American West Metals has tabled an “outstanding” set of metallurgical test results that highlight exceptional recoveries of 94.4 per cent zinc and 78 per cent copper from samples taken at its West Desert project in Utah.
The company is already sitting on a significant resource at the operation and says the results indicate a considerable slice of the operation’s mineralisation is amenable to low-cost, heap leach processing.
West Desert boasts a historical resource of over 59 million tonnes with a higher-grade, 16.5 million tonne core grading 6.3 per cent zinc, 0.3 per cent copper and 33 grams per tonne indium.
Notably, the project’s deposit is laced with two types of mineralisation - near-surface oxide material, which runs to a depth of a few hundred meters and a deeper-lying sulphide component.
The metallurgical test work was conducted on samples collected earlier this year and follows similar historical evaluations on West Desert-sourced material.
According to the company, legacy metallurgical programs returned high-quality zinc and copper recoveries. However, these were predominately focused on the sulphide portion of the site’s orebody.
American West said the metallurgical characteristics of the oxide material were briefly evaluated in 2009 by Nevada-based laboratory Kappes, Cassiday and Associates and returned excellent recoveries of zinc and copper with relatively low acid consumption.
The company subsequently caught wind of the findings and recognised West Desert could offer a two-pronged pathway to economic extraction - one using the site’s sulphide material and the other its oxide ore.
Following the theory produced American West’s latest round of test work results which yielded an 89.9 per cent zinc and 78 per cent copper recovery using traditional sulphuric acid leaching on the oxide material.
Metallurgical test work on material from the deposit’s sulphide material returned a staggering zinc recovery of 99.4 per cent.
American West has described the recoveries as a “breakthrough” in the project’s commercial viability and believes the exceptional zinc and copper grades could permit a staged extraction strategy that includes both open-pit and underground mining.
American West Metals Managing Director, Dave O’Neill said:“The test work confirmed that traditional acid leach processing can generate very high metal recoveries from the near surface oxide ores, which would be mined in an open pit operation.”The new work has also further validated the known excellent metallurgical properties of the sulphide ores in the high-grade Main Zone of the West Desert Deposit with almost 100% recovery of zinc.”
West Desert sits about 160km southwest of Salt Lake City and takes in around 330 acres of private land, over 300 mining claims and a single state metalliferous mineral lease that collectively accounts for an approximate 32 square kilometer land package.
Both zinc and copper have been tipped to play a leading role in the looming post-combustion economy.
Copper is abundantly used in the production of electric vehicles whilst zinc is chiefly used as a protective coating on wind turbines. The upswing of copper in particular has led prominent investment houses such as Goldman Sachs to coin the commodity the “new oil” and proclaim there is “no decarbonisation without copper”.
Demand for both materials are tipped to surge by 2050, as the world looks towards cleaner energy options and a number of early stage exploration companies today could be set to reap the benefits and that may well include American West Metals.
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By Matt Birney
