Studies on the Extraction of Lanthanides and Preparation of Pure Calcium Carbonate from Egyptian Phosphogypsum Produced during Phosphoric Acid Production Process

Abstract

Phosphogypsum (PG) is a waste material which produced as a byproduct during the commercial manufacture of phosphoric acid by the wet process. The produced phosphogypsum is transferred as a wet cake to open air storage known as stacks and stored in large stockpiles. The main environmental hazard associated with phosphogypsum stockpiles are the leaching of rain water into surface and underground water regime and the generation of airborne dust. In addition, these phosphogypsum stacks occupy large areas of land and require long-term expenditures for maintenance and monitoring. Long-term storage and maintenance of phosphogypsum present economic as well as potential environmental concerns. One of the most promising approaches to economically feasible processing of phosphogypsum is that in which a concentrate of rare-earth elements and a purified calcium carbonate product are