Wet-method phosphoric acid staged extraction and purification process

A wet-process phosphoric acid and purification process technology, applied in the fields of phosphorus compounds, inorganic chemistry, chemical instruments and methods, etc., can solve the problems of poor adaptability of wet-process phosphoric acid raw material diversity, difficult comprehensive cost of phosphorus resource conversion, etc. The effect of comprehensive purification rate and cost reduction

Active Publication Date: 2012-12-12
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Various existing wet-process phosphoric acid extraction and purification processes are aimed at specific grades of wet-process phosphoric acid raw materials, and use a certain extractant to produce phosphoric acid products of specific specifications. This situation causes a relatively prominent contradiction between the purification acid yield and purification cost , the ability to adapt to the diversity of wet-process phosphoric acid raw materials is relatively poor, which makes it difficult to further optimize the product structure and reduce the comprehensive cost of phosphorus resource conversion

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] (1) At a temperature of 50°C, according to methyl isobutyl ketone and P 2 o 5 Concentration is 50wt% wet-process phosphoric acid mass ratio is the ratio extraction wet-process phosphoric acid of 8:1, obtains loaded methyl isobutyl ketone and primary raffinate after phase separation;

[0018] (2) At a temperature of 50°C, use a mixed solvent of tributyl phosphate and n-butanol at a volume ratio of 3:1 to extract the primary raffinate obtained in step (1), the mixed solvent and a The volume ratio of grade raffinate is 10:1;

[0019] (3) Methyl isobutyl ketone loaded with phosphoric acid further removes sulfate radical impurities by adding barium carbonate aqueous solution, and then further removes metal impurities through washing and back extraction with water, so as to obtain phosphoric acid aqueous solution; the obtained phosphoric acid aqueous solution is adsorbed Further remove impurities such as fluorine and arsenic, and then prepare food-grade phosphoric acid prod...

Embodiment 2

[0024] (1) At a temperature of 40°C, according to methyl isobutyl ketone and P 2 o 5 The mass ratio of wet-process phosphoric acid with a concentration of 55wt% is 6:1 to extract wet-process phosphoric acid, and obtain loaded methyl isobutyl ketone and primary raffinate after phase separation;

[0025] (2) At a temperature of 40°C, use a mixed solvent of tributyl phosphate and n-hexane with a volume ratio of 5:1 to extract the primary raffinate obtained in step (1), the mixed solvent and the primary The volume ratio of raffinate is 5:1;

[0026] (3) Methyl isobutyl ketone loaded with phosphoric acid further removes sulfate radical impurities by adding barium carbonate aqueous solution, and then further removes metal impurities through washing and back extraction with water, so as to obtain phosphoric acid aqueous solution; the obtained phosphoric acid aqueous solution is adsorbed Further remove impurities such as fluorine and arsenic, and then prepare food-grade phosphoric a...

Embodiment 3

[0031] (1) At a temperature of 30°C, according to methyl isobutyl ketone and P 2 o 5 Concentration is 60wt% wet-process phosphoric acid mass ratio is the ratio of 3:1 to extract wet-process phosphoric acid, obtain loaded methyl isobutyl ketone and primary raffinate after phase separation;

[0032] (2) At a temperature of 30°C, extract the primary raffinate obtained in step (1) with a mixed solvent of tributyl phosphate and cyclohexane with a volume ratio of 10:1, the mixed solvent and a The volume ratio of grade raffinate is 2:1;

[0033] (3) Methyl isobutyl ketone loaded with phosphoric acid further removes sulfate radical impurities by adding barium carbonate aqueous solution, and then further removes metal impurities through washing and back extraction with water, so as to obtain phosphoric acid aqueous solution; the obtained phosphoric acid aqueous solution is adsorbed Further remove impurities such as fluorine and arsenic, and then prepare food-grade phosphoric acid pro...

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Abstract

The invention relates to a wet-method phosphoric acid staged extraction and purification process, and belongs to the technical field of chemical engineering separation. According to the process, wet-method phosphoric acid with a P2O5 concentration of 50-65 wt% is extracted by using methyl isobutyl ketone; a first-level raffinate acid obtained through phase separation is extracted by using another solvent A; and phosphoric-acid-loaded methyl isobutyl ketone and phosphoric-acid-loaded solvent A are respectively subjected to back extraction for producing phosphoric acid and phosphate products, and are regenerated. The solvent A is a mixed solution of tributyl phosphate and a diluent. The diluent is selected from n-butanol, kerosene, n-hexane, and cyclohexane. According to the process provided by the invention, different solvents are adopted in different stages, such that the solvents can be used in extractions within appropriate P2O5 ranges thereof, and advantages in separation capacities or purification capacities are performed. Therefore, co-productions of phosphoric acid and phosphate products of different quality levels are realized. The cost in upgrading phosphorus resource values is reduced, wet-method phosphoric acid purification rate is improved, and conditions are provided for flexibly arranging productions according to resource status and market demands.

Description

technical field [0001] The invention belongs to the technical field of chemical separation, and in particular relates to a step-by-step extraction and purification process of wet-process phosphoric acid. Background technique [0002] Phosphoric acid and phosphates are widely used in chemical, agricultural, daily chemical, electronics, food and other industries. The production methods of phosphoric acid mainly include thermal method and wet method, and the reaction between phosphoric acid and corresponding alkali is the main method for preparing phosphate. Compared with thermal phosphoric acid reduced by an electric furnace, wet-process phosphoric acid has obvious cost advantages and less environmental impact due to low energy consumption. However, since wet-process phosphoric acid comes from the crude phosphoric acid obtained by decomposing phosphate rock with inorganic acid (mainly sulfuric acid), the impurities in it are high and complex (including sulfate, fluoride ion, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B25/46
Inventor 吕阳成骆广生
Owner TSINGHUA UNIV
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