Method of preparing phosphotungstic acid from sodium tungstate as raw material

A technology of phosphotungstic acid and sodium tungstate, which is applied in the preparation of tungsten compounds, chemical instruments and methods, tungsten compounds, etc., can solve the problems of reducing production costs, and achieve the effects of efficient extraction, environmental friendliness, and short process

Active Publication Date: 2017-01-18
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0013] The technical problem to be solved by the present invention is how to reduce the production cost in the preparation of phosphotungstic acid with sodium tungstate as raw material, simplify the process steps, achieve green and pollution-free, and provide a new method for preparing phosphotungstic acid with sodium tungstate as raw material method

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Dissolve sodium tungstate in water, then add phosphoric acid and hydrochloric acid to generate a mixed aqueous solution containing phosphotungstic acid, in which tungsten trioxide is 100g / L, phosphorus is 20g / L, and hydrochloric acid is 2.5mol / L. Use 15% 2-octanol as the extractant, and the diluent is sulfonated kerosene, and then carry out four-stage countercurrent extraction, the volume ratio of the two phases is O / A (oil phase / water phase) = 1:1, and the loaded organic phase is obtained; The loaded organic phase uses distilled water as the stripping reagent to perform five-stage countercurrent stripping, and the volume ratio of the two phases O / A (oil phase / water phase)=5:1. The concentration of tungsten trioxide in the stripping solution is 479.4g / L, and white phosphotungstic acid crystals are obtained by evaporation and crystallization. Calculated based on the concentration of tungsten trioxide obtained from the back-extraction solution, the yield can reach 95.9%. ...

Embodiment 2

[0033] Dissolve sodium tungstate in water, then add sodium phosphate and sulfuric acid to generate a mixed aqueous solution containing phosphotungstic acid, in which tungsten trioxide is 10g / L, phosphorus is 10g / L, and sulfuric acid is 4mol / L. Use 10% nonanol as the extractant, and the diluent is sulfonated kerosene, and then carry out four-stage countercurrent extraction, the volume ratio of the two phases is O / A=1:5, to obtain the loaded organic phase; the loaded organic phase is back-extracted with distilled water Reagents are subjected to five-stage countercurrent back extraction, and the volume ratio of the two phases is O / A=10:1. The concentration of tungsten trioxide in the stripping solution was 384.4g / L, and it was spray-dried to obtain white phosphotungstic acid crystals. Calculated on the basis of the concentration of tungsten trioxide obtained in the stripping solution, the yield is up to 76.9%.

Embodiment 3

[0035] Dissolve sodium tungstate in water, then add calcium phosphate and nitric acid to generate a mixed aqueous solution containing phosphotungstic acid, in which tungsten trioxide is 80g / L, phosphorus is 50g / L, and nitric acid is 3mol / L. Use 50% decanol as the extractant, and the diluent is sulfonated kerosene, then carry out five-stage countercurrent extraction, the volume ratio of the two phases is O / A=1:1, to obtain the loaded organic phase; the loaded organic phase is back-extracted with distilled water Reagents are subjected to five-stage countercurrent back extraction, and the volume ratio of the two phases is O / A=1:1. The concentration of tungsten trioxide in the stripping solution is 76.3g / L, and high-purity white phosphotungstic acid crystals are obtained by evaporation and crystallization. Calculated on the basis of the concentration of tungsten trioxide obtained in the stripping solution, the yield is up to 95.4%.

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Abstract

The invention belongs to the technical field of heteropolyacid preparation, and particularly relates to a preparing method of sodium tungstate. Industrial sodium tungstate crystal is used as the raw material, an alcohol extraction agent is used for extracting to obtain a phosphotungstic acid water solution, phosphotungstic acid crystal can be obtained through evaporative crystallization or spray drying, organic phase and raffinate obtained after reverse extraction can be returned and used directly, and the process of organic phase regeneration is avoided. The method is short in process flow, low in manufacturing cost, high in product yield, environmentally friendly and capable of achieving large-scale industrial production.

Description

technical field [0001] The invention relates to the technical field of chemical industry, and more specifically relates to a method for preparing phosphotungstic acid from sodium tungstate. Background technique [0002] The heteropoly acid of Keggin structure generally refers to the inorganic compound expressed by the following general chemical formula: HxYZ 12 o 40 ·nH 2 O, where Y represents atoms such as P and Si, which are called central atoms or heteroatoms; Z represents atoms such as Mo and W, which become polyatoms; x is 3 or 4; n is a positive integer of 0-30. [0003] Heteropolyacids are one of the most active catalysts used in acid-catalyzed reactions and redox reactions. It has good catalytic performance for the hydration and esterification of olefins, the etherification of epoxides, the condensation of olefins and aldehydes, the alkylation of olefins, the epoxidation of olefins, and the aromatication of alkylenes. In addition, as a catalyst, heteropolyacid ha...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G41/00
CPCC01G41/003
Inventor 李永立赵中伟刘旭恒陈星宇李江涛
Owner CENT SOUTH UNIV
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