - Politechnico di Torino, Italy Prof. Lucian BOLUNDUȚ - University of Petroșani, Romania Prof. Ioan BUD - Universitatea Tehnică Cluj-Napoca, Romania Prof. Mihai Pascu COLOJA - Universitatea de Petrol și Gaze din Ploiești, Romania Prof. Ştefan COVACI - University of Petroșani, Romania Prof. Eugen COZMA - University of Petroșani, Romania Prof. Nicolae DIMA - University of Petroșani, Romania Prof. Carsten DREBENSTEDT - TU Bergakademie Freiberg, Germany Prof. Ioan DUMITRESCU - University of Petroșani, Romania Ph.D ing. George-Artur GĂMAN - I.N.C.D. INSEMEX Petroşani, Romania Prof. Ioan GÂF-DEAC - Universitatea Dimitrie Cantemir Bucureşti, Romania Ph.D eng. Edmond GOSKOLLI - National Agency of Natural Resources, Albania Prof. Monika HARDIGORA - Technical University of Wroclaw, Poland Prof. Andreea IONICĂ - University of Petroșani, Romania Prof. Alexandr IVANNIKOV - Moscow State Mining University - Rusia Prof. Oleg I. KAZANIN - National Mineral Resources University of Sankt Petersburg, Rusia Prof. Vladimir KEBO - Technical University of Ostrava, Czech Rep. Assoc.prof. Charles KOCSIS - University of Nevada, Reno, U.S.A. Prof. Sanda KRAUSZ - University of Petroșani, Romania Prof. Maria LAZĂR - University of Petroșani, Romania Prof. Monica LEBA - University of Petroșani, Romania Prof. Per Nicolai MARTENS - RWTH Aachen University, Germany Prof. Roland MORARU - University of Petroșani, Romania Prof. Jan PALARSKI - Silesian University of Technology - Gliwice, Poland Prof. George PANAGIOTU - National Technical University of Athens, Greece Prof. Lev PUCHKOV - Moscow State Mining University, Russia Prof. Pavel PAVLOV - University of Mining and Geology St. Ivan Rilsky Sofia, Bulgaria Prof. Sorin Mihai RADU - University of Petroșani, Romania Prof. Ilie ROTUNJANU - University of Petroșani, Romania Ph.D eng. Raj SINGHAL - Int. Journal of Mining, Reclamation and Environment, Canada Prof. Mostafa Mohamed TANTAWY - Assiut University, Egypt Prof. Mihaela TODERAȘ - University of Petroșani, Romania Prof. Lyuben TOTEV - University of Mining and Geology Sofia, Bulgaria Prof. Ingo VALMA - Tallin University of Technology, Estonia Assoc.prof. Ioel VEREȘ - University of Petroșani, Romania Prof. Yuriy VILKUL - Technical University of Krivoi Rog, Ukraine Prof. Işik YILMAZ - Cumhuriyet University, Turkey Acad. Dorel ZUGRĂVESCU - Geodynamics Institute of the Romanian Academy, Romania

CONTENTS

Bogdan CIORUȚA, Alexandru Leonard POP The philatelic testimonies of the Maramureș Mining (I): The beginnings of the local philatelic movement

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Camelia BĂDULESCU Research concerning the recovery of iron oxides from thermocentral ashes

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Camelia BĂDULESCU Use of zeolites in the process of cleaning waste industrial water with heavy metals contents

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Alecsandru Valentin TOMUȘ, Florin G. FAUR Location of underground mining works situated near areas with major tectonic accidents

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Valentin-Ion BOIAN, Marin PALCU, Iulian POPA, Daniel SCRĂDEANU Groundwater resources and reserves evaluation in the southern part of Suhard Mountains

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THE PHILATELIC TESTIMONIES OF THE MARAMURES MINING (I): THE BEGINNINGS OF THE LOCAL PHILATELIC MOVEMENT Bogdan CIORUȚA*, Alexandru Leonard POP** Abstract: The philatelic movement in Maramures County, and especially in Baia Mare area, has an old tradition, following the example of the mining activity. In the following pages, we try, therefore, to pay our tribute to the forerunners by presenting pieces that we have managed to identify and which we have arranged chronologically. We are convinced that precisely there are other pieces (stamps, postcards, occasional envelopes, advertising or specials stamps) that have escaped us, having as a theme the promotion of the Maramures mining activity, however we are confident that the work will find its usefulness. for those who value the beauty of carto-philately, and for the nostalgic who want to remember the evolution of local mining.

Key-words: Maramures mining, postal traffic, the first philatelic testimonies.

1. Introduction The philatelic movement in Maramures County, and especially in Baia Mare area, has an old tradition. Since the beginning of the last century, the existence of groups of philatelists holding exchange meetings was recorded. Also in the same period appeared in Baia Mare and a philatelic magazine, considered a valuable directory for postage stamp collectors. After the reunification of Romania, and especially after the middle of the last century, the philately is experiencing a real development, gaining a mass character - a period that lasted until 1995, when the philatelic phenomenon of Maramures started to suffer a real decline.

But returning shortly, in 1956 the first philatelic circle is established in Baia Mare, under the patronage of the Club of Metallurgical Plants for Nonferrous Metals. In the immediate period, new philatelic circles were set up, both in Baia Mare and in Sighetu Marmaiei, Vişeu de Sus and Borşa. In 1970 the philatelic circles of Baia Sprie and Cavnic were established. Throughout this period philatelic youth circles and students are established in almost every educational institution. Unfortunately, after the Revolution of 1989 they gradually disappear, the interest for philately, especially, among the " free youngers" being less and less.

The opening to the new and technology, in addition to the poor management of those who led the destinies of the Romanian philately (as well as the inflation that affected Romania for many years), by giving up the philatelic shops and counters in the

country, made the young ones to quickly move away from collecting postage stamps and philatelic effects. Only nostalgics and few of those who began to rediscover this passion after their teenage years remained.

The present work aims to make a foray into time and bring to light cracks from the old philatelic activity that existed in our county. We stopped, this time, after addressing the implications of philately in ecological education and promoting protected natural areas [1-3], respectively the implications of philately in relation to the ecological house, architecture and traditional crafts [4-7], and on the implications of philately in relation to mining activity - a well-tried topic on these lands, as a continuation, by others, of natural publications on mining activity [8-10], which have seen previously, and for a while, the light of the pattern .

Let us not forget that Maramures for several generations was a rich mining basin - a thing well exploited by the native philatelists. So we try to pay our tribute to the forerunners by presenting pieces (stamps, postcards, occasional envelopes, advertising stamps or specials) that we have managed to identify and which we have arranged chronologically.

We are confident that the work will find useful for those who value the beauty of cartophilately, and, equally, for nostalgic people who want to remember the evolution of local mining.

* Assoc. teacher PhD eng., inf. - Technical University of Cluj-Napoca, North University Centre of Baia Mare, Office of Informatics, Victor Babeș str., nr. 62A, 430083, Baia Mare, Romania ** Assoc. teacher, syst. eng. - Technical University of Cluj-Napoca, North University Centre of Baia Mare, Office of Informatics, Victor Babeș str., nr. 62A, 430083, Baia Mare, Romania

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Revista Minelor / Mining Revue - no. 1 / 2020

2. The first philatelic testimony of mining in Maramures During the period November 7-17, 1951 in Baia Mare, the first philatelic exhibition in the county, organized by "Miner's Day" was organized. On this occasion, an occasional envelope was published (see fig. 1) by the Ministry of Posts and Telecommunications through the P.T.T. Regional, Baia Mare [11, 12].

It is worth mentioning that, after the exhibition in Constanta in July of the same year, the exhibition hosted in Baia Mare was the second philatelic exhibition in the country.

For the creation of this philatelic piece, the first one with this theme addressed in our county, was used the image used to make the "first day" (FDC) envelope of the "Day of the Miner" issue, which appeared on August 12, 1951. This time the color of the pattern was red , the legends being changed.

Fig. 1. Occasional envelope - "Philatelic exhibition", 7-17.11.1951, Baia Mare For stamping, the stamps of the same issue were used (placed in the upper right corner) [13-15] to which was added the stamp with the nominal value of 2 lei from the "Five Year Plan" issue (LP #292) [16] representing the extraction of coal. The postage thus obtained was purely philatelic, the nominal value resulting not being in accordance with any of the postal tariffs in force at that date. The round stamp of the exhibition was applied in black ink, having as central graphic element, the chisel and the hammer - symbols of mining.

On the occasion of the Philatelic Exhibition in Baia Mare, which took place from October 6 to November 20, 1952, a maximum postcard was made [17, 18] (see Fig. 2). The illustration was stamped with the complete series of stamps "Miner's Day" (LP #328) [13, 19, 20], published on August 15, 1952, and obliterated with the special stamp of the philatelic event.

The supporting illustration, printed in sepia, represents the "Miner" statue displayed in front of the former building belonging to the Baia Mare Technical Middle School of Minerals. According to an article published by Cătălin Vischi in eMaramureș [21], on October 16, 2011, the statue, belonging to the Maramures sculptor Vida Gheza, had been unveiled on August 12, 1951 in Gheorghe Gheorghiu Dej Square (hereafter referred to as Victoria Square, and today known as it is the Revolution Square).

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

Fig. 2. Maximum postcard - "Philatelic Exhibition" Baia Mare - November 6-20, 1952 Seven years later it was replaced (August 9, 1958) with a similar work that exists today. Why the two statues were changed and what is the mystery around them, I invite you to find out by reading the article from the bibliography [21].

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The postage is also a purely philatelic one keeping the theme of the exhibition, the resulting nominal value not being in accordance with the postal rates in force at that date. The round stamp of the exhibition was applied in brown ink, without graphic elements, with the period of the exhibition mentioned centrally.

In trying to find more information about the "MaramureČ™ philatelic exhibition (1944-1969)", we were able to identify only the two occasional envelopes presented in (Fig. 3) [22, 23].

In the semi-illustration of the envelopes we find a stylized graphic of an entrance to the mine (wagons), the scaffolding of an extraction well, and in the background "Stefan Tower" - the emblem of the city of Baia Mare. In the foreground is sketched the face of a MaramureĹ&#x; miner.

Fig. 3. Two occasional envelopes from the Maramures Philatelic Exhibition, 1969 The envelopes are obliterated with the stamps of the show "25th anniversary of the liberation of the homeland" (LP #707) published on August 23, 1969 - and this time the stamp is a purely philatelic one.

The stamp of the exhibition was applied in two shades of ink (black and red). The envelopes were numbered and the print run was high (if we rely on the number of characters in the counter - probably somewhere around 10,000 copies).

As in any traditional mining town, in Cavnic there was an ancient mining band. In olden days, on holidays and Sundays, in the Lighet Park (where there are now blocks of flats - Independence Street) the band sang for those who went for a walk. The Miner's Day was celebrated with great honor on the band's agreements [24]. The event is marked on August 6, when the miners commemorate the ortaces killed during the Lupeni strike, from 1929 [25, 26].

This strike was the first major collective protest of the workers. The objectives of the protesters consisted in obtaining better working conditions, protective equipment, better pay and providing facilities to the families of underground workers, which would ensure their survival.

However, the strike has degenerated into numerous acts of violence, which resulted in the killing of over 20 workers and many others being injured. Since then, the day of August 6 has become officially the Day of the miner, according to Agerpres, having the meaning of commemorating the victims who sacrificed in the struggles to obtain 4

better working conditions and life. In the same context, the victims of the numerous accidents at work in mining and associated activities are also commemorated.

At the same time, Miner's Day promoted the preservation and perpetuation of the customs of the mining community. Today, however, the Miner's Day has become only once in the calendar [27].

Those who remember her stay a few moments in her thoughts, then with a bitter smile return to current affairs.

The first philatelic exhibition in Cavnic "Miner's Day 1970", was organized by the newly established philatelic club in the locality, under the aegis of the Association of Philatelists of Romania (AFR), the county branch of MaramureČ™, between 315 August 1970.

Fig. 4. Occasional envelope - The First Philatelic Exhibition in Cavnic, "Miner's Day - 1970"

Revista Minelor / Mining Revue - no. 1 / 2020

The anniversary envelope (see Fig. 4) [28-32], presents in semi-illustration a mining wagon loaded with ore coming out of a mine at the foot of the Gutâi mountains, next to a stylized portrait of the Maramureş miner. The envelope was stamped with the stamp of the show "Victoria on Fascism" (LP #727), published on May 9, 1970, and was obliterated by the stamp of the Cavnic Post Office on August 3, 1970. The stamp of the exhibition in which the miner's face appears in the illustration of the occasional envelope, it was applied in a complementary black ink, next to the AFR logo.

Established in 1970, the Baia Sprie Philatelic Circle has enjoyed from the beginning an active and creative collective, equally. In this context, even in the second year of existence, the group holds its first philatelic exhibition, which took place on May 1-25, 1971.

The occasional envelope of Fig. 5 [33] presents in semi-illustration a convoy of ore wagons loaded at the mouth of the mine in the city of Baia Sprie, having above them a laurel wreath that fits the party flag (PCR), as well as the text "May 8, 1921-1971", using it is printed, for the first time in Maramureș (from what we noticed), no less than two colors.

Fig. 5. Occasional envelope made at the Baia Sprie Philatelic Circle Exhibition, 1971 The exhibition was also celebrated by the anniversary of the semicentennial P.C.R. (hence the graphic elements used), when stamping the philatelic pieces made using the stamps of the show launched on May 8, 1971 (LP #764). The postage stamps were canceled with the stamp of the Post Office in Baia Sprie on 08.05.1971.

Interesting to mention is that at the time of launching the issue, stamps were already available to Maramureş philatelists. The stamp of the exhibition was complementarily applied, using red ink, in the central area of the envelope.

The philatelic activity in the municipality of Baia Mare had become a rich one at the beginning of the 70's, the Balaimarean philatelists occupying places on the podium at several competitions and exhibitions organized at national level. At the beginning of 1972, for example, the number of philatelists on the banks of the Domnițelor River had far exceeded the value of 700 active members.

Therefore the philatelic activity of the Maramureș County Branch of A.F.R. it was successfully conducted in several circles, clubs and other wellorganized associations.

One of these clubs, which was noted for its exceptional activity, was the one entitled "Săsar Club", its members, most of them miners at the Săsar mine and employed at the Mining Research Institute (hence the name), succeeding. to establish a true ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

philatelic school. The passion and devotion shown by the members paid off, with new memberships becoming more and more frequent.

In 1972, on December 30th, on the occasion of the 25th anniversary of the Republic's establishment (1947-1972), the club organizes the first edition of the exhibition "The Philatelic School of the Săsar Club".

The occasional envelope (see Fig. 6) [34, 35], printed in color (in three colors), has the legend "Anniversary of the Republic / 1947 / XXV / 1972", and in the graphic composition is the symbol of the two flags (the one the red of the party and the tricolor), the "Stefan" tower, a stamped corner in which the image of two young philatelists are reproduced, as well as the emblem with the chisel, the hammer and the candle of the miner (the reason why we selected this piece in the theme of our work).

In the central, upper part, the philatelic piece has the stamp, in black ink, with the mention "First exhibition / The philatelic school of the Săsar Club / 30.12.1972 / Baia Mare", having as a graphic element a stamp of rhomboidal form.

For stamping, the mark with the nominal value of 55 bani was used in the program "The XXV anniversary of the proclamation of the Republic" (LP #813) published on December 10, 1972, which was canceled with the stamp of the Baia Mare Post Office, on 30.12.1972.

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Fig. 6. Occasional envelope made by the Săsar Philatelic Club from Baia Mare, 1972 Work and sport have been, not infrequently, long periods of time. Almost every company in the county had in its organizational scheme a sports club in which the employees could enjoy recreational activities. Even mining operations did not depart from this "rule", many mining teams occupying top positions in the rankings.

In 1980, between July 21-28, it would take place on the stadium "August 23" in Baia Mare "International Football Tournament - Miner Cup".

On this occasion, the Balearic philatelists made an advertising stamp that was applied to the post office specially opened inside the stadium on July 28.

Those who wished could send correspondence or

obtain or make philatelic pieces with the special stamp. In the following figures we reproduce some pieces we encountered. We chose to include this stamp in our theme because the word "MINER" appears in the stamp legend, and the chisel and hammer were used in the graphic element - symbols specific to the mining activity.

The image of the "August 23" Stadium in Baia Mare was used to create two special envelopes that bore the occasional stamp. The first variant (A) shows the stadium on a white background (see Fig. 7a) [36, 37], while variant (B) presents the semiillustration on a yellow background (Fig. 7b) [38].

Fig. 7. Occasional envelope - Minerul Cup 1980: a) variant A; a) variant B Version A was stamped with the nominal value of 1.20 lei with the coat of arms of the municipality of Baia Mare, a piece published in 1979 (LP # 994), while the variant B was stamped using the stamp with the 20-money denomination of the "10 years" issue. of cosmonautics "(LP #642), piece published on February 10, 1967. In Fig. 8 [39] the stamp was applied to an entire postcard (code 0119/1978), noncirculated, issued on the occasion of the World 6

Football Championship in Argentina. The envelope is part of a series of six pieces, with the fixed mark of 55 money representing the cup of the world football championship on a yellow background. The sale price of the entire post office was 1 lei.

The Maramureş philatelists celebrated, in 1980, the "Miner's Day" on several "working fronts". Thus the philatelic groups from Baia Mare, Cavnic and Băiuț (those identified by us) have made thematic Revista Minelor / Mining Revue - no. 1 / 2020

anniversary stamps that were applied to the post offices in the respective localities on August 10th.

The philatelic group from Baia Mare made a stamp depicting the face of a miner wearing a helmet, and the text "NOROC BUN" is inscribed on its luminous beam. In the lower part appears the legend "10 AUGUST 1980 / MINING DAY - MARAMUREȘ".

In Fig. 9a [40] I rendered the image of an envelope "in white" which was stamped with the 10 bani stamp from the usual issue "Monuments" (LP #837) published on December 15th, 1973, and representing the infinity column from Târgu Jiu of the great Romanian sculptor Constantin Brâncuși.

Fig. 8. Special stamp applied to the entire postcard of W.C. of football, Argentina 1978

Fig. 9. Philatelic products made by the Baia Mare group: a) envelope "in white"; b) maximum cover Others, more daring, tried to achieve a maximum (Fig. 9b) [41] using as a support a black and white postcard, which, in the right-front plane, can be seen the statue "Miner" (rear view). As a postmark they used the stamp with the coat of arms of the municipality of Baia Mare, which presents as thematic elements the chisel and the hammer. Both pieces were obliterated with the stamp made by the Balearic philatelists.

At the Cavnic, the philatelic group in the locality, he designed a stamp in which an electrically operated mine train can be observed. The legend "DAY / MINER / MARAMUREȘ / 10 AUGUST / 1980" is aligned on the left side of the graphic box, it being bordered by the chiseled pair and the hammer arranged three times, vertically, on the right side.

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

The first piece identified (Fig. 10a) [42] by us bears the special stamp applied on the entire post code 0437/1976, a series of 12 semi-illustrated envelopes with samples from the Maramureș County Museum - Baia Mare. The present piece (with a fixed stamp with the name of 55 bani and the sale price 1 lei) presents a beautiful specimen of marcasite, a pseudomorphosis after baritone, extracted from the Dniester mine. The second piece identified (Fig. 10b) [43] bears the special stamp applied on the entire postal code 0443/1976, from the same series dedicated to the Maramureș County Museum - Baia Mare. The present piece presents a semi-illustration of a quartz sample, extracted from the Cavnic mine.

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Fig. 10. The special stamp applied on an entire postcard published in 1976: a) variant A; b) variant b In Fig. 11a [44] we have reproduced a letter circulated from Cavnic to Brad (Hunedoara County), in which the stamp of the event was used as a "day stamp" for postage stamps. The piece reached its destination on August 12 (after two days), as can be seen on the arrival stamp applied on the back of the envelope.

The stamp used to stamp the correspondence is the one that reproduces the coat of arms of the county of Maramureș from the usual program "The coat of

arms of the counties from R.S. Romania ”(LP #942) published on September 5, 1977. And this stamp is in the specifics of the mining theme because in the upper right corner an entrance to the mine is illustrated. And in Băiuț there were organized events on this occasion. The stamp applied here presents as a graphic element in the layout a mine lamp framed by the legend "MINER'S DAY / MARAMUREȘ / 10-AUGUST-1980" and bordered, on the right, by the symbol of the chisel and the hammer.

Fig. 11. Envelopes circulated, with the occasional stamp, on the relation: a) Cavnic - Brad; b) Băiuț - Brad In Fig. 11b [45] we find a letter circulated from Băiuț to Brad bearing the special stamp of the event.

And this letter also reached its destination in two days. For those who were curious to follow the cited sources, they could observe that the last two reproductions circulated have the same Dobra Ioan a Balaimian philatelist of the time. Perhaps readers who do not know the Maramures area very well will wonder how this person managed to be in two locations at the same time. During summer time between the two localities there is a 23 km road open to traffic (DJ 109F) over the Rotunda pass. A difficult road, with many curves, unfortunately not properly maintained, but with a wonderful landscape. But, under the conditions it offers, this 8

road allows you to travel the distance between the two localities in about 42 minutes (unless you are "lucky" to break your car there), avoiding a close bypass. 96 km via Baia Mare - Târgu Lăpuș (where it runs normally in winter, when DJ 109F is closed to traffic).

The second piece found bearing the stamp of the stamp presented here, I found on the whole postcard (code 0418/1979) reproduced in Fig. 12a [46]. The envelope is part of a series of six values, with the fixed mark of 55 bani and the sale price of 1 lei, realized on the occasion of the anniversary of "2000 years of documentary-archaeological attestation of the mining operations in the Barza - Brad area".

Revista Minelor / Mining Revue - no. 1 / 2020

Fig. 12. The special stamp applied to an entire postcard: a) published in 1979; b) published in 1976 In Fig. 12b [47] we find the special stamp applied to the entire postcard (code 0447/1976) dedicated to the Maramureș County Museum, Baia Mare. The semi-illustration shows a quartz sample, extracted from the Cavnic mine. Not every year

"Miner's Day" would be celebrated on the same date.

For example, in 1982 it was to be celebrated at Cavnic on August 8. This time the stamp (see Fig. 13) [48] was to bear the artistic signs of an artist passionate about the abstract.

Fig. 13. Occasional envelope with the stamp "Miner's Day Maramureș 1982", August 8, 1982, Cavnic The connection between the stylization of the mineral and the legend of the stamp "Cavnic / August 08, 1982 / Day / Miner / Maramureș" was made in interlocking boxes, the circle with the date and the place of shipment being located on the right, with the role of forgetting the stamp with which it was equipped. philatelic piece.

Because on the anniversary date a letter "other localities" up to 20 grams was charged with 2 lei, the Maramureş philatelists chose to use the postmark from the usual issue (LP #662) that reproduces the image of a postal truck. The envelope shown above bears, on the left side, the day stamp of the Cavnic post office.

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

3. Conclusions We are aware that the ones presented in this paper represent only a small part of the work that the Maramureş philatelists have done in this topic of our philately. Even though we were able to identify a number of other pieces, the time did not allow us to classify them or for most of them we did not find bibliographic information in order to be able to associate them with any major event to support it.

However, we are asking a request from the readers: if there is among you anyone who knows or has more information about this beautiful branch of Maramureş philatelic history and who wants to share his knowledge with us, we invite him, with great love, to collaboration.

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References 1. Pop A., Cioruța B., Coman M., (2017) Considerations regarding the implications of philately in ecological education, Scientific Bulletin of North University Center of Baia Mare, Series D, Mining, Mineral Processing, Non-ferrous Metallurgy, Geology and Environmental Engineering, Baia Mare, vol. XXXI, no. 1, pg. 57-62 2. Cioruța B., Pop A. L., Coman M., Lauran A., (2018) Implications of philately in promoting the protected natural areas (I): Ceahlău National Park, Scientific Bulletin of North University Center of Baia Mare, Series D, Mining, Mineral Processing, Non-ferrous Metallurgy, Geology and Environmental Engineering, Baia Mare, vol.

XXXII, no. 1, pg. 87-96 3. Pop A.L., Cioruța B., Coman M., (2018) Implications of philately in promoting the protected natural areas (II): "Pețea Creek" Natural Reservation, Scientific Bulletin of North University Center of Baia Mare, Series D, Mining, Mineral Processing, Non-ferrous Metallurgy, Geology and Environmental Engineering, Baia Mare, vol. XXXII, nr. 2, pg. 43-52 4. Pop A.L., Cioruța B., (2017) Valences of communication through stamps (I): ecological house and traditional architecture, Scientific Bulletin of North University Center of Baia Mare, Series D, Mining, Mineral Processing, Non-ferrous Metallurgy, Geology and Environmental Engineering, Baia Mare, vol.

XXXI, no. 2, pg. 83-92 5. Cioruța B., Pop A., Coman M., (2018) A Philatelic Review Regarding the Romanian Architectural Tendencies, Acta Technica Napocensis: Civil Engineering & Architecture vol. 61, no. 3, Special Issue: International Conference - Architecture Technology and the City, Workshop Questions, pg. 207216 6. Coman M., Cioruța B., Pop A.L., (2019) Reflections of wood processing in the Romanian philately – part 1: imobil heritage & traditional architecture, Proceedings of the International Conference “Wood Science and Engineering in the third Millennium”, 12 th edition, Transilvania University of Brașov, 0709.11.2019, Publishing House of Transilvania University, ISSN 1843-2689, vol. 1, pg. 208-220 7. Coman M., Pop A.L., Cioruța B., (2019) Reflections of wood processing in the Romanian philately – part 2: mobil heritage & traditional wooden-crafts, Proceedings of the International Conference “Wood Science and Engineering in the third Millennium”, 12 th edition, Transilvania University of Brașov, 0709.11.2019, Publishing House of Transilvania University, ISSN 1843-2689, vol. 1, pg. 221-230 8. Cioruța B. (Ed.), Pop A. L., Coman M., (2019) Philatelic reflections on Romanian mining activities (1945-1975), Lambert Academic Publishing, ISBN-13: 978-613-9-94757-7, ISBN-10: 613994757X, pg. 96

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10. Cioruța B., Pop A.L., Coman M., (2019) Reflections and implications of philately in the promotion of mining and mineral samples, fossils and gems in Romania (I): 1945-1960, Journal of Geography, Environment and Earth Science International (JGEESI ®), vol. 21, no. 3, pg. 1-20 11. Cioruța B., Pop A.L., Coman M., (2019) Reflections of illustrated postcards in the promotion of Romanian mining activities, International Conference “Scientific Research and Education in the Air Force” (AFASES®), 31 May - 02 June 2019, “Henri Coandă” Air Force Academy, Brașov, pg. 98-106 12. www.ebay.com/itm/1951-Miner-Miners-Day-MineMining-Bergmann-Romania-Stamp-Expo-CDScover/192914326817?hash=item2cea970521:g:bOQAA OSwySlaBzmG 13. picclick.com/1951-MinerMinersDayMineMiningBergmannRomaniaStamp-Expo-CDScover-192914326817.html 14. Tudor Gh., Chiricheș C., Mermeze Gh., (2017) Catalogul mărcilor poștale românești 1858-1989 (LP #11233), Editura AXA, București.

15. colnect.com/ro/stamps/stamp/312122Miner_in_work_clothing_shaft_tower-Day_of_MinersRomania 16. colnect.com/ro/stamps/stamp/350650Miner_in_Dress_Uniform-Day_of_Miners-Romania 17. colnect.com/ro/stamps/stamp/459719Coal_production-Five-Year_Plan_1951_to_1955Romania 18. www.delcampe.net/en_US/collectibles/stamps/miner als/romania-1952-mining-memorial-card-minerscommemorative-monument-mine-cachet194847260.html 19. www.okazii.ro/expo-baia-mare-1952-cp-filatelicacu-stampila-speciala-seria-ziua-minerului-a184480101 20. colnect.com/ro/stamps/stamp/543941Miner_with_jackhammer_in_front_of_the_entrance_to_t he_mine-Day_of_the_miners-Romania 21. colnect.com/ro/stamps/stamp/312141Miner_with_jackhammer_in_front_of_mine_entranceDay_of_Miners-Romania 22. Vischi Cătălin DEZVALUIRI – ELUCIDAREA UNUI MISTER – Statuia minerului din Baia Mare, operă a celebrului sculptor Vida Gheza, a fost înlocuită, eMaramureș din 16 octombrie 2011, ediție on-line (www.emaramures.ro/ dezvaluiri-elucidarea-unui-mister-statuia-minerului-dinbaia-mare-opera-a-celebrului-sculptor-vida-gheza-a-fostinlocuita), accesat la data de 22 ianuarie 2020 23. www.delcampe.net/en_US/collectibles/stamps/miner als/romania-1969-minerals-mineraux-exploration-covermining-day-o-96214736.html

Revista Minelor / Mining Revue - no. 1 / 2020

24. www.delcampe.net/en_US/collectibles/stamps/miner als/mining-industry-special-cover-1969-romania229552298.html

36. www.delcampe.net/en_US/collectibles/stamps/miner als/minings-republic-anniversary-special-cover-1972romania-263925746.html

25. Crișan Mircea Fanfara minerilor, articol postat pe site-ul Cavnic – OrașulCavnic.ro - prima pagină a orașului de la poalele Gutâiului, (orasulcavnic.ro/fanfara-minerilor), accesat la 23 ianuarie 2020

37. www.delcampe.net/en_US/collectibles/stamps/soccer /famous-clubs/mining-football-cup-1980-special-coverobliteration-concordante-romania-160110036.html

26. Cîmpian Marius 6 AUGUST – Ziua Minerului era sărbătorită cândva și în Maramureș, din 6 august 2019, Axa News Maramureș, ediție on-line (www.axanews.ro/mm/6august-ziua-minerului-era-sarbatorita-candva-si-inmaramures.html), accesat la data de 23 ianuarie 2020 27. *** Petrecere de „Ziua Minerului”, la Petroșani, articol publicat în ediția on-line (www.servuspress.ro/petrecerede-ziua-minerului-la-petrosani.html) a cotidianului Servus Hunedoara,accesat la 23 ianuarie 2020 28. Teremtuș Nicolae Ziua Minerului, o dată în calendar şi-atât!, articol publicat la data de 17 august 2019, în ediția on-line (www.gazetademaramures.ro/ziua-minerului-o-data-incalendar-si-atat) a săptămânalului Gazeta de Maramureș, accesat 23 ianuarie 2020 29. www.delcampe.net/en_US/collectibles/stamps/miner als/mining-romania-cover-1970.html 30. www.delcampe.net/en_US/collectibles/stamps/miner als/mining-miner-mine-minerals-romania-1972-cavnica-f-r-county-maramures-cover-special-day-miner671486782.html 31. picclick.com/1970-Miners-DayCavnicMineMaramuresBergmannMineurRomaniaspecialcover-192967348009.html 32. www.delcampe.net/en_US/collectibles/stamps/miner als/occasional-envelope-minerals-mining-romania406378097.html

38. www.delcampe.net/en_US/collectibles/stamps/soccer /covers-documents/59160-miners-cup-soccercompetition-special-cover-1980-romania.html 39. www.delcampe.net/en_US/collectibles/stamps/soccer /other/football-miners-cup-1980-special-coverobliteration-concordante-romania.html 40. www.delcampe.net/en_US/collectibles/stamps/socce r-world-cup/1978-argentina/soccerr-world-cupargentina78-miners-cup-special-postmark-coverstationery-entier-postal-1980-romania-389024313.html 41. www.delcampe.net/en_US/collectibles/stamps/miner als/miner-day-1980-meter-mark-on-cover-romania164241737.html 42. www.delcampe.net/en_US/collectibles/stamps/miner als/maxi-card-minerals-romania-day-oilman-10-august1980-baia-mare-432297165.html 43. www.delcampe.net/en_US/collectibles/stamps/miner als/minerals-marcasite-mining-cover-stationery-entierpostal-1980-romania.html 44. www.delcampe.net/en_US/collectibles/stamps/miner als/roumanie-minerals-mineraux-quartz-cavnic-postalstationnery-94849209.html 45. www.delcampe.net/en_US/collectibles/stamps/miner als/miner-s-day-1980-meter-mark-on-cover-romania164242102.html 46. www.delcampe.net/en_US/collectibles/stamps/miner als/romania-1980-mining-mineral-explotacion-mineracancell-on-cover.html

33. www.delcampe.net/en_US/collectibles/stamps/miner als/occasional-envelope-minerals-mining-romania406378069.html

47. www.delcampe.net/en_US/collectibles/stamps/miner als/romania-1979-minerals-mineraux-stibina-coverpostal-stationery-entier-postaux-rare-cancell67152223.html

34. www.delcampe.net/en_US/collectibles/stamps/miner als/mineraux-mineral-mining-1971-very-rare-coverromania-204482056.html

48. www.delcampe.net/en_US/collectibles/stamps/miner als/roumanie-minerals-mineraux-quartz-cavnic137151592.html

35. www.delcampe.net/en_US/collectibles/stamps/roman ia-1948-republics/covers-documents-2/romanianrepublic-anniversary-special-cover-1972-romania598767562.html

49. www.delcampe.net/en_US/collectibles/stamps/miner als/roumanie-obliteration-thematique-mineraux-cavnic8-aout-1982-ziua-minerului-maramures-132544740.html

Scientific reviewer Prof.eng Ph.D Ioan-Lucian BOLUNDUȚ UNIVERSITY OF PETROȘANI

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

11

RESEARCH CONCERNING THE RECOVERY OF IRON OXIDES FROM THERMOCENTRAL ASHES Camelia BĂDULESCU* Abstract: The paper presents the research undertaken in order to recover the iron oxides from the

ashes resulting from the burning of the Jiu Valley coal. By knowing the processes that take place during the combustion of coal in the outbreaks and the chemical and mineralogical properties of the ashes, the idea of recovering the iron oxides was advanced, with the aim of obtaining an iron concentrate with a content that would make it usable in the steel industry.

This approach seeks to restore today one of the most important industrial wastes (ash) which, besides being a polluting agent with adverse repercussions on the environment, can also constitute sources of secondary raw materials, which can be used by technologies adapted to their specific characteristics.

Key words: Jiu Valley coal, ash, iron oxides, marketable Fe concentrate 1. Introduction The ashes from thermoelectric power plants, due to the volume and the multiple possibilities of use, represent the most important industrial waste with special economic and ecological implications, whose use must be a major concern, being imposed by a number of factors such as:  limiting the natural resources of useful minerals;  environmental protection;  finding new sources of secondary raw materials that can be used efficiently after their processing by conventional or unconventional technologies;  limited duration of operation of ash ponds.

Currently in Romania, ash is only used in a proportion of 1% in the construction and construction materials industry, taking into account their specific physic-chemical and mineralogical properties.

In the process of producing electricity in thermos electric power stations, very large quantities of ash are obtained.

In most cases these residues have been and still are considered as waste without use and their disposal represents through the transport, handling and storage operations - important non-productive expenses, which increase the cost price.

The processing of these wastes and the obtaining of reusable by-products is an important problem - at least from a quantitative point of view - and the present work is trying to bring it up to date.

* Assoc.prof.eng. Ph.D. University of Petroșani 12

2. Research concerning the recovery of iron oxides from thermocentral ashes Case study - Ashes from CET Paroșeni 2.1.

The chemical and mineralogical characteristics of the ash from CET Paroseni Knowing the characteristics of the ashes from C.T.E. it is important to establish the areas of their complex and efficient use in various fields.

Coal burning The ash, consisting of the mineral substances remaining after the combustion of the fuel mass, varies considerably from one fuel to another and has a chemical composition different from that of the initial mineral materials due to the reactions that accompany the burning process.

This does not correspond either qualitatively or quantitatively to the waste because, through combustion, a series of reactions occur:  at temperatures above 400 ° C, some minerals begin to lose crystallization water such as iron oxide: 4FeO + O2  2Fe2O3  temperature rise above 570C causes the transformation of iron sulphides into sulfur dioxide and iron oxides as follows: pyrite in the range of 300-500C dissociates thermally by passing into pyrotine according to the reaction: 2FeS2  2FeS + S2 At temperatures above 500 ° C, the iron sulphide resulting from the decomposition of pyrite is oxidized to form iron oxides according to the reaction: 2FeS + 7/2 O2 =Fe2O3 + 2SO2 Siderite during heating, undergoes two main thermal transformations, namely: decomposition of carbonate at 450600 oC which takes place with heat absorption and obtaining ferrous oxide and carbon dioxide, and then, with increasing Revista Minelor / Mining Revue - no. 1 / 2020

temperature, an exothermic effect occurs, related to FeO oxidation to Fe3O4, the final product of oxidation being Fe2O3.

The following transformation reactions take place: 3FeCO3  3FeO + 3CO2 3FeO + CO2  Fe3O4 + CO 3FeCO3  Fe3O4 + 2CO2 + CO 2Fe3O4 + CO2  3Fe2O3 + CO All these transformations are accompanied by secondary reactions, which ultimately determine the chemical composition and properties of the ashes.

Due to their content in the various mineral substances presented above, in the thermodynamic conditions of combustion and cooling, the ashes are presented structurally as consisting of crystalline phases (12-24%) and glass phase (66-88%).

By correlating the thermal analysis, the röntgenostructural and the microscopic observations, the transformations undergone by the main mineral components of the coal at the combustion in thermal power stations were highlighted.

Fig. 1. Röntgendifractometric analysis The physical and mechanical analyzes showed that the ashes from CTE Paroseni are presented as compact powders, as micro-porous spheres or as compact or cavernous glass spheres, high magnetic susceptibility.

Chemical composition Inorganic coal substances, through burning turn to ash. It contains a number of elements present in large quantities known as major elements or macro-elements.

They are found in quantities of more than 1% by weight of ash having a weight that decreases in the order: Si, Al, Fe, Ca, Mg, S, Na, K, Ti, P. Apart from macro-elements whose distribution determines the oxide composition of the ash in coal, there are in small quantities (between 1 ppm and 1%) a number of other elements, known as trace elements, rare elements, minor elements or microelements. Table 1 presents the macro-element contents of the ash from CET Paroșeni.

Table 1. The macro-elements contents of the ash deposit from CET Paroșeni Sample SiO2 Fe2O3 Al2O3 TiO2 CaO MgO SO3 Na2O K2O (%) (%) (%) (%) (%) (%) (%) (%) (%) 47,12 8,68 20,08 0,055 6,30 2,50 0,22 0,98 1,87 Paroseni pound It is found that the major components are: SiO2, Al2O3 and Fe2O3, their sum exceeding 70% which attests the possibility of formation of glass phases as well as of silicates, calcium alumina, etc. with favorable implications on the hydraulic capacity of these ashes.

In the absence of an internationally accepted ash classification criterion, it was proposed by Academic Press (USA) to introduce a classification according to the ratio% SiO2 and% Al2O3 as well as the quantities of% CaO and% SO3. According to this criterion the ashes can be classified into 4 classes: ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

- alumino-silico ash characterized by the ratio

% SiO 2 2 % Al 2 O3 %CaO < 15 - alumino-silico ash characterized by the ratio

% SiO 2 2 % Al 2 O3 % CaO <15

13

The ashes from Paroșeni belong to the silicoaluminous type.

The mineralogical analysis of the ashes from CET Paroseni highlighted the following minerals:

- sulfocalcic ash, for which: % CaO >15 şi %SO3>3 - calcium ash, at which: %CaO>15 şi SO3<3.

Table 2. The mineralogical analysis of the ashes deposit from Paroșeni Content [%] Mineral Chemical formula magnetite hematite sfen pyrite calcite dolomite oxidized sulphate and carbonate compounds of Pb,Zn,Cu metacaolinite caolinite chlorite complex silicates

Fe3O4 Fe2O3 CaTi(SiO4) FeS2 CaCO3 Ca,Mg(CO3) -

0,1 0,35 3,0 0,1-0,15

Al2O3.2SiO2 Al4(Si4O10)(OH)8 (Mg,Fe)5(AlSi3O10)(OH)8 SiO2

2.2. Magnetic concentration tests Considering that the weight of iron ores represented by magnetite, hematite, including those resulting from burning pyrite in the ash of Paroșeni is about 10%, the concentration tests were oriented towards magnetic separation.

This method of concentration is based on the different magnetic properties of the minerals subjected to separation. The process of separation in the magnetic field is characterized by a complexity of phenomena related both to the physico-chemical characteristics of the minerals in the composition of the ore and to the nature of the environment in which the separation takes place, as well as to the constructive characteristics of the magnetic separators.

The main factor influencing the magnetic preparation is the magnetic susceptibility which, depending on its permeability, in turn is directly related to the nature of the substance and its electronic structure. The main factors that influence the magnetic susceptibility of useful mineral substances are:  the presence of mechanical impurities, fixed on the mineral granules;  the presence of impurities contained in the crystalline network and the chemical composition of minerals. The mode of association of crystals that form mineral granules may influence their susceptibility. If the crystals are of different species, the susceptibility depends on the percentage of magnetic 14

10

30-35 35-40 5-10

substance. An influence was also found for granules formed of microcrystals of different orientations;  size of granules. This parameter has a relatively small influence on magnetic susceptibility. From a practical point of view, the influence of the size on the susceptibility can be neglected;  the intensity of the magnetic field inductor. The influence of the magnetic field on the minerals is appreciable only in the case of ferromagnetic substances, when due to the hysteresis phenomenon it is important to know the value of the magnetic field and all the treatments to which the material was subjected;  temperature. Ferromagnetic substances are not influenced by the temperature below the Curie point (Curie temperature - represents the maximum temperature up to which a ferromagnetic substance can be magnetized). The temperature can indirectly influence the magnetic susceptibility, if by its variation phenomena of allotropism occurs;  physical treatments.

Essentially the process of magnetic concentration consists in the different action of the magnetic forces on the components of a mixture in competition with forces of another nature that act in the opposite direction (mechanical forces, viscosity, etc.).

By the triple action of the magnetic forces, the competing forces and the interaction forces, the concentration mixture is divided inside a magnetic separator into a magnetic component, a non-magnetic Revista Minelor / Mining Revue - no. 1 / 2020

one and most often into an intermediate component.

Practical experience has shown that non-magnetic impurities appear in separation products in magnetic ones and vice versa, the separation being complete only in ideal cases.

In order to know the intimate structure of the ash and especially the way of presenting the iron compounds in the ash mass, chalcographic sections were executed on ash samples, the image of which is shown in figure 2.

Fig. 2. Chalcographic section of the ash sample

1-iron oxides 2-cavities 3-waste basis mass

By microscopically examining the ash sample, one can notice the almost globular shape of the iron compounds and at the same time the free existence of these compounds in the silicon mass of the ash.

This form of presentation can be explained by a prior technical study of the combustion process in the drilling.

Thus, in the case of CTE Paroşeni whose ash were analyzed, taking into account the combustion regime, the type of the outbreak, the quality of the coal, etc., a maximum temperature of about 1800C˚ is recorded in the furnace, so that the melting temperature of the of oxides (1030-1580C˚).

This situation determines the melting of the iron oxides and once the ash is drawn towards the lower part of the furnace, by lowering the temperature, solidification of these compounds takes place under unhindered conditions.

Several magnetic separation tests were performed using the Davis magnetic separator provided by the laboratory, at different magnetic field intensities and different working dilutions.

In the table 3 presents the iron contents obtained at different intensities of the magnetic field, at a working dilution of 5 m3/t established as optimal.

Fe content (%)

Table 3. The variation o iron content, depending of the intensity of the magnetic field Sample The intensity of the magnetic Fe content (%) field H (Öe) 1 700 40,91 2 900 45,2 3 1000 48,7 4 1200 51,89 60 Fe content (%) 50 40 30 20 10 0

700

900

1000 1200 Intensity of the magnetic field (Oe)

Fig. 3. The variation of iron content, depending of the intensity of the magnetic field ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

15

The highest iron content was obtained for a magnetic field intensity of 1200 Ă&#x2013;e, respectively 51.89%.

The technological scheme of magnetic concentration of the heavy fraction obtained at the pre-concentration on the tables is presented in fig.4.

Primary magnetic separation

Table 4 presents the Fe contents, the weight and Fe extractions of the obtained products after following the preparation scheme from fig.4, independent for every operation.

Magnetic product cleaning

Radioactive product Magnetic product enrichment

Fe content

Fig. 4. Technological scheme for magnetic concentration of ash from CET Paroseni Table 4. The parameters and indices obtained at the magnetic concentration Specification Primary magnetic separation Magnetic product enriching Magnetic product cleaning

Weight extraction (%) 89,95 10,05 77,24 22,76 30,62 69,38

Following the reprocessing of the products obtained at the primary magnetic separation, an increase of the iron content was obtained from 51.89% to 55.31% at the enrichment of the magnetic product, respectively a reduction of the iron content from 27.89% to 20.19 % as a result of the nonmagnetic product being restated. By applying the wet magnetic concentration method in the weak field, a magnetic product and a non-magnetic radioactive product with 0.016 mRem/h radioactivity were obtained.

3. Conclusions The research carried out in our country and abroad regarding the obtaining of iron oxide concentrates is a major concern for the complex and integral recovery of the ashes from C.T.E. ParoČ&#x2122;eni.

The separation of iron oxides from ash has a double importance and necessity: - creation of a new source of concentrates of ferrous substances usable in the steel industry; - deferred ash from C.T.E. for use in obtaining alumina.

16

Fe content (%) 51,89 27,89 55,31 40,23 45,03 20,19

Fe recovery (%) 94,027 5,97 82,33 17,67 49,44 50,56

In this research field, encouraging results were recorded in different countries such as Poland, Slovakia, Romania.

From the point of view of the chemical composition, respectively of the iron content, the concentrate is similar to the iron concentrates used in the agglomeration or pelletizing process.

The iron is found in these ashes, generally, in the form of magnetite, faialite, hematite, and alkali and alkaline ferrous ferries in a very fine crystalline state, concentrated especially in the spherical granules, accompanied by glass silicates. For the purposes pursued, iron ore minerals of magnetite type are of interest. Magnetite and hematite were identified both in the free granules and especially punctually impregnated in the mass of quartz and silicates. Their weight in the mass of ash is 10-11%.

Conclusive results were obtained by applying the magnetic concentration method, at a magnetic field intensity of 96 KA / m, resulting in a magnetic product whose weight represents 5.92% of the ash mass, at an iron content of 55.31 %.

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References 1. Bãdulescu C., Crãescu I., Traistã E., Ionescu Cl. Research regarding the recovery of some useful mineral substances from the ash resulting from the burning of coal, Ses.comunicãri ştiinţifice Univ. Petroşani, vol.XXVI, p.37., (1993).

2. Bãdulescu C., Traistã E., Ionescu Cl. Precious Metal Extraction from the Ash Resulted from JiuValley Bituminous Coal Burning, 6-th Balkan Conference on Mineral Processing, Ohrid, Macedonia, p.87, (1995).

3. Bãdulescu C., Traistã E. The Administration of Barren Gangue and Flying Ashes Spoil Dumps from Jiu-Valley, România ,3-th Conference on Environment and Mineral Processing, Ostrava, p.141., (1996).

4. Beral I., Zapan C. Chimia anorganicã, Ed. Tehnicã, Buc., s. 842, 862, 869, (1986).

5. Michalikova F., Florekova L. Occurence and Properties of Utility Components in Energetical Fly Ashes, 3-th Conference on Environment and Mineral Processing, Ostrava, p. 314, (1996).

6. Michalikova F., Florekova L.ş.a.

Reclaining of Utility Components by Treatment of Energetical Fly Ashes, 6-th Balkan Conference on Mineral Processing, Ohrid, p. 358, (1995).

7. Michalikova F., Florekova L. Magnetic Separation of Energetical Fly Ashes, 5-th International Symposium on the Reclamation Treatment and Utilization of Coal Mining Wastes, Ostrava, (1996).

8. Neniţescu C.D. Enciclopedia de chimie, Ed. Stiinţificã şi Enciclopedicã, Buc., vol.II, p.247, (1986).

9. Nowak Z. Symposium on Fly Ash Utilization, Pittsburg, (1973)

Scientific reviewer Assoc.prof.eng. Ph.D Emilia-Cornelia DUNCA UNIVERSITY OF PETROȘANI

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

17

USE OF ZEOLITES IN THE PROCESS OF CLEANING WASTE INDUSTRIAL WATER WITH HEAVY METALS CONTENTS Camelia BĂDULESCU* Abstract: The paper presents laboratory tests for the purification of mine waters with the help of zeolites, using as zeolite clinoptinolite, this being a natural zeolite, with a large capacity to remove metal ions from mine waters. The combination of different wastewater cleaning processes results in wastewater treatment technologies. The technological flow must ensure the reduction of pollutant concentrations below the limit allowed by the legislation in force. Mainly, the purification of mine waters requires pH adjustments, ensuring the conditions for producing redox reactions and stabilizing the residues resulting from the treatment. The main processes for wastewater treatment, classified according to the mechanism that leads to the reduction of the pollutant are: physical, chemical and biological processes. Their combination allows for advanced purification.

Key words: industrial waste water, heavy metals, chemical processes, physical processes, biological processes, zeolites 1. Introduction The waste water from the mining industry does not comply with the quality conditions required by the legislation in force regarding: pH, total suspensions, sulphate content, heavy metals, fixed residue, etc.

As pollutants, heavy metals are among the most toxic because of their long persistence in solutions and the difficulty of being transformed into insoluble compounds in surface waters. The danger of heavy metal contamination is increased in the presence of complexing agents, which strongly bind these metals into soluble compounds, which cannot be removed during water treatment.

Pollution of industrial wastewater is the most massive and harmful category of pollution. The causes of the pollution of industrial wastewater emissions originate from the „gaps” in the conception about the production process, the summary examination of the secondary phenomena that influence the results of the basic process, the elimination of waste and by-products without special concerns regarding the consequences that may have on the environment.

In heavy metal pollution of industrial waste water, the largest contributions have the activity of the mining industry, the mineral processing industry, the metallurgical industry, the chemical industry.

Due to their special properties (adsorption, desorption, ion exchange, catalytic), zeolites have become successfully used in the field of control and steering of polluting processes.

Cleaning treatment with zeolites can be said to be a natural and clean method. In addition, the retained substances can be recovered, which represents an economic advantage or an

* Assoc.prof.eng. Ph.D, University of Petroșani 18

internalization of environmental costs. Worldwide, the first place in terms of consumption of zeolites is occupied by Western Europe, followed by North America and Asia; at the end of the ranking - Central and Eastern Europe (Male A., A. Marton, 1989).

Romania, especially Transylvania, has deposits of zeolites which, however, are not sufficiently utilized. Currently there are only a few companies that deal with the exploitation of zeolite volcanic bushes.

2. Procedures of industrial wastewater cleaning The choice of one of the processes is based on: the quantity of effluent, the content in pollutants, the quality conditions imposed by the legislation in force, the financial means of the economic agent.

Physical procedures for wastewater treatment In these processes, pollutants do not undergo transformations into other substances. These processes include: sedimentation, flotation, centrifugation, filtration, membrane separation, phase transfer.

Sedimentation involves the gravitational separation of coarse particles, not dissolved in water, under the influence of the gravitational field; this process can be intensified by coagulation and flocculation (R. Sarbu, 2008).

Flotation is the separation process based on the differences between the surface properties of the solid particles. At the base of this process is the adhesion of solid particles to the gas bubbles with the formation of bubble-particle aggregates to be transported to the surface of the water, forming a foam that is removed by different processes (S. Krausz, P. Ilie, 2001).

Centrifugation is the process of separating the suspensions from the water in centrifugal field.

Revista Minelor / Mining Revue - no. 1 / 2020

Sedimentation rates are high, which results in a greater mass separation of mineral suspensions in the unit of time.

Filtration - is the process of passing water through a porous environment, on which the retention, through predominantly physical phenomena, of some of the constituents of waste water takes place.

Membrane separation. The membrane is defined as a phase that acts as a barrier for the molecular or ionic species in the water, through which the membrane can only pass water molecules.

Of the processes that use membrane separation, the largest use is: direct and reverse osmosis, ultrafiltration and electro-dialysis.

Chemical procedures for wastewater treatment Through chemical purification processes, the pollutants are transformed into other substances more easily separated such as: insoluble precipitates, gases, which have a lower harmful activity or are more likely to be removed. The chemical procedures applied for wastewater treatment are: neutralization, oxidation and reduction, precipitation, coagulation and flocculation, ion exchange on resins.

Neutralization is a process by which the pH of a water is regulated by the addition of acids or bases.

This process also has the effect of reducing the corrosive properties of the water.

Oxidation and reduction - the purpose of this process is to convert undesirable chemical compounds into less harmful ones.

Precipitation realizes the transformation of pollutants from wastewater into insoluble products that can be subsequently separated from water.

Cyanides, salts of alkali metals, sulphides, orthophosphates, proteins, aromatic amines can be removed by precipitation.

Coagulation and flocculation. The term coagulation is used to describe the destabilization process produced by the compression of the two electrical coatings that surround the colloidal particles, which makes it possible to aggregate them and thereby decrease the specific surface of the system. The term flocculation refers to destabilization by adsorption of large polymer molecules that form bridges between particles.

Treatment by ion exchange is based on the property of some materials, which come into contact with mineralized water (containing ionized salts), replacing the ions in the water with the ions coming from the material itself.

Processes for biological treatment of waste water By biological purification is meant the complex of operations and technological phases through which the organic matter existing in the waste water

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, PetroĹ&#x;ani, Romania

is transformed, with the help of cultures of microorganisms, into products of harmless degradation and a new cell mass (biomass), harmless.

Biological treatment of wastewater containing metal ions can be done by two methods: 1.Reduction of metals and their precipitation in the form of sulfides by means of sulfate-reducing bacteria; Sulphate-reducing bacteria have the ability to reduce the sulphate ion by several steps, until the formation of hydrogen sulphide, which reacts with metal ions from wastewater and transforms them into precipitating sulfides and thus can be separated and removed by decantation and filtration.

2. Extraction of metals from water through their sorption on biological materials, process known as bio-sorption of metals. (C. Badulescu, 2010). The process uses living or dead biomass to hold impurities, especially rare metals and radioactive metals, from waste water.

3. Research on the use of zeolites in treatment of waters loaded with metal ions General considerations Zeolites are minerals that have hydrated aluminosilicates in their composition and have a high porosity structure having large areas of internal and external surface for ion exchange.

Zeolites have a significant importance in the efficiency of water treatment processes with concentrations of silicon dioxide, aluminum oxide, as well as the exchangeable cations K +, Ca2+, Mg2+ and other elements present in lower concentrations.

Depending on the proportion of exchangeable cations, the type of zeolite can be characterized.

The selectivity is the characteristic of the ion exchange material to have affinity for the particular ions and is closely interrelated with the intensity of the fields in the zeolite pores.

Zeolites with high intensity fields, with higher Al content, are more selective than metal cations with a high charge density (Li+, Na+).If the solution contains different ions having the same charge, the selectivity increases, in proportion to the increase in the atomic number. (Li+> Na+> NH4+> K+).

The exchangeable cations in the volcanic tuffs of zeolites, such as (Na+, K+, Ca2+, Ba2+) are located in a network of channels being surrounded by water molecules, which gives them high mobility, being able to exchange metal ions.

Zeolites have a negative electrical charge due to isomorphic substitution of cations in mineral structures. They have a high affinity for metal cations and a low affinity for anions (T. Rusu, A. Rusu-2009). The heavy metals in the form of dissolved ions will move through the channels of the 19

zeolite materials replacing their exchangeable cations: (Na+, K+, Ca2+, Mg2+) (T. CÄ&#x192;tuneau, et all, 2010).

The adsorption efficiency of metal ions is determined by the relation: đ??śđ?&#x2018;&#x2013;â&#x2C6;&#x2019;đ??śđ?&#x2018;&#x201C; Ρ(%) = đ??śđ?&#x2018;&#x201C; .100 where: Ciâ&#x20AC;&#x201C;ions concentration before adsorbtion; Cf â&#x20AC;&#x201C;ions concentration after adsorbtion.

Natural zeolites have multiple advantages over cation exchange resins, as they have a low cost price, having a very high selectivity for different metal cations. For the definition and identification of the different types of natural zeolites, chemical and

instrumental analyzes of great importance are used, for the development of research on water treatment (Szollosi-MoČ&#x203A;a A, et all, 2017).

A general technological scheme for treatment with zeolites of waste water with metal ions, with zeolites, is shown in Figure 1.

The technological flow involves the removal of coarse materials with the help of a grate, the settling of mineral suspensions with the help of the decanters, after which, the waters charged with metal ions, will pass through the sludge decanter and will be treated in three steps passing through filters with zeolites, in order to efficiently remove them. of heavy metals (Semsettin A, Gul Huseyin, 2007).

Fig.1 The technological scheme for treatment with zeolites of waste water with metal ions The research has focused on purifying mine waters, charged with heavy metal ions, using zeolite as clinoptinolite because it has a very good adsorption capacity, being a natural zeolite, applicable because it has a very good removal efficiency of metal ions. Clinoptilolite is part of the

stability group and is one of the most representative exponents of volcanic bushes in our country.

In the table no. 1 presents the chemical and mineralogical composition of the volcanic tuff clinoptinolite. (T.Rusu , A. Rusu, 2009).

Table 1. The chemical and mineralogical composition of the volcanic tuff Chemical compound % Mineralogic compound SiO2 11,7- 12,62 Clinoptilolite + heulandite Al2O3 68,12- 70,06 Volcanic glass Fe2O3 0,67-1,06 Quartz CaO 3,36-4,82 Biotite MgO 0,55-0,82 Limonite, goethite K2O 2,20-3,5 Celadonite, chlorite Na2O 20,40-20,60 TiO2 0,18-0,24 P.C. 8,40- 10,61 20

% 20-80 10-64 2-5 2-3 0,5 1,2

Revista Minelor / Mining Revue - no. 1 / 2020

Laboratory research has focused on removing from the analyzed mine waters heavy metals: cadmium, copper, zinc, iron, manganese. The metal concentrations in the analyzed water sample are shown in table no.2 (NTPA001 / 2005) Table 2. Concentrations of metals in the analyzed water sample Metal Metal Admissible concentration concentration (mg/l) for evacuation (mg/l) Cadmium 0,077 0,2 Copper 0,249 0,1 Iron 0,870 5 Manganese 9,61 1 Zincum 17,90 0,5

Photo zeolite Zeolite volcanic tuff requires a succession of preparatory operations (physical treatment, chemical treatment) in order to be used in ion exchange processes. The physical treatment consists of grinding the volcanic tuff in the ball mill, followed by its sorting on granulometric classes (<0.2 mm, 0.2-0.4 mm, 0.4-0.6 mm and 0.6-1, 0 mm) with the help of a vibrating site.

The physical treatment is completed with the washing step of the zeolite volcanic tuff with distilled water until the complete removal of very fine powder that could clog the pores, followed by drying in the oven at 105 ° C for 6 hours.

The chemical treatment consists of bringing the natural zeolite into the form - Na, which has proven to be the most efficient in ion exchange processes.

The treatment involves the introduction of the zeolite resulting from the physical process together with the sodium chloride solution, in a stirrer, the solid ratio: liquid used being 1:10, the conditioning time being one hour. After decanting the solution, the solid is washed with distilled water until the pH of the water reaches 7. The zeolite in the form - Na (Z - Na) is thus obtained.

The highest concentration is zinc and manganese with significant exceedance of the maximum permissible concentrations. In order to determine the physic-chemical properties of the waters, the pH and the conductivity of the samples collected from the discharged waters from the analyzed mining areas were determined.

The samples collected from the waters of the mining perimeters have pH values between 3.09 and 5.8, the value admitted by NTPA 001/2005 being 6.5-8.5. The experimental tests aimed at obtaining the highest purification yields.

In the table no. 3 shows the pH and conductivity values for the water samples from mining perimeters, the settling time on the zeolite columns being 1 hour, 2 hours and 72 hours.

In order to study the degree of purification, under static regime, experiments were performed on the purification efficiency of the samples, the residual water samples being kept on the columns with zeolites for one hour, two hours, respectively 72 hours. (table 3)

Table 3. pH values and electrical conductivity of waste water after settling on columns with volcanic tuff Column pH ,unit.pH Conductivity, ÎźS/cm Settling

Settling

Settling

Settling

Settling

Settling

time

time

time

time

time

time

1hour

2 hours

72 hours

1hour

2hours

72 hours

Column 1

6,89

7,25

6,89

921

1163

1153

Column 2

7,39

7,29

7,39

1036

1203

1244

Column 3

7,57

7,45

7,57

1117

1244

1276

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21

8

1400

1 hour

7

1200

2 hours

6

1 hour 2 hours

1000 72 hours

5 4

72 hours

800 600

3

400

2

200

1

0

0

column 1 column 2 column 3

column 1 column 2 column 3

Fig. 2. pH variation in correlation with the settling time in columns with zeolites

Fig. 3. Conductivity variation (ÂľS/cm) in correlation with the settling time in columns with zeolites

In order to determine the degree of purification of the water samples charged with metal ions, the initial concentration of the metals and the concentration following the purification were determined using the purification columns. (table 4).

Figure 4 shows the degree of purification achieved, on the three columns with zeolites, depending on the time of settling the waste water on columns, respectively 1 hour, 2 hours, 72 hours.

Table 4. The degree of purification on columns according to the time of the stand Metal The degree of The degree of The degree of purification, % purification, % purification, % 1 hour 2 hours 72 hours Cadmium 93,22 94,92 99,00 Copper 22,10 57,20 76,38 Iron 91,16 92,07 96,09 Manganese 85,10 97,22 96,70 Zincum 99,60 99,00 97,04 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

98.99

78.05

95.82

96.27

96.98

96.67

92

98.07

99.04 72 hours

58.1

2 hours 91.2

92.34

99.58

86.3

1 hour

23.09 Cd

Cu

Fe

Mn

Zn

Fig. 4. Degree of purification (%) on columns with zeolites, depending on the time of waste water stationing 4. Conclusions Experimentation of new efficient and lower cost methods, compared to other methods, for removing metallic pollutants from mine waters is one of the priorities in the field of water purification from mining areas.

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Industrial waste waters are characterized by a high concentration of heavy metals whose elimination or reduction implies the application of physical, chemical or biological processes. By combining different processes, wastewater treatment technologies are born whose flow must Revista Minelor / Mining Revue - no. 1 / 2020

ensure the reduction of pollutant concentrations below the limits imposed by the legislation in the field.

In order to choose the most suitable method of treatment of wastewater containing heavy metals, a comparative study is required, depending on the composition of the waste water to be treated, the level of neutralization that can be achieved and the concrete conditions existing in the respective locations.

Volcanic tuff is abundant, is environmentally friendly and cheap to exploit, having efficiency similar to the synthetic resins used today, but very expensive.

The most important benefits of using zeolites for the manufacture of filter cartridges required for industrial wastewater treatment are: light and durable; environmentally friendly and recyclable; resistant to temperature variations; resistant to atmospheric agents, acids, corrosions and immune to mold and lichens; easy to install; easy to move.

The use of the natural ion exchanger - the clinoptinolite volcanic tuff - for the retention of copper, zinc, cadmium, manganese, iron ions has the following advantages: - high natural availability - accessible exploitation - rich resources - low price - recycling possibilities.

The ion exchange between the zeolites and the metal ions analyzed is a process of adsorption chemical reaction - desorption, and through experimental research it was concluded that, from a kinetic point of view, ion transfer through the pores of the zeolites is the stage that conditions the process.

3. Bennett, P.G. et al Biological treatment of acod mine waters- case studies.

In Proceedings of second International Conference on the Abatement of Acidic Drainage, 1991; 4. Cătuneanu T, Mircea L. Reciclarea apelor uzate industrial, cu conłinut de metale grele, prin schimb ionic , A XI- a Conferință multidisciplinară Prof. Dorin Pavel, Sebeș, 2010; 5. Krausz S, Ilie P. Teoria și tehnologia flotației, Ed. Matrix Rom, Bucuresti, 2001; 6. Sârbu R. Procedee și echipamente de epurare a apelor reziduale, Ed Focus, Petroșani, 2008; 7. Rusu T, Rusu A. Purificarea Apelor Reziduale cu ajutorul Schimbătorilor de Ioni Naturali, ProEnvironment 2 (2009) ; 8. Semsettin A, Gul Huseyin Concentration of heavy metals in water and chub (Leuscicus Chepalus) from the river Yildiz , Turkey , Journal of enviromental Biology ,2007; 9. Szollosi-Moța A., Prodan Maria, Ghicioi E, Nălboc Irina, Moldovan Clementina Heavy metals removal from mining drainage acid water by use of natural zeolites Environmental Enginering and Management Jurnal, Iași - Iunie 2017, Vol 16, No 6.

1383-1388; 10. xxx NTPA 001/2005 – Valori-limită de încărcare cu poluanți a apelor uzate industriale și orășenesti în receptori naturali

Bibliografie 1. Bădulescu C. Biotehnologii în protecția mediului, Ed Universitas, 2010, Petrosani 2. Bărbat A., A. Marton The zeolite volcanic tuff, Cluj-Napoca, Editura Dacia, 1989;

Scientific reviewer Assoc.prof.eng.Ph.D Daniela-Ionela CIOLEA UNIVERSITY OF PETROȘANI

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

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LOCATION OF UNDERGROUND MINING WORKS SITUATED NEAR AREAS WITH MAJOR TECTONIC ACCIDENTS Alecsandru Valentin TOMUȘ*, Florin G. FAUR** Abstract The paper presents a method for determining the minimum safety distance of underground workings from areas with major tectonic accidents (block faults). Of course, the proposed method was applied for a case study (a concrete situation encountered in one of the underground mining operations in the Jiu Valley), and for its validation other determinations must be made, for other similar situations.

Keywords: tectonic accidents, mining support establishment, safety pillar 1. Introduction The sedimentary of the Jiu Valley mining basin is a rock stratification massif; it is a succession of extremely diversified layers, of variable thicknesses, which gives it a dense sediment structure. Based on the fact that it can be ascertained, it can be stated from a geo-mechanical point of view, the rock massif is of discontinuous heterogeneity.

The tectonic evolution of the depression in Petroșani is a development as it recedes, given that it exists in certain parts and in other parts of the basin.

The litho-facial evolution of the basin sedimentary is diversified; this occurred in the eastern area for a longer period than in the western area.

The phenomena and actions of tectonic nature with general orientation northwest-west-south is a product in time or a series of cracks and fractures, the care gives the mining basin Jiu Valley appearance with graben.

The main categories of rocks related to the Jiu Valley coal basin are sandstones, clays, marls, marllimestone, micro-conglomerates, with their varieties. From the geological mapping carried out so far, it was found that, starting from the bed of layer 3, the types of intercepted rocks are, in order: sandstones, clays, marls or coal.

the massif are the consequences of macro and microscopic fragmentation, with special influence on these mining works related to the technological process of coal extraction.

Therefore, the elaboration of the framework methods for the exploitation of coal seams, but especially of the thick ones, extracted by the method with undermined coal bank, must be the exact knowledge of the areas with tectonic accidents of the massif [3].

The analysis of the stability of the mining works (inclined attack planes) executed near the areas with tectonic accidents must take into account both the parameters that characterize the natural conditions (depth of exploitation, the nature of the rocks in the fault and the roof of the layer) and those specific to exploitation conditions (shape and size of the work profile, execution technology).

The depth of location of mining works (plans, attack galleries) is one of the most important technical-mining factors in ensuring their stability.

As the depth increases, there is practically a change in the geo-mechanical properties of the surrounding rocks, a transition of them to a limit state that influences the stability of the work. The natural and secondary state of tension is amplified [3].

2. Theoretical considerations In the coal mines of the Jiu Valley the assessment of the stability of mining works located near tectonic disturbances is based on the experience gained over time by mining in this basin in conjunction with systematic research on the geological, hydrogeological, mechanical and rheological characteristics of rocks and coal (pit coal) which make up the analyzed area.

Knowledge of these characteristics is a sine qua non condition for the location of mining works (eg. inclined planes of attack) near major tectonic disturbances (block faults) because heterogeneity, anisotropy, heterotopy and non-elastic behavior of ______________________________________ * Eng. Ph.D University of Petroșani ** Lect.eng Ph.D University of Petroșani

3. Determining the stability of mining works located in areas with tectonic accidents One of the procedures to ensure the stability of inclined planes (galleries) of attack located in areas with tectonic accidents is to leave some safety pillars.

To determine their size, the block fault was assimilated with a slope.

In order to verify the stability of the slope, in addition to knowing its geometric elements, it is necessary to choose the calculation values for the geotechnical characteristics of the component rocks [2, 5].

In the following, knowing the stratigraphic columns based on research drilling, the existing mapping at mining operations, as well as geomechanical studies, conducted over time by

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Revista Minelor / Mining Revue - no. 1 / 2020

specialists in the field, will present an example of calculating the stability of a step that it has in its composition a thick layer of coal and the rocks from its direct roof, a step whose slope is assimilated to a fault.

The calculation data are as follows: - the apparent (volumetric) weight of the coal in the step composition: γac = 13 kN/m3; - apparent (volumetric) weight of the rocks in the direct roof: γas = 26 kN/m3; - coal cohesion: cc = 1500 kN/m2; - cohesion of waste rocks: cs = 6000 kN/m2; - the internal friction angle of the coal: φc = 400; - the internal friction angle of waste rocks: φs = 500; - angle of inclination of the fault (slope of the step): β = 600 or slope 1: m = 1: 0.58; - inclination of the coal seam and the direct roof: α = 450; - thickness of the coal layer: g = 25 m; - thickness of rocks from the direct roof: g1 = 12 m; ( g  g1 )  sin 600 - step height: H = = 33 m; cos(600  450 ) - the stress at the upper part of the analysed fault area: p = 2000 kN/m; - stress on the fault (slope): p = 2000 kN/m.

For the stability analyses of the slope, a specialized software in geo-technics was used. This is a 2D software that analyzes the stability of natural and artificial slopes, with complex geometry, composed of homogeneous or heterogeneous rocks, developed by Rocscience. It is designed to assess the safety factor or the probability of failure, for circular or non-circular surfaces, for weakly cohesive or cohesive materials [6]. Although it is a very simple software to use, the program can create and analyze complex models, under normal static conditions or taking into account seismic shocks, overloads, the influence of groundwater, cracks due to tension or various structures to increase the stability reserve (retaining walls, anchors etc.)

Slide analyses the stability by the method of vertical stripes at the equilibrium limit. Individual surfaces can be analyzed or methods for determining critical slip surfaces for a given slope can be applied.

The first step in using the software is to model the slope and introduce the physical and geomechanical characteristics of the rocks (volumetric weight, cohesion and internal friction angle).

The next step is to define the sliding surface or grid that contains possible sliding surfaces. The program automatically calculates the stability coefficients, using for this purpose several methods (Fellenius, Janbu, Bishop, Spencer, Morgenstern-

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

Price etc.). Finally, the critical slip area is determined, which corresponds to the minimum value of the stability coefficient [1].

Only the Fellenius method was used for this study, as this method (confirmed by countless previous studies) leads to the lowest values of the stability coefficient. The method assumes that the sliding surface follows a cylindrical-circular (curved) pattern. The stability of the slope is analyzed in the hypothesis of the boundary equilibrium between the active and passive forces acting on the sliding prism [1, 4]. To calculate the value of the stability coefficient, the sliding prism is divided into several vertical strips. The forces acting on each strip (in the absence of seismic shocks) are highlighted in fig. no. 1.

Fig. 1. Forces acting on a strip [1] Notations in the figure: Wi – strip’s weight; Ni – normal component of the force of gravity; Ti – tangential component of the force of gravity; Ei – horizontal forces transmitted to neighboring strips; Xi – vertical forces between neighboring strips; αi – inclination of the strip (to the horizontal); li – width of the strip; The numerical solution of the stability coefficient was obtained assuming that the horizontal and vertical forces that occur along the strips (Ei, Xi) are equal to zero. Starting from the equilibrium condition, the stability coefficient Fs of a slope is calculated by the formula [1]:

n n tg  Wi  cos  i   c  li 1 1 Fs  n   Wi  sin  i 1 where: c – rock’s cohesion along the strip; φ – angle of internal friction along the strip; n – number of considered strips.

25

Fig. 2. Determining the minimum stability coefficient and the critical sliding surface In the analyzed model, the overloads given by the weight of the rocks acting on the upper berm and on the slope p = 2000 kN/m were also taken into account (fig. no. 2).

After running the calculation algorithm, the solution, from fig. no. 2 (potential sliding surface, corresponding to the lowest value of the stability factor), is obtained. From this figure, it can be observed that the farthest point of the critical sliding surface to the slope, and so to the fault, is at 25.393 m.

4. Conclusions and suggestions The proposed method for determining the minimum distance for the location of underground mining works from areas with major tectonic accidents is a simple one, which can be applied to other concrete situations encountered in practice.

The minimum distance of underground mining works from areas with major tectonic accidents is similar to that determined by other procedures and methods, but which involves a much larger volume of calculation and complex modeling.

Following the results of the above calculations, for this case study, it is proposed that the location of the inclined planes (galleries) of attack of the abattoirs be made at a minimum safety distance of 25.5 m from the areas with major tectonic accidents (block faults).

Also, if the advance direction of the working front is towards the fault, the exploitation will be stopped at a distance of at least 25.5 m from it.

26

This minimum safety distance is variable, specific for each situation analyzed, as it depends both on the characteristic geometric elements (slope inclination, coal layer inclination, its thickness, etc.) and on the physical and geo-mechanical characteristics of coal and rocks in direct roof.

References 1. Lazăr, M., Nyari, I.M., Faur, F. Methodology for Assessing the Environmental Risk due to Mining Waste Dumps Sliding - Case Study of Jiu Valley, Carpathian Journal of Earth and Environmental Sciences, Vol. 10 (3), pp. 223-234, 2015.

2. Manea, S. Assessment of the landslide risck (in Romanian), Conpress Publishing, București, 1998.

3. Onica, I., Mining Exploitations (in Publishing, Petroșani, 2016.

Romanian),

Universitas

4. Popa, A, Geotechnics (in Romanian), U.T. Press Publishing, ClujNapoca, 2004.

5. Roman, F. Applications in geotechnical engineering (in Romanian), Geo Publishing, București, 2011.

6. *** www.rocscience.com

Scientific reviewer Prof.eng. Ph.D Mircea GEORGESCU UNIVERSITY OF PETROȘANI Revista Minelor / Mining Revue - no. 1 / 2020

GROUNDWATER RESOURCES AND RESERVES EVALUATION IN THE SOUTHERN PART OF SUHARD MOUNTAINS Valentin-Ion BOIAN*, Marin PALCU**, Iulian POPA***, Daniel SCRÄ&#x201A;DEANU**** Abstract: The evaluation of groundwater resources and reserves was performed in Ousorul â&#x20AC;&#x201C; Livada hydrostructure, located in the southern part of Suhard Mountains, by using a site-specific algorithm, specially developed for this purpose. The general evaluation of groundwater potential was completed by basic climate and hydrological studies. Therefore, the specific groundwater discharge was extracted from river hydrographs while the value of yearly evopotranspiration was calculated from climate data. The conceptual model of the hydrostructure, developed in a previous phase of the research work, was further completed with hydrogeological parameters, calculated from pumping tests performed in four boreholes, by graphic-analytical methods Key words: evapotranspiration, specific groundwater discharge, pumping tests, resources and reserves 1. Introduction The objective of this scientific paper is to calculate the groundwater resources and reserves in a study area from the south part of Suhard Mountains. The studied perimeters is bordered to the South by Dorna river, to West by Cosna rivers, to North by the water divide between Catariga and Ciotina valleys until Livezii peak (1,389 m), continued to Ousorul crest (1,638 m), and the water divide towards Haju peak (1,238 m), and to the East by the water divide between Haju and Selesvar rivers. The perimeter was such selected to overlay the hydrographic basins.

2. Methods The field works were conducted based on a research contract for groundwater resources, while the data processing and interpretation were realized as part of doctoral thesis proposed by Valentin-Ion Boian â&#x20AC;&#x153;Complex hydrogeological research in flysch area of Carpathian orogenâ&#x20AC;?. The conceptual model was developed by the authors as part of the same doctoral program, and the results were published in Revista Minelor, 2019, Vol. 25, Issue 4, p24-28.

2.1. Climate works Considering that groundwater recharge is done by surface infiltration (rain, snow melting, morning dew), the research program included weather monitoring, by using the automatic digital Davis station, WeatherLink model, with continuous data storing. The weather station was located in Dealu Floreni area, STEREO70 coordinates: X = 517,255, Y = 652,104, at an altitude of 890 m, consisting of

* Ph.D stud. eng. geol., University of BucureČ&#x2122;ti ** Ph.D stud. eng. geol., GeoAqua Consult SRL *** Lect.eng. Ph.D, University of BucureČ&#x2122;ti **** Prof.eng. Ph.D, University of BucureČ&#x2122;ti ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, PetroĹ&#x;ani, Romania

weathervane for wind speed and direction, temperature sensor, and pluviometer for rain measurement, with reading frequency of 2h and continuous data storage of 1 month. The weather monitoring was extended continuously during August 2005 â&#x20AC;&#x201C; October 2009.

Starting from the general water balance equation: đ?&#x2018;&#x192; = đ??¸ + đ?&#x2018;&#x2026; + đ??ź, where: P = total precipitation, E = evapotranspiration, R = surface runoff, I = groundwater infiltration, we can calculate the yearly value of evapotranspiration, by using Turc formula, as described by Roberto Chetoni in Acque Minerali e Termali, Italgrafica Segale Segrate, 2000, chapter 9.7.17: đ?&#x2018;&#x192; đ??¸đ?&#x2018;&#x; = ; đ??ż = 300 + 15đ?&#x2018;&#x2021; + 0.05đ?&#x2018;&#x2021; 3 2 â&#x2C6;&#x161;0.9+đ?&#x2018;&#x192;2 đ??ż

where: Er = real evapotranspiration, in mm/yr, P = yearly precipitation in mm/yr, L = evaporation capacity, T = yearly mean air temperature, in °C 2.2. Hydrological research The hydrological study was conducted in the following steps: ď&#x201A;§ Mapping of hydrographic basins out of the level curves exported from satellite images SRTM (Satellite Radio Topographic Mission); ď&#x201A;§ Hydraulic measurements on the downstream section of all collectors from the study area, in order to calculate the limnimetric keys; ď&#x201A;§ Flow monitoring of all collectors, during June 2008 â&#x20AC;&#x201C; May 2010; ď&#x201A;§ Calculation of river flow rates at to 5% and 80% probability from the time series, corresponding to storm events and minimum discharge values; ď&#x201A;§ Calculation of main hydro-morphological parameters for each hydrographic basin.

27

The hydrographic basins were mapped according to geomorphological rules, by digitizing the topographical map. For the main river collector of each hydrographic basin, the morphology and flow rate were measured in situ, in order to calculate the limnimetric keys. In parallel with the measurements for the limnimetric keys, there was implemented a weekly monitoring program for the water level, during June 2008 â&#x20AC;&#x201C; June 2010.

The hydro-morphological parameters calculated are the surface of hydrographic basins, flow rate at 5% and 80% return rate, specific groundwater discharge, and the contribution of groundwater discharge to total flow rate. The hydromorphological calculation followed the methodology described by Ugo Maione in Le Piene Fluviale, 2nd Edition, La Goliardica Pavese, 1999.

In this handbook, the author describes the various possibilities to extract the groundwater discharge value from the storm events hydrographs or from multiannual hydrographs computed for large basins.

And the most straightforward method consists in integrating the area underneath the minimum flow rate curve. For the current paper, the 5% and 80% return rates were selected to calculate the reference flow rates for storm events and groundwater discharge, as probability of corresponding flow rate in the time series.

The specific groundwater discharge, expressed in L/s/km2, as mean value for the hydrographic basin, is calculated by dividing the groundwater discharge (which corresponds to the 80% return rate of the river flow rate in the time series) to the basin area. This parameter is very valuable to understand the groundwater potential. Practically, by multiplying the specific groundwater discharge with the estimated depression cone are of the pumping boreholes, one can understand the potential exploitation flow rate.

2.3. Pumping tests The hydraulic properties of aquifers (transmissivity, hydraulic conductivity, storage coefficient) were determined by graphical-analytical processing of pumping tests, performed in the research boreholes, without piezometers. In the study area, there were 5 boreholes drilled.

In borehole F1, the pumping tests couldnâ&#x20AC;&#x2122;t be performed, considering there was only limited infeed of groundwater from the clay-marly formations. The pumping test data was collected on-site in hard-copy documentation, and subsequently converted in electronic format and processed in InfinitExtent and StepMaster software.

The pumping tests data processing follows the detailed methodology described by Antonio di Molfeta, in Ingegneria degli Acquiferi, Politeko, 28

Torino, 2002, chapter 6.2.2.1, out of which we retain the summary table with the diffusivity equation solutions, the computed parameters and type of diagram used in the graphical plotting of pumping tests data.

Fig. 1. Main methods for pumping test data processing, constant flow rate, transitory regime where: s = drawdown, Q = pumping flow rate, T = transmissivity, S = storage coefficient, r = radius of depression cone, t = time, đ?&#x2018;&#x160;(đ?&#x2018;˘đ?&#x2018;&#x17D; , đ?&#x2018;˘đ?&#x2018;? , đ?&#x203A;˝) = Theiss function, ne = efficient porosity, K = hydraulic conductivity, B = leakage factor 3. Results 3.1. Computation of yearly evapotranspiration value The main advection of atmospheric masses is made from the W-WNW and NE directions, determining the character of temperate climate continental, with oceanic and boreal nuances. The dominance of westerly winds stands out as an essential characteristic of the Dornelor basin climate, imposed by the regional atmospheric circulation, and favored by the orographic opening represented by the low area of BârgÄ&#x192;ului mountains (to the west), in contrast to the Suhard and CÄ&#x192;limani mountains (towards NW, E, SW).

Between August 2005 - October 2009, there was a decreasing trend in the amount of precipitation falling annually, as well as a decrease in the maximums in the rainiest period of the year, May August. This trend is due to the changes in the general circulation of the atmosphere, registering in recent years the increasing participation of western air masses, compared to the north-northeast, boreal.

If in 2005, the atmospheric circulation in the strictly Western direction had an incidence of about 15%, in the following years it increases to 16%, 18%, 25%, and 20% respectively in 2009. The western air masses carrying significant amounts of humidity in the formation areas, reach the area of the Dornelor basin after strongly discharging on the Western frame of the Western Carpathians and then a second time on the Western slope of the Rodna mountains, Revista Minelor / Mining Revue - no. 1 / 2020

giving rise to increased nebulosity, but lacking significant precipitation in the Dornelor depression.

If in the months I - X of 2006 there were 832 mm of rainfall, this amount decreased progressively, to 709 mm, 710 mm, reaching 563 mm in 2009. In terms of the distribution of the amount of annual rainfall, there is a cyclicality, in the sense that in 2006 and 2009 a unimodal distribution of the amount of precipitation is specific, which falls especially in the summer months of May - August, while in 2007 and 2008, the amount of precipitation is distributed much more evenly, in cycles of every two to three months, this favoring the ground infiltration, leading to increased aquifer flows.

mm/year (in the case of the Oușorul-Livada hydrostructure) at an average annual temperature of 5°C.

Fig. 3. Hydrographic basins – 3D view

Fig. 2. Monthly precipitation As a consequence of the decrease in the amount of annual precipitation, the thermal inertia of the soil and implicitly the atmospheric one decreased, in 2009 there were increasing atmospheric and soil thermal amplitudes. Due to the lack of water in the soil, the thermal energy from solar radiation is transferred to the mineral skeleton, which has a lower caloric potential than water, resulting in high temperatures during the day and low at night, stimulating the evapotranspiration process, which for example reached of 100 mm only in May of 2009, the period when the thermal amplitude of the soil had values of about 20°C. The strongest trend of continentalization of the climate is noticeable in 2009, by increasing the difference between soil and atmospheric temperature, constantly registering values between 1.5 and 2°C, between May and September.

Analyzing from a statistical point of view the time series regarding the monthly atmospheric thermal amplitude, the monthly soil thermal amplitude and the monthly soil-air thermal amplitude, by drawing a tendency curve that respects a polynomial equation of degree 5, the same continentalization trend is found.

Based on Turc's formula, the value of evapotranspiration is equal to 366 mm/year, considering the total amount of precipitation 1,250 ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, Petroşani, Romania

3.2. Computation of hydro-morphological parameters The Dorna River, the main surface water collector in the area, has a fan-shaped hydrographic network and has a south-north flow direction on the upper course, while after Podu Cosnei the direction of flow will be oriented to the east. The Dorna river basin has an area of 595 km2, and the length of the river is 46 km. Among the tributaries of Dorna river, most important ones are Cosna, Teșna and Dornișoara.

The Catariga, Pârâul Alb and Haju basins reach the northern interfluve, occupying its entire length in the studied perimeter. These are in fact the only river basins with a typical dentricular shape. The rest of the river basins are smaller, interspersed between the three listed above.

The Coşna - Dorna confluence area, developed on a syncline that induces a sinking of the structure and implicitly of the landscape, has a strong impact in the form of hydrographic basins, in the sense of their curvature towards the confluence point. The Șarul Negru, Batca Cofii, Pârâul Negru, Batcilor, Dulcani, Jgheabul Oușorului and Jgheabul Strugurelului basins are simple creek courses bordered by long interfluves, without having developed a network of tributaries.

Fig. 4. Cheie limnimetrică Pârâul Alb aval 29

The hydrometric measurements allowed the creation of the limnimetric keys on the downstream sections of all streams in the area, and the monitoring during June 2008 - May 2010 allowed the creation of the flow hydrograph and implicitly the extraction of the groundwater discharge, as statistical value from the series of measurements, at 80% return rate.

From a geological point of view, the most atypical river basin is Haju, as it is developed entirely in crystalline schist. Therefore, the hydrological interpretations of the resulted values for this basin are particular compared to the rest of the basins:  The specific groundwater discharge of 1.19 L/s/km2, falls into a middle-upper class in the whole perimeter;





Following the hydrogeological mapping, a low permeability of these rocks was highlighted, the only groundwater flows being those developed in the alteration zone; In the upper area of the river basin there is a spring line at the border with the sedimentary formations, through which significant volumes of water are discharged from the suspended structure Oușorul - Livada;

Fig. 5. Flow rate series on Pârâul Alb downstream Denumire rau

Suprafata bazin

Debit 5%

Debit 80%

Haju Jgheabul Strugurelului Jgheabul Ousorului Paraul Alb Paraul Dulcani Paraul Batcilor Paraul Negru Paraul Floreni (Batca Cofii) Sarul Negru Catariga

[m2] 4.202.422 1.260.838 1.289.129 5.526.362 2.345.028 2.590.609 2.690.525 2.270.541 1.128.903 1.966.555

[m3/s] 22,3 9,77 9,0 27,2 14,2 16,3 13,4 13,8 7,17 13,0

[m3/s] 0,005 0,002 0,002 0,009 0,002 0,002 0,002 0,002 0,001 0,003

Scurgere subterana specifica [L/s/km2] 1,19 1,59 1,55 1,63 0,85 0,77 0,74 0,88 0,89 1,53

Participare scurgere subterana [%] 0,02 0,02 0,02 0,03 0,01 0,01 0,01 0,01 0,01 0,02

Fig. 6. Hydro-morphological parameters Pârâul Alb basin is highlighted as the most productive in terms of groundwater discharge, with values of 1.63 L/s/km2, and with a participation of 0.03% in the total flow, this being the smallest gap between the 5% and the 80% return rate flows, which shows an increased storage capacity.

Immediately lower values are recorded at the Catariga creek, whose upper course, and in fact the entire river basin, are extended, as in the case of the Paraul Alb, in deposits of Pg2 age. High values of groundwater discharge are also recorded in the Jgheabul Strugurelului and Jgheabul Oușorului, being also correlated with the outcrop of Pg2 deposits.

The lowest values of groundwater contribution to surface flow rate are found in the streams from the central area, which on the one hand don’t have favorable infiltration conditions, being short courses, and on the other hand due to the bedrock, mainly of marly-clayey rocks.

30

From the water balance equation, knowing the values of the total precipitation of 1,250 mm/year, and of the evapotranspiration of 366 mm/year (determined in the previous chapter for the Oușorul - Livada structure), results a difference of 884 mm/year. This value is practically the volume of water available for surface and groundwater discharge. From the analysis of Paraul Alb hydrograph, if we use the 80% return rate as specific to the groundwater discharge, results a value of 707 mm/year available for aquifer recharge, and the difference of 176 mm/year represents exclusively the direct surface runoff.

3.3. Computation of hydraulic conductivity The hydrodynamic tests - with constant flow, short and long term, or efficiency - have been processed by several methods, with the aim of calculating the hydraulic transmissivity and conductivity, and the storage coefficient. If for the storage coefficient, the values can be assimilated with the results of the laboratory determination of Revista Minelor / Mining Revue - no. 1 / 2020

porosity (accepted relationship in the case of nonconfined aquifers), the results of hydraulic conductivity differ greatly, as the pumping test leads to the calculation of a specific value of the entire aquifer thickness opened by the drilled borehole.

The hydraulic transmissivity determined by the graphic-analytical calculation cannot be considered representative as the thickness of the aquifer depends Foraj on the piezometric level in the case of non-confined aquifers.

In conclusion, the results of these processes will retain the average values of hydraulic conductivity, as an essential parameter in the hydrodynamic calculation, as well as the values of the storage coefficient.

F5

As recognized by surface geological and hydrogeological research, the Lt + Pr range is notable for good permeability, being the main structure favorable to groundwater accumulations, as evidenced by the values of hydraulic conductivity, 0.4 m/day.

Tip test

Durata

Debit

Metoda

[L/s]

Debit constant 12 zile

7,8

Eficienta

1,25 2,04 3,00 4,00 5,00 6,00 7,00 10,00

8h

Debit constant 160 zile

6,99

Theis recuperare faza 1 Theis recuperare faza 2 Theis recuperare faza 3 Theis Walton Hantush Neuman Eden-Hazel pas 1 Eden-Hazel pas 2 Eden-Hazel pas 3 Eden-Hazel pas 4 Eden-Hazel pas 5 Eden-Hazel pas 6 Eden-Hazel pas 7 Eden-Hazel pas 8 Theis Walton Hantush Neuman

Transmisivitate Conductivitate Inmagazinare hidraulica hidraulica [m2/zi] 22,57 65,41 86,70 58,77 58,77 58,77 44,00 70,91 70,91 70,91 70,91 70,91 70,91 70,91 70,91 40,50 40,50 40,50 34,21

[m/zi] 0,43 0,43 0,43 0,32 0,30 0,30 0,30 0,25

[-] 0,35 0,35 0,35 2,49 0,14 0,14 0,14 0,49

Fig. 9. Summary table with hydrogeological parameters of F5 4. Evaluation of resources and reserves

Fig. 7. Pumping test data, F5, constant flowrate

A unitary approach and an exhaustive definition of groundwater resources and reserves are presented

by Marin Palcu et al, in the article Theoretical Aspects Concerning Groundwater Reserves and Resources Assessment and Administration, GeoEco-Marina 15/2009, a scientific paper that reveals the principles of analytical calculation of resources and reserves starting the unitary volume water balance.

Fig. 8. Processing F5 pumping test data For F5 drilling, we performed a pump test with a flow rate of 7.8 L/s for 12 days, a pump test with a flow rate of 6.99 L/ s for 160 days, and an efficiency test, with eight pumping stages for 8 hours. The borehole was drilled in a limestone flysch formation, associated with the Lutetian - Priabonian interval on the entire intercepted thickness. The mapping of core samples and geophysical well measurements reveals several groundwater infeed depths, and a potentially high flow rate. For these reasons, the testing program associated with this drilling was the most extensive.

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, PetroĹ&#x;ani, Romania

Fig. 10. Water flows in a representative unit volume đ?&#x153;&#x2022;â&#x201E;&#x17D;

đ?&#x2018;&#x2020; đ?&#x153;&#x2022;đ?&#x2018;Ą đ?&#x2018;&#x2018;đ??´ +

đ?&#x153;&#x2022; đ?&#x153;&#x2022;â&#x201E;&#x17D; (â&#x2C6;&#x2019;đ?&#x2018;&#x2021; đ?&#x153;&#x2022;đ?&#x2018; ) đ?&#x2018;&#x2018;đ??´ đ?&#x153;&#x2022;đ?&#x2018;

Âą đ?&#x2018;¤đ?&#x2018;&#x2018;đ??´ Âą đ?&#x2018;&#x201E; = 0 ,

where: S = storage coefficient, h = piezometric head, t = time, A = recharge area, s = horizontal distance, w = infiltration module, Q = flow rate 31

The above-mentioned authors define the water reserve as the volume of water contained in an aquifer structures. In the case of a non-confined aquifer, similar to the OuĹ&#x;orul-Livada structure, the equation describing the groundwater reserve is: đ?&#x2018;&#x160; = â&#x2C6;&#x2018;đ?&#x2018;&#x203A;đ?&#x2018;&#x2013;=1 đ?&#x2018;&#x161;Ίđ??ť , where: W = groundwater reserve, m = porosity, Ί = surface, H = piezometric head.

In the same article, the groundwater resource is defined as the water flow through the wet crosssection of the aquifer, based on the following formula: đ?&#x2018;&#x201E;đ?&#x2018;&#x203A;đ?&#x2018;&#x2013; = â&#x2C6;Ť đ?&#x153;&#x2014;đ?&#x2018;&#x2018;â&#x201E;Ś, where: Q = groundwater resource, Ę&#x2039; = velocity, Ί = cross-section area The hydrodynamic model used further on falls into the family of analytical models, for which the author proposes a new method, developed especially for the investigated hydrostructure.

Fig. 11. Calculation elements of the analytical model The working hypotheses used derive from the conceptual model, namely: ď&#x201A;ˇ Non-confined aquifer: impermeable bed represented by the marly-sandstone formation Pg1-2, while model top is represented by the topographic profile; ď&#x201A;ˇ Constant piezometric head on the model border takes over the head values from the topographical map; ď&#x201A;ˇ Recharge exclusively by net precipitation: calculated at 700 mm/year; ď&#x201A;ˇ Homogeneous and isotropic porosity of 5%; ď&#x201A;ˇ The piezometric surface follows the topographic profile, and varies depending on the recharge value; In a theoretical cross-section of the structure, we can define the following geometric elements: ď&#x201A;ˇ Land elevation: CT

32

ď&#x201A;ˇ

Dynamic piezometric head: NHD, representing the free surface of the aquifer, as it is naturally generated by the effect of topography, recharge value and hydraulic conductivity ď&#x201A;ˇ Static piezometric head: NHS, representing the interpolated surface of the contour points ď&#x201A;ˇ Lowest discharge point of the structure: CD ď&#x201A;ˇ Bed level: CC ď&#x201A;ˇ Theoretical static reserve: RST ď&#x201A;ˇ Real static reserve: RSR ď&#x201A;ˇ Dynamic reserve: RD ď&#x201A;ˇ Total potential volume available for dynamic reserve: VT ď&#x201A;ˇ Surface of the hydrogeological basin: SB ď&#x201A;ˇ Recharge factor: w ď&#x201A;ˇ Grid size: dx dy ď&#x201A;ˇ Porosity: n The analytical calculation is performed in a grid of 5,418 cells with dimensions of dx = 35.07 m and dy = 34.92 m.

Revista Minelor / Mining Revue - no. 1 / 2020

The static reserve is given by the volume of water stored in the aquifer, up to the minimum natural discharge level of the structure. Thus, at the discharge elevation 1,026 m, represented in the field by the exit point of the Paraul Alb stream from the hydrogeological basin, we have a free horizontal plane surface (extended to the intersection with the contour of the structure) of 6,635,515 m2, and a volume of groundwater stored of 7,463,252 m3, considering the general porosity of the aquifer of 5%. This volume can also be called the theoretical static reserve, since in the multiannual hydrogeological regime it is not possible to reach the complete discharge of the structure up to the minimum level.

The dynamic reserve is calculated in two stages: ď&#x201A;§ By interpolating the constant head points from the border, resulting a surface with a general NE-SW slope; the volume of water stored in the aquifer up to this level can be considered the real static reserve, having a calculated value of 75,602,153 m3 (it also includes the value of the theoretical static reserve) ď&#x201A;§ By recharge input over the real static reserve, the final hydrodynamic piezometric surface is reached, thus resulting in the value of the dynamic reserve, 4,644,860 m3 On the total aquifer structure, we have a ratio between the dynamic reserve and the total potential volume available for the dynamic reserve of 0.24: đ?&#x2018;&#x2026;đ??ˇ đ?&#x2018;&#x2020;đ??ľ đ?&#x2018;¤ = (đ??śđ?&#x2018;&#x2021; â&#x2C6;&#x2019; đ?&#x2018; đ??ťđ?&#x2018; ) đ?&#x2018;&#x203A; đ?&#x2018;&#x2018;đ?&#x2018;Ľđ?&#x2018;&#x2018;đ?&#x2018;Ś đ?&#x2018;&#x2030;đ?&#x2018;&#x2021; 6.635.515 đ?&#x2018;&#x161;2 đ?&#x2018;Ľ 0,7 đ?&#x2018;&#x161;/đ?&#x2018;&#x17D;đ?&#x2018;&#x203A; = = 0,24 18.868.615 đ?&#x2018;&#x161;3 The resulting ratio will be used to determine the share of the dynamic piezometric level, following the variation of the topographic profile, based on the formula demonstrated as follows on a representative unit volume: đ?&#x2018;&#x2018;đ?&#x2018;Ľ đ?&#x2018;&#x2018;đ?&#x2018;Ś (đ?&#x2018; đ??ťđ?&#x2018;&#x2018; â&#x2C6;&#x2019; đ?&#x2018; đ??ťđ?&#x2018; ) đ?&#x2018;&#x203A; = 0,24 đ?&#x2018;&#x2018;đ?&#x2018;Ľ đ?&#x2018;&#x2018;đ?&#x2018;Ś (đ??śđ?&#x2018;&#x2021; â&#x2C6;&#x2019; đ?&#x2018; đ??ťđ?&#x2018; ) đ?&#x2018;&#x203A; đ?&#x2018; đ??ťđ?&#x2018;&#x2018; = đ?&#x2018; đ??ťđ?&#x2018; + 0,24 (đ??śđ?&#x2018;&#x2021; â&#x2C6;&#x2019; đ?&#x2018; đ??ťđ?&#x2018; ) The groundwater resource is given by the groundwater flow through the wet cross-section of the aquifer. Thus, on a total cross-section of 12,670 m2, on the entire border of the hydrogeological basin, a water flow of 21.12 L/s is drained naturally, through the hydraulic gradient. ď&#x201A;§ Discharge surface on the hydrogeological model border: 12,670 m2; ď&#x201A;§ Hydraulic conductivity: 0.4 m/day; ď&#x201A;§ Hydraulic gradient: 0.36 đ?&#x2018;&#x201E; = 12.670 đ?&#x2018;&#x161;2 đ?&#x2018;Ľ 0,4 đ?&#x2018;&#x161;/đ?&#x2018;§đ?&#x2018;&#x2013; đ?&#x2018;Ľ 0,36 = 21,12 đ??ż/đ?&#x2018;

ISSN-L 1220-2053 / ISSN 2247-8590 Universitas Publishing House, PetroĹ&#x;ani, Romania

Fig. 12. Piezometric head map 5. Conclusions The climatological study carried out in the area reveals the continentalization trend, which determines the reduction of groundwater infiltration, due to the concentration of precipitation in short periods of the year, and the increase of the average annual temperature. However, the orography and the geological constitution of the OuČ&#x2122;orul - Livada structure contributes to the development of the most productive aquifer in the studied area, a conclusion noted since the preliminary results provided by the hydrological study. The specific groundwater discharge, with a value of 1.63 L/s/km2, double compared to other river basins in the area, determined the continuation of hydrogeological studies in this structure, by computing the characteristics of the aquifer and the evaluation of resources and reserves.

Thus, by developing an analytical model specific to this hydrostructure, it was possible to determine both the static reserve of the aquifer and the dynamic reserve (this one being practically available for sustainable exploitation) at a value of 4,644,860 m3, considering the general porosity of the aquifer of 5%.

The interpretation of the pumping tests led to the determination of the hydraulic conductivity of the aquifer by various graphic-analytical processing methods, at a value of 0.4 m/day, which was further used for the calculation of the groundwater resource on the total discharge area on the border of the structure, at a value of 21.12 L/s.

References 1. Acworth R. I. et al.

Long-term spatio-temporal precipitation variability in arid-zone Australia and implications for groundwater recharge, Hydrogeology Journal, 2016

33

2. Albu M. Mecanica apelor subterane, Editura tehnică, Bucureşti, 1981 3. Atanasiu I. Geologia regiunii Şarul Dornei (Câmpulung) – Măgura Calului (Năsăud). D. S. Com. Geol., vol. XXXVIII (1950-1951), Bucureşti, 1954 4. Atanasiu I., Dimitrescu R., Semaka Al. Studiul petrografic al eruptivului din M. Bârgăului. D. S. Com. Geol., vol. XL, 1956 5. Athanasiu S. Studii geologice în districtul Suceava. Depozitele cretacice de la Glodul. Bul. Soc. de Științe, vol. VII. Bucureşti, 1998 6. Băncilă I. Geologia Carpaților Orientali, Editura Științifică, 1958 7. Bulgaru L., Koczur I., Koczur M., Şuvăilă A., Şuvăilă Anca, Ştefănuţ V. Prospecțiuni geologice pentru hidrocarburi în partea de N și de NE a bazinului Transilvaniei (munții Bârgăului), parte nord – vestică a munților Călimani, perimetrul Măgura Ilvei – Ilva Mare – Coșna – Neagră Șarului – Leșu (jud. Suceava și Bistrița Năsăud). Problema ¼ 1969. Arh. Prospecțiuni S.A. Bucureşti, 1969 8. Carbonnel J. P., Drobot R. Modeles Mathematiques en Hydrogeologie (modele matematice în hidrogeologie), Editura Didactica și Pedagogica, Bucuresti, 1995 9. Carvalho Resende T. C. et al.

Assessment of the impacts of climate variability on total water storage across Africa: implications for groundwater resources management, Hydrogeology Journal, 2018 10. Chen X. et al.

A new method for mapping variability in vertical seepage flux in streambeds, Hydrogeology Journal, 2008 11. Chetoni R. Aque Minerali e Termali, Italgrafica Segale Segrate, 2000 12. Domenico, P.A. and Schwartz, F.W. Physical and chemical Hydrogeology, John Wiley, New York, 1990 13. Gheorghe, A. Analiza și sinteza datelor hidrogeologice, Editura tehnică, Bucureşti, 1973 14. Golită E., Golită N. Apele minerale din jud. Suceava (Sinteză hidrogeologică 1969 – 1970). Problema I. B. b. 1.1. Arh. Prospecțiuni S.A. Bucureşti, 1970 15. Hayashi M. et al.

Watershed-scale response of groundwater recharge to inter-annual and inter-decadal variability în precipitation (Alberta, Canada), Hydrogeology Journal, 2014

34

16. Hillberg et al.

Interaction of various flow systems in small alpine catchments: conceptual model of the upper Gurk Valley aquifer, Carinthia, Austria, Hydrogeology Journal, 2016 17. Helbig M. Spațial and seasonal variability of polygonal tundra water balance: Lena River Delta, northern Siberia, Rusia, Hydrogeology Journal, 2012 18. Jeelani G. Aquifer response to regional climate variability in a part of Kashmir Himalaya in India, Hydrogeology Journal, 2008 19. Maione U. Le Piene Fluviale (Studiul inundațiilor), Ediția a 2-a, La Goliardica Pavese, 1999 20. Manahan S. E. Environmental Chemistry, Lewis Publisher, Chelsea, 1991 21. Molfeta A. Ingegneria degli Acquiferi, Politeko, Torino, 2002 22. Nastev et al.

Developing conceptual hydrogeological model for Potsdam sandstones în southwestern Quebec, Canada, Hydrogeology Journal, 2008 23. Palcu M., Albu M., Witek Ghe. Theoretical Aspects Concerning Groundwater Reserves and Resources Assessment and Administration. GeoEco-Marina 15/2009 24. Singh V. P. Environmental Hydrology, Kluwer Academic Publisher, Dordrecht, 1995 25. Scradeanu D., Gheorghe A. Hidrogeologie generala. Bucuresti: Editura Universității din Bucuresti, 2007 26. Scrădeanu D. Modele geostatistice în hidrogeologie, Editura didactică și pedagogică, R.A.-Bucureşti, 1996 27. Vassolo et al.

Hydrogeology of a weathered fractured aquifer system near Gitega, Burundi, Hydrogeology Journal, 2018 28. Wang L. et al.

Investigating spațial variability of vertical water fluxes through the streambed în distinctive stream morphologies using temperature and head data, Hydrogeology Journal, 2017

Scientific reviewer Prof.eng. Ph.D Eugen COZMA UNIVERSITY OF PETROȘANI Revista Minelor / Mining Revue - no. 1 / 2020

Aims & Scope Revista Minelor - Mining Revue publishes original and advanced research papers, new developments and case studies in mining engineering and technologies aiming new and improved techniques also suitable for civil applications.

The journal covers all aspects of mining, environmental issues and technologies relating to exploration, exploitation and processing of mineral resources, mining survey, computers and simulation, performance improvement, cost control and improvement, all aspects of safety improvement, rock mechanics and interface between mining and law.

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Subject coverage Mining exploration,Mine planning and design,Drilling and blasting,Mining survey, Materials handling - excavation, haulage and disposal,Mining rock mechanics and ground control, Mine drainage,Mining process control and optimization, Computers, micro-processors and artificial intelligence based technology used in mining,Mine information technologies, Mining mechanization, automation and robotics, Reliability, maintenance and overall performance of mining systems, Emerging technologies in mining and mineral engineering, Interaction between minerals, systems, people and other elements of mining and mineral engineering, Simulation of mining systems, Mining health and safety, Environmental impact assessment, Mineral economics, Business systems in mining engineering, Risk assessment and management in mining and mineral engineering, Mining sustainable development

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