Inside Mining July 2017

ISSN 1999-8872 • R50.00 (incl. VAT) • Vol. 10 • No. 07 • July 2017

www.miningne.ws

af r ic an u pdates on th e

g ro un d a n d un d e rg ro un d

Chamber of Mines

Accelerating efforts

South32

Recycling tailings, creating jobs

botswana diamonds

Unearthing hidden treasures

Rare

Group

Meet the new CEO special feature

Unlocking

Alexkor

I am pleased to report that Alexkor is now on the path to financial recovery and future sustainability.

This has been a transformative year." Vimal Bansi, Acting CEO P19

contents

a f r i c a n u p dat e s o n t h e g ro u n d a n d

u nde rground

08

10

Furukawa rock breaker Excavator-mounted rock breakers from Furukawa are proving to be extra-durable in the field, dismantling the belief that rock hammers should be regarded as “consumables” with a relatively short lifespan.

16

30

Editor’s Comment 3 The timing of it all

special feature 19 Alexcor

Cover Story 4 New CEO for Rare

Open-pit mining 29 Managing dust in open-pit mines 30 Practical approach to steeper slopes

Africa Round-up 6 News from around the continent Botswana Diamonds 8 Big challenges for junior miners 10 Digging deeper for diamonds Fossil Fuel Foundation 14 The complexities of coal combustion Coal mining 16 New plant for tailings dam Chamber of Mines 18 Accelerating efforts

july

2017

ON THE COVER p4

Mineral Processing 32 Separating waste rock 34 Supplier teamwork to benefit mines Comminution 36 Mobile crushers a major force in modern mining

Education & Training 38 Guiding graduates into the workplace Market News 39 The latest news from the African mining industry

special feature P19 21 The age of diamonds 24 Ensuring responsible operations 25 A future shining bright

Rare Group's new CEO, Renier Viljoen, brings with him significant experience in the piping and plastic injection moulding fields. @mining_news www.facebook.com/pages/ Mining-News

Endorsed by In sid e M in in g 0 7 | 2017

1

editor's comment

Publisher Elizabeth Shorten Editor Mientjie Kleinhans Journalist Phila Mzamo Head of design Beren Bauermeister Design consultant Frédérick Danton Chief sub-editor Tristan Snijders Sub-editor Morgan Carter Contributors Roger Baxter, Rosemary Falcon, Lourens Jansen van Rensburg Client services & production manager Antois-Leigh Botma Production coordinator Jacqueline Modise Head: e-commerce Roxanne Segers Financial manager Andrew Lobban Administration Tonya Hebenton Distribution manager Nomsa Masina Distribution coordinator Asha Pursotham Printers United Litho Johannesburg Tel: +27 (0)11 402 0571 ___________________________________ Advertising sales

Annemarie Prins Tel: +27 (0)11 233 2600 annemarie@3smedia.co.za ___________________________________ No. 9 3rd Avenue, Rivonia 2191 PO Box 92026, Norwood 2117 Tel: +27 (0)11 233 2600 Fax: +27 (0)11 234 7274/5 www.3smedia.co.za ___________________________________ Annual subscription:

The timing of it all

S

o we’re already more than halfway through the year.

Just where has the time gone? That said, I am pleased to present to you the July issue of Inside Mining, which takes us to some interesting places.

We bring our readers something truly unique this month– an

extended profile on alluvial diamond mining expert Alexkor. The precursor to this government-owned entity started operations in Alexander Bay, Northern Cape, in 1928 and the area’s rich deposits continue to yield diamonds to this day. We take a look at Alexkor’s recent successes and its sustained commitment to the local community.

Then, Botswana Diamonds CEO James Campbell discusses the state of the diamond industry in Southern Africa with us.

The Chamber of Mines South Africa CEO Roger Baxter puts pen to paper with a gripping piece on the Mining Charter and his thoughts on the future of mining in the country. Speaking of the Charter: unless you’ve been living under a rock, you will know that Minister of Mineral Resources Mosebenzi Zwane recently

South Africa: R550.00

revealed the reviewed BBBEE Charter for the industry. One of the

(incl vat & postage)

stated aims of Mining Charter III is to provide policy and regulatory

African countries: US$80

certainty in order to seek investment for the development of

Foreign: US$100 Email: subs@3smedia.co.za ISSN 1999-8872 Inside Mining Copyright 2017. All rights reserved. ___________________________________ All material in Inside Mining is copyright protected and may not be reproduced either in whole or in part without the prior written permission of the publisher. The views of contributors do not necessarily reflect those of the publishers.

the mining industry. Critics have been quite clear in their rejection of the charter, saying it does just the opposite, encouraging divestment.

Share prices plummeted within the hour of Minister Zwane’s briefing, and the Chamber of Mines rejected the unilateral imposition of the Charter on the industry almost immediately.

Mining Charter III has been gazetted and came into operation right away. It will be interesting to watch how the industry reacts to the uncertainty and what I predict will be long and tedious litigation.

It is safe to say that interesting times are ahead of us.

The Chamber’s CEO Roger Baxter provide some insight on its position as well as his undeniable optimism towards the industry.

To our avid readers, be sure to sign up and get the latest updates and inside scoops from the mining industry. Check out what we are talking about on our website and Facebook page, or follow us on Twitter and have your say.

Mientjie Kleinhans @mining_news www.facebook.com/pages/ Mining-News

In s id e Min in g 0 7 | 2017

3

COVER STORY | Rare Group

Rare Plastics has the capability of coiling pipes 110 mm – 180 mm in lengths up to 150 m

Operational management capabilities, and proven financial and system management experience are some of the skills that Renier Viljoen will bring to Rare as the new CEO. His six years in the piping industry and experience in plastic injection moulding will add to his unique offering.

V

for Rare manufacturing environment. “I like

being more hands-on, you get first-hand

to challenge the way that things

information in real time,” stresses Viljoen.

have been done in the past and am continuously looking for new and

Background

sometimes unconventional ways of

Viljoen is a qualified chartered

improving the business,” Viljoen explains.

accountant and served his articles

Recipe for success

at Baker Tilly Greenwoods Chartered Accountants in Cape Town. He was

Viljoen believes the recipe to success

previously involved in the plastic-

is: “You need to surround yourself with

injection moulding industry before joining

people who are the best in their field

Rare in 2012 as a group accountant. In

and you need to empower them to

2013, he was promoted to the position of

make decisions. Although we all wish to

financial director.

In July 2016, he was appointed as the

iljoen has worked his way

believe so, we cannot succeed on our

up the ranks within the

own. I believe one needs to take action

managing director of Rare Plastics, the

organisation, meaning

quickly and decisively; the worst decision

division that runs the group’s HDPE pipe

that he has an excellent

you can make as a leader is to make no

manufacturing plant in Meyerton. When

decision at all.

the previous CEO, Wally van Coller,

understanding of how Rare’s business

4

New CEO

operates and fits together. He also

“One also needs to understand

retired at the end of February 2017,

brings a good work ethic as well as

the markets one is dealing in. Many

Viljoen assumed the role of CEO. He

a diligent, disciplined approach,

managers make the mistake of being

also continues in his role as managing

which is especially important in a

too far removed from their markets. By

director of Rare Plastics.

Ins i de Mi n i n g 0 7 | 2 0 1 7

Another achievement for the company was the acquisition of a large pipe coiler

New accreditations Rare Plastics was recently awarded certification by South African Technical Auditing Services (SATAS) for the manufacture of HDPE pipes to the requirements of SANS 4427 Part 2. SATAS is an independent auditing and certification body that is SANS ISO 17065 accredited through the South African National Accreditation System. SATAS is thus accredited to issue certificates for the relevant SANS standards.

“The fact that Rare has decided to receive accreditation from SATAS rather than SABS, as was previously the case, does not change any aspects of the quality or the manufacturing process of the HDPE PE100 pipes. The pipes still comply with SANS 4427 Part 2. The reason for the use of an alternate accreditation agency other than SABS has been well documented in the media in recent times.

"The SATAS certification logo is well established and products bearing the mark are accepted by structural designers, local authorities as well as the relevant state authorities,” explains Viljoen.

New products Not only has the group received a new CEO, but it also introduced Rare Plastics

One also needs to understand the markets one is dealing in. Many managers make the mistake of being too far removed from their markets.” Renier Viljoen, CEO, Rare

Co-extruded (RPC) technology to its “We have various projects

product portfolio. RPC is a three-layer

company was the acquisition of a large

HDPE pipe with a crack-resistant inner

pipe coiler, with the unit being used

planned for the next three years

and outer layer, ideally suited for the

to coil 4 km of 180 C16 pipe in 75 m

that will enable us to optimise our

rehab of structurally damaged pipelines

coils – a first in the local African HDPE

production output and at the same

using trenchless technologies.

pipe sector.

time reduce our production costs

The RPC technology is especially

Rare Plastics has the capability to coil

in order to unlock more value

suited to South Africa’s ageing

pipes of 110 mm to 180 mm diameter in

for stakeholders. We are

water pipeline infrastructure, and

lengths up to 150 m, thus minimising the

continuously looking at ways to

can cost-effectively replace old,

cost of connections.

expand our product offering in

damaged and leaking pipelines. An RPC pipe’s service life is not affected

Future plans

by surface damage caused during the

“We are continuously striving to increase

installation process.

our presence in the African market. We

“This lends the technology to mining

infrastructure,” concludes Viljoen.

have a few initiatives with this specific

applications as well – and it will

focus that we believe will bear fruit in

withstand extremely abrasive slurry

the future. The HDPE pipe manufacturing

materials for five or six times longer than

environment, which a large portion

traditional methods,” says Viljoen.

of our business is based on, is a

Another achievement for the

order to better utilise our current

low-margin market.

www.rare.co.za

In sid e M in in g 0 7 5 | 2017

5

Mining news

from around the continent

receiving mineral revenue transfers. He said one of the key recommendations from the Gheiti process is for every district assembly to create a special account to hold resource funds.

Namibia

Swakop Uranium to investigate hazardous waste leak Swakop Uranium is investigating claims that the tailings dam at its Husab mine is leaking dangerous waste material into underground water sources.

Ghana

A photo posted on social media The displeasure arose after the

showing the mine’s tailings dam

participants learned, from a

allegedly leaking attracted a wave of

presentation on ‘2014 Mining Sector EITI

negative reactions, especially around

The utilisation of mineral revenues

Report’, that their district had received

fears that scarce groundwater in the

received by Ghana’s Ellembelle District

GH₵344 561.93 (R1 021 447.82) in

Namib’s Kahn and Swakop rivers is

Assembly of the Western Region for

2012 and GH₵292 935.00 in 2014 but

being contaminated.

road projects, as well as the assembly’s

that the funds were utilised on other

office complex, has raised concerns

infrastructure.

Extractive industry initiative neglects deteriorating road

among traditional leaders and citizens of the area.

Citizens are angered by the state’s

Their sentiments were summarised

Percy McCallum, told The Namibian

by Nana Kwasi Kutuah IV, chief of

that the mine had taken note of

Nkroful, as follows, “This road should be

the concerns.

utilisation of these funds and that

constructed; if for no other reason than

spending has not included the

to honour Dr Kwame Nkrumah.”

maintenance and upkeep of the

Swakop Uranium’s vice-president for human resources and business support,

In the presentation, Kweku Boa-

“Please be advised that the company is investigating the issues raised on the tailings dam,” he said.

main road from Esiama to Nkroful, the

Amposem, the Gheiti aggregator, who

The public, in response to the social

capital of the Ellembelle District.

is also head of consulting firm Boas

media post, accused the company of

and Associates, drew the audience’s

poor management and construction

Transparency Initiative (Gheiti) officials

attention to the fact that the

at what could become one of the

briefed the district assembly officials,

assembly’s reported utilisation of the

biggest uranium mines in the world.

assembly members, chiefs and citizens

funds was difficult to assess because

on the 2014 reports on the mining and

the assembly, at the time of reporting,

from heavy and radioactive metals

oil and gas sectors.

did not have a dedicated account for

such as uranium, thorium and radium,

Ghana Extractive Industries

The tailings dam is where the waste

washed with sulfuric acid, is stored.

“A leak could pose a major

A leak from the Husab tailings dam in Namibia could pose a major environmental threat to the Swakop groundwater supply

environmental threat to the Swakop groundwater supply, as those metals cause an increase radon gas levels, which permeates into the groundwater,” the source of the photo and information claimed.

The executive director of the Namibian Uranium Institute, Gabi Schneider, said she was aware of the social media reports, but could not answer for Swakop Uranium. She noted, however, that Swakopmund’s drinking water would not be affected as Swakopmund does not get its water from the Swakop and Kahn rivers. The town draws water from the Omdel aquifer and the Areva desalination plant.

6

Ins i de Mi n i n g 0 7 | 2 0 1 7

Tanzania's president, John Magufuli

South Africa

of their equity interests. The warning

mineral resources, thanks to contracts

echoed a statement by ratings agency

that were signed during the second,

Ratings agency Moody’s has warned

Fitch, which said the government was

third and fourth regimes.

that the new Mining Charter regulations

prioritising radical transformation even

However, those of a contrary view

seeking to accelerate black ownership

if it leads to a weaker business climate

question the accuracy of the data and

in South Africa’s mining industry will

and hampers growth.

dismiss the “unending probes” into the

Rating agency's warning

deter investment, raise costs and

The Chamber of Mines, which

industry as “political drama aimed at

represents the majority of South

gaining political mileage ahead of the

The ratings agency – which recently

African mining companies, said it

2020 general election”.

changed South Africa's debt rating and

would challenge the new rules in

outlook from stable to negative, citing

court, arguing that there had been

one of the key sectors that shape politics

the country's structural weaknesses and

insufficient consultation.

and elections, especially in Lake Zone,

diminish cash flow generation.

For almost a decade, mining has been

dependence on external capital – said

which is the basket of almost 50% of

in a statement, “The higher BEE equity

the votes.

holding requirement is credit negative

Tanzania

use cash, or raise debt to facilitate the

Just how much gold does Tanzania have?

equity transfer.”

The question of how much gold mining

because it will likely require miners to

Tanzania’s five major gold mines are located in the Lake Victoria gold belt, in the Lake Zone.

Two probe committees formed by

firms are taking out of Tanzania, and

President Magufuli, so far, bring the

revised Mining Charter in June, raising

whether the country is getting its fair

total number of probes since 2004

the minimum threshold for black

share of revenues, continues to be a

to seven. Yet, seven probes and

ownership of mining companies to

divisive issue. For this reason, President

dozens of recommendations later, the

30% from 26%.

John Magufuli appointed a committee

controversy is far from over.

The government published its

Anglo American, AngloGold Ashanti, Gold Fields, Petra Diamonds, Sibanye Gold and South32 would

to probe the issue. They released a report with shocking findings.

Critics of the mining firms found that

Magufuli says he is prepared to write the new chapter by making foreign mining firms pay Tanzania its fair share

be the most negatively affected

the actual quantities of gold in gold-

of earnings from gold. He said he is

miners if the revised Mining Charter is

copper concentrate impounded in

now waiting for the second report

implemented, Moody’s said.

Dar es Salaam were more than the

before making what he has termed

declared figures. This puts an emphasis

“further major decisions that would

expects current shareholders to be

on their long-held view that mining

determine the future of the country’s

unlikely to support a further dilution

firms are plundering the country’s vast

mining sector”.

The ratings agency added that it

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diamonds

Big challenges for junior miners There are two major challenges in the diamond mining industry, according to James Campbell (pictured left), MD of Botswana Diamonds. While there are solutions to sourcing financing, he is not sure how to solve the lack of diamond mine knowledge and expertise in the younger generation. By Mientjie Kleinhans

C

ampbell believes that the

small London financial institutions,

because these projects are not banka-

biggest challenge in the

and the other £150 000 from two high-

ble. You can only raise equity for explo-

mining industry, especially

worth individuals in South Africa,”

ration and development, and you can’t

for junior miners, is finding

says Campbell.

get equity here. I find that you can raise

finance, particularly for exploration

equity quicker and more efficiently in

projects. It is one of the topics that have

prove the funding challenges in South

Botswana than you can in South Africa.

taken priority at many conferences and

Africa is for the country to implement

They are willing to put money in explo-

events for a number of years.

legislation incentivising people to invest

ration in their country.”

“People often ask me the question:

in high-risk projects. “In Canada, flow-

The second challenge, and this has be-

why do you have to raise money in

through shares give tax incentives to

gun to worry Campbell a little more

Canada or the UK for projects in Afri-

people to invest in high-risk projects.

as time goes on, is that De Beers was

ca, or South Africa? Sadly, the JSE just

I’ve been a long-standing advocate of

basically the “finishing school” for peo-

doesn’t fund high-risk ventures. We

something similar to this in our country.

ple in the diamond industry, particularly

know that there are a number of high-

Why can’t we do this in South Africa?”

in the technical line. “About 20 years

net-worth individuals in South Africa, but

he asks.

ago, almost all keynote speakers would

I also think the money is offshore and

According to Campbell, financing

be De Beers people. They were the

that is why investment money comes

comprises 90% of problems in the mining

best explorationists, metalurgists, mining

from Canada and the UK.

industry, particularly from an explora-

engineers, and so on, not because De

tion and development perspective,

Beers said this was so, but because the

lion) to fund our first half of work this

because one can’t raise bank finance.

industry said it was. I was very fortunate

year, of which £350 000 came from

“Nor should you raise bank finance,

to learn under these people, like Alex

“We raised just over £500 000 (R8.4 mil-

8

He believes that the only way to im-

Ins i de Mi n i n g 0 7 | 2 0 1 7

Bostwana Diamonds commences exploration drilling

Some of the exploration samples gathered van Zyl, who discovered Venetia Dia-

This means having highly prospective

for themselves, in partnerships, or small

mond Mine,” says Campbell.

ground in your jurisdiction on which you

groupings of people.

“Nowadays, De Beers is a fraction of the size it used to be. Many people

can do business.”

The second pillar is to have the right

“With larger companies, one typically has to pay a higher fee for somebody

might be doing different things now.

team. “The team that we have at

who might know less than you do,

I’m looking at the next generation of

Botswana Diamonds is chiefly the old

because they have to fund a big of-

technical people, and it worries me,

African Diamonds team. And African Di-

fice. I don’t have an office. We only

as there are no viable successors to

amonds is the company that ventured

have three full-time employees in our

our generation.

with De Beers, then with Lucara, and

company and that is how we work,

“Today’s conferences are being

was then bought out by Lucara, and

and we are a £6 million company,”

planned by the same organisers as

we gave shareholders 25 times their

explains Campbell.

20 years ago. Who is going to take

investment. The reason for the success

over the next generation of diamond

is because the team made the right

Projects

explorationists, because you need

corporate and technological decisions

“We are busy with lots of new business

the experience and the knowledge

at the time.”

work. It is a challenge to both bring in

to do it? Where are the younger peo-

new business that you believe has the

ple to take over from these mentors?

Smaller companies

I’d like to hope that the big diamond

Campbell says that he is a firm believer

channel as well as fund it. We, as the

companies in the country like Petra

in not using large companies as suppli-

board, have great projects that we be-

and De Beers are generating them,

ers. “I believe in getting the best person

lieve in, and while they are already fund-

but I don’t see them at conferences,”

for the job. Typically, what happens is

ed for the first half, we obviously have to

laments Campbell.

that the best people don’t want to work

ensure that they are funded for the sec-

for large companies. They want to work

ond half,” concludes Campbell.

Unfortunately, he too does not know

legs to go all the way down the resource

the solution to that problem. “I hope that the larger companies will focus on this, and not just say they do. I would hope that junior companies would be keen to look at this problem as well.

What gives me a sense of optimism around this is that conferences being held by the older-generation experts are being attended by young students.

Presenting and sharing specific information around particular decisions, for example, is important to try to give students insight,” says Campbell.

Recipe for success The recipe for success in the exploration industry is based on two pillars, according to Campbell. “The first pillar is obviously being in the right area.

“I find that you can raise equity quicker and more efficiently in Botswana than in South Africa.”

diamonds

Exploring for more diamonds

Botswana Diamonds has been granted six mining licences, and is currently exploring brownfield projects in South Africa and greenfield projects in Botswana.

Its flagship is the Vutomi project in Frischgewaagt, Limpopo. Mientjie Kleinhans finds out more about these operations.

V

utomi has a portfolio of over

east of Marsfontein was under-explored.

commenced a gravity physical survey

20 high-interest kimberlites,

We have done extensive work on the

to help us identify more drilling targets,

many of which are diamon-

kimberlite dykes and blows east of

which we want to start drilling during the

diferous, in the Limpopo,

Marsfontein and have already under-

course of July this year,” says Campbell.

North West and Free State provinces of

taken a significant drilling campaign, on

He adds that the purpose of doing

South Africa. Frischgewaagt is located

which we have already reported,” says

all of this is to define a resource on the

about 50 km south-east of Polokwane, in

James Campbell, managing director,

kimberlite. The kimberlite has been found

Limpopo, and immediately east of the

Botswana Diamonds.

and the diamond value has been deter-

Marsfontein Diamond Mine, which was

“We have taken samples to under-

mined. Once the micro diamond work is

operated by De Beers in the 1990s. What

stand the geology, and samples of mi-

done, the diamond grade will be deter-

is notable about Marsfontein is that it

cro diamonds, which we hope to report

mined, and through the geophysics and

had a payback in three and a half days.

on soon. Half of the analysis has been

the drilling, the size value will be deter-

completed and, so far, the results have

mined. “This will hopefully be able to

been very encouraging. We recently

qualify the project for inferred resource,

“It is a small, but very rich mine and our belief is that the area immediately

10

Ins i de Mi n i n g 0 7 | 2 0 1 6

diamonds

Searching for diamonds

Highlights from Frischgewaagt and for an exploration company like Bot-

use in exploration is very old-fash-

swana Diamonds, that will be a declara-

ioned, but it still works, and that is

tion of our first maiden resource, which is

sampling. Sampling is a very basic

a big step,” explains Campbell.

technology. If you are in a mountain-

Key issues

ous area, you take a stream sample in an area of concentration. In a flat

He adds that the key issue for the

area, one will take a 30 ℓ soil sample.

company is to find blows on the dykes,

That soil or stream sample will then be

where it expands outwards. “We are

screened to concentrate it and recover

looking for these very small features,

kimberlite indicators.

which would be evidence of very-high-

“Highly qualified mineralogists extract

grade diamonds in this area. A lot will

the minerals and analyse their chemis-

depend on the size of the blow and

try. So from one garnet, you can deter-

whether it will be open-pit or under-

mine whether or not it is: a) kimberlitic,

ground operation.”

and b) from a diamond stability field,

Technology used

which means it could contain diamonds. It is a very painstaking process

The two main areas of exploration tech-

as these minerals could be between 0.3

nology used in the project so far include

mm and 0.5 mm in size,” says Campbell.

geophysics, which comprises ground

•3 4 percussion and nine diamond drill holes completed on the kimberlite dyke • T wo blows discovered on the kimberlite dyke system from this drill programme • High-interest olivines, G10 and G9 garnets recovered • Samples submitted for micro diamond analysis – results are expected within two months • T he geology is very similar to the high-value Marsfontein mine, located 20 km away • Modelled per carat value of €259 on diamonds recovered from earlier drilling

magnetics and EM24 technology at the

Evaluation technology

moment. “We are looking for magnetic

Once a diamond has been found, the

or other contrasts between the kimber-

next step is to apply evaluation tech-

lite and the surrounding rock, on the

nology to determine its size and value.

assumption that the kimberlite will have

According to Campbell, one would

a geophysical contrast with the sur-

typically use a quadrone that provides

micro diamonds from the core sample,

rounding rock. Where it becomes diffi-

the perimeters of the pipe and internal

we performed caustic fusion and then

cult is when the kimberlite doesn’t have

geology. “One can also take a kimber-

extrapolated the micro diamonds into

a geophysical contract, because then

lite sample from core drilling and do

the micro diamond population to get

you can’t see it,” explains Campbell.

micro diamond analysis to look for very

a total content curve. That is what we

small diamonds. Once we extracted the

have done at Frischgewaagt so far. We

“The other technology that one can

In sid e M in in g 0 7 | 2016

11

diamonds only have half of the results thus far, but

and were awarded licences in April,”

on the surface. It is laborious work in a

if they are encouraging, the next step

says Campbell.

remote part of world, but we believe

is large diamond drilling. We may con-

He adds that all of these licences will

template that phase next year, making

to make new discoveries in this area,”

use of reverse flood drilling. That will take

swana Diamonds’ joint venture with Al-

says Campbell

us from inferred to indicated resource,”

rosa, and will strengthen the company’s

says Campbell.

exploration portfolio in Botswana.

“In the Central Kalahari is Gem Di-

Orapa region The Orapa region is prolific in terms of

Botswana projects

amonds Cargo Operations, which is

diamond mines currently operating

Botswana Diamonds has two areas of

currently under care and maintenance.

there. There are three mines operated

major interests – one in South Africa and

Petra Diamonds has also discovered

by Debswana, and the Firestone VK 11

the other in Botswana. “We have two

kimberlite in the area, which they call

Operation, which is also currently under

joint ventures in Botswana: one with BCL,

KX36 and are currently evaluating. This is

care and maintenance. “Probably the

which is chiefly in the Kalahari Central

an area where one needs sophisticated

most notable out of these is Lucara’s

Game Reserve, and one with Alrosa,

exploration technology to be able to

Karobe mine, which was originally dis-

which is the world’s largest diamond

find the kimberlite beneath 40 m to 80 m

covered by De Beers in the 1960s. We

mining company. We also have opera-

of Kalahari sand.

turned what was a sub-marginal, small

tions in the Central Kalahari and Orapa

“Finding this kimberlite requires a

regions. As part of the ongoing analysis

large technological arsenal, and the

something that is most probably one of

of historical data and previous work, we

kimberlite that has been found so far

the top 10 profitable mines in the world

identified these particular licence areas

was recovered from one or two grains

at the moment with the application of

towards the end of last year. There is potential for future discoveries and, therelicences. In Botswana, licence application and processing is quick and easy. We applied just before Christmas,

Ins i de Mi n i n g 0 7 | 2 0 1 7

kimberlite discovery in the 1960s into

bond technology,” says Campbell.

He explains that there are two things one has to look at in diamond explora-

fore, we have applied for those

12

that we have the technology to be able

go to Sunland Resources, which is Bot-

“We are looking for blows on the dykes, which would be evidence of very-high-grade diamonds in this area.”

tion: grade and diamond values. “You need to look at the two together to give you a dollar per tonne value. If you look at Karobe, it is probably sitting at over US$350 per carat at a grade of 20 carats per 100 tonnes. Then you multiply the two together to get to a dollar per tonne value. Ideally, we would like to find a high-grade, high-value deposit. Life

tends to work in a way where you find something marginal and you end up spending more money and energy in defining it,” explains Campbell.

Drilling challenges Diamonds are typically extracted through drilling.

Drilling often breaks larger diamonds into smaller ones, which can lead to an underestimation of the grade and diamond value. Diamonds need to be recovered as whole as possible. “For example, if you break a 10 carat diamond into two five carat diamonds, the value of

Frischgewaagt drilling & sampling The Frischgewaagt project consists of a minimum 4 km long kimberlite dyke/ blow system and Vutomi has already undertaken detailed ground geophysics and sampling. It is currently in the process of performing a core and percussion drilling programme, which will give both Botswana Diamonds and Vutomi a better indication of size and grade. The sampling programme, which was undertaken in 2016, yielded a raw diamond value of US$180/ct from 247 carats and kimberlite intersections in the dyke/blow system have been between 1 m and 17 m.

two five carat diamonds is way below the value of the single

much more sophistication in the anal-

understanding the difference is an-

10 carat one.

ysis of the diamond results themselves.

other matter. This is true expertise,”

“There is still room for improvement,

says Campbell.

“Solving this problem is incredibly difficult. Previously, mines used stomp cable

but there are few people in the world

“Many people can say that they

torque drilling, but the mere action of

that know and understand this. Larger

have found kimberlite deposits, but

the drill broke the diamonds, and later

companies have lost their expertise to

very few people can say that they

reverse flood rotary drilling dropped dia-

a large degree, but it is also a balance,

have found diamond mines and that is

mond breakage from about 80% in the

or a mixture of both science and expe-

quite different. Around 6 000 kimberlite

1960s to 20% or 30%. This is still not good

rience. One can understand the math-

deposits have been discovered, but

enough,” says Campbell.

ematical models and have a PhD, but

only 60 diamond mines have been

actually seeing a project throughout

established. Finding an economically

its life cycle – from exploration, through

viable kimberlite deposit is a major

to mining and the end result – and

challenge,” concludes Campbell.

He explains that although the technologies have remained the same, there is

In sid e M in in g 0 7 | 2017

13

Fossil Fuel Foundation

The complexities of

coal combustion Coal – a source of life-saving heat, power and chemicals needed to produce thousands of valuable industrial products, and provider of the means by which the country’s valuable iron, steel and ferroalloy metals can be extracted – is often misunderstood, and can be a source of grave danger if not properly handled and stored.

Professor Rosemary Falcon* explains.

S

ince coal was first “discov-

The inferno problem

start of such happenings while other

ered” by our ancestors, it has

Self-heating, or what is popularly known

factors will allow the process to con-

been associated with burning

as spontaneous combustion, occurs in

tinue until full combustion is reached.

– heat for body warmth and

a multitude of locations. It manifests as

It is these factors that need to be tak-

fire for cooking. Coal was discovered in

hot spots in coal seam faces, stockpiles,

en into account. The basic truth be-

the Molteno area and transported by

trains, trucks, in the holds of ships, stor-

hind this is an understanding of what

ox wagon to the Kimberley diamond

age bunkers, mills and in ducts leading

triggers the heating process.

mines during the mid-1800s. Coal mines

to boilers in power stations. It can lead

in KwaZulu-Natal dispatched their coal

to coal dust explosions of significant

Fanning the flame

to the gold mines in the Witwatersrand

proportions following methane outbursts

The so-called complexities surround-

followed by coal from the Mpuma-

and to flaming infernos associated with

ing self-heating then relate to the

langa coalfields (the Old Transvaal),

the reopening of old coal mined areas

conditions that exacerbate the initia-

which now supply the country’s power

in order to extract old pillars left behind

tion of self-heating and the handling

generation and export.

from earlier operations. Much research

of the heat thus generated thereafter.

Coal was also used for powering

has been undertaken over the last two

Namely, coal stored in layers or par-

train-hauling locomotives, ships and

centuries to understand and solve the

cels of relatively small sizes permits the

eventually multiple factories for indus-

problem, and to learn how to predict,

slow passage of air through the bur-

try. In all this time, one common factor

prevent and control the process once

den – this is not sufficient to dissipate

emerged – coal can self-ignite. It does

it has started. Many master’s and PhD

heat but is sufficient to continue the

not need a tinder box, nor careful

projects have been generated on this

oxidation process. This set of circum-

nurturing with the addition of oil, die-

topic over the years.

stances occurs in many environments

sel, wood and paper to become a flaming inferno.

14

Ins i de Mi n i n g 0 7 | 2 0 1 7

The simple truth of the matter is that certain key factors will trigger off the

including the floor of mine goafs, in bends of ducts, on the lateral sides of

Fossil Fuel Foundation

1 2 3

3

crucial facts

All coals will oxidise and, by absorbing oxygen on to its surface, coal will emit heat. This is an exothermic (heat-generating) process beginning when ambient temperatures are above 40oC. Once started, this process continues at ever-increasing rates of temperature output in the presence of air. Some coals are more likely to oxidise faster and therefore generate more heat than others.

If coal has undergone weathering to the point of becoming dry (loss of inherent moisture), the attachment of moisture (rain, humidity, water) on to the dry surface generates heats of wetting, which once again trigger off an exothermic process. This source of temperature abates once the moisture balance has been reached but the heat may generate the oxidation process in the presence of just sufficient quantities of air.

The presence of pyrite nodules, when wetted or oxidised, generate heat through self-heating up to 10 times faster than normal coal particles.

Once heat is generated, either the heat has to be removed and conducted away, or the source of oxygen requires to be eliminated.

Self-heating control is, in principle, as simple as that.

bins and hoppers, and in specific loca-

locations. Heating coal leads to the

not sufficient to dissipate the heat. To

tions within mixed particle-sized stock-

devolatilisation of volatiles at certain

control the process, there are only two

piles, rendering these areas most liable

temperatures and the emission of dan-

possibilities: dissipate the heat or re-

to self-heating leading to the point of

gerous combustible gases that, in the

move the source of air.

combustion.

presence of a point of ignition (flame

Similarly, factors leading to the gen-

Knowledge in the fields above can

from a match, spark from friction when

save lives, products and equipment.

eration of heat through heat of wet-

mining equipment strikes sandstone,

Recently, 10 people died at sea in

ting occur when dry coal is re-wetted

peak combustion and flame reached

ships carrying coal due to self-heating

through exposure to rain, humidity

by self-heating coal), will ignite and

and gas explosions, and 17 people

or water sprayed on to eliminate dust. This also occurs when fresh, moist coal is loaded on to dry weathered coal or vice versa in trains, trucks or on stockpiles. Under these cir-

Coal, the most valuable mineral commodity to this country, needs to be treated with the respect it deserves

died when a ship sank in a storm after an explosion ripped the hatches off and destabilised the ship.

Large storage bins have also exploded in the past, opening up like peeled

cumstances, heating reactions occur

explode. This is especially dangerous in

bananas, and boilers have exploded

in specific locations at the interface

a closed environment such as a goaf,

taking observers with them.

between wet and dry coals, and are

bunker or a ship’s hold. Under such cir-

Coal, the most valuable mineral

fanned by air passing through at an

cumstances, fine coal particles picked

commodity to this country, needs to

optimal rate to continue the self-heat-

up in the gaseous explosion can gener-

be treated with the respect it deserves.

ing process.

ate what is known as a dust explosion –

Not doing so can lead to disasters of

a second phase of combustion, whose

considerable proportions.

Many additional external factors can be brought in to explain the causes of self-heating, one being the exposure

consequences can be devastating.

But the facts remain. There are only

of coal to external heat such as being

two factors that initiate self-heating

loaded into a ship’s hold with one wall

– i.e. oxidation and heats of wetting

adjacent to the ship’s boiler. This trig-

– and only one factor that allows the

gers the heating process and oxidation

process to continue to full-scale spon-

continues at an increasing rate in the

taneous combustion – i.e. air flow of

presence of sufficient air in specific

a sufficient rate to allow oxidation but

*Professor Rosemary Falcon is from the School of Chemical and Metallurgical Engineering at the University of the Witwatersrand, and the Fossil Fuel Foundation.

In sid e M in in g 0 7 6 | 2017

15

coal

New plant

for tailings dam

An overview of the existing processing plant

South32 has been recycling the old tailings dam at the Van Dijksdrift coal project since 2013. Now, its BBBEE partner, Lurco, will also benefit from the approximately 60 million tonnes of B-grade, 4 800 J/kg coal. By Mientjie Kleinhans

M

ore than just recycling the tailings dam to benefit from the coal still in the dam, the dam has to be cleared to get

to the remaining pillars underground in an effort to extract more coal from the mine.

It may take a couple of years before the mine will open up the area. In the mean-

time, the tailings dam, with an estimated 60 million tonnes of coal, provides an income to two different companies.

“While both South32 and Lurco will benefit from the same tailings dam, they will each have their own processing plant to wash coal for Eskom, which will be transported by rail,” says Hendrik Nortje, site manager, Fraser Alexander.

Original plant South32 started recycling the tailings dam

Hendrik Nortje, site manager, Fraser Alexander

16

Ins i de Mi n i n g 0 7 | 2 0 1 7

when the processing plant was commissioned in 2013, in Phase 1 of the operation, to test and prove the concept. Initially, the

The ultra-fine filter press

Inside the control room of the processing plant

One of the cyclones in operation

400 tph plant

600 tph plant

800 mm cyclones x 2

1 000 mm cyclones x 2

200 tph plant x 2

300 tph plant x 2

tion by processing an additional 200 tph.

1 centrifuge

2 centrifuges

“The two processing plants are identi-

50 tph filter press

35 tph filter press

plant processed 200 tph. In 2015, the mine started with Phase 2 of the opera-

cal and situated next to each other. The two processing plants were originally

600 tph of coal. The plant will consist

designed to process 400 tph of coal,”

of two modules with two 1 000 mm cy-

explains Nortje.

clones, and only one centrifuge com-

feeder. For safety’s sake, the stockpile is

bining the product. Each module will

divided into two parts. While the one pile

process 300 tph.

is filled up, the other is reduced. “This pre-

The original plant consists of two modules and two 800 mm cyclones, each with their own spiral plant. It also has

The ultra fines will be processed through

two centrifuges, one for dewatering and

a 60 tph spiral plant and a 35 tph filter

one for fines of -1 mm material. There

press. From there, a radial stacker will

are also two 50 tph filter presses with

stockpile the coal.

99 plates.

New plant

“Construction and erection of the plant

table 1 Comparison of old and new plant

vents interaction between the trucks and front-end loader,” explains Nortje.

Unique “What makes this project unique is that

started in March, with commissioning

all three processing plants were designed

planned for November 2017,” says Nortje.

specifically to wash discard coal. And

Currently, one excavator loads three

the benefit of the new plant is that it will

of Lurco in close proximity to the exist-

777 dump trucks, which move the mate-

create almost 70 new job opportunities,”

ing processing plant, and will process

rial to the front-end loader to supply the

concludes Nortje.

The new plant will be erected on behalf

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Chamber of Mines

Accelerating efforts The Chamber of Mines hosted its 127th AGM on 24 May. Speaking at this event, I had the opportunity to outline the significant contribution the mining industry continued to make towards South Africa’s economy during 2016.

By Roger Baxter*

T

wo weeks after the AGM, the

in taxes were paid to the South African

mineral prices, have helped provide

Chamber published its Facts and

government. The taxation contribution

some recovery to the sector, although

Figures 2016 booklet; the inten-

does not include the R6 billion contrib-

some components are struggling. At

tion is to showcase the work of

uted to skills development or the other

current prices, over half of the platinum

the mining industry through accurate

levies and tax contributions the industry

sector is marginal or loss-making, which is

data, and to provide insight into what

makes to the country. Mining remains a

a significant challenge for the country.

the numbers mean for South Africa and

significant contributor to employment,

the future of the industry. Just one day

with 457 332 individuals employed di-

In conclusion

later, the DMR released its reiteration of

rectly by the sector at the end of 2016.

My review of the year inevitably fo-

the Mining Charter. We, as the Cham-

This represents just over 5.4% of all formal

cused on the challenges faced by the

ber, have made it clear that we will

(non-agricultural) employment nation-

industry. I also took the time to pause

challenge the Charter in court, and we

ally. In total, these employees earned

and consider the role of mining and the

are bringing an urgent interdict to pre-

R120 billion in 2016, and contributed

Chamber of Mines in South Africa in the

vent the implementation of the Charter

around R18 billion to the fiscus in terms

past and going forward.

until the court challenge is complete.

It is ironic, perhaps, that the publication of the DMR’s Charter slashed R50 billion from the market capitalisation of SA-listed mining equities the day after we produced a document show-

I continued to speak on how this industry has contributed greatly to the South African economy and its people. It has also done this at a cost – to people and to the environment – sometimes intentionally, sometimes not. This is an indus-

ing the value of mining to the country. It

of PAYE tax. Total employment in the

try that, today, must recognise its past

is worth reflecting on the role of mining

economy attributable to mining is about

and address the legacies that it has

in South Africa, I think.

1.3 million people, demonstrating the

to bear. It is also an industry that must

huge multiplier effects of mining.

look forward to ensuring that future

Critical to the economy

While the sector recovered to some

Mining has played a vital role in the

extent during 2016, the industry is still

economy for over a century and a half.

facing significant challenges.

legacies are positive, value-accretive and responsible.

We have accelerated our efforts in

In 2015, the industry made an ag-

dealing with legacy issues and great

R304 billion towards SA’s GDP, represent-

gregate loss of over R30 billion as it

progress is being made. We and our

ing 7.3% of overall GDP. If the indirect

grappled with cost pressures, falling

members remain committed to inclu-

multipliers and induced effects are con-

global prices and production challenges

sive growth and meaningful economic

sidered, the overall contribution to GDP

(including the negative impact of inap-

transformation in the sector.

is about 17%. Mining directly contributed

propriate Section 54 safety stoppages).

R93.3 billion to fixed investment, while

In 2016/17, the green shoots of recovery,

*Roger Baxter is the CEO of the Cham-

R3.7 billion in royalties and R12.5 billion

spurred by an improvement in some

ber of Mines South Africa.

In 2016, the mining industry contributed

18

457 332 people were employed directly through mining at the end of 2016

Ins i de Mi n i n g 0 7 | 2 0 1 7

special feature | alexkor

Operating a growing, profitable and sustainable mining organisation, and contributing to the developmental needs of the communities.

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special feature | alexkor

The age of

di am

nds

While Alexkor’s roots were planted almost 90 years ago in Alexander Bay in the Northern Cape, the area’s diamonds have their own fascinating, 100-million-year history.

lexkor was established in

Alexkor’s distinctive competencies

terms of the Alexkor Limit-

are its quality of diamonds and its unique land and mineral resources.

ed Act (No. 116 of 1992)

Over the life of mine, approximately

and later amended to its current form by the Alexkor Amend-

10 000 000 carats of gemstone-quality

ment Act (No. 29 of 2001). The or-

diamonds have been recovered.

ganisation is a listed Schedule 2 public entity owned by government

A little history

through the Department of Public

In 1908, the first diamonds were dis-

Enterprises. The Minister of Public

covered along the west coast of

Enterprises – currently Minister Lynne

Southern Africa at Kolmanskop near

Brown – is the shareholder

Luderitz, in what was then German

representative.

South West Africa. This led to the

The company has two divisions or

subsequent discovery of the rich dia-

business units: the Alexander Bay

mond deposits mined by Consolidat-

Mining – Alexkor RMC (Richtersveld

ed Diamond Mines along what is now

Mining Company) JV – and the Alex-

the Namibian coastline.

kor Corporate Unit. The Mining Divi-

It was not until 1925 that the

sion is the core business of the com-

first diamond was discovered in

pany, exploiting a large land-based

Namaqualand on the Port Nolloth

diamond resource and extensive

Reserve. Shortly thereafter, con-

diamondiferous marine deposits.

activities are complemented by explora-

centrated prospecting operations

While Alexkor, as a commercial

tion, ore reserve planning, rehabilitation

began between the Cliffs north of Port

state asset, is not a strategic asset

and environmental management, while

Nolloth and the Orange River estuary,

in the national sense, it has signifi-

Alexkor’s non-core business activities

with minor activity taking place to the

cant strategic importance for the

consist of residential services, community

south towards Kleinzee. In 1926, the rich

Namaqualand region.

services, outside engineering services,

deposits at Alexander Bay were discov-

external transport services, guest houses,

ered. These deposits proved so rich that,

Alexkor’s core business is the mining of diamonds on land, along rivers, on beach-

a fuel station and an airport.

The management of considerable

es and in the ocean

investment funds, together with tra-

along the north-west

ditional support services, such as IT

coast of South Africa. These

in 1927, the government prohibited diamond prospecting on state-owned land in Namaqualand.

During this time, prospecting operations

and HR, constitutes additional

at Kleinzee were laying the foundation

non-core business activities.

for what was to become the De Beers

In sid e M in in g 0 7 | 2017

21

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Alexkor

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special feature | alexkor

Namaqualand Mines. In 1928, the South African government

River to the Orange River, as well as along the Namibian coast

started mining operations at Alexander Bay. This was to be-

as far north as Conception Bay, and possibly beyond.

come Alexkor.

In 1954, the offshore diamond prospecting commenced

The size and quantity of wave-transported diamonds decrease as the distance from the palaeo river mouths that have

and between 1961 and 1965, a Texan entrepreneur –

acted as point sources for the gems increases. The tailing-off

through the Marine Diamond Corporation (now De Beers

is much more gradual northward from the river mouths than

Marine) – provided the impetus needed for geological ex-

southward – this being attributed to strong northward-directed

ploration on the continental shelf by exploiting diamonds

longshore drift. Exploration for marine alluvial diamonds both

offshore along the coastline of modern-day Namibia.

onshore and in the surf zone shows that there are preferential

This has manifested itself into a growing industry, with dia-

localities in which marine sedimentary deposits have higher

monds having been discovered and mined in the near- and

probabilities of containing diamonds. These include gullies,

offshore environments along the coastline, from south of the

potholes and bedrock depressions, all of which are associated

Olifants River in South Africa to some 120 km north of Hot-

with marine wave-cut terraces. Palaeo drainage channels, the

tentots Bay in Namibia. So, it’s clear that the region is rich in

southern side of headlands and wave-abraided terraces all

diamond deposits, but why is that?

have higher probabilities of containing diamonds.

Source of the diamonds

minerals. Consequently, they are generally found close to

It is estimated that a vast resource of 90% to 95% gem-quality

the bedrock and are deposited in high-energy environment

diamonds exists off the west coast of Southern Africa.

sediments containing pebbles, cobbles and boulders. These sed-

Diamonds have a higher specific gravity than most common

The diamonds occurring in marine gravels along the west-

iments commonly owe their existence to storm beach deposits

ern coast originated from kimberlites intruded into the interior

along the base lines of low cliffs that back wave-cut terraces.

of South Africa during the Cretaceous period, between 80 and 120 million years ago. Since the Late Cretaceous, erosion resulting from continental uplift has removed an estimated 1 400 m of the kimberlite pipes and surrounding country rocks. The bulk of the erosion took place during the Late Cretaceous and little denudation of the Southern African interior occurred during the Tertiary, when mammalian species started to flourish and diversify.

The gradual change from a warm, humid climate during the Late Cretaceous to arid conditions in the Late Tertiary resulted in a dramatic reduction in the volume of sediment supplied to this coastline in the Cenozoic. The implication of this is that by the end of the Cretaceous, most of the diamonds released by erosion were made available in this area. During this period, the main drainage system from the diamondiferous interior to the western coast was along a river that debouched on to the continental shelf via the present-day Olifants River.

Tectonic uplift, differential erosion rates and climatic aridification resulted in the so-called Kalahari River (proto Orange River) capturing the headwaters of the Karoo. By the end of the Miocene, the modern Orange River drainage system was established and would have acted as the principal transport route for diamonds to reach the coast.

Secondary river courses – such as the Buffels and Swartlintjies rivers, which were far more active in the past – have cut back into the old interior land surfaces and reworked fossil gravels.

This latitudinal change in the palaeo drainage pattern of major river systems flowing to the west coast during the Cretaceous and Tertiary, together with powerful wave action and longshore drift, produced diamondiferous deposits along the length of the west coast from south of the Olifants

MYEZO ENVIRONMENTAL MANAGEMENT SERVICES Environmental Stewardship We are an environmental consulting company providing services cutting across various sectors and specialising in mining. Our diverse team of experts are registered with the South African Council for Natural Scientific Professions. The founder is also registered as an auditor with the Institute of Environmental Management and Assessment (UK).

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Ensuring responsible operations

awarding shallow water contracts

people, especially young people, so as to

to redundant Alexkor employees.

enable them to take charge of their own

The organisation is also involved

lives. Over R2 750 000 has been provided

in the upliftment and empower-

in direct funding to nursery, primary and

ment of women, and provides

secondary schools throughout the region.

opportunities for local small-scale mining companies.

Supporting education

I

With regional poverty being rife,

Tourism Namaqualand is one of the least explored regions in South Africa. It is a world surprisingly diverse, often starkly beautiful.

t is undisputed that mining impacts

there is a serious need for extensive

the environment and the commu-

education and social development pro-

ate wealth for local communities, through

nities within which it takes place.

grammes, and Alexkor is committed to

sustainable job creation.

Alexkor has made a commitment to

the improvement of the standard of ed-

The mining area itself has considerable

both the people and environment in the

ucation in Namaqualand. The company

tourism potential based on unique biodi-

Namaqualand region.

currently provides ABET classes to current

versity, a rich mining history and a Ramsar

employees and the community, and of-

site at the mouth of the Orange River. This

fers learnership programmes.

site has been proclaimed a World Herit-

Mining, particularly the diamond industry, is the backbone of the regional economy and is the largest contributor

Previously, the Alexkor Development

This largely untapped potential can cre-

age Site and forms part of the |Ais-|Ais/

to labour remuneration in the region.

Foundation (ADF) has provided close

Although not the biggest employer in

to 1 000 bursaries, at a cost of almost

Namaqualand, Alexkor provides em-

R3 000 000, to disadvantaged local stu-

tourism development in the region:

ployment to approximately 2 500 people

dents. In addition, study loans to the val-

• funding of the local tourism

directly and indirectly.

ue of close to R1 500 000 have been paid

Alexkor provides potable water to Alexander Bay and Port Nolloth and, in its en-

out to students all over Namaqualand.

The development of the human re-

Richtersveld Transfrontier Park.

Alexkor provides the following to support

website Diamondcoast • running of guest houses in and around Alexander Bay

deavour to create jobs for local commu-

sources potential is a matter of the

• running of the local airport

nities, has created alternative economic

highest priority for the ADF. Grants made

• local museum

activity for retrenched employees by

to schools are aimed at empowering

• river mouth.

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special feature | alexkor

A future shining bright Under acting CEO Vimal Bansi, Alexkor has managed to steady the ship and charter a course for future sustainability.

Inside Mining looks at what has brought about this turnaround.

L

ike most of South Africa’s state-owned assets, Alexkor has had its share of ups and downs since its founding in 1992. Di-

amond mining production can be somewhat unpredictable, and dips in production, accompanied by the fluctuating global economic climate and rand exchange value, have seen the organisation weather some tough times over the years.

In recent years, though, Alexkor’s growth has largely been steady and positive. Between 2012 and 2015, its annual revenue almost doubled (though not year-on-year), although the company saw a significant dip in operational output last year, producing almost 30 000 fewer carats than the previous year, and a revenue decline of 6%, from R211 million in 2015 to R197 million.

This year, however, the company has flourished. Under the steadfast leadership of acting CEO Vimal Bansi and COO Humphrey Mokwena, Alexkor is now on firm footing.

After last year’s shortfall, Bansi firmly believes that the company is on the

In sid e M in in g 0 7 | 2017

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25

PSJV & IMDSA Mining operations in Alexander Bay take place through the Pooling and Sharing Joint Venture (PSJV), which is 51%-owned

by Alexkor and 49%-owned by the local Richtersveld community, and strategic partner International Mining and Dredging South Africa (IMDSA). The latter is responsible for deep-sea mining production.

path to financial recovery and sustain-

Although this spike in production bodes well for Alexkor, pru-

ability. “This has been a transformative

dent management is what really lies at the heart of ensuring

year, where improvements have taken

a positive outlook. “Ensuring the sustainability of Alexkor and

hold. I believe this bodes well for the

the PSJV is of utmost importance to all our stakeholders,”

overall good of the company and the

explains Bansi.

communities we serve,” he states.

Behind this recovery has been a boom in carat production, as well as

• increase land carat production by sweating current assets

cost saving measures introduced in the

• progress and finalise the mid-waters mining project

last financial year. “Carat production

• monitor and co-manage deep-sea mining operations

at Alexander Bay increased significant-

• finalise coal beneficiation study

ly this year. Over 160 000 gemstone

• explore diamond beneficiation.

quality diamonds were recovered

Humphrey Mokwena, COO, Alexkor

In November 2016, Alexkor aligned its strategic objectives to focus on the following priorities:

compared to 45 492 carats produced

Land carat production

the previous year. Of these, the PSJV

“In order to increase land carat production, we embarked on

recovered 50 000 carats and IMDSA mined 112 000 carats,”

an exploration programme to improve the level of resource

says Bansi. The result of this amazing production has been an

confidence from an inferred to an indicated/measured

annual turnover in excess of R757 million – some 96% higher

category,” Bansi explains. Alexkor has also budgeted for an

than the previous year’s turnover of R386 million.

airborne geophysical survey in this financial year, which is intended to guide its land-based exploration initiatives. “Further,

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cesses and have systems in place to ensure that our marine contractors are better managed. These efforts have already yielded a significant increase in carat production,” he adds.

Mid-water concessions

Our areas of expertise COMMERCIAL

we remain focused on the optimisation of our mining pro-

Drafting of all types of commercial agreements, corporate restructuring, advising on compliance and governance, and mergers and acquisitions;

“The mid-water concessions have the potential to be lucrative targets, based on current shallow-water mining results where stones of exceptional quality and value continue to be mined. The mid-water tender evaluation and adjudication

Merger and acquisition filings, competition issues, and advisory opinions

was completed and four companies were identified as hav-

Liquidation applications, interrogations, and business rescue;

ters. Mining is expected to commence in the coming year,”

ing the technical and financial capacity to mine the mid-waBansi comments.

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Diversification As part of its mineral diversification strategy, Alexkor’s pursuit of a business case for coal received approval from the Minister of Public Enterprises in May 2016, Bansi explains. “Our intention is to invest in an existing coal washing plant situated in the Witbank/Middelburg coal-mining hub. Coal beneficiation has long been an opportunity for Alexkor, where it is envisaged to leverage a state-owned company relationship – in this case Alexkor-Eskom – to enter into a coal supply agreement.” Due diligence and the follow-up business case were completed in February 2017, with very encouraging results.

Diamond beneficiation A key strategy in the future sustainability of Alexkor is diamond beneficiation. “As a primary producer of gem-quality diamonds, Alexkor is in a favourable position to enter and

26

In sid e M in in g 0 7 | 2 0 1 7

special feature | alexkor

become a serious player in this space,” asserts Bansi.

Looking to learn from the best, company representatives visited India (where 95% of global diamond production is

“Carat production at Alexander Bay increased significantly this year. Over 160 000 gemstone-quality diamonds were recovered compared to 45 492 carats produced the previous year.”

beneficiated) this year to learn more about diamond beneficiation and is now looking at bringing these skills to South Africa.

Beyond strategic objectives aimed at ensuring organisational sustainability, Alexkor has consistently placed an emphasis on

initiatives, Alexkor plays a vital role in the well-being of the communities within which it operates. Placing a focus on the social upliftment and development of these communities, Alexkor and the PSJV invested more

than R5 million in CSI programmes in 2016.

Through good corporate governance and its responsible and uplifting interactions with local communities, Alexkor has paved the way for sustainable operations.

And with 2016 having been the bumper year it was, the immediate future of Alexkor is looking particularly bright.

developing and maintaining positive stakeholder relationships.

Bonded to the community “Fostering sound and positive engagement with all our stakeholders is important to Alexkor. We are proud to provide employment to approximately 2 500 people directly and indirectly in the region,” states Bansi. Through various CSI

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open-pit mining

T

here are a number of cost-saving

comes to dust management involves

advantages associated with using

preserving natural resources, such as

road suppression solutions. A re-

water, and improving the environmen-

duction in water use equates di-

tal conditions for all human resources

rectly to the reduction of machinery use

employed on the mine. This needs to

– less grading and less water spraying

be done by employing the use of in-

reduces the use of diesel, tyre wear and

novative dust suppressing products at

routine maintenance schedules.

a fraction of the cost, while preserving

Using less machinery on a daily basis also reduces mines’ carbon footprint.

the environment.

Mines have both a legal and social

The average unpaved road on a mine

responsibility. Dust generated through

is sprayed five to six times with water to

mining activities can be harmful to hu-

effectively suppress dust, while road sup-

man health over an extended period

pression solutions such as I-CAT’s Road

of inhalation. That is why legislation has

Dust Solution are sprayed up to twice a

been adapted to protect employees

day – showing a significant reduction in

from such risks. Using a dust suppression

a 24/7 mining operation.

product on haulage roads decreas-

Best practices

The macromolecules function as an active surface agent to weigh down dust particles

es the harmful dust generated by haulage vehicles.

Mines need to comply with legislation

Some dust suppression products do,

and keep their dust levels lower than

however, contain ingredients that are

from becoming airborne. GreenBit and

the legislated levels, which can be

harmful to the environment. But I-CAT’s

GreenGrip are less environmentally

done by using dust fallout monitoring.

RDC 20 product is both an environmen-

friendly than RDC 20, but are still less

This process identifies critical areas and

tally friendly and effective dust suppres-

harmful to the environment than other

uses dust fallout buckets to measure

sant. It forms a cross-linked matrix that

products on the market.

and assess the dust in a certain area.

binds the fine particles of dust together

Best practice to keep in mind when it

to weigh them down and keep them

Managing dust in open-pit mines

Water is a valuable commodity and is priceless during a time of drought. The last thing that mines want to do is use water to suppress dust in a time where water savings are a top priority. There are many products available that use less water. By Lourens Jansen van Rensburg*

Importance Dust suppression plays a vital role in protecting miners against harmful dust, as it increases visibility and control on the roads, making the mine and the surrounding areas safer. Dangerous road conditions, limited visibility and harmful dust generated by haulage trucks and high traffic volumes are among the reasons why dust suppression is so important. Uncontrolled dust can also cause slippery roads when wet or corrugated roads that require constant grading when dry. *Lourens Jansen van Rensburg is the business development and marketing director at I-cat.

The average unpaved road on a mine is sprayed with water five to six times to effectively suppress dust

In sid e M in in g 0 7 | 2017

29

l a c i t c Pra

o t h c a o r p p a

s e p o l s r e p e ste s te e p , and its

nd mine o m a i d st s f ro n t s. ’s highe u d l o r i r o a w v n is the llenge o a h c Le t š e n g t n a c a s i gn i f i p ro v i d e a 6 Mt/a reduction in the peak waste

W

Hazard identification involves a range of geotechnical monitoring

activities comprising instru-

mentation, survey, and visual inspection by geotechnical personnel. Lidar scanners were purchased for the purpose of

mining compared with the previous

monitoring slope deformation that might

hile the steepening of

mine plan, coupled with an increase in

not be picked up by visual observation.

slope angles can improve

the net present value (NPV) and life of

Hazard plans are used to define poten-

the economics of an

mine,” writes the author.

tially hazardous situations in the pits.

an increased risk of slope failure, which

Slope stability risk management

of historical trends from monitoring and

can be both costly and catastrophic. In

Madowe explains that the steepening

comparisons with predicted perfor-

the paper ‘Design and implementation

of the slope angles in waste was ena-

mance from the geotechnical models.

of steeper slope angles on a kimberlite

bled by operational improvements in

Consequence assessment with re-

open-pit diamond operation – a prac-

the areas affecting pit slope stability.

spect to the safety of personnel and

tical approach’ by A Madowe, the au-

This section provides an overview of

equipment in the pits is determined

thor discusses the possible consequenc-

these improvements.

with reference to assessment of the

open-pit mine, this brings

es and steps taken at the mine.

“Slope failures are inherently costly

“The purpose of slope stability risk management is to assist in providing a

Exposure assessment involved a study

impact and severity of the risk from the identified hazard.

events, because they can be cata-

safe working environment for the open-

strophic, resulting in multiple fatalities,

pit mining operation by managing the

such as evacuation, buttressing (con-

equipment damage, and temporary

geotechnical risk. Letšeng seeks exter-

struction of berms), the installation of

or permanent closure of a mine. The

nal assurance from world-renowned

ground support, changes to pit designs,

steepening of the basalt slope angles

geotechnical consultants on the deter-

as well as the installation of survey

at Letšeng Diamond Mine followed

mination of the optimal slope designs

prisms and utilisation of scanners to

operational improvements that were

for the pits,” writes the author.

monitor the identified high-risk areas.

introduced through improved blasting

30

slopes

The aspects of the mine’s slope stabil-

Mitigation involves a range of options

Standardised procedures cover as-

practices and geotechnical controls.

ity risk management are described in

pects such as data collection and

The steeper slope design resulted in

the paper as follows:

record management, the operation of

Ins i de Mi n i n g 0 7 | 2 0 1 7

open-pit mining

Slope failures are inherently costly events, because they can be catastrophic, resulting in multiple fatalities, equipment damage, and temporary or permanent closure of a mine

lidar scanners, mining practices, evac-

widths, mining dilution, and min-

geotechnical sign-off for each high

uation, working under high walls, and

ing recovery (the minimum mining

wall immediately after completion of

pit design changes. The procedures

width is the minimum cutback width

mining in order to ascertain that the

include a ‘Code of Practice to combat

that allows the selected fleet to

wall has been mined to standard and

rock fall and slope instability accidents

operate efficiently)

would not pose future risks to mining

at Letšeng Diamonds’.

personnel and equipment

• plant recovery and annual

• improved geotechnical data col-

plant capacity

Incorporation into the mine plan

• any other relevant parameters such

The author writes that a review of the

as environmental, legal, social and

mine plans was required to evaluate

governmental factors.

the economics of the new pit slope an-

lection that resulted in better rock mass characterisation • introduction of slope monitoring using lidar scanners, including the formu-

gles. At the beginning of the life-of-mine

Conclusion

planning process, a ‘Mine Planning

The steepening of the slope angles in

procedure in the case of detection

Input Parameters’ document is created

waste led to significant improvements in

of a slope movement beyond set

as a repository of the mine design and

the mine plans and NPV. The steepen-

planning input parameters.

lation and adoption of a pit clearing

threshold limits • commissioning of a purpose-built scal-

ing of the slopes was enabled through

The mine planning inputs were docu-

the improvements that were introduced

er for dislodging loose rocks on the pit

mented as:

in blasting, geotechnical controls, data

• the latest geological model that de-

collection and the communication of

“However, the steeper slope requires

fines the grades, diamond price per

geotechnical hazards.

the mine to be more vigilant in the are-

kimberlite phase and tonnes of the

The improvements in blasting were:

as of geotechnical control. An ongoing

various rock types in and around the

• introduction and advances in trim

pit slope angle reconciliation on both

high walls.

deposit, as well as the classification

or buffer blasting and pre-splitting

basalt and kimberlite slopes will need to

(measured, indicated or inferred) of

around the final pit perimeter

be carried out on a regular basis, with

the various blocks in the model in ac-

enhanced the protection of final

decisions taken on the performance

cordance with the SAMREC Code

pit walls

of the slopes and modifications to the

• introduction of electronic timing

• pit slope design parameters such

slopes, as and when required. Quality

as bench height, berm width and

systems in blasting led to improved

assurance and quality control on the

batter angles

blasting by exploiting the flexibil-

pit limit blast design patterns remain

ity and greater accuracy of the

among the most important factors in

electronic systems

ensuring that the limit blasts are carried

• financial data consisting of exchange rates, annual diamond price escala-

out in the most effective manner,” con-

• introduction of multiple primers in blast

tions, royalties, marketing and selling

holes to improve fragmentation.

costs, discount rate, mining and

cludes Madowe.

treatment unit costs, overhead (fixed)

The improvements in geotechnical con-

costs, and capital costs

trols were:

*Read the full paper: www.saimm.

• the initiation of a process of

co.za/Journal/v116n08p723.pdf

• haul road design, minimum mining

Geotechnical unit

Hoek-Brown geomechanical parameters

table 1 Summary of the rock mass strength parameter

UCS (MPa)

GSI

Mi

MR (1)

D

E (GPA)

V

Ơ3 max (MPa)

C (KPa)

ɸ (°)

Basalt

126

70

14

350

0.7

14.9

0.23

1.0

185

59

Kimberlite

41

50

5

300

0.8

1.1

0.25

1.0

285

33

In sid e M in in g 0 7 | 2017

31

mineral processing | Diamonds

overcome problems such as ore

Separating waste rock

dilution experienced in minerals processing operations.

They add that the benefits are lower energy and water costs, reduced ore dilution, lower environmental impact and improved profit margin. In sensor-based sorting, materials are mechanically sorted based on certain physical properties that are detected by a sensor.

“Research has found that, with NIRS scanners, it is possible to obtain a ‘fingerprint’ of a sample that is directly related to its mineralogical composition.

Molecules absorb NIR radiation by means of electronic and vibrational transitions.

Nowadays, there are many sensors available in the market that utilise different material properties – the choice of a

Near-infrared spectroscopy sorting technology uses the differences in material characteristics to separate kimberlite from waste rock. This new technology was commissioned at the Cullinan Diamond Mine to determine its viability in the diamond winning process flow sheet.

T

sensor is dependent on the mineralogy of the ore,” write the authors. According to them, traditional metallurgical techniques for diamond winning from kimberlitic ore involve size reduction, dense-medium separation (DMS), and final recovery by X-ray technology. “These techniques have no ability to remove waste rocks that are often associated with the kimberlite. The

he paper ‘Separation of kimberlite

spectroscopy (NIRS) technology for ore

kimberlite ore body at Cullinan Diamond

from waste rocks using sensor-

sorting is a new concept for the minerals

Mine (CDM) is intruded by sills and dykes of

based sorting at Cullinan Diamond

processing and mining industry. “NIRS has

waste rock, and the current mining meth-

Mine’ by authors T Mahlangu,

been used for decades in the laboratory

od cannot separate the waste material,”

N Moemise, MM Ramakokovhu,

for the identification of pure minerals, and

write the authors.

PA Olubambi and MB Shongwe,

has its roots in the recycling, food and

describes the test work that led to the

pharmaceutical industries.”

Preliminary results

decision to conduct the pilot-scale study.

They continue that sensor-based sorting

The authors discuss the overall results

The authors note that using near-infrared

is an advanced technology that can help

of the tests that were carried out only

Classifier Test sensitivity setting (%)

Feed (kg)

Kimberlite in feed (kg)

Waste Kimberlite lost in feed Roug.

Scav. (kg) (%) (%)

Kimberlite recovery

Waste removal

(kg)

(%)

(kg)

(%)

1

50

958

457.1

509.9

1.03

-

452.0

98.89

480.0

94.13

3

55

1 220

616.5

603.5

5.64

-

583.0

94.57

560.5

92.87

4

65

1 149

600.0

549.0

1.76

-

591.5

98.58

474.5

86.43

5

60

1 376

685.0

691.0

2.93

-

666.0

97.23

629.0

91.02

6

50

1 189

581.1

607.9

4.28

-

579.1

99.66

525.5

86.44

table 1 Results of rougher stage sorting table 2 Results of scavenger stage sorting

Feed (kg)

1

45

1 268

589.0

679

5.87

2

45

1 047

535.2

511.8

3

50

992

505.8

486.2

Test

32

Kimberlite Waste lost Kimberlite in feed in feed (kg) Roug.

Scav. (kg) (%) (%)

Classifier sensitivity setting (%)

Ins i de Mi n i n g 0 7 | 2 0 1 7

Kimberlite recovery

Waste removal

(kg)

(%)

(kg)

(%)

0.24

587.5

99.75

622.0

91.61

4.83

0.34

533.6

99.69

473.4

92.50

6.34

0.22

504.8

99.80

463.0

95.23

in the rougher stage. “The average kimberlite recovery was calculated to be 97.8%, while the average waste removal was calculated to be 90.2% at the scavenger stage. The scavenger stage was used to recover the kimberlite misclassified into the waste stream from the rougher stage. Approximately 4.1% of the kimberlite is calculated to be lost at the rougher stage. The average kimberlite recovery was calculated to be 99.8% and the average waste removal was calculated to be 93.1%,” report the authors.

According to Mahlangu et al., the results clearly indicate that the introduction of a scavenger stage improves the separation efficiency and minimises the potential for diamond loss. “It is also seen that kimberlite recovery decreases at a low classifier sensitivity. This is due to the fact that low classified sensitivity reduces the aggressiveness of the machine with respect to its ejecting potential. In both the rougher and scavenger stages, the kimberlite recovery was calculated to be above 95%, which clearly indicates that the COLOR/NIRS sorter is able to discriminate between the CDM kimberlitic and waste rocks,”

Research has found that, with NIRS scanners, it is possible to obtain a ‘fingerprint’ of a sample that is directly related to its mineralogical composition

Realising possibilities from mine to market.

explain the authors. They add that there is a relatively high loss of the kimberlite ore when using only a rougher stage. However, introducing the scavenger stage minimised the risk of kimberlite loss to an average of 0.3%. The kimberlite lost was above target for tests 2, 3, and 8 because the aggressiveness of the machine was kept low.

Throughout the duration of the project, the tailings stream was sampled to monitor the average kimberlite loss. Kimberlite

Resource Evaluation

Mine Planning

Mining & Mine Development

Materials Handling

Environment & Approvals

Transport to Market

Non-Process Infrastructure

loss is an indication of potential diamond loss, and should be kept to a minimum. The acceptable kimberlite loss was set at a target of below 5%. It was possible to keep the kimberlite loss below 5% for several months, but in January 2015, a high loss of ore occurred. It was decided to stop the sorter until the prob-

Mineral Processing

Tailings & Waste Management

Smelting & Refining

lem was found and rectified. The sorter was found to have lost programming and had to be reprogrammed with preclassified samples. It was also realised that the kimberlite loss was above target when the screen sprays were blocked and the feed coated with mud.

Conclusion In the conclusion of the paper, Mahlangu et al. note that, based on the test work, the COLOR/NIRS sorter is generally a good tool to separate Cullinan kimberlite from waste rocks.

“The introduction of a scavenger stage will improve the kimberlite recovery and also minimise diamond loss. The pilot plant test work results were not consistent since the sensing technology is based on the surface properties of the material; hence, the feed needs to be clean and free of dust or mud prior to sorting.

“However, this is not always the case in a production environment, particularly for kimberlite ores, which have a high content

WorleyParsons adds value through our full scope of services from pit to port including studies, mine planning, impact assessments, permitting and approvals, project management, construction management and global procurement.

Our Mining Centre of Excellence in Johannesburg has niche expertise in underground and open cast mining and provides quality project development and engineering solutions for small to large projects across all areas of base metals, the coal supply chain, chemicals, ferrous metals, alumina, aluminium and iron ore.

Supported by the WorleyParsons global group, we pride ourselves on customising solutions for local environments and committing to our customers’ goals.

of clay material. Due to the risk of diamond loss as a function of kimberlite lost, it is recommended that a scavenger stage be implemented in further kimberlite preconcentration processes using the same sorting system,” conclude the authors.

www.worleyparsons.com

wprsainfo@worleyparsons.com

mineral processing | Diamonds

Supplier teamwork to

benefit mines

The use of vibratory screens is key in coal processing, and process engineers often explore the life, efficiency and capacity of different screen panels to improve screening performance.

Specialist OEM Kwatani warns, however, that it is vital to keep screen manufacturers in the loop when changing panel types.

I

n the design and manufacturing process, panel specifications need to be

A Kwatani feed preparation doubledeck vibration screen en route to an iron ore mine

carefully integrated with the structural and mechanical features of the screening

machine, explains Derrick Alston, executive director, Kwatani. “In the coal sector – where large, high-tonnage screening machines are often employed under demanding and sometimes highly corrosive conditions – mines can optimise performance, cost per tonne and machine lifespan by facilitating better cooperation between screen OEMs and panel suppliers.”

Alston emphasises that screening machines are designed for a certain weight and performance of screen panel.

“When we build a vibrating screen for a mine, we test it extensively with the panels specified by the customer,” he explains.

“These panels are expected to deliver certain

Kwatani dewatering screens on the test rig prior to dispatch to a platinum mine

throughputs and end products for the mine, but their performance is also based on how the machine has been designed. So a different type of panel may have unintended impacts that could be detrimental to the machine’s lifespan and, indeed, its performance,” Alston adds.

A Kwatani screen on the test rig before dispatch to a coal mine

Among the panel properties that affect performance are: the panel’s open area, mass, the type of material being treated, the panel material, the accuracy of the panel dimensions, the fastening method, the aperture shape (including when slotted apertures are used), and the direction of the slot in relation to the material flow.

An overweight issue According to Kwatani’s COO, Kenny MayhewRidgers, “When inspecting and maintaining our machines, we sometimes find that the panels used to replace the originals exceed the maximum design weight by up to twice as

34

Ins i de Mi n i n g 0 7 | 2 0 1 7

mineral processing | Diamonds much. This can change the dynamics and

mine level,” Mayhew-Ridgers says.

that all elements of the screening

overload the screening machine.”

“They therefore have a lot to offer in

machines’ operation must be aligned.

It is also vital to monitor the performance

A panel provider might even change

a collaborative relationship with OEMs

the screen frame so that their panels fit

and mines, which is essential to ensure

of new panels once they are fitted, and

the screening machine, says Mayhew-

that the customer gets what they are

to engage with the customer and the

Ridgers. “If this frame is substantially

looking for, and the screening operation

machine OEM to confirm the results of

heavier than the original, it could result in

runs optimally.”

any panel changes or to report any issues

a change in the centre of gravity so that it

that may arise.

is no longer aligned with the exciter drive.

Entrenching collaboration

As a result, the screen could develop a

The end user can, in fact, facilitate this

mining customers to report in detail on

pitching motion.”

collaboration to ensure that each player

repairs or adjustments, for instance,” he

is focused not only on supplying their own

says. “So this is good practice for panel

the screening machine often leads

products and services, but is also taking

suppliers and it would assure the customer

to reduced performance or higher

stock of the broader demands of the

that the intended results are being

maintenance costs on the machine.

mine’s process operations. The customer

achieved. It would also help identify

“These kinds of issues are often blamed

can arrange regular joint meetings with

any problems at an early stage, before

on the OEM of the screening machine,

the screen OEMs and the panel suppliers

extensive damage is caused.”

although the source of the problem

to discuss and implement the best options

is not always immediately clear,”

for any improvements in the process.

A mismatch between the panels and

explains Alston.

“OEMs are generally required by their

“In certain areas of South Africa, we

The compatibility of panels also affects the lifespan of the screening machine.

A well-maintained and well-operated

work very closely with panel suppliers and

machine will not only help a mine

our service technicians often even travel

hold down its processing costs,

He acknowledges that the mine’s process

to a site together to inspect machinery,”

but will also reduce the cost of

engineers are often looking for better

says Mayhew-Ridgers. “This makes for a

refurbishing the machine at the

efficiencies, so they may want to try

very constructive relationship, as a full

end of its life cycle.

different panels to improve performance.

inspection that considers both the panels

“The customer is important

and the screening machine, highlighting

to both the machine OEM and

recommend that they keep the screen

any concerns as early as possible can

panel provider, so better

OEM in the loop,” Alston says. “The OEM

then take place.”

communication and

Optimising efficiencies

“This is as it should be, but we

can then advise from a mechanical point

cooperation between

He highlights that the total cost of

of view on potential areas of concern.

ownership is really the only way to assess

the two just

We have had great successes in the past

the value that OEMs and suppliers add to

makes sense,”

where we, as the OEM, have worked

the customer’s business, so it is important

says Alston.

closely with the mine and the panel supplier to find an optimal solution.”

“Most panel suppliers conduct considerable R&D, which contributes greatly to the efficiencies of vibratory screening and to productivity at

When inspecting and maintaining our machines, we sometimes find that the panels used to replace the originals exceed the maximum design weight by up to twice as much.” Derrick Alston, executive director, Kwatani

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LOESCHE South Africa (Pty) Ltd | Block C, Empire Park, 55 Empire Road Parktown, 2193 Johannesburg, South Africa | www.loesche.com

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t

The past two decades have seen a significant rise in the use of mobile crushing equipment in the local and Southern African mining industry.

Sandro Scherf (pictured above), CEO of Pilot Crushtec International, is a firm advocate of the mobile concept.

he traditional pit mining process,

are known to represent the single biggest

begins with the drilling and blast-

cause of fatalities in open-pit mining.

ing of rock, from which fragments are broken down to significantly

The equation changes in the operator’s favour with the utilisation of

smaller sizes, depending on the properties

a mobile crusher or – depending on

of the material and applications involved.

the application – a chain of primary,

They may vary from the extraction of pre-

secondary and tertiary crushers at the

cious metals from ore-bearing rock to the

face. Fed by the same excavator,

shaping and sizing of the rock itself for use

material is processed directly and is

in aggregate production or specialised

ready for cost-effective transportation to

building applications.

the refinery or direct shipment from site

So far, so good. But it is in the next stage

to point of sale. Another alternative is the

of the cycle that costs can escalate and

use of conveyors to transport material

inefficiencies emerge.

away from the pit straight to the next

Stumbling blocks

stage in the process.

The bottom line is that cycle times are

Material is loaded by an excavator at

substantially reduced and productivity

the face on to a truck that carries the

increases, hand in hand with a significant

load across haul roads to a permanent

reduction in fuel, vehicle maintenance

crushing plant, where the cargo is

and labour costs.

unloaded and the truck returns to the

Mobility is now regarded as a key

face. The process is inherently inefficient,

component in purchasing decisions,

as trucks carry loads well below their

which favour track-driven mobile crushers

capacity. Large, uneven chunks of rock

as they can easily go where mining goes.

create voids – areas of empty space in

In the pit, they follow seam and strata

the bucket – which means the vehicle

and are easily relocated to a place of

is underutilised and potentially unstable.

safety when blasting is required. When

The more trucks employed, the greater

the need to relocate from one site to

the potential for lengthy and costly idling

another arises, plant is loaded and

times. Safety is another major concern,

trammed directly to the face. The critical

as collisions involving mobile machinery

issue is that the whole operation can be conducted by a single driver/operator using the machine’s on-board radio remote control system.

While fixed static plants were once regarded as an asset, they

Mobile

crushers

A major force in

modern mining

comminution could possibly be seen as a serious disadvantage in today’s business environment. Conventional static plants are time-consuming to install and may require a substantial civils component.

Once established, site operations are essentially governed by their location, and removal to another location is costly, time-consuming and may involve major environmental liabilities.

It is no secret that the initial capital outlay in purchasing a mobile crusher

Contractors emerge as an important segment of the industry as mining companies are taking the view that their core business centres on drilling, blasting and extraction

is greater than that of buying a static plant of equivalent output. However,

handling and ore beneficiation are fast

relays these details to the owner’s

unless the fixed plant is to be utilised

becoming the province of highly skilled,

control centre, irrespective of where

for an extended period, short-term

specialist contractors.

the machine is located. Regular service

economies are outweighed by longer-

One of the benefits of investing in

intervals are rigorously applied to ensure a long and cost-effective working life.

term efficiencies and increased

a mobile crushing solution is that it is

commercial opportunities.

not only built to last but is supported

The mining industry has come under

by electronic control and monitoring

intense scrutiny over the past decades

systems. In our own organisation,

concerning issues relating to safety,

We are convinced that Metso mobile

experienced technical staff have been

health and the environment, and the

crushing plants represent highly

trained by Metso to identify and rectify a

design of the modern mobile crusher

effective operational solutions to many

problem even in the remotest of sites.

reflects the strides that have been

Maximising operational efficiency

niche players in mining. Mine owners

The mission to maximise the crusher’s

made in providing a safe working place

operating multiple sites are making

working life begins well before the

for the operator and respect for the

informed investments in this category of

product is delivered. These products are

surrounding environment. This is hardly

product. They include mining and quarry

immensely versatile and can be adjusted

surprising as our own Metso products are

operators, plant hire specialists and

to suit the processing of a wide range

made in Finland and must operate under

mining contractors.

of ores and materials in line with owner/

the most stringent regulatory conditions

operator requirements.

at home.

At Pilot Crushtec International, we have seen contractors emerge as an

Complementing the on-board

Today’s mobile crusher is a

important segment of the industry as

monitoring systems that provide instant

sophisticated piece of equipment,

mining companies are taking the view

reference to the mechanical and

clever but not fragile, delivering

that their core business centres on

hydraulic health of the machine, an

performance and productivity to mines

drilling, blasting and extraction. Materials

independent communication network

and contractors.

In sid e M in in g 0 7 | 2017

37

education & training

Guiding graduates into the workplace

Beyond job scarcity, graduates are finding it increasingly difficult to find employment.

Phila Mzamo explores the different skills development approaches of two industry powerhouses to combat graduate unemployment.

T

he lack of practical work ex-

Different methods

qualifications in the form of bachelor’s

perience for recent graduates

The thyssenkrupp graduate

degrees in mining, mechanical

in the mining industry often puts

programme takes graduates

and electrical engineering. The

them at a disadvantage. As

fresh out of tertiary education

programme runs for 24 months,

graduates cannot compete with peo-

and employs them – giving them

offering graduates the opportunity

ple who possess both a tertiary edu-

training over a 12-month period in

to choose a career in both

cation and job experience, they often

a focused field of study. “As far as

technical areas in mining and the

remain unemployed, leaving them

possible, we have tried to place the

specialist stream.

unable to earn a living, build a career and make a positive contribution to both the sector and the South African economy.

Using two different approaches to graduate

“To properly manage the mining industry, urgent skills cultivation is needed. As the industry grows, the solutions we offer our customers as manufacturers and service providers have changed a lot.”

“Our graduates spend their 24 months rotating through the various business units. Here, they will obtain practical experience and knowledge of the company’s key operational

programmes, companies thyssenkrupp

graduates in divisions that match

areas,” says Frances Graham, executive

and Barloworld Equipment have

their line of study,” explains Siphindile

director: HR, Barloworld Equipment.

recognised these issues and have both

Madonsela, head: HR and director

contributed to making sure the mining

at thyssenkrupp Industrial Solutions.

How does the future look?

sector does not incur a deficit of

“The graduates spend the full period

Madonsela explains, “It is the duty of

qualified and trained technicians.

in the department to which they have

every company to be progressive on

been assigned, to ensure that they

the skills development front. We

receive thorough training and

believe our programme will add

understanding of their particular area.”

On the other hand, Barloworld’s graduate

value and present a win-win not only for thyssenkrupp but also for the country as a whole.”

“To properly manage the

development

mining industry, urgent skills

programme focuses

cultivation is needed. As the

on people with

industry grows, the solutions we offer

formal academic

our customers as manufacturers and service providers have changed a

Graduates participating in the thyssenkrupp graduate programme - Kethu Nkwanyana, Yastira Singh, Zakithi Chili, Kamogelo Molokwane, Johannes Magomane

38

Ins i de Mi n i n g 0 7 | 2 0 1 7

lot. The needs of our customers must be met and the only way to do that is to make sure that we encourage and facilitate sufficient training, and the development and upskilling of graduates,” Graham concludes.

MARKET news

market news

from around the continent

Rock breakers for real hard labour Excavator-mounted rock breakers from Furukawa are proving to be extra-durable in the field, dismantling the belief that rock hammers should be regarded as “consumables” with a relatively short lifespan.

Furukawa’s unique monoblock construction with no through-bolts, as well as fewer moving and wear points, can last for years in the hardest labour conditions.

“The power-to-weight ratio of the Furukawa FXJ range has a hammer weight to joules output that is unmatched in the industry. For the contractor, this means saving money on operating costs, diesel and, in many instances, it frees up larger excavators for production work,” says James Linton, national product manager, ELB Equipment – the exclusive distributor of Furukawa rock breakers in Southern Africa.

The system’s lighter weight and harder hitting power mean that smaller breakers can do the same work as their bulkier

ABB awarded order for HV circuit breakers Global automation and power group ABB has been awarded an order,

by Fluor, for five intelligent compact disconnecting circuit breakers (DCBs) for the Additional Oxygen Capacity Train 17 project for Sasol Synfuels Operations in Secunda, Mpumalanga.

The project comprises of the construction and commissioning of the world’s largest air separation unit at the Secunda site, to provide additional high-pressure oxygen production capacity. “We are proud to provide Fluor with a compact solution for Sasol that delivers higher substation availability and lower environmental impact,” says Confidence Mabulwana, regional market manager: High Voltage Products, ABB South Africa.

The DCBs, which are required to bypass the current limiting reactors to start large motors, will help to address the challenge of space at the Oxygen Train 17

project substation. “The ABB units are compact because they provide the functionality of a circuit breaker and a disconnector combined in a single unit. Without the need for separate disconnectors, as much as 50% to 75% less space is required. Unplanned outages are reduced by up to 70%, according to Cigré’s report on high-voltage circuit breakers reliability, which means a low life cycle. During construction, there is less civil work, “ adds Mabulwana.

According to ABB, the environmental impact of its DCBs is substantially lower, and maintenance intervals are significantly reduced to 15 years, depending on environmental pollution, both natural and industrial. ABB will supply the units from Sweden on a tight delivery schedule and the cold commissioning will be done by ABB’s local engineering team.

FXJ 275 rock breaker from Furukawa

counterparts from other manufacturers. transferring less shock to the excavator due to larger slip-buffer plates that eliminate impact recoil shock on the excavator’s boom.

ELB Equipment has a comprehensive range of Furukawa rock breakers and attachments for almost any application.

In addition, the company has the highly convenient F6-BHL breaker, which has been specially designed for use on backhoe loaders to provide solutions in construction–type environments, road building, demolitions etc.

“In today’s tough market, it is important that contractors realise that a rock breaker need not only last the duration of a contract and then be discarded. This has misled some to settle for cheap hammers that cost 20% less, but at the same time give them 40% less availability,” concludes James.

James Linton, national product manager, ELB Equipment

In sid e M in in g 0 7 | 2017

39

market news

Marthinusen & Coutts operates the largest independent high-speed dynamic balancing machine in sub-Saharan Africa

Precision balancing of rotors Operator of the largest independent high-speed dynamic balancing machine in sub-Saharan Africa Marthinusen & Coutts, a division of Actom, notes how critical it is to ensure the highest degree of accuracy when balancing rotating machines.

The company, which has an in-depth understanding of the importance of precision-balancing rotating machines, believes this will minimise vibration levels, thereby increasing reliability and reducing maintenance costs.

“Our customers, which include major local and international OEMs, benefit significantly through access to an independent balancing service offering with this level of capacity and quality,” says Mike Chamberlain, marketing and commercial executive, Marthinusen & Coutts. “The 32 t Schenck HM7 U/S balancing machine, located at Marthinusen & Coutts’ 9 500 m² high-tech workshop in Cleveland, near In-house balancing of rotors not only speeds up the process, but also reduces the cost and the turnaround time of repairs

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Johannesburg, is in constant use.”

The HM7 U/S has a measuring range of between 100 rpm and 5 000 rpm. It is 9 m long, has a journal size of 400 mm and a swing of 2.4 m. The machine is fitted with a CAB 920 H computer measuring system with advanced functionality.

“This state-of-the-art technology makes changeovers to new rotor types quick and straightforward, and the machine is capable of balancing larger high-speed rotors dynamically at full operating speed,” Chamberlain says. He adds that, on occasion, and depending on the design of the rotor and the individual customer’s requirements, balancing can be done at 10% overspeed or more if required.

Marthinusen & Coutts also performs on-site vibration and dynamic balancing with its recently acquired Bently Nevada ADRE 408 portable vibration and balancing system.

Chamberlain says that the balancing is in line with international best practice, with industry standard balancing certificates being issued for each completed rotor.

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