Preparation method of phosphotungstic acid

A technology of phosphotungstic acid and tungstic acid is applied in the preparation of tungsten compounds, chemical instruments and methods, tungsten compounds, etc., to achieve the effects of easy large-scale industrial production, low preparation cost and simple process

Active Publication Date: 2017-01-04
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] The technical problem to be solved in the present invention is how to reduce the production cost in the preparation of phosphot

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Put white tungstic acid in water, then add phosphoric acid and hydrochloric acid to generate a mixed solution containing phosphotungstic acid, in which tungsten trioxide is 120g / L, phosphorus is 5g / L, and hydrochloric acid is 3mol / L. 15% n-octanol is used as the extractant, the diluent is sulfonated kerosene, and then four-stage countercurrent extraction is performed, and the ratio is O / A (oil phase / water phase) = 1:1; the loaded organic phase is back-extracted with water Reagents were subjected to five-stage countercurrent back extraction, compared to O / A (oil phase / water phase) = 5:1. The concentration of tungsten trioxide in the stripping solution is 549.6g / L, and white phosphotungstic acid crystals are obtained by evaporation and crystallization. Calculated on the basis of the concentration of tungsten trioxide obtained in the stripping liquid, the yield is up to 91.6%.

Embodiment 2

[0032] Put white tungstic acid in water, then add sodium phosphate and sulfuric acid to generate a mixed solution containing phosphotungstic acid, in which tungsten trioxide is 10g / L, phosphorus is 5g / L, and sulfuric acid is 4mol / L. 15% nonanol is used as the extractant, the diluent is sulfonated kerosene, and then four-stage countercurrent extraction is carried out, and the ratio is O / A=1:5; the loaded organic phase uses water as the stripping reagent, and five-stage countercurrent stripping is carried out , compared to O / A=10:1. The concentration of tungsten trioxide in the stripping solution was 423.5g / 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 liquid, the yield can reach 84.7%.

Embodiment 3

[0034] Put artificial scheelite (calcium tungstate) in water, then add calcium phosphate and nitric acid, and get a mixed solution containing phosphotungstic acid after reaction, in which tungsten trioxide is 100g / L, phosphorus is 40g / L, and nitric acid is 2.5mol / L . 50% decanol is used as the extractant, the diluent is sulfonated kerosene, and then five-stage countercurrent extraction is carried out, and the ratio is O / A=1:1; the loaded organic phase uses water as the stripping reagent, and five-stage countercurrent stripping is carried out , compared to O / A=1:1. The concentration of tungsten trioxide in the stripping solution is 96.3g / 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 liquid, the yield is up to 96.3%.

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Abstract

The invention belongs to the technical field of heteropolyacid preparation, and particularly relates to a preparation method of phosphotungstic acid. The method includes the steps of making white tungstic acid or artificial scheelite as the raw material react with a phosphorous compound and an inorganic acid water solution, conducting extraction through an alcohol extraction agent, directly conducting reverse extraction on a load phase through water to obtain a phosphotungstic acid water solution, and conducting evaporative crystallization or spray drying to obtain phosphotungstic acid crystals. An organic phase obtained after reverse extraction directly returns to the extraction step, and the organic phase regeneration process is not needed; raffinate can be repeatedly used after consumption acid is supplemented. The method is short in technological process, low in manufacturing cost, high in product yield, environmentally friendly and free of pollution and can be used for large-scale industrial production, and a mother solution can be recycled.

Description

technical field [0001] The invention relates to the technical field of chemical engineering, and more specifically relates to a preparation method of phosphotungstic acid. 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. 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 has the advantages of high ca...

Claims

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Application Information

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IPC IPC(8): C01G41/00B01J27/188
CPCB01J27/188C01G41/003
Inventor 赵中伟李永立
Owner CENT SOUTH UNIV
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