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82 www.resourceworld.com F E B R U A R Y / M A R C H 2 0 1 8 MININGWORLD PhD student, Vinoth Kumar, is researching the occurrence of Rare Earth Elements in selected British Columbian coal deposits. Photo courtesy of Geoscience BC. Rare earth elements from coal? by Kathrine Moore C omprised of 17 elements (15 lan- thanides, yttrium, and scandium) Rare Earth Elements (REEs) are used in magnets, in clean-energy, medical, commu- nication, transportation and defense related technologies. REEs play an important role in our modern lives. The name however is a bit of a misnomer; even though rare earth elements are more abundant in earth's crust than their name implies, only a few deposits have high enough concentrations to make mining them economical. Adding to the challenge is the fact that processing and separating REEs is a complex and expensive endeavour. The price of REEs just hasn't been high enough to motivate companies to meet those challenges. According to US Geological Survey's Mineral Commodities Summary 2017, "In 2016, excess global supply caused prices for many rare-earth compounds and met- als to decline, and China continued to dominate the global supply. In China, the rare-earth mining production quota for 2016 was set at 105,000 tons, unchanged from 2015. China's rare-earths industry continued its consolidation into six major industrial entities. Through September 2016, China had exported 35,200 tons of rare-earth materials, a 50% increase com- pared with exports for the same period in 2015." However, there is some interesting research going on in the United States and Canada around potential new sources of REEs and their extraction. The United States National Energy Technology Laboratory (NETL) is exploring coal deposits as a potential source of REEs. In a report, titled Rare Earth Elements Program 2016, NETL states "The overall objective of this program is to demonstrate the techno-economic feasibility of domes- tic REEs separation technologies by 2023-2025. Technologies for recovering REEs are focused on separating REEs from coal and/or coal by-products containing a minimum of 300 ppm total REEs, and con- centrating the REEs to a level greater than or equal to 2 wt% in resulting processed streams." On November 20, 2017 the University of Kentucky reported that "research- ers have produced nearly pure rare earth concentrates from Kentucky coal using an environmentally-conscious and cost- effective process, a groundbreaking accomplishment in the energy industry". "As far as I know, our team is the first in the world to have provided a 98 percent pure rare earth concentrate from a coal source," said Rick Honaker, professor of mining engineering. In Canada, Geoscience BC is partly funding Vinoth Kumar's research, a PhD student under supervision of prof. Maria Holuszko in the mining department at the University of British Columbia on the occurrence of Rare Earth Elements in selected British Columbian coal deposits. Kumar states that "Even though the lit- erature indicates the presence of REEs in some Canadian coal deposits, especially in British Columbia coalfields, there has been no effort to properly quantify and characterize these deposits and no analysis of extraction techniques. The purpose of Kumar's ongoing research is, "to character- ize and quantify the REEs and their mode of occurrence in BC coal deposits and coal processing products, and to study the pos- sible extraction of these elements." Kumar's research is based on an approxi- mately 300 kg run-of-mine sample from five seams collected at two coal mines in the East Kootenay coalfields, BC. Two types of tests upgrading coal were conducted: • the Release Analysis Test is a technique that is considered to produce an ideal separation for the flotation response of any coal. • the Agglomeration is a process where very fine particles of coal like those found in coal tailings ponds could be recovered. The presence of REEs in agglomerated coal products were also studied in this project. If successful, this agglomeration process may encourage cleaning tailings as a value- added product with REEs recovery from the tailings ponds. Kumar stated, "Five coal samples from BC coal deposits were tested for the presence of REEs by ALS Geochemistry (Vancouver, BC) and it was found that total REEs con- centration on an ash basis varied from 240 to 570 ppm. It was inferred from the data that REEs in the coal samples are associated with both the organic and inorganic por- tions of the coal constituents. The highest concentration was reported in the flotation product with low ash content, indicating that some of the REEs are associated with the organic matter of the coal. Further stud- ies will include sequential extraction, X-ray diffraction analysis and detailed SEM-EDX, required to estimate the quantity of REEs associated with organic matter and inor- ganic matter of the coal samples." Kumar concluded that, "With the devel- opment of extraction techniques for REEs in coal, these elements will be extracted as byproducts of coal mining, which strengthens the brownfield operations by increasing profitability and possible green credits as these REEs are used in the clean energy technologies. In the case of the green field operations, the possibility of extracting REEs from coal will increase the competitiveness of the deposits and its feasibility for actual mining and extraction." n