Recovery of rare earth elements from phosphogypsum

Abstract Phosphogypsum is a common large-tonnage waste of phosphoric fertilizers industry. The article describes a technology for complex treatment of a phosphogypsum Sredneuralsky Copper Smelting Plant (Sverdlovsk region, Russia) containing 0.43–0.52% of rare earth elements (REE). Joint co-crystallization of REE with gypsum provided a low degree of REE leaching in the direct leaching process. It was shown that combination of mechanical grinding treatment, ultrasonic impact and resin-in-pulp process provided significantly higher degrees of REE leaching from the phosphogypsum (from 15 to 17% to more than 70%). In addition, it was shown that the products after phosphogypsum treatment can be successfully used instead of natural gypsum as an addition for cements in the production of building materials.