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:: Dundee Sustainable Technologies Achieves Gold Extraction Yields 14% Higher than Cyanide in its Demonstration Program
Dundee Sustainable Technologies Inc. is proud to announce that it has successfully completed its demonstration program on a pyrite concentrate (the "Program") at its Thetford Mines demonstration plant (the "Plant") (refer to November 9, 2015 press release).
This Program was initiated in July 2013 when the Corporation began the engineering and then the construction of the demonstration plant in order to demonstrate at an industrial scale its cyanide-free process for gold extraction. By achieving this important milestone, the Corporation is fulfilling another step of its strategy for the commercialisation of the technology.
Throughout this Program, DST processed a total of 170 Tonnes of a gold and copper bearing refractory pyrite concentrate from a region where the use of cyanide is restricted. The Program demonstrated that the DST process had an average extraction yield 14% higher than cyanidation, with results up to 90% gold recovery. The Corporation submitted these results to the Environmental Technology Validation ("ETV") program of the federal government, for an independent review and validation. This examination process is underway and the report is expected in the coming weeks.
The Program also allowed DST to confirm the efficiencies of the components of the Plant which responded well and according to expectations. In that regard, the oxidation circuit successfully removed 99% of the sulfide content while keeping full control over the gases to produce on-spec sulfuric acid that was shipped to DST's client. The chlorination circuit also delivered the anticipated copper and gold recoveries that were higher on average than cyanide yields on the same samples. Finally, the process successfully demonstrated its closed circuit operation with the recycling and regeneration of the reagents and all solid residues met environmental norms.
With the Program completed, the Corporation will now proceed with the next step of its strategy to commercialize the technology. To that effect, the Plant will be used in 2016 to process gold concentrates from selected sites in order to produce technical-economic studies that will evaluate the operating expenses and capital expenditures of an industrial implementation of DST chlorination process.
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