An even simpler process could produce higher-grade concentrate from Commerce Resources’ Ashram deposit.
An advanced rare earths project with relatively simple mineralogy could benefit from an even more efficient process of separating wheat from chaff. A paper presented at a Cape Town technical conference last month explains how Commerce Resources’ (TSXV:CCE) Ashram deposit could increase recovery to over 50% rare earth oxides through flotation alone. Previous tests on two flowsheets have already produced concentrates grading more than 45% REO as the northern Quebec project moves towards pre-feasibility.
Delivered to the Flotation ’17 conference, the paper titled Flotation of Rare Earth Minerals from Fluorite by pH-Shift was written by lead author Gerhard Merker of Merker Mineral Processing, with Ashram project manager Darren Smith and Henning Morgenroth of UVR-FIA. The study based its findings on work conducted for Ashram at UVR-FIA in Germany.
“The key to this success was the discovery of the significant role of pH in the separation of rare earth minerals from fluorite as well as various carbonates,” stated Commerce. “Without such a separation, a mineral concentrate at appreciable recovery could not exceed 20% REO using flotation alone. As such, a multi-stage flotation technique comprising milling and sizing, high solids conditioning and a controlled pH-shift, which is not conventionally applied to REE [material], was developed…. In terms of the Ashram deposit, the technique continues to hold significant promise as an alternative processing approach.”
Ashram remains one of the world’s few advanced projects capable of upgrading its whole rock to a high-grade concentrate similar to that of current REE producers, the company added. The carbonatite-based deposit features the minerals monazite, bastnasite and xenotime, all familiar to conventional processing. Ashram also hosts a strong distribution of the critical elements neodymium, europium, terbium, dysprosium and yttrium.
While Commerce wrapped up its summer-fall field program in October, an assay lab continues to work through core from a 14-hole, 2,014-metre drill program intended to increase and upgrade the project’s 2012 resource. In addition to Ashram’s field work, metallurgical studies and project planning, Commerce has been investigating early-stage niobium-tantalum-phosphate potential on the Miranna area about one kilometre away.
Looking at its advanced tantalum-niobium deposit in southern British Columbia, Commerce signed an MOU in July to test a one-tonne sample from its Blue River project for a proprietary method of processing.