The company highlighted that the metallurgical results to date are in line with previous expectations in the project’s preliminary economic assessment back in 2016.
"It is very pleasing to see that the results from the ongoing detailed column leach test-work confirm and support the recoveries and acid consumption predictions from the BKM PEA,” said Peter Bird, Asiamet chief executive.
“This information will be coupled with the outcomes of the hydrodynamic testing currently in progress and nearing completion, to provide key inputs to the design criteria for the proposed leaching, solvent extraction and electro-winning facilities at BKM.
“The significant amount of quality data generated from this metallurgical programme together with our detailed resource models provides a very solid basis for the mining and process engineering now underway.”
Bird added: “The BKM bankable feasibility study (BFS) continues to progress to plan, with concurrent work ongoing in the social and environmental, commercial/financial and technical disciplines.
“We look forward to reporting the results of the long column leaching and hydrodynamic test-work shortly, along with outputs from the other BFS work streams and our exciting ongoing exploration activities as they come to hand."
Positive test results
The company reported that following a 200-day leach cycle the majority of the soluble copper was recovered, and the amount of soluble copper present in the residual material was less than 0.1% copper for most columns.
Soluble copper recoveries, for the preferred crush size, ranged from 73% to 89% with recoveries for the composites representing a significant proportion of the orebody being in the 80% to 85% copper.
Rates of copper extraction from the short columns suggest optimal soluble copper recovery can be achieved with favourable acid consumption characteristics, and the company said this is “highly positive” for the project’s logistics and project economics.
Asiamet added that early indications suggest that long column leaching performance appears to be consistent with the short columns. Material from the long column testing, which was a 270 day cycle, has been sent for analysis.