A method for recovering ferric phosphate from ferric phosphate slag

Abstract

This invention provides a method for recovering and preparing ferric phosphate from ferric phosphorus slag. The method includes the following steps: leaching the ferric phosphorus slag with phosphoric acid, separating the solid and liquid phases to obtain a leachate; mixing iron powder with the leachate to perform a copper removal reaction, obtaining a copper-removed liquid; using a chelating resin to adsorb aluminum from the copper-removed liquid, obtaining an aluminum-removed liquid; subjecting the aluminum-removed liquid to oxidation and crystallization to obtain ferric phosphate slurry; and after solid-liquid separation, washing, and drying, obtaining orthorhombic ferric phosphate and mother liquor; the oxidant used in the oxidation is hydrogen peroxide. The method for recovering and preparing ferric phosphate from ferric phosphorus slag provided by this invention uses only phosphoric acid as the leaching agent and pH buffer system. The synthesis process relies on the self-buffering properties of phosphate-dihydrogen phosphate to regulate the crystallization reaction, completely avoiding the auxiliary material consumption caused by acid-base neutralization in traditional wet processes; it also has lower costs and yields orthorhombic ferric phosphate with higher purity, meeting the requirements for battery applications.

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