A kind of production method of α-high-strength gypsum powder

Abstract

The invention relates to a production method of alpha-gypsum powder with high strength. The production method comprises the following steps: (1) mixing phosphogypsum with a dry basis mass content larger than or equal to 95% with water to prepare slurry; (2) adding a crystal modifier in the slurry, and transforming the crystal under the conditions of the temperature of 115-130 DEG C and the pressure of 0.2-0.55 Mpa; (3) dehydrating until the free water mass content is smaller than or equal to 15%, and drying the material at the temperature of 135-150 DEG C, purifying the exhaust gas generated during the drying process, removing the dust, discharging the water vapor after purification and dust removal to the air, after the dust is collected, entering the step (4) to crush and modify the dried material in the step (4); (4) crushing and modifying the dried material, controlling the particle size range after crushing to be 75-125 microns, and screening the material to obtain the alpha-gypsum powder with the high strength and different particle sizes. The production method disclosed by the invention solves the waste discharge problem, protects the environment, implements comprehensive utilization of the resource, is simple in technology, high in strength of the alpha-gypsum powder, and good in quality.

Description

technical field

[0001] The invention belongs to the fields of modeling gelling material production and environmental treatment, and relates to a method for producing α-high-strength gypsum powder with phosphogypsum. Background technique

[0002] High-strength gypsum powder has high strength (up to 40MPa in 7 days) and compactness, so it is called high-strength gypsum. High-strength gypsum powder should be made of high-grade gypsum raw materials. At present, natural gypsum with a dihydrate gypsum content of more than 85% is mainly used as raw materials. In order to realize the comprehensive utilization of resources and reduce environmental pollution, the country has gradually begun to use desulfurization gypsum, citric acid waste residue or phosphogypsum and other industrial by-products to produce α-high-strength gypsum powder. However, the impurities contained in phosphogypsum have a great adverse effect on the formation and index of hemihydrate gypsum, and it is difficult ...

Examples

Embodiment 1

[0036] A kind of production method of α-high-strength gypsum powder, the steps are as follows:

[0037] (1) Mix 5 tons of phosphogypsum with a mass content of 96% on a dry basis with water to obtain a solid material with a specific gravity of 1200kg / m 3 slurry;

[0038] (2) Add 250 g of a crystal-transforming agent to the slurry prepared in step (1) at one time, and conduct crystal-transforming for 1.5 hours at 115° C. and 0.2 MPa. The described crystal-transforming agent is citrate;

[0039] The heating method is to heat the heat transfer oil with high-pressure steam first, and then use the heated heat transfer oil to heat the slurry;

[0040] During the crystal transformation process, the pressure is adjusted by adding compressed air;

[0041] (3) Remove the material obtained in step (2) to a free water mass content of ≤15%, and dry it at 140° C. for 1 hour; purify and dedust the tail gas generated during the drying process, and discharge the purified and dedusted water va...

Embodiment 2

[0046] A kind of production method of α-high-strength gypsum powder, the steps are as follows:

[0047] (1) Mix 5 tons of phosphogypsum with a mass content of 95% on a dry basis with water to obtain a solid material with a specific gravity of 1250kg / m 3 slurry;

[0048] (2) Add 500 g of a crystal-transforming agent to the slurry prepared in step (1), and conduct crystal-transforming for 1.8 hours at 118° C. and 0.3 MPa. The described crystal-transforming agent is an alkyl sulfonate;

[0049] The heating method is to heat the heat transfer oil with high-pressure steam first, and then use the heated heat transfer oil to heat the slurry;

[0050] During the crystal transformation process, the pressure is adjusted by adding compressed air;

[0051]The addition method of the crystal transformation agent is added through the pump according to the crystal transformation situation, and can be adjusted in real time;

[0052] (3) Remove the material obtained in step (2) to a free wat...

Embodiment 3

[0057] A kind of production method of α-high-strength gypsum powder, the steps are as follows:

[0058] (1) Mix 5 tons of phosphogypsum with a mass content of 95% on a dry basis with water to obtain a solid material with a specific gravity of 1300kg / m 3 slurry;

[0059] (2) Add 750 g of a crystal-transforming agent to the slurry prepared in step (1) at one time, and conduct crystal-transforming for 2 hours at 122° C. and 0.4 MPa. The described crystal-transforming agent is an alkyl sulfonate;

[0060] The heating method is to heat the heat transfer oil with high-pressure steam first, and then use the heated heat transfer oil to heat the slurry;

[0061] During the crystal transformation process, the pressure is adjusted by adding compressed air;

[0062] (3) Remove the material obtained in step (2) to a free water mass content of ≤15%, and dry it at 145° C. for 1 hour; purify and dedust the tail gas generated during the drying process, and discharge the purified and dedusted...

technical field

[0001] The invention belongs to the fields of modeling gelling material production and environmental treatment, and relates to a method for producing α-high-strength gypsum powder with phosphogypsum. Background technique

[0002] High-strength gypsum powder has high strength (up to 40MPa in 7 days) and compactness, so it is called high-strength gypsum. High-strength gypsum powder should be made of high-grade gypsum raw materials. At present, natural gypsum with a dihydrate gypsum content of more than 85% is mainly used as raw materials. In order to realize the comprehensive utilization of resources and reduce environmental pollution, the country has gradually begun to use desulfurization gypsum, citric acid waste residue or phosphogypsum and other industrial by-products to produce α-high-strength gypsum powder. However, the impurities contained in phosphogypsum have a great adverse effect on the formation and index of hemihydrate gypsum, and it is difficult ...

Examples

Embodiment 1

[0036] A kind of production method of α-high-strength gypsum powder, the steps are as follows:

[0037] (1) Mix 5 tons of phosphogypsum with a mass content of 96% on a dry basis with water to obtain a solid material with a specific gravity of 1200kg / m 3 slurry;

[0038] (2) Add 250 g of a crystal-transforming agent to the slurry prepared in step (1) at one time, and conduct crystal-transforming for 1.5 hours at 115° C. and 0.2 MPa. The described crystal-transforming agent is citrate;

[0039] The heating method is to heat the heat transfer oil with high-pressure steam first, and then use the heated heat transfer oil to heat the slurry;

[0040] During the crystal transformation process, the pressure is adjusted by adding compressed air;

[0041] (3) Remove the material obtained in step (2) to a free water mass content of ≤15%, and dry it at 140° C. for 1 hour; purify and dedust the tail gas generated during the drying process, and discharge the purified and dedusted water va...

Embodiment 2

[0046] A kind of production method of α-high-strength gypsum powder, the steps are as follows:

[0047] (1) Mix 5 tons of phosphogypsum with a mass content of 95% on a dry basis with water to obtain a solid material with a specific gravity of 1250kg / m 3 slurry;

[0048] (2) Add 500 g of a crystal-transforming agent to the slurry prepared in step (1), and conduct crystal-transforming for 1.8 hours at 118° C. and 0.3 MPa. The described crystal-transforming agent is an alkyl sulfonate;

[0049] The heating method is to heat the heat transfer oil with high-pressure steam first, and then use the heated heat transfer oil to heat the slurry;

[0050] During the crystal transformation process, the pressure is adjusted by adding compressed air;

[0051]The addition method of the crystal transformation agent is added through the pump according to the crystal transformation situation, and can be adjusted in real time;

[0052] (3) Remove the material obtained in step (2) to a free wat...

Embodiment 3

[0057] A kind of production method of α-high-strength gypsum powder, the steps are as follows:

[0058] (1) Mix 5 tons of phosphogypsum with a mass content of 95% on a dry basis with water to obtain a solid material with a specific gravity of 1300kg / m 3 slurry;

[0059] (2) Add 750 g of a crystal-transforming agent to the slurry prepared in step (1) at one time, and conduct crystal-transforming for 2 hours at 122° C. and 0.4 MPa. The described crystal-transforming agent is an alkyl sulfonate;

[0060] The heating method is to heat the heat transfer oil with high-pressure steam first, and then use the heated heat transfer oil to heat the slurry;

[0061] During the crystal transformation process, the pressure is adjusted by adding compressed air;

[0062] (3) Remove the material obtained in step (2) to a free water mass content of ≤15%, and dry it at 145° C. for 1 hour; purify and dedust the tail gas generated during the drying process, and discharge the purified and dedusted...

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