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A pretreatment method for shortening the setting time of phosphogypsum used in the production of paper-faced gypsum board

A paper-faced gypsum board and setting time technology, applied in the field of phosphogypsum processing, can solve the problems of long setting time of beta gypsum, difficult quality assurance, substandard strength of finished products, etc., and achieve the effects of easy promotion, low cost and simple reaction conditions

Active Publication Date: 2021-04-27
YUNNAN PHOSPHATE CHEM GROUP CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a pretreatment method for shortening the coagulation time of phosphogypsum used in the production of gypsum boards to solve the problem of condensation of β gypsum in the production of gypsum boards due to the presence of water-soluble phosphorus, fluorine and organic matter in phosphogypsum The time is long, the strength of the finished product is not up to the standard, and the quality is difficult to guarantee

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Take 100g of phosphogypsum, dry it at 70°C for 24 hours, grind it, dry it at 160°C for 2 hours, and prepare β-gypsum. The initial setting time is 9'23", and the final setting time is 15'37". Meet the requirements of GB / T 9775-2008 for plasterboard. When the phosphogypsum is pretreated without adding additives, its setting time is long.

Embodiment 2

[0025] Take 100 g of phosphogypsum, add 0.1 g of concentrated sulfuric acid, stir for 10 min, then add 0.1 g of potassium sulfate, and stir for 10 min to obtain mixture a. Then the mixture a was dried at 70° C. for 24 hours and then pulverized, and the particle size of the pulverized mixture b was ≤480 mesh. The mixture b was then dried at 160°C for 2 hours to prepare β-gypsum. The initial setting time was 5′43″ and the final setting time was 8′15″, meeting the requirements of GB / T 9775-2008 for paper-faced gypsum boards.

Embodiment 3

[0027] Take 100 g of phosphogypsum, add 2.5 g of concentrated sulfuric acid, stir for 11 min, then add 2.5 g of potassium sulfate, and stir for 12.5 min to obtain mixture a. Then the mixture a was dried at 70° C. for 24 hours and then pulverized, and the particle size of the pulverized mixture b was ≤450 mesh. The mixture b was then dried at 160°C for 2 hours to prepare β-gypsum. The initial setting time was measured as 4′21″ and the final setting time was 6′32″, which met the requirements of GB / T 9775-2008 for paper-faced gypsum boards.

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Abstract

The invention discloses a pretreatment method for shortening the setting time of phosphogypsum used in the production of paper-faced gypsum boards, and relates to the technical field of phosphogypsum processing. The method comprises the following steps: adding additives to phosphogypsum, stirring evenly to obtain a mixture a; drying the mixture a at 70° C. for 24 hours, and grinding after drying to obtain a mixture b; drying the mixture b at 160 Dry at ℃ for 2 hours to obtain β-gypsum for the production of gypsum boards. The auxiliary agent is composed of two raw materials, one of which is 98% concentrated sulfuric acid, and the other is one or two of sodium sulfate, calcium chloride, and potassium sulfate; the total amount of raw materials added is 0.2% of the mass of phosphogypsum 5%. Use concentrated sulfuric acid to carbonize organic matter in phosphogypsum, use one or two of sodium sulfate, calcium chloride, and potassium sulfate to solidify water-soluble phosphorus and water-soluble fluorine, so that the setting time in the production of plasterboard is greatly shortened . The method has simple reaction conditions, short technological process, and is easy to popularize; the amount of additives added is small, and the cost is low.

Description

technical field [0001] The invention relates to the technical field of phosphogypsum processing, in particular to a pretreatment method for shortening the setting time of phosphogypsum used in the production of paper-faced gypsum boards. Background technique [0002] The main component of phosphogypsum is calcium sulfate dihydrate, which is a by-product of the wet-process phosphoric acid production process. At present, nearly 50 million tons of phosphogypsum are newly stockpiled in my country every year, and the utilization rate in 2018 only reached 39.7%. The current total stockpile exceeds 300 million tons. It is also getting bigger and bigger. In addition to environmental problems such as phosphogypsum pollution that have been exposed in recent years, the country has paid more and more attention to the use of phosphogypsum. In areas where the phosphorus chemical industry is developed, the policy of "determining production according to use" has been introduced. Ensure the e...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B11/036C04B11/26C04B11/024
CPCC04B11/024C04B11/036C04B11/26
Inventor 龚丽何宾宾魏立军姜威欧志兵周琼波彭桦牛司江
Owner YUNNAN PHOSPHATE CHEM GROUP CORP