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Method for extracting tungsten and molybdenum through acid decomposition of high-molybdenum scheelite

A technology of scheelite and acid decomposition, applied in the direction of improving process efficiency, etc., can solve the problems of increasing tungsten smelting costs, hydrogen sulfide harming production and environment, and polluting the environment, so as to reduce production and operation costs and increase product added value , The effect of reducing the decomposition cost

Active Publication Date: 2018-08-21
CENT SOUTH UNIV
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  • Claims
  • Application Information

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 2,000 yuan / ton of environmental protection tax on the hazardous waste alkali cooking slag, which greatly increases the cost of tungsten smelting; third, in order to separate the associated molybdenum in scheelite, it is necessary to add sulfide to separate molybdenum by sulfide , the process will produce toxic gas hydrogen sulfide that will endanger production and the environment; fourth, in order to produce tungsten products with qualified impurity content, ammonia water or ammonium chloride and other ammonia reagents must be used as transformation reagents in the current tungsten smelting process , so the production process will inevitably produce a large amount of ammonia nitrogen wastewater, 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

Method used

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  • Method for extracting tungsten and molybdenum through acid decomposition of high-molybdenum scheelite

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0055] The raw material that this embodiment adopts is WO 3 High-molybdenum scheelite with a grade of 40%, a Mo grade of 5%, and a particle size of 120 μm.

[0056] A method for acid-decomposing high-molybdenum scheelite to extract tungsten and molybdenum, comprising the following steps:

[0057] (1) Leaching reaction: Add high-molybdenum scheelite into a sulfuric acid solution with a concentration of 150g / L. The liquid-solid ratio of the system is 5:1. The leaching reaction is carried out at 150°C and 0.5Mpa for 3 hours; 99.5% Tungsten is converted into tungstic acid, 10.5% of molybdenum is converted into molybdenum acid, and the leaching rate of molybdenum is 89.1%;

[0058] (2) extracting molybdenum in the leachate: filter the reaction product obtained in step (1) to obtain decomposition residue and leachate; add extractant (30% P204+10%TBP+kerosene) to the gained leachate to control the volume of the organic phase and the water phase The ratio is 1:1, mixed, and the extr...

Embodiment 2

[0065] The raw material that this embodiment adopts is WO 3 High-molybdenum scheelite with a grade of 30%, a Mo grade of 25%, and a particle size of 50 μm.

[0066] A method for acid-decomposing high-molybdenum scheelite to extract tungsten and molybdenum, comprising the following steps:

[0067] (1) Leaching reaction: Add high-molybdenum scheelite into hydrochloric acid solution with a concentration of 200g / L, the liquid-solid ratio of the system is 5:1, and carry out leaching reaction at 200°C and 2.5Mpa for 3 hours; 99.5% Tungsten is converted into tungstic acid, 2.5% of molybdenum is converted into molybdenum acid, and the leaching rate of molybdenum is 97.2%;

[0068] (2) Molybdenum extraction in the leachate: filter the reaction product obtained in step (1) to obtain decomposition residue and leachate;

[0069] Add sulfuric acid to the leaching solution, the molar ratio of the amount of sulfuric acid to the calcium ion content in the leaching solution is 1:1, and perfo...

Embodiment 3

[0075] The raw material that this embodiment adopts is WO 3 High-molybdenum scheelite with a grade of 55%, a Mo grade of 2.5%, and a particle size of 150 μm.

[0076] A method for acid-decomposing high-molybdenum scheelite to extract tungsten and molybdenum, comprising the following steps:

[0077](1) Leaching reaction: Add high-molybdenum scheelite into a nitric acid solution with a concentration of 200g / L, and at the same time add tungstic acid with 10% tungsten ore mass. The liquid-solid ratio of the system is 7:1. Carry out leaching reaction for 4 hours; 99.5% of tungsten is converted into tungstic acid, 1.2% of molybdenum is converted into molybdenum acid, and the leaching rate of molybdenum is 98.2%;

[0078] (2) Molybdenum extraction in the leachate: filter the reaction product obtained in step (1) to obtain decomposition residue and leachate;

[0079] Add sulfuric acid to the leaching solution, the molar ratio of the amount of sulfuric acid to the calcium ion content...

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Abstract

The invention relates to a method for extracting tungsten and molybdenum through acid decomposition of high-molybdenum scheelite. The method comprises the following steps: leaching the high-molybdenumscheelite with an acid solution, and extracting a leachate to extract molybdenum; extracting a leaching residue with hydrogen peroxide to obtain a solution containing peroxotungstic acid and peroxymolybdic acid, and heating or introducing SO2 to obtain tungstic acid and a solution containing the peroxomolybdic acid; extracting the tungstic acid with hydrogen peroxide, and heating or introducing SO2 to obtain tungstic acid and a solution containing the peroxomolybdic acid; repeating for several times till pure tungstic acid is obtained; preparing tungsten trioxide or tungsten powder from the pure tungstic acid; and heating or introducing SO2 into the solution containing the peroxomolybdic acid, dissolving obtained molybdic acid in a hydrogen peroxide solution to prepare a peroxomolybdic acid solution, and performing ultrasonic spraying pyrolysis to prepare molybdenum trioxide powder or molybdenum powder. By the method, the separation effect is good and the operation process is simple and easy to control, so that the method is easy to popularize and apply industrially.

Description

technical field [0001] The invention relates to the technical field of rare metal metallurgy, in particular to a method for acid-decomposing high-molybdenum scheelite to extract tungsten and molybdenum. Background technique [0002] At present, the mainstream technology for processing high-molybdenum scheelite in the industry is to first use alkaline reagents such as sodium hydroxide or sodium carbonate to obtain crude sodium tungstate solution and alkali boiling residue by pressure cooking. The crude sodium tungstate solution contains a certain amount of molybdenum, which needs to be vulcanized first, and then acidified to precipitate and separate molybdenum in the form of molybdenum trisulfide. This process will inevitably produce a large amount of toxic gas hydrogen sulfide. The acidified solution adopts a weakly basic extractant or a weakly basic ion exchange resin to absorb tungsten in it, and then back-extracts or desorbs with ammonia water to obtain an ammonium tungs...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B3/06C22B3/26C22B34/34C22B34/36
CPCC22B3/06C22B34/34C22B34/36C22B3/26Y02P10/20
Inventor 陈星宇赵中伟
Owner CENT SOUTH UNIV
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