Patent ID: 8574518

Claim:
A process for the production of iron (III) orthophosphate of the general formula FePO 4 ×nH 2 O (n≦2.5) comprising: a) producing an aqueous solution containing Fe 2+ ions by introducing, iron (II), iron (III) or mixed iron (II, III) compounds selected from the group consisting of hydroxides, oxides, oxide hydroxides, oxide hydrates, carbonates and hydroxide carbonates, together with elementary iron, into a phosphoric acid-bearing aqueous medium, to dissolve Fe 2+ ions and to react Fe 3+ with elementary Fe in a comproportionation reaction to give Fe 2+ , b) separating solids from the phosphoric-acid aqueous Fe 2+ solution, and c) adding an oxidation agent to the phosphoric-acid aqueous Fe 2+ solution to oxidize iron (II) in the solution to precipitate iron (III) orthophosphate of the general formula FePO 4 ×nH 2 O.