IM‘s December issue includes major features on consultants. Metallurgical consultants, of course, play a major role in determining the viability or not of projects. Its all very well to have the ore, but can the valuable constituents be extracted. Their work can also enhance project economics. For instance, Leyshon Resources expects to be able to produce a high grade zinc concentrate as well as gold and silver metal from a single ore type at its Zheng Guang project in Heilongjiang, northeast China. Independent metallurgical consultancy Metallurg of Australia reported on the latest test program on the proposed gold and zinc flotation circuit undertaken by AMMTEC (Australian Metallurgical & Mineral Testing Consultants) of Western Australia.
Recovery of gold from sulphide ore has improved from 84% to 87% based on the leaching of gold and silver metal from a high grade concentrate produced from the proposed whole of ore flotation circuit. Further grinding and flotation of the same concentrate produced a saleable zinc concentrate grading 47% zinc at a recovery of 87% zinc. The results confirm that there will be no requirement for mining and treating separate ore types; meaning that a single gold/zinc sulphide ore can be supplied to the plant. This will have considerable benefits in terms of grade control and lower mining costs as larger volumes of ore can be mined without incurring the difficulty of separating the ore types.
Metallurgical test work is ongoing to further refine the results achieved to date and confirm the proposed process design. Gold and silver recovery from the near surface oxide and transition ores oxide treated through a proposed conventional CIL circuit have previously been reported at 89% and 74% respectively. Managing Director Paul Atherley: “We are delighted with these results. The ability to bulk mine a single ore type and produce gold, silver metal with a saleable high grade zinc concentrate is very encouraging. It will also be a very straightforward process route to allow the company to bring to bear the full benefits of low Chinese capital and operating costs to the project."
