Maximum Value Minerals Processing

⎪ Materials handling ⎪ Maximum value minerals processing MechChem Africa talks to Cedric Walstra, Glencore Technology’s Africa business development manager, who paints a broad picture of the high-recovery, high- efficiency processing equipment on offer from the technology side of Glencore’s business. joined Xstrata Technology about cost of grinding circuits. Intense grinding ten years ago, while Glencore was a is achieved using inert ceramic grinding “ shareholder, but Glencore took us over media that leads to improved metallurgical Iabout four years ago and the name performance compared with conventional was changed to Glencore Technology,” begins steel media. Walstra, adding that Glencore Technology “Anglo Platinium has some 26 IsaMills develops, markets and supports niche tech- currently in operation. These are horizontal nologies for the global mining and minerals fine grinding mills with cantilevered shaft and processing and metals’ extraction industries, eight grinding discs. Each mill is filled to 70 to “and not only for the mines owned by the 80% of capacity with ceramic grinding beads. Above: A Jameson flotation cell in operation at Lumwana in Zambia. The system offers the highest possible Glencore Group.” As the shaft rotates, the discs and beads cause throughput in a very small footprint, with froth washing maximising the concentrate grade in a single “Glencore Technology is a standalone attrition grinding,” Walstra explains. flotation stage. Left: IsaKidd Technology, shown here in use at the Kamoto Copper Company (KCC) in the company that partners with several tech- “Kidney shaped holes in the discs allow the DRC, is the global benchmark in copper electrowinning accounting for over 11 mtpa of copper production from over 100 licensees. nology suppliers to develop cutting edge progressively milled material to pass down the equipment. My involvement has been mostly mill, with most milling taking place in the feed “The IsaMill is the most energy efficient, from one to the other. “But we tend not to moving parts, keeping installation and main- whole process can be automated,” he informs with IsaMill™ fine grinding technology and end. A patented rotating product separator highest intensity large scale grinding machine compete head-to-head with mechanical tenance costs to a minimum and equipment MechChem Africa. Jameson flotation cells, but I am currently on the discharge end is used to pump coarse on the market. It has a small footprint, and in- flotation cells because there are some niche availability very high. responsible for promoting the whole range material back to the feed end and a feed pump stallation and maintenance access are simple,” applications for our Jameson floatation cells,” “Cell designs are flexible, making them IsaSmelt technology to mining companies in southern African,” he pushes slurry forward under 150 to 180 kPa Walstra notes. says Walstra. ideal for new projects and excellent for low Another of Glencore Technology’s innova- tells MechChem Africa. of pressure,” he adds. “The first is for scalping duty. A Jameson cost plant expansions. Over 300 Jameson tions is IsaSmelt™, which is a high-intensity, Without having to use screens or cyclones Albion process technology cell at the head of a train of mechanical cells Cells have been installed, treating a range of low-cost submerged lance smelting process IsaMillTM grinding technology for external classification, the system allows Associated with IsaMills, Glencore’s Albion can be used to pull off high-grade material that materials including coal, base and precious that is simple to operate and can be used for Based on technology developed from the only fine ground material down to 5.0 to Process™ is a combination of ultrafine grind- is at final grade concentration. This takes the metals, potash, bitumen, graphite, and for a range of applications including copper and Netzsch mill and adding a patented product 10 µm to discharge. “Our systems are typically ing and oxidative leaching at atmospheric load off the rest of the flotation bank, allowing recovering organics in solvent extraction lead smelting. separator, different media and lining materi- used for tertiary (or quaternary) grinding and pressure. Feed materials to the Albion Process for finer tuning and higher overall efficiencies processes,” he adds. One of the key strengths of the technology als, Glencore Technology’s IsaMill™ is a highly flotation concentrate regrinding with typical are, generally, base or precious metal concen- to be achieved,” Walstra explains. is the growing IsaSmelt family itself. Glencore energy efficient, high intensity, large-scale input feed sizes of up to 300 µm, also known as trates. The sulphides in the feed are oxidised The other application is the cleaning of IsaKidd technology Technology produces the BBOC™ – Bottom grinding machine. mainstream inert grinding (MIG) and ultrafine and liberated, allowing the wanted metals to the final concentrate. “What we are finding is “IsaKidd Technology is the benchmark in Blown Oxygen Cupel – a technology that Glencor’s IsaMill reduces the energy grinding (UFG), respectively,” he says. be recovered by conventional means. that we can replace existing cleaning circuits copper electrowinning technology, providing injects oxygen directly into the reaction zone “The process uses our HyperSparge™ tech- with two Jameson cells and a single row of world-class plants following the integration of the cupel, improving process performance nology where we introduce the gas required mechanical cells. This gives a significantly of the ISA and KIDD Processes in 2006,” and oxygen utilisation. The technology is well for the leaching process at supersonic speed. smaller footprint and lower power consump- Walstra says. suited to most refining duties where base This creates very fine bubbles in the slurry, tion, while still achieving the best possible The combined technologies account for metals are selectively oxidised and eliminated improving energy transfer efficiencies and concentrate grades,” he assures. over 11 mtpa of copper production from from precious metal products, such as slimes increasing leaching speeds,” says Walstra. “Via The Jameson flotation cell introduces over 100 licensees worldwide, including bullions, PGM-bearing feeds, high purity silver gas injection, we achieve fine control of the slurry via an orifice or slurry lens, which Glencore’s own operations. “We provide cli- refining and retorted Parkes crusts. BBOC™ chemistries of leached concentrates, extract- creates a jet that sucks in atmospheric air. ents with a comprehensive range of technol- technology is now installed in over a dozen ing exactly what is required and leaving the Consistently fine bubbles are generated and ogy, process support and equipment includ- sites worldwide. rest for later processing,” he adds. mixed into the medium without requiring me- ing; Isa 2000 cathodes, BR and HP cathodes, “Glencore Technology solutions are avail- There are four Albion Process plants chanical agitators or spargers. “Intense mixing duplex (LDX) cathodes, electro-handling able to any mining site that sees the benefit currently in operation. Two plants treat zinc of the slurry and bubbles causes the particles equipment, robotic stripping machines and and, while we do service Glencore Group sulphide concentrates in Spain and Germany, of interest to attach to individual bubbles and tankhouse cranes. mining operations, we are an independently a plant in the Dominican Republic is treating froth to the surface for immediate removal as “We partnered with a Japanese company run company that services the whole mining a refractory gold/silver concentrate, while concentrate. called Mesco for the supply of cathode strip- industry,” Walstra assures. the fourth plant is treating refractory gold “The system offers the highest possible ping machines: These remove electroplated “Many of these technologies were de- in Armenia. throughput in a very small footprint, with materials from the cathodes. The plates are veloped at Mount Isa, an operating mine in froth washing maximising the concentrate left in the electrolytic cells for a predeter- Australia, which makes them highly practical Jameson flotation cells grade in a single flotation stage. The system mined time and then taken out and flexed to and effective. So a key strength is that our Based on an invention by Graham Jameson, is easy to control, fast to respond and offers detach the deposit – hence the advantage people have all worked with the technologies the Jameson flotation cell replaces a train steady and reliable performance irrespec- of using thinner and stronger LDX stainless on mining sites. They are ‘hands-on’ guys with Glencore Technology’s highly energy efficient IsaMills™ are now meeting the grinding requirements at Anglo of traditional mechanical cells with slurry tive of changes in feed flow,” Walstra tells steel materials. Once washed, the plates can a broad knowledge of mining with Glencore Platinium’s Waterval Retrofit plant. of decreasing concentration gravitating MechChem, adding that there are also no be reused in the electrowinning cell – and the Technologies,” Walstra concludes. q 18 ¦ MechChem Africa • May 2017 May 2017 • MechChem Africa ¦ 19.

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