Preparation method for high-purity iron phosphate and use thereof

The present application belongs to the technical field of battery materials. Disclosed are a preparation method for a high-purity iron phosphate and use thereof. The preparation method comprises the following steps: mixing and stirring an iron phosphide waste, an acid liquid, an oxidant, and an adsorbent, heating and leaching, and performing solid-liquid separation to give a first filtrate and a first filter residue; adding an alkali liquid to the first filtrate, adjusting the pH and preserving the heat, and performing solid-liquid separation to give a second filter residue and a second filtrate; performing heat treatment on the second filter residue to give iron oxide; performing high-energy ball milling on the iron oxide, and adding a surfactant for activation to give a slurry; and mixing the slurry with phosphoric acid, heating for reaction, performing solid-liquid separation, washing a solid phase, and then sintering to give iron phosphate. According to the present application, iron oxide and phosphoric acid are prepared from the iron phosphide waste and the like as raw materials. After activation, by means of a low-temperature reaction, the high-purity iron phosphate is prepared. The reaction process is closed-loop preparation, and less waste is produced.