The document discusses the di-hydrate process for producing phosphoric acid. The wet process involves reacting phosphate rock with sulfuric acid, adding recirculated weak phosphoric acid to precipitate calcium sulfate. A dihydrate filter then separates the phosphoric acid from the calcium sulfate dihydrate. The document also mentions that advanced membrane filtration can replace traditional solvent extraction, reducing waste discharge and allowing production of various grades of industrial phosphoric acid. Finally, it provides a link to more information on phosphoric acid production, applications, processes, patents, consultants, company profiles, and suppliers.