METHOD FOR DECOMPOSITION OF FLUOROAPATITE Russian patent published in 2003 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to methods for treatment of natural phosphate raw - apatite, namely, methods for decomposition of complex fluorine-containing raw - fluoroapatite. Fluoroapatite ground to particles size less 160 mcm is dried and mixed with stoichiometric amount of phosphorus pentoxide. Mixture is heated to temperature above 170 C and treated with gaseous fluorosulfonic acid. Evolving gaseous products of decomposition - meta-phosphoric acid and hydrogen fluoride are removed and formed calcium fluorosulfonate as the reaction product is hydrolyzed with stoichiometric amount of steam-like water at temperature above 170 C. Evolving gaseous fluorosulfonic acid and hydrogen fluoride are used in technological process of decomposition of fluoroapatite and calcium sulfate as a solid residue represents commercial product. The proposed technology is wasteless, ecologically pure and economically gained one. Invention can be used for preparing meta-phosphoric acid and hydrogen fluoride used in chemical industry and calcium sulfate (anhydride) used in production of building materials. EFFECT: improved decomposition method.