Concentration of rare earth minerals from coal by froth flotation

Minerals & Metallurgical Processing , 2017, Vol. 34, No. 3, pp. 132-137

Zhang, W.; Honaker, R.; Groppo, J.

DOI: https://doi.org/10.19150/mmp.7613

Rare earth elements (REEs) found in coal are in the form of minerals, ion-adsorbed onto clay surfaces or inner layers, or organically bound. Rare earth minerals such as monazite exist in coal and have grain sizes smaller than 5 µm. In this study, froth flotation was successful in concentrating rare earth minerals existing in a thickener underflow material derived from Fire Clay seam coal that contained around 431 ppm of total rare earth elements (TREE) on a dry ash basis. Conditioning with fatty acid followed by processing using multiple stages of conventional flotation produced a final concentrate containing 2,300 ppm TREE. Using a laboratory flotation column to limit hydraulic entrainment, the TREE content was further enriched to around 4,700 ppm, which equated to an enrichment ratio of 10:1.

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