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GOLD EXTRACTION_proof 19/07/2016 14:54 Page 8 GOLD EXTRACTION eHPCC: an image representing the machine constructed and scheduled to be commissioned early July 2016 and how eHPCC might be used in a large throughput application. For a small throughput only one feeder and eHPCC might be needed CSIRO Gold Processing Team Leader Paul Breuer and Senior Project Engineer Rueben Rajasingam met with executives from privately owned Prima Resources. Prima was founded by two former Alcoa mechanical engineers in 2013. Prima Resources is in early discussions with Linden Roper, JTG Consultants, also an ex Alcoa Engineer, who conceived the eHPCC, a concept of combining a crushing, milling and classification circuit into a single unit. A prototype of the company’s highpressure crushing mill has been successfully tested in laboratory trials over the last three years. A 2.5 t/h eHPCC prototype is to start trials at Bapy Mining LLC, according to Prima Resources Managing Director Gaye Money. The mill is anticipated to significantly reduce 9106 - EMA 2016 VIS HP AD INTERNATIONAL MINING 210X138 PATHS.indd 1 energy consumption, capex, and opex, with elimination of grinding media, dependant on the material and the number of milling machines in the circuit it replaces, according to Prima, which has shown an interest in the CSIRO technology to explore new processing opportunities. Breuer said discussions were still in their conceptual stages, but the technology had the potential to transform the gold sector in the same way as CIL processing in the 1980s. Prima Resources has also formed an alliance with West Drill to investigate using the new CSIRO process to commercially develop uneconomic gold deposits. Breuer notes that by “uneconomic we are referring to the use of current technologies, such as gravity (where cyanidation can’t be used) or cyanidation. There are not only low grade deposits but also high grade small deposits that this technology can unlock with the reduced regulatory approvals and requirements as compared to cyanide.” Dr Yeonuk Choi, Senior Manager, Strategic Technology Solutions, Barrick Gold (Canada) gave the Gold-PM keynote address at this May’s ALTA 2016 conference: Selecting the Best Process for the Treatment of a Refractory Gold Ore Barrick’s Experience (available from ALTA Free Library). He emphasised that the choice of process, in most cases, will be site specific, influenced by the metallurgical and mineralogical 2016/06/20 10:59 AM