Process for preparing high-purity ammonium paratungstate

Abstract

The invention relates to a process for preparing high-purity ammonium paratungstate, which can obtain a non-ferrous metal product, namely the ammonium paratungstate with low impurity content, whereinthe impurity content of the ammonium paratungstate is low and is lower than 70 ppm, and the ammonium paratungstate can be directly used for preparing deep processed products of tungsten, such as tungsten powder with low impurity content and the like. The process comprises the following four process steps: (1) a process step of preparing a sodium tungstate solution by using a tungsten concentrate (Fe, Mn)WO4, white tungsten (CaWO4) or a tungsten middling product as a raw material; (2) a process step of performing ion exchange on the sodium tungstate solution; (3) a process step of performing impurity removal and filtration by using an ammonium tungstate solution; and (4) a process step of performing crystallization, washing, drying and screening. The process for preparing the high-purity ammonium paratungstate optimizes the technological processes, improves the quality of a product, and reduces the preparation cost of the product.

Description

technical field [0001] The invention relates to a process for preparing ammonium paratungstate, in particular to a process for preparing high-purity ammonium paratungstate. [0002] In this patent specification, the term "high-purity ammonium paratungstate" refers to ammonium paratungstate whose total amount of impurities can be controlled within 70ppm, that is, ammonium paratungstate with low impurity content. [0003] The so-called "ammonium paratungstate" is also called APT. [0004] The term "sieving particle size" refers to the particle size of minerals passing through -320 mesh ≥ 95% after ball milling. [0005] The term "supernatant from pressure filtration" refers to the crude sodium tungstate solution, which is the crude sodium tungstate solution obtained after many times of pressure filtration. [0006] The term "post-delivery solution" refers to the solution discharged after the sodium tungstate solution passes through the ion exchange column adsorption operation....

AI Technical Summary

Problems solved by technology

[0010] With the continuous development of the tungsten industry, the ammonium paratungstate product produced by the existing ion exchange method only reaches the national standard zero-level standard, which is increasingly unable to meet the needs of the production of deep-processed tungsten products.

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