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US 5,531,975 AGranted
Process for the production of phosphoric acid and calcium fluoride
AssigneePhosphate Engineering & Construction Co., Inc.
InventorsWilliam R. Erickson, Leif E. Bouffard
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Abstract
Fluosilicic acid is reacted with phosphate rock in order to produce wet process phosphoric acid and calcium fluoride which is later reacted with sulfuric acid to produce hydrogen fluoride and calcium sulfate. The hydrogen fluoride is then stripped from the phosphoric acid and recovered as either anhydrous hydrogen fluoride or concentrated hydrofluoric acid or reacted with aluminum trihydrate to produce aluminum fluoride; with sodium carbonate to produce sodium fluoride/bifluoride; or with ammonia to produce ammonium fluoride/bifluoride.
Claims5
A process comprising:
- reacting phosphate rock and fluosilicic acid to produce a reaction slurry comprising phosphoric acid, calcium fluoride, silicon dioxide and undigested phosphate rock and wherein an excess stoichiometric amount of calcium to fluorine is initially present in the slurry and, thereafter
- separating phosphoric acid and calcium fluoride from the undigested phosphate rock and silicon dioxide.
Dependencies are inferred from the claim text.