Preparation method of oxalate

Abstract

The invention discloses a preparation method of oxalate and relates to the technical field of preparation methods of the oxalate. The method includes the following steps: (1) adding one mole part of metal salt into a first organic solvent, stirring for 10-20min to mix evenly and obtain a metal salt organic solvent, adding 0.5-1.5 mole parts of oxalic acid into a second organic solvent, and stirring for 10-20min to mix evenly and obtain an oxalic acid organic solvent; (2) cooling the metal salt organic solvent and the oxalic acid organic solvent to a temperature ranging from-40DEG C to-80DEG C; (3) mixing the metal salt organic solvent and the oxalic acid organic solvent, stirring for 10-20min to obtain a mixed solution; and (4) stopping cooling, naturally warming the mixed solution, and evenly precipitating the oxalate precipitation. The method is simple in process, easy to operate, suitable for mass production and capable of preparing the oxalate with high purity, small particle diameters and even distribution.

Description

technical field [0001] The invention relates to the technical field of oxalate preparation, in particular to a method for preparing oxalate by a precipitation method. Background technique [0002] Ferrous oxalate is one of the raw materials for the preparation of lithium iron phosphate, a new lithium-ion battery cathode material. Its purity and particle size have an important impact on the performance of the battery. Among them, Fe 3+ The existence of serious influence on the charging and discharging performance of the battery. The synthesis of ferrous oxalate in the prior art mainly adopts the chemical precipitation method, mixing the ferrous salt solution with oxalic acid or oxalate solution, and controlling the particle size and morphology of ferrous oxalate by controlling the process parameters of the synthesis process . Since the crystal structure of most metal oxalates is relatively similar, it is easy to form eutectic precipitates with relatively uniform particles, ...

AI Technical Summary

Problems solved by technology

[0005] The main problem of this method is that no matter what feeding method is used, it is difficult to ensure uniform supersaturation in the reaction system. Therefore, in the process of precipitation formation, the steps of nucleation, growth, and agglomeration cannot be effectively controlled, so that the particles Coarse and wide particle size distribution, which seriously affects its application performance

In the synthesis of single-component products, no matter how the feeding order and feeding speed are adjusted by the direct precipitation method, it is difficult to ensure that the supersaturation of the solution is consistent, and there is always a local over-concentration phenomenon throughout the whole process, which eventually leads to an excessively wide particle size distribution of the product.

During the co-precipitation process, due to the difference in the solubility product of each component, it is easy to form a sandwich type composite precipitation, and there are large differences in the distribution of different components in the product, which seriously affects the reprocessing performance of the product