A method for selectively reclaiming lithium and copper in waste lithium iron phosphate batteries

Abstract

The invention discloses a method for selectively recovering lithium and copper in waste lithium iron phosphate batteries, and relates to the technical field of electronic waste recovery and treatment. The method comprises: mixing waste lithium iron phosphate batteries, inorganic acid and oxygen, reacting at 96-150°C, and separating solid and liquid after the reaction to obtain leaching solution and iron phosphate leaching residue; mixing the leaching solution with a separating agent To separate the copper in the leaching solution, and then add alkaline substances to adjust the pH to remove impurity iron and impurity aluminum to obtain a purified solution; precipitate the purified solution and sodium salt to obtain a lithium product. In this application, the destruction of the structure of the waste lithium iron phosphate electrode material is achieved in a high-temperature oxidative acidic environment, especially at a temperature of 96-150°C, and only a small amount of inorganic acid is needed to achieve efficient leaching of lithium and copper. However, Fe is almost not leached, and high-value lithium and copper can be recovered; the process is short, the equipment is simple, and the cost of reagents is low.

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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