Preparation method of lithium iron phosphate

The invention belongs to the technical field of recovery and recycling of battery materials, and particularly relates to preparation method of lithium iron phosphate. The method for preparing lithiumiron phosphate from crude lithium phosphate comprises the following steps: a pure lithium solution is obtained through stirring washing, acid dissolution, phosphorus removal and step-by-step impurityremoval, then an iron source, a phosphorus source and a carbon source are added, and the lithium iron phosphate is obtained through mixing treatment. The preparation method reduces loss of lithium tothe minimum extent and makes the recovery rate of lithium 99% or above, low-cost crude lithium phosphate is used as a raw material to obtain the lithium iron phosphate with high purity and good performances, phosphate byproducts generated in the reaction process are used in other ways, only less waste liquid and waste residues are generated, the production cost is reduced, and the method is environmentally friendly and has