Method for recycling ardealite

A phosphogypsum and action time technology, which is applied in the field of phosphogypsum recycling and reuse, can solve the problems of corrosiveness of structural materials, prolonged gypsum solidification time, unsatisfactory actual effect, etc., and achieves environmental protection, simple and effective implementation, and good waste. The effect of the recycling effect

Inactive Publication Date: 2015-06-24
WEIFANG UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, the comprehensive utilization technologies of phosphogypsum mainly include building material product technology, cement co-production of sulfuric acid and cement retarder technology, etc., because these technologies contain free sulfuric acid, phosphoric acid and hydrofluoric acid in phosphogypsum, they will make plaster for Buildings are corrosive to structural materials, or corrode the models and equipment for making gypsum prefabricated parts, and at the same time prolong the setting time of gypsum, the actual effect is not ideal
Phosphogypsum can be used as a cement retarder after a little treatment, and it can also be used as a building block or brick, but the amount is limited, and it is difficult to fundamentally solve the accumulation of phosphogypsum

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Embodiment 1: a method for recycling phosphogypsum, comprising the following steps:

[0024] (1) Preparation of phosphogypsum slurry: 200kg of phosphogypsum containing 0.45% of rare earth elements and water were mixed in a ratio of 1:3, stirred, left standing for 0.2h, and mixed with 0.08% of grinding aid relative to the total amount of the mixture, The grinding aid is polymerized polyol, and adding a small amount of grinding aid can prevent particle agglomeration and improve material fluidity, thereby improving ball milling efficiency, shortening the grinding time, and then ball milling with a ball mill to make phosphogypsum slurry;

[0025] (2) Leach solid phosphorus: process phosphogypsum slurry with 3.5% sulfuric acid solution, by weight, the ratio between the added sulfuric acid and phosphogypsum slurry is 1:3.2, the temperature is controlled at 28°C, and stirred for 0.4 hours, Stand still for 3 hours to leach solid phosphorus, the solid phosphorus phase is separat...

Embodiment 2

[0033] Embodiment 2: a method for recycling phosphogypsum, comprising the following steps:

[0034] (1) Preparation of phosphogypsum slurry: 200kg of phosphogypsum containing 0.45% of rare earth elements and water were mixed in a ratio of 1:4, stirred, left standing for 0.35h, and mixed with 0.1% grinding aid relative to the total amount of the mixture, The grinding aid is polymerized polyol, and adding a small amount of grinding aid can prevent particle agglomeration and improve material fluidity, thereby improving ball milling efficiency, shortening the grinding time, and then ball milling with a ball mill to make phosphogypsum slurry;

[0035] (2) Leach solid phosphorus: process the phosphogypsum slurry with 4.85% sulfuric acid solution, by weight, the ratio between the sulfuric acid added and the phosphogypsum slurry is 1:3.6, the temperature is controlled at 31 ° C, and the stirring process is carried out for 0.5 hours, Stand still for 4 hours to leach solid phosphorus, t...

Embodiment 3

[0043] Embodiment 3: a method for recycling phosphogypsum, comprising the following steps:

[0044] (1) Preparation of phosphogypsum slurry: 200kg of phosphogypsum containing 0.45% of rare earth elements and water were mixed in a ratio of 1:5, stirred, left standing for 0.5h, and mixed with 0.12% of grinding aid relative to the total amount of the mixture, The grinding aid is polymerized polyol, and adding a small amount of grinding aid can prevent particle agglomeration and improve material fluidity, thereby improving ball milling efficiency, shortening the grinding time, and then ball milling with a ball mill to make phosphogypsum slurry;

[0045] (2) leaching of solid phosphorus: process phosphogypsum slurry with 6.2% sulfuric acid solution, by weight, the ratio between the added sulfuric acid and phosphogypsum slurry is 1:4.0, the temperature is controlled at 34 ° C, and stirred for 0.6 hours, Stand still for 5 hours to leach solid phosphorus, the solid phosphorus phase is...

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Abstract

The invention discloses a method for recycling ardealite. The method comprises the following steps: (1) doping water and a grinding aid into ardealite to prepare ardealite slurry; (2) treating the ardealite slurry by using a 3.5-6.2% sulfuric acid solution to leach out solid phosphorus; (3) treating the ardealite slurry treated in the step (2) by using an 8-10% of sulfuric acid solution to leach out rare earth metals; (4) adjusting the pH value by using sulfuric acid, adsorbing the rare earth metals by using a cation exchanger, and performing desorption by using a desorption agent; (5) precipitating the rare earth metals from the solution by using oxalic acid; (6) rinsing, drying and roasting insoluble compounds of the rare earth metals; (7) performing a method of recycle leaching; and (8) performing separation by crystallization on calcium sulfate in a secondary mother solution in the step (3), and washing and drying. According to the method disclosed by the invention, phosphorus, rare earth metals and calcium sulfate in ardealite are leached out by stages, the leaching rate is high, the purity is high, the whole technological process is stable, the implementation manner is simple and effective, and the utilization ratio of resources is greatly improved.

Description

technical field [0001] The invention relates to the technical field of chemical waste recycling and environmental protection, in particular to a method for recycling phosphogypsum. Background technique [0002] Phosphogypsum waste residue is mainly produced in the phosphorus chemical industry (phosphate fertilizer) industry. It is an industrial by-product gypsum produced in the production of high-concentration phosphorus compound fertilizer. The main component of phosphogypsum is CaSO4 2H2O, with a pH value of about 1.5 to 4.5, which is acidic , the water content is very high, and the free water contained can reach 20%-25%. Studies have shown that the concentration of inorganic fluoride (excluding calcium fluoride) in the phosphogypsum solid waste of enterprises using wet slag transportation is greater than 100mg / L, which exceeds the "Leach Toxicity Identification of Hazardous Waste Identification Standards" (GB5085.3 -2007), it belongs to hazardous waste. In 2006, the Stat...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F11/46
CPCC01B25/02C01F11/468C01F17/206C01P2006/80
Inventor 台夕市李法辉张运臣
Owner WEIFANG UNIVERSITY
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