Method for extracting tungsten from phosphotungstic acid/phosphotungstate solution

A technology of phosphotungstic acid and phosphotungstic acid, which is applied in chemical instruments and methods, tungsten compounds, inorganic chemistry, etc., to achieve the effect of avoiding large acid loss

Active Publication Date: 2016-01-27
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In short, there is currently no particularly effective method for efficiently extracting tungsten from sulfur-phosphorus mixed acid systems.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] This embodiment provides a method for extracting tungsten from phosphotungstic acid / phosphotungstate solution, comprising the following steps:

[0031] (1) First to WO 3 The concentration is 212g / L, P 2 o 5 The concentration is 180g / L, H 2 SO 4 In the phosphotungstic acid solution with a concentration of 90g / L, according to the molar ratio of tungsten to 1.5:1, add hydrogen peroxide with a concentration of 30%, and stir the reaction to make tungsten form peroxytungstic acid;

[0032] (2) Then heat the mixture to 60°C and pass SO 2 , control SO 2 The feeding rate of the reaction time is adjusted to 60 minutes until the solution becomes colorless, and the tungsten is precipitated in the form of tungstic acid;

[0033] (3) directly calcining the washed tungstic acid precipitate to obtain tungsten trioxide;

[0034] (4) The mixed solution of sulfuric acid and phosphoric acid obtained by filtration is returned for WO 3 Scheelite with a content of 45% decomposes.

Embodiment 2

[0036] This embodiment provides a method for extracting tungsten from phosphotungstic acid / phosphotungstate solution, comprising the following steps:

[0037] (1) First to WO 3 The concentration of 253g / L, P 2 o 5 The concentration is 20g / L, H 2 SO 4 In the phosphotungstic acid solution with a concentration of 10g / L, according to the molar ratio of tungsten to 2:1, add hydrogen peroxide with a concentration of 28%, and stir the reaction to make tungsten form peroxytungstic acid;

[0038] (2) Then control the solution to 20°C and pass through SO 2 , adjust the reaction time to 120 minutes until the solution becomes colorless, so that tungsten is precipitated in the form of tungstic acid;

[0039] (3) Dissolve the washed tungstic acid precipitate with ammonia water to obtain ammonium tungstate solution, and then obtain APT through evaporation and crystallization, which has reached the national 0-level standard after testing;

[0040] (4) The mixed solution of sulfuric acid...

Embodiment 3

[0042] This embodiment provides a method for extracting tungsten from phosphotungstic acid / phosphotungstate solution, comprising the following steps:

[0043] (1) First to WO 3 The concentration is 152g / L, P 2 o 5 The concentration is 300g / L, H 2 SO 4 In the phosphotungstic acid solution with a concentration of 10g / L, according to the molar ratio of tungsten to 2:1, add hydrogen peroxide with a concentration of 28%, and stir the reaction to make tungsten form peroxytungstic acid;

[0044] (2) Then heat the solution to 50°C and pass through SO 2 , adjust the reaction time to 120 minutes until the solution becomes colorless, and tungsten is precipitated in the form of tungstic acid;

[0045] (3) Dissolve the washed tungstic acid precipitate with ammonia water to obtain ammonium tungstate solution, and then obtain APT through evaporation and crystallization, which has reached the national 0-level standard after testing;

[0046] (4) The mixed solution of sulfuric acid and p...

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Abstract

The invention relates to a method for extracting tungsten from a phosphotungstic acid / phosphotungstate solution. The method comprises following steps: (1), hydrogen peroxide is added to the phosphotungstic acid / phosphotungstate solution, and a mixed solution containing peroxo-tungstic acid is obtained; (2), tungstic acid is precipitated with a reduction reaction or a decomposition reaction, filtered and washed, and a tungstic acid precipitate and a filtrate are obtained; (3), tungstic acid is calcined, and tungsten trioxide is prepared; or, tungstic acid is dissolved in ammonia water, an ammonium tungstate solution is prepared, and APT (ammonium paratungstate) is prepared through evaporative crystallization; (4), the filtrate returns to the phosphotungstic acid / phosphotungstate solution for recycling. According to the method, existence forms and characteristics of various species in a mixed acid solution system are taken into consideration, and tungsten obtained through extraction can be directly used for preparing tungsten products; the method has the advantages of good separation effect, simple and easily controlled operation process and easiness in industrial popularization and application.

Description

technical field [0001] The invention relates to the field of rare metal metallurgy, in particular to the technical method of extracting tungsten. Background technique [0002] With the continuous mining and utilization of high-quality wolframite resources, its reserves and grades are decreasing day by day, and complex scheelite is becoming the main tungsten ore resource. However, the endowment of scheelite resources in my country is poor. In order to cleanly and efficiently process complex scheelite resources, Central South University has developed the "Synergy Decomposition Technology of Tungsten Ore with Sulphur-Phosphorus Mixed Acid System". The tungsten can be efficiently leached, and the tungsten content in the decomposition slag can be reduced to less than 0.5%. Since the sulfur-phosphorus mixed acid leaching system is used, the composition of the obtained leach solution is complex, and tungsten exists in the form of phosphotungstic heteropolyacid. Generally, 1 mole of...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G41/00
CPCC01G41/00
Inventor 陈星宇赵中伟
Owner CENT SOUTH UNIV
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