Device and method for preparing battery-grade iron phosphate by using byproduct ferrous sulfate

Abstract

The invention relates to a device and method for preparing battery-grade iron phosphate by using titanium dioxide byproduct ferrous sulfate, the device comprises a purification device and a synthesis device, the synthesis device comprises an oxidation kettle connected to the downstream of the purification device, a reaction separation kettle connected to the downstream of the oxidation kettle and an alkali liquor kettle communicated to the upstream of the reaction separation kettle, and the reaction separation kettle is provided with a heating assembly. The membrane assembly comprises a hollow rotating shaft arranged in the reaction separation kettle in a penetrating manner and a plurality of hollow membranes distributed on the hollow rotating shaft at intervals, the hollow membranes are communicated with the hollow rotating shaft and can enable liquid to penetrate through the surface to enter the inner cavity, and the hollow rotating shaft is used for discharging separated clear liquid; according to the invention, engineering measures such as isothermal premixing, step-by-step addition of alkali liquor, parallel feeding for controlling the material flow ratio, uniform feeding between liquid distributor membranes, multi-blade strong shear mixing, clear liquid in-situ discharge and wet material in-situ washing are adopted, and various process conditions are strictly controlled, so that the consistency and quality stability of products are achieved.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and relates to a device and a method for preparing battery-grade iron phosphate by utilizing by-product ferrous sulfate. Background technique [0002] Iron phosphate can be used as non-toxic anti-rust pigment, catalyst and ceramic glaze coating. In recent years, in the battery field, iron phosphate has been widely used as a raw material for battery cathode materials (such as lithium iron phosphate). Ferric phosphate can be obtained by the reaction of ferrous salt and phosphoric acid / phosphate under the action of oxidant, and the commonly used ferrous salt is ferrous sulfate. At present, the production of titanium dioxide in my country is mainly based on the sulfuric acid method. For every 1t of titanium dioxide produced, about 3.5-4t of ferrous sulfate is produced as a by-product. However, because it contains various impurities such as titanium, magnesium, manganese and aluminum, mos...

AI Technical Summary

Problems solved by technology

The advantage of this method is that the recovery rate of iron is high, and the disadvantage is that the removal rate of impurities is low, and the relevant process conditions are difficult to control during the actual preparation of colloids.

However, the consistency and quality stability of the current industrialized FePO4 preparation process is difficult to strictly control, so it is particularly important and urgent to find a high-activity, high-quality and stable iron phosphate synthesis process

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