Production method of ultrafine cell level ferric orthophosphate

Abstract

The invention relates to a method for producing ultrafine battery-level positive ferric phosphate. The method comprises the following steps that: a ferrite solution is added into a catalytic reaction kettle, added with sulphuric acid to adjust the pH value and slowly added with hydrogen peroxide while stirring to perform oxidation reaction; the dissolved phosphate solution is added to the catalytic reaction kettle, added with soda ash or ammonia to control the pH value and strongly stirred to obtain slurry of the positive ferric phosphate; the slurry is water-washed, press-filtered and separated to obtain a positive ferric phosphate filter cake; a conversion reaction kettle is added with an aqueous solution of phosphoric acid and added with the filter cake, the pH value and the temperature of the obtained mixing solution are adjusted, and the mixing solution is stirred; the mixing solution is placed in a thermal insulation reaction kettle, heated and stirred for a few hours until the mixing solution becomes pink, and the slurry of the positive ferric phosphate is obtained; and the slurry is water-washed, press-filtered, dried and crushed to obtain a finished product of the positive ferric phosphate. The method has the advantages of complete reaction and high reaction ratio, 28 to 29 percent of the total iron content Fe<3+> of the obtained products and even and thin grain diameter, and the D50 is less than or equal to 2um, the P is more than or equal to 16 percent, the grain is ultrafine and high in purity, and has even grain diameter; and because waste slag discharged in the production of a titanium pigment or industrial acid pickling waste liquid is used as a raw material, the environment is protected, and the product cost is lowered.

Description

technical field [0001] The invention relates to a production method of battery-grade iron orthophosphate, in particular to a production method of ultrafine high-purity battery-grade iron orthophosphate. Background technique [0002] Iron orthophosphate FePO 4 2H 2 O, the main component is FePO 4 , the existing ferric orthophosphate production process is generally to use phosphate to directly react with ferrous salt solution to generate ferric orthophosphate. The resulting product has a large particle size, and the particle size distribution is extremely uneven. 28%, generally only 22-26%. In addition, in the existing production of titanium dioxide, every ton of titanium dioxide produced will produce 3-4 tons of waste residue containing ferrous sulfate. Industrial production will produce a large amount of pickling during degreasing and derusting Waste liquid has caused serious pollution to the environment that human beings depend on for survival. Therefore, realizing the r...

AI Technical Summary

Problems solved by technology

[0002] Iron orthophosphate FePO 4 2H 2 O, the main component is FePO 4 , the existing ferric orthophosphate production process is generally to use phosphate to directly react with ferrous salt solution to generate ferric orthophosphate. The resulting product has a large particle size, and the particle size distribution is extremely uneven. 28%, generally only 22-26%. In addition, in the existing production of titanium dioxide, every ton of titanium dioxide produced will produce 3-4 tons of waste residue containing ferrous sulfate. Industrial production will produce a large amount of pickling during degreasing and derusting Waste liquid has caused serious pollution to the environment that human beings depend on for survival. Therefore, realizing the recycling of industrial waste and producing high-purity and ultra-fine iron orthophosphate suitable for the cathode material requirements of iron-lithium batteries is a direction of the present invention.