A kind of method that acid decomposes scheelite to prepare tungsten oxide and tungsten powder

Abstract

The invention relates to a method for preparing tungsten oxide and tungsten powder by acid decomposition of scheelite. With the scheelite as raw materials, the method comprises the following steps: (1) the leaching reaction is performed; (2) the filtration washing is performed; (3) hydrogen peroxide is extracted; and tungsten is decomposed and extracted; (4) the hydrogen peroxide is dissolved by multiple times; and tungsten acid is decomposed and purified; (5) tungsten trioxide is prepared through calcining of pure tungsten acid; and (6) tungsten acid peroxide solution is sprayed and pyrolyzedto prepare the tungsten oxide and the tungsten powder. The method consumes no hydrochloric acid or nitric acid, and only consumes cheap and easy-obtained sulfuric acid, so that the scheelite decomposition cost is greatly reduced; the acid decomposition is adopted; decomposition slag is gypsum, and can be used as construction materials; dangerous and waste alkali boiling slag is not generated, sothat the enterprise production and operation cost is greatly reduced; the hydrogen peroxide is adopted as an extracting agent of the tungsten acid, so that ammonia and nitrogen waste water is not generated, a process for generating the ammonia and nitrogen waste water for tungsten smelting by many years is abolished, and the environmental protection cost is greatly reduced; and various tungsten terminal products and the tungsten powder are directly prepared, so that the product additional value of tungsten smelting enterprises is improved.

Description

technical field [0001] The invention relates to the field of chemical production, in particular to a method for acid-decomposing scheelite to prepare tungsten oxide and tungsten powder. Background technique [0002] At present, the mainstream technology for processing scheelite in industry is to first use alkaline reagents such as sodium hydroxide or sodium carbonate to obtain crude sodium tungstate solution and alkali cooking residue by pressure cooking. Crude sodium tungstate solution is converted into ammonium tungstate solution by ion exchange technology after being diluted with a large amount of water, and is also transformed into ammonium tungstate solution by solvent extraction. This mainstream technology is currently facing several serious problems: First, alkaline pressure cooking needs to consume alkali such as sodium hydroxide or sodium carbonate. The cost of scheelite decomposition is very high; secondly, alkali pressure cooking will produce alkali cooking slag,...

AI Technical Summary

Problems solved by technology

This mainstream technology is currently facing several serious problems: First, alkaline pressure cooking needs to consume alkali such as sodium hydroxide or sodium carbonate. The cost of scheelite decomposition is very high; secondly, alkali pressure cooking will produce alkali cooking slag, which has been listed in the national hazardous waste catalogue, and tungsten smelting enterprises are not allowed to dispose of it at will, and must be handed over to qualified enterprises for paid treatment, and The state also charges an environmental protection tax of 2,000 yuan / ton for the hazardous waste alkali cooking slag, which greatly increases the cost of tungsten smelting; third, in order to produce tungsten products with qualified impurity content, the current tungsten smelting process must also Ammonium reagents such as ammonia water or ammonium chloride are used as transformation reagents, so a large amount of ammonia nitrogen wastewater will inevitably be generated during the production process, resulting in environmental pollution

Moreover, the main purpose of its invention is to separate tungsten and molybdenum according to the stability difference between peroxytungstic acid and peroxymolybdic acid in acidic solution, and does not involve the purification method of tungsten

Images