Method for preparing iron phosphate from ferro-nickel alloy

Abstract

The invention discloses a method for preparing iron phosphate from a nickel-iron alloy, which comprises the following steps of: simultaneously adding a nickel-iron leaching solution, an oxidizing agent and a precipitating agent at a certain feeding rate for reaction, while in the prior art, directly taking a nickel-iron solution as a reaction base solution, and directly adding the oxidizing agent and the precipitating agent into the base solution; and iron phosphate particles are directly generated in the base solution. Compared with the method of directly using the ferronickel leaching solution as the base solution for reaction, the method disclosed by the invention has the advantages that the feeding rate of the ferronickel leaching solution can be well controlled, the whole reaction system is more convenient to control, the reaction is quicker and more sufficient, in addition, more importantly, the content of S and Ni in the reaction system is greatly reduced, the entrainment of S and Ni in iron phosphate is reduced, and the yield of the ferronickel leaching solution is increased. And the quality of an iron phosphate product is effectively improved.

Description

technical field [0001] The invention relates to the field of lithium ion battery precursors, in particular to a method for preparing iron phosphate from a nickel-iron alloy. Background technique [0002] In recent years, with the rapid economic development and the massive consumption of chemical energy, there is a huge demand for alternative energy production, storage and transmission. In the field of energy storage, lithium-ion batteries occupy the current focus and mainstream due to their high energy density, and have been widely used in power vehicles and portable electronic products. For lithium-ion batteries, the electrode material becomes a key factor restricting its performance; among the electrode materials, LiFePO 4 It stands out for its good cycle stability and thermal stability. [0003] LiFePO is currently produced industrially 4 The main processes are ferrous oxalate process, iron red process and ferric phosphate process. The ferrous oxalate process is simpl...

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Problems solved by technology

Chinese invention patents CN106829907A and CN113025822A use sulfuric acid and phosphoric acid mixed acid to leach ferronickel alloy raw materials, obtain ferronickel leaching solution through solid-liquid separation, and then directly add oxidant and precipitant to the ferronickel leaching solution to react to obtain iron phosphate products. The process uses ferronickel The leaching solution is directly added to the oxidizing agent and reducing agent as the bottom liquid, so that the generated ferric phosphate will be placed in a reaction system containing a large amount of S and Ni. As the reaction progresses, the entrainment of S and Ni in the ferric phosphate is increased, resulting in the ferric phosphate Product does not meet industry standards

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