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Pics from topto bottom:Flotationpilot-plantcampaign onNkomati ore.The NkomatiNickel Mine(photocourtesyNkomatiNickel).Pilot-plantoperatorstake samplesfrom themanganesesolventextractioncircuitto purifythe cobaltelectrolytebeforeelectro-Copperelectro-the KOVPCMZ, Nkomati’s nickel reserves have increased by 50 percent – to 485 377 tons. The by-product reserves have also43 per cent, and 4.181 million ounces of PGMs, a 70 per centincrease. Based on these positive results, LionOre and ARMcommissioned DRA to proceed with a bankable feasibility studyfor the large-scale expansion of the concentrator plants.The proposed large-scale expansion, planned for 2010, willincorporate mining of the PCMZ, increasing annual productionto approximately 20 000 tons of nickel and extending the life ofthe mine to beyond 2020. An interim expansion exploiting thedisseminated MMZ will maintain nickel production at its currentlevel of about 5 000 tons per year after the massive sulphidemineralisation is depleted in 2008.Mintek has carried out process development work for a numberof copper-cobalt projects in Zambia and the DRC. Among thesea South African mining company in the DRC for many years. Thestarted up in September 2006. The second phase, which will involvecobalt metal on-site at Ruashi, is under construction.Mintek began bench and pilot work, which would be used in the bankablefeasibility study for phase II of the project, in April 2006. Three campaignswere conducted, and the work was completed during March 2007.In the design of the solvent-extraction and electrowinning circuit, Mintekworked closely with Metorex’s design company, TWP Matomo ProcessPlant. The plant has been designed for a capacity of 120 000 tons of ore permonth. When the phase II expansion is completed, production at Ruashi isexpected to increase to 45 000 tons of copper cathode and approximately 3500 tons of cobalt metal and cobalt carbonate per annum.A major process development campaign was conducted for the KOV coppercobaltproject, also in the DRC. A total of 27 tons of material was delivered tolaboratory tests to determine the optimum leach conditions, integrated piloting of theleaching, copper solvent extraction and electrowinning circuit, and Aspen simulationLME Grade A standard (higher than 99.95 per cent copper), were produced. The KOVcomplex, which contains one of the world’s largest high-quality copper and cobaltresources, is being re-developed by Nikanor plc. The project will include a major27 500 tons per year of cobalt products.Dense-media separation, milling, and leaching testwork were carried out to investigate aGreen Team Consultants International.Mintek has been involved in numerous projects to remove iron and manganese fromdilute cobalt sulphate solutions by oxidative precipitation using air/SO 2. This technologyis attractive as it can be done at ambient temperature, relatively low pH, and ferrousiron is quantitatively removed within 1-2 hours. In order to produce cobalt cathode of thedesired quality, iron, manganese, copper, zinc, and aluminium must generally be removedfrom the feed to electrowinning. The requirements to produce an intermediate cobalt saltare generally less stringent, but usually iron, aluminium, and manganese still need to beremoved.annual report 2007 26