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New method for decolorizing and whitening phosphogypsum

A phosphogypsum, a new method of technology, applied in the direction of calcium/strontium/barium sulfate, etc., can solve the problems of phosphogypsum decolorization and whitening that are rarely reported in literature, and achieve good whitening effect, simple operation process and low operation cost Effect

Inactive Publication Date: 2013-02-13
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] At present, there are few literature reports on the decolorization and whitening of phosphogypsum

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] The method for the decolorization and whitening of phosphogypsum in the present embodiment is to operate as follows:

[0020] a. Calcination

[0021] Weigh 20 g of ground phosphogypsum into a calcined crucible, place it in a muffle furnace at 550° C., calcinate at a high temperature for 60 min, cool down, and set aside.

[0022] b. Pickling

[0023] Weigh 10g of the calcined phosphogypsum obtained in step a into a single-necked flask, add 40g of 30wt% sulfuric acid solution, keep the temperature at 90°C, stir and react for 180min, after the reaction is completed, filter and separate, wash, dry, and grind to obtain decolorization and whitening treatment After the phosphogypsum sample was tested, its whiteness was measured to be 87.1%.

Embodiment 2

[0025] The method for the decolorization and whitening of phosphogypsum in the present embodiment is to operate as follows:

[0026] a. Calcination

[0027] Weigh 20g of the ground phosphogypsum into a calcining crucible, place it in a muffle furnace at 400°C, calcinate at a high temperature for 40min, cool down, and set aside.

[0028] b. Pickling

[0029] Weigh 10g of the calcined phosphogypsum obtained in step a into a single-necked flask, add 40g of 35wt% hydrochloric acid solution, keep the temperature at 85°C, stir and react for 150min, after the reaction is completed, filter and separate, wash, dry, and grind to obtain decolorization and whitening treatment After the phosphogypsum sample was tested, its whiteness was 79.8%.

Embodiment 3

[0031] The method for the decolorization and whitening of phosphogypsum in the present embodiment is to operate as follows:

[0032] a. Calcination

[0033] Weigh 20 g of ground phosphogypsum into a calcining crucible, place it in a muffle furnace at 650° C., calcinate at high temperature for 70 min, cool down, and set aside.

[0034] b. Pickling

[0035] Weigh 10g of the calcined phosphogypsum obtained in step a into a single-necked flask, add 40g of 25wt% nitric acid solution, keep the temperature at 90°C, stir and react for 120min, after the reaction is completed, filter and separate, wash, dry, and grind to obtain decolorization and whitening treatment After testing the phosphogypsum sample, its whiteness was measured to be 81.9%.

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Abstract

The invention discloses method for decolorizing and whitening phosphogypsum. The method comprises the following steps: firstly, removing the organic impurities in the phosphogypsum through a calcination process under a suitable condition; secondly, carrying out decolorizing and whitening to the phosphogypsum by taking sulfuric acid and hydrochloric acid as pickling agents; and finally, carrying out filtering, washing and drying to obtain a whitened phosphogypsum sample. The method has the characteristics of simple operating process, low operating cost and good whitening effect, and opens a new way to the large-scale industrialized treatment and comprehensive utilization of discarded phosphogypsum.

Description

1. Technical field [0001] The invention relates to the comprehensive utilization of industrial by-product phosphogypsum waste residue, in particular to a new method for decolorization and whitening of phosphogypsum. 2. Background technology [0002] Phosphogypsum is the solid waste produced in the production process of wet-process phosphoric acid. It takes about 2 tons of sulfuric acid to produce 1 ton of phosphoric acid and produces 4-5 tons of phosphogypsum at the same time. The annual discharge of phosphogypsum in my country's phosphorus chemical industry is about 50 million tons. During the "Eleventh Five-Year Plan" period, the average comprehensive utilization rate of phosphogypsum in domestic enterprises was only 20%, and a considerable amount of phosphogypsum was still disposed of in the form of direct stacking, which not only occupied a large amount of land resources, but also brought heavy burdens to production enterprises. Therefore, from the perspective of environme...

Claims

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Application Information

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IPC IPC(8): C01F11/46
Inventor 王百年师梦杨保俊董晓祥
Owner HEFEI UNIV OF TECH
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