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Method and apparatus for preparing high strength gypsum by using phosphogypsum

A technology of high-strength gypsum and phosphogypsum, applied in chemical instruments and methods, inorganic chemistry, calcium/strontium/barium compounds, etc., can solve the problems of human living environment hazards, low comprehensive utilization rate, soil and air pollution, etc., and achieve the reaction conditions The effect of easy realization, excellent product quality and simple process

Inactive Publication Date: 2017-03-22
HUBEI YIHUA GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, the annual discharge of phosphogypsum in my country is 50 million tons, which is basically treated by stockpiling. At present, the cumulative stockpiling exceeds 200 million tons, and the comprehensive utilization rate is less than 10%. At present, most of the phosphogypsum is stacked in the open air, occupying a large area of ​​land. and soluble P 2 o 5 and F ˉ And so on with the rain leaching. Produce acidic wastewater, causing serious pollution of soil, water system, and atmosphere, and causing harm to human living environment

Method used

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  • Method and apparatus for preparing high strength gypsum by using phosphogypsum

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Embodiment 1

[0021] Embodiment 1: a kind of method adopting phosphogypsum to prepare high-strength gypsum, concrete steps are:

[0022] 1) Wash the phosphogypsum with 2% urea solution and then filter, wherein the mass ratio of urea to phosphogypsum is 1:10, and then wash and filter with clean water several times;

[0023] 2) Add water to the phosphogypsum obtained in step 1), control the solid-to-liquid mass ratio at 1:3, then add a crystal modifier with a mass of 0.09% of the phosphogypsum, and react at 95-98°C for 4 hours, and then within 10 minutes Filtering and washing, the temperature of the water used for washing is controlled at 70-80°C; after filtering and washing, the water content of the material is below 15wt%, and the chloride ion content is below 0.5wt%; the obtained material is dried at 70-100°C , the time is controlled within 30 minutes, and finally high-strength gypsum is obtained.

[0024] Among them, the purity is 90%, the initial setting time is 4 minutes, the final set...

Embodiment 2

[0026] A method for preparing high-strength gypsum by using phosphogypsum, the specific steps are:

[0027] 1) Wash the phosphogypsum with urea solution with a mass concentration of 8% and then filter, wherein the mass ratio of urea to phosphogypsum is 1:8, and then wash and filter with clean water several times;

[0028] 2) Add water to the phosphogypsum obtained in step 1), control the solid-liquid mass ratio at 1:4, then add a crystal modifier with 0.15% of the mass of phosphogypsum, react at 95-98°C for 6 hours, and then within 10min Filtering and washing, the temperature of the water used for washing is controlled at 80-90°C; after filtering and washing, the water content of the material is below 15wt%, and the chloride ion content is below 0.5wt%; the obtained material is dried at 70-100°C , the time is controlled within 30 minutes, and finally high-strength gypsum is obtained.

[0029] Among them, the purity is 95%, the initial setting time is 4 minutes, the final sett...

Embodiment 3

[0031] A method for preparing high-strength gypsum by using phosphogypsum, the specific steps are:

[0032] 1) Wash and filter the phosphogypsum with 5% urea solution, and then wash and filter with water for several times;

[0033] 2) Add water to the phosphogypsum obtained in step 1), control the solid-liquid mass ratio at 1:2, then add a crystal modifier with 0.10% of the mass of phosphogypsum, react at 95-98°C for 4.5 hours, and then within 10min Filtering and washing, the temperature of the water used for washing is controlled at 70-90°C; after filtering and washing, the water content of the material is below 15wt%, and the chloride ion content is below 0.5wt%; the obtained material is dried at 70-100°C , the time is controlled within 30 minutes, and finally high-strength gypsum is obtained.

[0034] Among them, the purity is 88%, the initial setting time is 3 minutes, the final setting time is 30 minutes, the 2-hour flexural strength is 4 MPa, and the absolute dry compre...

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Abstract

The invention discloses a method and an apparatus for preparing high strength gypsum by using phosphogypsum. The method comprises: carrying out washing filtration on phosphogypsum by using a urea solution, carrying out washing filtration with clear water, adding water to the phosphogypsum, controlling a solid-liquid mass ratio at 1:2-4, carrying out a reaction for 4-6 h at a temperature of 95-98 DEG C, and filtering and washing within 10 min, wherein the temperature of the water for the washing is controlled at 70-90 DEG C; after the filtering and the washing, making the water content of the material less than 15 wt% and the chlorine ion content of less than 0.5 wt%; and drying the obtained material at a temperature of 70-100 DEG C and controlling the time within 30 min to finally obtain the high strength gypsum. According to the present invention, the process is simple, the equipment investment is low, the reaction conditions are easy to achieve, the production energy consumption is low, the high strength gypsum application field is expanded, and the important effects are provided for the promotion of the development in building materials, molds, and other related industries.

Description

technical field [0001] The invention belongs to the field of phosphorus chemical production, and specifically relates to a method and a device for preparing high-strength gypsum from solid waste phosphogypsum produced in the production process of phosphoric acid as a raw material. Background technique [0002] Phosphogypsum is the most important industrial by-product in the production of phosphorus chemical industry in my country, and it is the precipitate mainly composed of calcium sulfate dihydrate discharged from the production process of phosphate fertilizer enterprises. Every ton of P produced 2 o 5 It is necessary to discharge 4.5-5.5 tons of phosphogypsum, the color is gray or yellowish, the pH value is between 2 and 4, and the chemical composition is relatively complex. [0003] At present, the annual discharge of phosphogypsum in my country is 50 million tons, which is basically treated by stockpiling. At present, the cumulative stockpiling exceeds 200 million to...

Claims

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Application Information

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IPC IPC(8): C01F11/46
CPCC01F11/466C01P2006/80C01P2006/90
Inventor 张战利
Owner HUBEI YIHUA GRP CO LTD