Method For Manufacturing Ammonium Sulphate And Calcium Carbonate From Phosphogypsum

A method for manufacturing ammonium sulphate and calcium carbonate from phosphogypsum, characterized in that it comprises the following steps:

• dispersing phosphogypsum in water to form a phosphogypsum liquid suspension,
• sparging a mixture of gaseous ammonia and gaseous carbon dioxide in the phosphogypsum liquid suspension to precipitate calcium carbonate, the gaseous carbon dioxide and the gaseous ammonia being mixed in a mixer before being introduced simultaneously into the phosphogypsum liquid suspension,
• filtering the phosphogypsum liquid suspension to produce a filtrate comprising ammonium sulphate, and a solid residue comprising the calcium carbonate precipitate,
• evaporating the filtrate to obtain ammonium sulphate and drying the solid residue to obtain calcium carbonate.