Removal of Iron from Pyrite-Rich Coal Refuse by Calcination and Magnetic Separation for Hydrometallurgical Extraction of Rare Earth Elements

In the metallurgical extraction of rare earth elements (REEs), ratio contaminant ions to REEs in leachate dictates cost and operational efficiency downstream processes. The current study investigated potential iron contamination removal from feed hydrometallurgical process by calcination followed magnetic separation. 2.20 specific gravity sink fraction Baker coal seam coarse refuse was pulverized finer than 180 μm, calcined at various temperatures, separated into non-magnetic fractions using a wet high-intensity separator different field strengths. untreated feed, products, their subsequent were subjected acid leaching tests with 1.2 M sulfuric 75 °C 1% w/v solids concentration. recovery light heavy (LREEs HREEs, respectively) along concentration common (Al, Ca, Fe) measured as output variables. weight percent material maximized approximately 29% temperature 400 °C. Magnetic this strength 1.15 Tesla resulted rejection 81% iron. Leaching provided significantly higher Fe relative fraction. subsequently 600 dehydroxylate clays released REE minerals same manner treatment original material. A comparison elemental concentrations resulting both showed only slight reduction content This finding combined loss conclusion that step unfavorable.