AMERICAN WEST METALS LIMITED American West Metals Limited announced excellent results from metallurgical test work on the near surface and sulphide ores at the West Desert Project in Utah (West Desert or the Project). A number of historical metallurgical programs have been completed on the West Desert ores and all have demonstrated excellent metallurgical properties and the ability to produce high quality zinc and copper concentrates. However, the majority of these tests were focused on the sulphide portion of the orebody.
A single test on the oxide material was completed in 2009 by Kappes, Cassiday and Associates (KCA) in Reno, Nevada. This work had shown promising results, with excellent recoveries of zinc and copper, and with relatively low acid consumption. This was recognised as a potential pathway to economic extraction of the oxide ores at West Desert.
The aim of the latest phase of metallurgical work was to confirm the historical work by KCA and to understand and optimise the process further. The test program was completed by BASE Metallurgical Laboratories of Kamloops, BC, Canada. The recent test work was completed on drill core samples from the 2022 diamond drilling program, and has shown outstanding results that demonstrate the potential viability of the oxide and transitional ores to traditional processing techniques.
The acid leach test work on a range of different sized oxide material has produced up to 89.9% recovery for zinc, 78% recovery for copper, and with relatively low acid consumptions. Testing of high-grade sulphide ores from the Main Zone of the West Desert Deposit has confirmed historical results and produced exceptional recoveries of over 99% for zinc using simple sulphide flotation. Heap leaching is widely used as a low cost and simple processing technique and can be used to recover very low concentrations of base and precious metals.
The amenability of the oxide ores to this process method unlocks the near surface potential of the West Desert Deposit and supports the potential for a staged open pit and underground mining scenario.
