Method for recovering valuable metal from waste lithium iron phosphate positive electrode

The invention relates to a method for recovering valuable metals of a waste lithium iron phosphate positive electrode, which comprises the following steps: discharging and disassembling a waste lithium iron phosphate battery, crushing and carrying out high-temperature treatment on a lithium iron phosphate positive electrode plate obtained by disassembling, uniformly mixing a high-temperature treatment product with a carbon material, and roasting in a high-purity Cl2 atmosphere, so as to obtain the valuable metals of the waste lithium iron phosphate positive electrode. And then carrying out graded quenching condensation on the roasted gas-phase product, respectively recovering ferric chloride and aluminum chloride, carrying out water immersion on the roasted solid-phase product, filtering to obtain a lithium chloride aqueous solution, and adding sodium carbonate for precipitation to obtain lithium carbonate. According to the method, a one-step carbon thermal chlorination method is combined with a two-stage que