A method for decomposing wolframite under oxygen pressure and preparing tungsten oxide and tungsten powder

A wolframite and tungsten oxide technology, applied in the field of chemical production, can solve the problems of high price, increase the cost of tungsten smelting, and pollute the environment, reduce production and operation costs, increase product added value, and reduce decomposition costs. Effect

Active Publication Date: 2020-07-14
CENT SOUTH UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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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 wolframite decomposition is very high; second, alkali pressure cooking will produce alkali cooking slag, which has been listed in the national hazardous waste catalog, 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

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  • A method for decomposing wolframite under oxygen pressure and preparing tungsten oxide and tungsten powder

Examples

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Effect test

Embodiment 1

[0037] This example provides a method for decomposing wolframite by oxygen pressure and preparing tungsten oxide and tungsten powder. The raw material used in this method is wolframite with a grade of 40% and a particle size of 120 μm. The method is specifically as follows:

[0038] (1) Oxygen pressure leaching reaction: Add wolframite to a sulfuric acid solution with a concentration of 200g / L, the liquid-solid ratio of the system is 6:1, feed oxygen to control the oxygen pressure to 5Mpa, and carry out the leaching reaction at 150°C 3 hours, 99.4% of tungsten is converted into tungstic acid;

[0039] (2) Filtration and washing: filter the reaction product obtained in step (1) to obtain decomposition residue and leaching solution; add sulfuric acid to the leaching solution and return to step (1) as a raw material for leaching reaction;

[0040] (3) hydrogen peroxide extraction-decomposition and extraction of tungsten: wash the decomposed slag obtained in step (2) and mix it wi...

Embodiment 2

[0044] This example provides a method for decomposing wolframite by oxygen pressure and preparing tungsten oxide and tungsten powder. The raw material used in this method is wolframite with a grade of 10% and a particle size of 160 μm. The method is specifically as follows:

[0045] (1) Oxygen pressure leaching reaction: Add wolframite to a sulfuric acid solution with a concentration of 120g / L. The liquid-solid ratio of the system is 10:1. The leaching reaction is carried out under the condition of 180°C and controlled oxygen pressure of 10Mpa for 1 hour, and the 99.5 % of tungsten converted into tungstic acid;

[0046] (2) Filtration and washing: filter the reaction product obtained in step (1) to obtain decomposition residue and leaching solution; add sulfuric acid to the leaching solution and return to step (1) as a raw material for leaching reaction;

[0047] (3) hydrogen peroxide extraction-decomposition and extraction of tungsten: wash the decomposed slag obtained in ste...

Embodiment 3

[0052] This example provides a method for decomposing wolframite by oxygen pressure and preparing tungsten oxide and tungsten powder. The raw material used in this method is wolframite with a grade of 70% and a particle size of 60 μm. The method is specifically as follows:

[0053] (1) Oxygen pressure leaching reaction: adding wolframite to a sulfuric acid solution with a concentration of 160g / L, then adding solid tungstic acid accounting for 10% of the wolframite mass, the liquid-solid ratio of the system is 4:1, and the Oxygen is introduced into the leaching reaction for 5 hours at 150°C and the oxygen pressure is controlled at 6Mpa, and 99.3% of the tungsten is converted into tungstic acid;

[0054] (2) Filtration and washing: filter the reaction product obtained in step (1) to obtain decomposition residue and leaching solution; add sulfuric acid to the leaching solution and return to step (1) as a raw material for leaching reaction;

[0055] (3) hydrogen peroxide extractio...

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Abstract

The invention relates to a method for oxygen-pressing and decomposing wolframite and preparing tungsten oxide and tungsten powder. The method takes wolframite as a raw material and comprises the following steps of: (1) performing oxygen-pressing and leaching reaction; (2) filtering and washing; (3) performing hydrogen peroxide extraction and decomposing extracted tungsten; (4) performing hydrogenperoxide multi-time extraction and decomposing and purifying tungstic acid; (5) roasting pure tungstic to prepare tungsten trioxide; and (6) spraying a tungsten acid peroxide solution and performing pyrolysis to prepare tungsten oxide and tungsten powder. An acid decomposition reagent adopted by the method is cheap and easily available, so that tungsten ore decomposition cost is greatly reduced; acid is adopted to decompose under an oxygen-pressure condition, so that hazardous waste alkali cleaning slag is not generated, and enterprise production and operation cost is greatly reduced; hydrogenperoxide is adopted as an extracting agent of tungstic acid, so that ammonia-nitrogen wastewater is not generated, the process of using ammonia-nitrogen wastewater generated by many years by tungstensmelting is abolished, and environment-friendly cost is greatly reduced; and various tungsten terminal products (tungsten oxide) and tungsten are directly generated, so that the product additional value of tungsten smelting enterprises is increased.

Description

technical field [0001] The invention relates to the field of chemical production, in particular to a method for decomposing wolframite under oxygen pressure and preparing tungsten oxide and tungsten powder. Background technique [0002] At present, the mainstream technology for processing wolframite in industry is to first use sodium hydroxide to pressure cook to obtain crude sodium tungstate solution and alkali cooking residue. 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 wolframite decomposition is very high; second, alkali pressure cooking will produce alkali cooking slag, which has been listed in th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B34/36C22B3/06C22B3/44C01G41/02
CPCC01G41/02C22B3/06C22B3/44C22B34/36Y02P10/20
Inventor 陈星宇刘旭恒赵中伟
Owner CENT SOUTH UNIV
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