Method for producing high purity battery level iron oxalate from pickle liquor

Abstract

The invention relates to a method for producing high-purity battery grade iron oxalate by utilizing pickle liquor, comprising the following steps: the pickle liquor is pre-treated for lowering spent acid content, thus leading the pickle liquor to generate ferrite solution with a certain concentration; then after strict filtering and magnetic separation, the ferrite solution is transported into a reaction kettle, then industry ammonia is added and the solution is stirred for reaction to generate ferrous hydroxide gelatin; the soluble oxalic acid solution is slowly added in and stirred, and then the mixture is stirred by a conversion reaction kettle and heat preservation is carried out, thus obtaining iron oxalate slurry after reaction; iron oxalate mother solution is separated in the iron oxalate slurry, and the separated iron oxalate is washed, dried and crashed for obtaining high-purity superfine iron oxalate products. The method has the beneficial effects that: the pickle liquor in industrial production is fully utilized; a two-step liquid phase method of oxidation and conversion is adopted for leading the reaction to be more fully, so that the reaction rate is greatly improved, the grain diameter of the finished products iron oxalate is fine and uniform, D50 is less than or equal to 5mum, and the content of the iron oxalate is more than or equal to 95.5 percent; furthermore, the pickle liquor is used as raw material, and cyclic utilization and environmental protection of the industrial waste are utilized, thus changing waste into valuable and greatly lowering the production cost.

Description

technical field [0001] The invention relates to a method for producing ferrous oxalate, in particular to a method for producing high-purity battery-grade ferrous oxalate by utilizing pickling waste liquid. Background technique [0002] The molecular formula of ferrous oxalate is FeC 2 o 4 2H 2 O, the existing ferrous oxalate production method is to utilize ferrous sulfate heptahydrate particles produced in the titanium dioxide production process to make a solution, directly add ammonia or other reactants in the oxalic acid solution, make it react to generate ammonium oxalate solution, and then Then make the ammonium oxalate solution react with ferrous sulfate to produce ferrous oxalate. The shortcoming of the process is that the obtained ferrous oxalate particle size is relatively large, generally exceeding D 50 >15um. The particle size distribution is extremely uneven, and the particles are wrapped with other substances, so the content is low, usually FeC 2 o 4 2H ...

AI Technical Summary

Problems solved by technology

[0002] The molecular formula of ferrous oxalate is FeC 2 o 4 2H 2 O, the existing ferrous oxalate production method is to utilize ferrous sulfate heptahydrate particles produced in the titanium dioxide production process to make a solution, directly add ammonia or other reactants in the oxalic acid solution, make it react to generate ammonium oxalate solution, and then Then make the ammonium oxalate solution react with ferrous sulfate to produce ferrous oxalate. The shortcoming of the process is that the obtained ferrous oxalate particle size is relatively large, generally exceeding D 50 >15um. The particle size distribution is extremely uneven, and the particles are wrapped with other substances, so the content is low, usually FeC 2 o 4 2H 2 The total content of O is 98%-99%, generally about 98%

In addition, in the existing large-scale industrial production process, a large amount of pickling waste liquid will be produced, which must be neutralized before it can be discharged, resulting in a serious waste of manpower and material resources, and will bring serious environmental pollution