Method of recovering lithium and copper from waste lithium iron phosphate battery selectively

Abstract

The invention discloses a method of recovering lithium and copper from a waste lithium iron phosphate battery selectively and relates to the technical field of electronic waste recovery processing. The method comprises the following steps of mixing the waste lithium iron phosphate battery with an inorganic acid and oxygen to react at 96-150 DEG C, and carrying out solid-liquid separation after thereaction to obtain a lixivium and an iron phosphate leaching residue mixing the lixivium with a separator to separate copper in the lixivium, and then adding an alkaline substance to adjust the pH toremove impurities iron and aluminum to obtain a purified liquid; and precipitating the purified liquid and sodium salt to obtain a lithium product. According to the method, a waste lithium iron phosphate electrode material structure is damaged in a high-temperature oxidant acidic environment. In particular, at 96-150 DEG C, it is only needed to add a small amount of inorganic acid to leach lithium and copper efficiently while Fe is hardly leached, so that lithium and copper with high value can be recovered. The method is short in process flow, simple in equipment and low in reagent cost.

Description

technical field [0001] The invention relates to the technical field of recycling and processing of electronic waste, in particular to a method for selectively recycling lithium and copper in waste lithium iron phosphate batteries. Background technique [0002] Lithium-ion batteries have become the main type of power batteries due to their significant advantages of high voltage, large specific energy, light weight, long cycle life and good safety performance. Lithium iron phosphate power batteries are widely used in power vehicles, energy storage power stations and other fields due to their excellent safety, stability and cycle performance, low price and no pollution. With the continuous improvement of production capacity, about 15% of the total power batteries are scrapped every year. [0003] The lithium and copper resources contained in the electrode materials of waste lithium iron phosphate batteries are scarce resources. At present, the traditional process of recycling...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the consumption of acid and alkali reagents is relatively large

CN106340692A proposes to use H 3 PO 4 -H 2 o 2 Systematic method for treating the positive electrode material of the invalid lithium iron phosphate battery, controlling the pH value of 2.0 to 4.5, so that lithium can be selectively leached in the form of lithium dihydrogen phosphate, and the filter residue is iron phosphate and carbon powder; but phosphoric acid and hydrogen peroxide are more expensive , high recycling cost

CN105937038A uses lithium iron phosphate as the positive pole, metal or carbon electrode as the negative pole, and aqueous solution as the electrolyte. Driven by the potential, the lithium ions in the positive electrode material of the lithium battery move into the electrolyte aqueous solution to form a lithium-containing solution. The migration rate of lithium Reach more than 90%; but the process of this method is relatively complicated, and the recovery rate of lithium is not high

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