by Greg Klein | October 5, 2015
Phase II metallurgy has delivered what Commerce Resources TSXV:CCE calls a milestone in rare earths processing for its Ashram deposit in northern Quebec. A mini-pilot plant produced the project’s highest-grade concentrate so far, comparing favourably with hard-rock operations globally, the company announced October 5. Results will be incorporated into Ashram’s pre-feasibility study.
Tests at the Colorado lab showed the leach process to be scalable from a bench level of less than four kilograms to the pilot level above 300 kilograms using both continuous and batch methods. The result was a total rare earths oxides concentrate grading 48.9% with an overall recovery of about 63% using residue produced from the leach pilot. Additional processing produced 45.7% TREO at about 71% recovery, while potential remains for further optimization.
The results “demonstrate that the flowsheet for the Ashram deposit is simple, robust and scalable using standard commercial methods,” said president Chris Grove.
Second-phase pilot plant work continues, part of a larger program to confirm the scalability of the overall flowsheet and produce several kilograms of mixed rare earth carbonate concentrate and mixed rare earth chloride concentrate, Commerce stated.
Meanwhile the company has a 32-hole/3,000-metre summer program of mostly infill drilling underway to upgrade Ashram’s resource. In mid-September Commerce released high-grade, near-surface assays from the deposit’s winter/spring campaign. The company has also been taking part in community consultations and, last spring, announced potential savings in development costs through a new infrastructure model.
Commerce also holds the Blue River tantalum-niobium deposit, a southeastern British Columbia project with a 2011 preliminary economic assessment.