Preparation method of tungstate with hexagonal prism shape

Abstract

The invention concerns a preparation method of tungstate with a hexagonal prism shape. The method includes the following steps: adding a surfactant and water to a solution containing tungstate radicals and performing uniform mixing under stirring to obtain an initial liquid of a solution A, wherein the molar volume ratio of the tungstate radicals to the initial liquid of the solution A is 0.1-2.0 mol / L, and the mass volume ratio of the surfactant to the initial liquid of the solution A is 0.05-2.0g / L; then adding a pH regulator to regulate the pH value to a range of 4.0-7.0 to form the solution A; dissolving a precipitant into water to form a solution B, wherein the molar volume ratio of the precipitant to the solution B is 0.5-6.0 mol / L; and adding the solution A and the solution B to a reaction kettle by adopting a method of concurrent feeding, performing a reaction, performing solid-liquid separation, and performing water washing to remove impurities, so as to obtain the tungstate finished product. Production equipment of the invention can be common equipment, operation is simple, safe and reliable, production cost is low and yield is high.

Description

Technical field [0001] The invention relates to a preparation method of tungstate, in particular to a preparation method of hexagonal prism tungstate. Background technique [0002] With the development of modern science and technology, higher requirements have been put forward for the preparation of tungsten, tungsten alloys and tungsten compounds. Especially in recent years, the demand for high-purity and excellent performance tungsten and its compounds in the high-tech and deep processing fields has increased. Urgently, tungstate is an important intermediate raw material in tungsten smelting, and its preparation and process research have important value and significance. [0003] At present, the more common tungsten compounds in the production of metal tungsten are ammonium paratungstate and ammonium metatungstate. Among them, the preparation methods of ammonium paratungstate mainly include neutralization, evaporation, ion exchange and extraction. The evaporation method is mostly...

AI Technical Summary

Problems solved by technology

[0003] Ammonium paratungstate and ammonium metatungstate are the common tungsten compounds currently used in the production of metal tungsten. Among them, the preparation methods of ammonium paratungstate mainly include middle method, evaporation method, ion exchange and extraction method. Evaporation method is often used in industrial production, but evaporation crystallization is used. When ammonium paratungstate is prepared by the method, it is difficult to control the particle size of the product. Generally, only products with a Fischer particle size of 25-60 μm can be crystallized, which is difficult to meet the requirements for the production of ultra-fine tungsten powder; there are many preparation methods for ammonium metatungstate. There are differences in the manufacturers themselves, and the preparation techniques used are also not the same. According to the difference in the preparation of ammonium metatungstate solution in the previous stage of the process, they can be roughly divided into two categories: 1. Solid phase conversion method, such as thermal reaction using ammonium paratungstate as raw material Degradation method, but the disadvantages of this method are large investment, high cost, high energy consumption, and unstable product quality; 2. Liquid phase conversion method, such as solvent extraction method, ion exchange method, neutralization method, electrodialysis method, Nanofiltration method, etc. This method is mainly to obtain ammonium metatungstate solution by adjusting the pH value of the raw material solution

[0004] The preparation of ammonium paratungstate and ammonium metatungstate mostly requires evaporation and concentration steps at the end, and most of the product particles are large, which is not conducive to the performance improvement of subsequent products, and evaporation crystallization requires high energy consumption and high manufacturing costs