West Mining Corp. (“West” or the “Company”) is pleased to announce it has now received final reports for initial metallurgical and mineralogical test work completed on the Gold Mountain and Kena Gold Zones of its 100% owned Kena Gold-Copper project in southeastern British Columbia. The Kena Property hosts several large gold and copper zones. The Kena Gold and Gold Mountain Zones contain the recent gold resource estimate shells, hosting 2.77 million ounces of gold inferred and 0.56 million ounces of gold indicated at 0.25 g/t cut-off (Bird, 2021; see News Release dated May 11, 2021).
Bureau Veritas Minerals Metallurgical Division conducted a preliminary metallurgical testing program on two composite drill core samples – Composite 1 from the Kena Gold Zone and Composite 2 from the Gold Mountain Zone. The goal of this test work is to evaluate the amenability of these samples to conventional mineral processing procedures.
Composite 1 and Composite 2 assayed 1.0 g/mt Au and 0.906 g/mt Au, respectively, by averaging standard fire assay and metallic assay results.
QEMSCAN Bulk Mineral Analysis (BMA) showed these the two test composites contained 3.7-4.1% sulphide minerals, mainly as pyrite. Silicates were the dominantly gangue minerals.
Gold deportment study by Trace Mineral Search (TMS) showed that more than 99% of the gold in these two composites occurred as very fine-grained native gold and electrum. About 24% of the gold in Composite 1 were found in gold-tellurium bearing minerals. The average gold grain sizes of these two composite samples ranged from 1.6 to 2.3 μm.
Bond ball mill work index testing showed a BWi of 11.0 kWh/tonne for Composite 1 and 16.0 kWh/tonne for Composite 2 at a closing screen of 150 mesh, indicating that the mineralization is moderate-hard to ball mill grinding.
Three process options including sulphide flotation, bottle roll cyanidation and gravity concentration were evaluated in this test program. The responses of the test samples to three process routes at grind sizes varied from 75 μm to 150 μm are summarized below.
- Sulphide flotation was able to recover up to 88.7% gold from Composite 1 and 90.5% gold from Composite 2 respectively, at 13.1% to 15.2% mass pulls.
- Bottle roll cyanidation of ground whole-ore yielded encouraging gold recoveries of 80.0-85.5% from Composite 1 and 92.8-94% from Composite 2 by leaching at 40% solids for 72 hours using 1.0 g/L sodium cyanide.
- Results showed that in direct cyanidation, Composite 2 was not grind sensitive in the size range of 75 μm and 150 μm. In flotation tests, Composite 1 was not grind sensitive in the tested size range.
- Gravity concentration alone was ineffective to recover gold from these samples. Single pass gravity concentration with cleaning yielded no more than 11.6% gold recoveries for both samples.
- A combination of gravity pre-concentration followed by cyanidation of gravity scalped tailing at 75 μm grind resulted in gold recoveries of 81.4% and 95.6% for Composite 1 and Composite 2, respectively.
- A combination of gravity pre-concentration at 75 μm followed by flotation of gravity tailings and then cyanidation of flotation concentrates yielded gold recoveries of 71.6% and 87.6% for Composite 1 and Composite 2, respectively.
A comparison among test results from flotation and whole-ore cyanidation at 75 μm is presented in the following table.
||Gold Recovery, %
This preliminary testing program showed that the two composite samples from the Kena Project are amenable to whole-ore cyanidation and sulphide flotation processes.
“This recent metallurgical test work speaks volumes for the project and is a major step in our advancement of Kena as a whole. Combined with the earlier resource estimate, the non-refractory nature of the mineralization and the high gold recoveries are extremely positive parameters that allow the Company to continue its successful path moving the project forward,” states Nicholas Houghton, CEO of West Mining Corporation.
The initial phase of the 2022 diamond drilling program on the Gold Mountain Zone, now completed, consisted of 2400 metres in 9 diamond drill holes. Pending assay results will be released upon receipt.
Linda Dandy, P.Geo., a "Qualified Person" for the purpose of National Instrument 43-101, has reviewed and approved the contents of this news release.