Method for preparing low-silicon red cake through reduction, hydrolysis, vanadium precipitation and desilicication

Abstract

The invention relates to the field of silicon removal and low-silicon hydrolysis red cake preparation, in particular to a method for preparing a low-silicon red cake through reduction, hydrolysis, vanadium precipitation and silicon removal. The method comprises the following steps: providing a vanadium-containing solution; acid is added into the vanadium-containing solution, the pH value is adjusted to be 5-6, a reducing agent is added for a reduction reaction, and a reduced vanadium solution is obtained; acid is added into the reduced vanadium solution, the pH value is adjusted to be 1.5-3, a reaction is carried out for 0.5-3 h at the temperature of 90-100 DEG C, after the reaction is finished, filtering is carried out, a vanadium precipitation filter cake is obtained, the filter cake is pulped and washed with deionized water, and then drying is carried out. According to the method for preparing the low-silicon red cake through reduction, hydrolysis, vanadium precipitation and desilicication, deep desilicication can be carried out on the vanadium-containing solution, the silicon content in the prepared red cake is reduced to 20 ppm or below, and the desilicication effect is excellent.

Description

technical field [0001] The invention relates to the fields of silicon removal and preparation of low-silicon hydrolysis red cakes, in particular to a method for preparing low-silicon red cakes by reducing and hydrolyzing vanadium precipitation and desiliconization. Background technique [0002] Red cake (or hydrolyzed red cake) is a common intermediate product of vanadium precipitation. Due to its high water content, high impurities, and low vanadium content, red cake is basically not produced in the process of industrial production of vanadium pentoxide , but the red cake does not need to be deaminized in the process of remelting, so it is more used to prepare vanadium pentoxide with higher purity. Silicon is the main impurity element in the red cake, which greatly affects the final product quality and range of applications. After the promotion and implementation of low-silicon red cakes, the application field of vanadium can quickly move towards the field of higher-end ne...

AI Technical Summary

Problems solved by technology

The chemical impurity removal method is divided into aluminum salt removal method, magnesium salt removal method, calcium salt removal method, iron salt removal method, etc. according to the silicon removal agent added. The chemical removal method has the advantages of simple operation, low cost, The vanadium loss rate is small, and it is easy to industrialized production. The content fluctuates, and it is difficult to control the amount of impurity removal agent when chemical removal is used, resulting in incomplete removal of impurities and unstable quality of the final product

The ion exchange method has disadvantages such as cumbersome operation, a large amount of waste water generated during resin desorption and regeneration, long production cycle and small production capacity.

At the same time, a small amount of impurity ions will be replaced with active functional groups during the ion exchange process, so the purpose of complete purification cannot be achieved; the static precipitation method is also called the hydrolysis precipitation method, and the pH of the solution is adjusted without adding reagents. Hydrolyze to form silicic acid polymers, and the polymers are further condensed to form fine particles of silica. This method is only used in acidic solutions. The static precipitation method has long standing time, difficult filtration, and low desiliconization rate. and other shortcomings

The existing desiliconization methods all have one or more problems such as low desiliconization rate, introduction of impurities, complex process flow, high cost, etc., and cannot fully meet the needs of industrial production of high-purity vanadium products