Continuous process for preparing sodium orthophosphate slurries from natural soda ash and orthophosphoric acid

摘要

Unmilled commercially available granular "natural" soda ash is reacted with orthophosphoric acid to produce a highly concentrated slurry at a molar Na:P ratio of about 1.5 in a continuous process. Problems associated with incomplete reaction are solved and the slurry can be dried to the double salt Na3H3(PO4)2 or reacted with aqueous sodium hydroxide to produce a superior precursor for manufacturing sodium tripolyphosphate.