Medallion Resources Ltd, today reported detailed results of its bench-scale metallurgical tests, strongly supporting the viability of the Company's plan to extract rare earths from by-product monazite sand.
The metallurgical tests recovered an average of 91% of ten rare-earth elements and yielded a mixed rare-earth concentrate from the tested monazite. This high-purity chemical concentrate is expected to be suitable for input into standard commercial rare-earth refineries or separation plants, which separate the concentrate into individual rare-earth oxides and other rare-earth products. Medallion's sample concentrate product will soon be provided to interested refineries for testing under appropriate confidentiality arrangements.
"Our bench-scale testing applied a tried-and-true caustic-leach process approach, was fed with by-product monazite from a major mineral-sands miner, and yielded a high-purity rare-earth concentrate. This is an excellent result suggesting our project plan is sound and offers relatively low technical risk," commented Don Lay, Medallion President & CEO. "This is also a key de-risking step and, combined with feedstock agreements and a low capital-cost processing facility in North America, both of which we are advancing, indicates a viable path to new rare-earth production."
The tested by-product monazite sand sample contained approximately 47% rare-earth oxide (REO) content -- with the rare-earth elements found predominately in the mineral monazite, a rare-earth phosphate. The test recovery percentages for the ten commercial rare-earth elements (and yttrium) ranged between 72% and 96%, with a weighted average recovery of 91%. Although this is an excellent recovery percentage, the Company is confident that further metallurgical testing can improve the recovery values to even higher levels and also optimize individual rare-earth element recoveries based on market pricing.
Significantly, the tests showed that the magnet-related elements (Nd, Pr, Dy, Tb) are critical to the project's economics, as in this case they represented 86% of the value of the concentrate, using current standard Chinese FOB prices (source: Asian Metal August 2015).
All metallurgical testing was conducted at the lab of J E Litz and Associates of Denver, Colorado, using a standard commercial caustic-leach process to extract rare-earths from monazite. The test flow sheet mimicked a commercial process in all regards except for the recycling of leach solutions. Standard laboratory equipment was used, including a bench-scale autoclave for accurate temperature control. The standard-method rare-earth ICP assays (Inductively Coupled Plasma spectroscopic analysis of fused mineral samples and four-acid digested lab-produced samples), used to measure the rare-earth quantities of the different test products and to calculate mass balances and rare-earth recoveries, were performed by Hazen Research, Inc. of Denver, Colorado. Standard QA/QC procedures for tests of this type were implemented to ensure reliability of results. William H Bird, PhD, PGeo, who is the Company's Chief Technical Advisor and Qualified Person, oversaw the tests and approves of the technical information contained in this news release.