Minerals processing feedwells, including tangential swirl, radial recirculation and flow asymmetry. The biggest advances made by Roymec Technologies in understanding thickener shortcomings and consequently in developing its patented Radflow feedwell were principally made in a 1 m diameter Perspex scale model unit. This model was built to scale off the plans of an operating 21 m diameter Roymec Technologies full scale thickener. “Ultimately we have designed the Radflow feedwell, (entirely different to any currently available feedwell) which counters all of the adverse effects encountered on operating units thereby ensuring that flocculated feed is symmetrically introduced into the thickener body”, says Essack. The Radflow feedwell works by dissipating energy and distributing the feed particles evenly across the thickener which does not inhibit settling, particularly directly below the feedwell, with no associated asymmetry. This also means the rakes need to do very little work to draw the pulp to the centre. The resultant settling pattern is suggestive that the flux rate of the thickener can be dramatically increased using the Radflow feedwell. Additional benefits of the Radflow feedwell seen during testing include: • intense mixing in the feedwell zone, which allows for intense flocculant/feed contact and therefore a reduction in flocculant consumption • an auto-dilution effect, in which eddies formed on the outer surface of each blade draw supernatant surrounding the flow shaper back inwards. “With a more efficient feedwell design, thickeners could operate close to the average flocculant settling rate measured during testwork. This is equivalent to saying that a traditional (current) thickener could be replaced with a thickener of almost half the area when utilising the Radflow feedwell,” Essack sums up. “This results in a
RIGHT Flocculant make up plant using bolted tanks - Malawi BELOW Ion Exchange plant at Langer Heinrich - Namibia
phenomenal saving in terms of thickener cost, space requirement, power consumption and overall operating costs.” The company has already conducted on-site test work at Gold One International’s plant in Springs, and is due to send its 2.5 m diameter test thickener to Exxaro’s Leeuwpan coal plant operation.
A new shareholder and a growing global presence The year 2011 saw Tamela Holdings, a black owned and managed investment company, acquire a 15% stake in Roymec Technologies. Tamela founding members, Vusi Mahlangu and Sydney Mhlarhi have significant investment backgrounds, and are looking to create long term strategic partnerships with management and shareholders in the manufacturing, industrial and financial services sectors. “Their hands on approach to business will assist with alternate strategic
ABOVE New and old board & management members
paths and help us grow locally, while affording Roymec the opportunity to contribute to the growth of local BBBEE entities,” says Essack. In terms of expanding its global footprint, Roymec has established a partnership with engineering company, PWA Technology, a Malaysia-based engineering and trading company. “That part of the world has not been as dramatically affected by major business fall-outs as a result of the recent recession. This coupled with the fact that many mining houses are looking to Far East Asia for new project opportunities we believe will result in significant business.” And signs of this can already be seen. “We have supplied kit (linear screens, thickeners and flocculant plants) to two gold projects in the country namely, Peninsula Golds’ Raub and Monument Minings’ Selingsing.” The company has also secured a South American partner to grow its footprint on the mining-rich continent. “Tecpromin in Chile is focused largely on the supply of minerals processing equipment and with the use of our designs and through local fabrication facilities, will tailor our equipment for their markets throughout Chile, Brazil, Argentina and Peru,” continues Essack. “We have been regionally locked into the African continent since our establishment over 10 years ago, and while we have had great success we acknowledge the need to be less exposed to the cyclical nature of minerals project activity on the African continent,” Essack outlays. Despite this the company is currently involved with numerous contracts in Africa for major projects such as FQML’s Kansanshi Oxide project, Katanga’s Phase 4 project and the FMI’s Tenke Fungurume expansion project.
Inside Mining 04/2012
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