PRODUCTION OF IRON ORTHOPHOSPHATE Russian patent published in 2014 - IPC C01B25/37 C01G49/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing iron (III) orthophosphate of general formula FePO₄·nH₂O, where n≤2.5, the iron (III) orthophosphate obtained using said method and to use thereof to produce lithium ferrophosphate (LiFePO₄) as a cathode material for lithium-ion batteries. The method of producing iron (III) orthophosphate includes a) preparing an aqueous solution containing Fe²⁺ ions by introducing iron (II), iron (III) or mixed iron (II, III) oxide compounds selected from hydroxides, oxides, oxide hydroxides, oxide hydrates, carbonates and hydroxide carbonates, together with elementary iron, into a phosphoric acid-conataining aqueous medium, to dissolve Fe²⁺ ions and to react Fe³⁺ with elementary Fe in a comproportionation reaction to give Fe²⁺, b) separating solids from the phosphoric-acid aqueous Fe²⁺ solution, and c) adding an oxidation agent to the phosphoric-acid aqueous Fe²⁺ solution to oxidise iron (II) in the solution to precipitate iron (III) orthophosphate.

EFFECT: obtained iron (III) orthophosphate has high degree of purity.

16 cl, 4 dwg, 7 ex