Method for preparing alpha semi-hydrated gypsum pulp and plaster products by desulphurizing gypsum

A technology of dihydrate gypsum and hemihydrate gypsum, which is applied in the field of gypsum products, can solve the problems of undiscovered high-strength α-type hemihydrate gypsum, and achieve the effects of eliminating the drying process, improving compressive strength, and high compressive strength

Inactive Publication Date: 2008-12-31
SOUTHEAST UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Domestic desulfurization gypsum mainly produces β-type hemihydrate gypsum (i.e. construction gypsum), the dry compressive strength is b

Method used

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  • Method for preparing alpha semi-hydrated gypsum pulp and plaster products by desulphurizing gypsum
  • Method for preparing alpha semi-hydrated gypsum pulp and plaster products by desulphurizing gypsum
  • Method for preparing alpha semi-hydrated gypsum pulp and plaster products by desulphurizing gypsum

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] A kind of α-type hemihydrate gypsum slurry is prepared with desulfurization dihydrate gypsum:

[0026] Step 1: Take the desulfurized dihydrate gypsum from the power plant, and mix the desulfurized dihydrate gypsum from the power plant with water to form a slurry. The slurry concentration is between 10% and 50%. In this embodiment, the slurry concentration is 10%. 50%, 17%, 32% or 45%, and then add a crystal form modifier to the slurry, and the crystal form modifier adopts one of the following crystal form modifiers:

[0027] ①The crystal form modifier is succinic acid, sodium succinate or magnesium succinate, the dosage is 0.5‰~8‰ of the mass of desulfurized dihydrate gypsum, for example: the dosage is 0.5‰, 8‰ of the mass of desulfurized dihydrate gypsum , 0.9‰, 3‰ or 7‰;

[0028] ②The crystal form modifier is compounded by one of succinic acid, sodium succinate and magnesium succinate and one of magnesium sulfate and aluminum sulfate, and the mass ratio of the two be...

Embodiment 2

[0032] Using the α-type hemihydrate gypsum slurry obtained by the method described in Example 1 as a raw material, carry out centrifugal dehydration or vacuum dehydration; the α-type hemihydrate gypsum after centrifugal dehydration or vacuum dehydration is not dried, but directly poured into a mold to produce Gypsum blocks or other α-type hemihydrate gypsum products.

[0033] In this embodiment, the α-type hemihydrate gypsum slurry whose temperature is not lower than 90°C is centrifuged or vacuum dehydrated at this temperature; revolutions per minute; the vacuum degree of vacuum dehydration is 450mmHg, 500mmHg or 650mmHg, and the temperature of centrifugation or vacuum dehydration is 90°C to 120°C. Specifically, 90°C, 105°C or 120°C can be selected.

Embodiment 3

[0035] Main technological scheme of the present invention is:

[0036] ① First, the power plant desulfurization dihydrate gypsum raw material, crystal form modifier and water are metered and prepared into a slurry with a certain concentration, and pumped into an externally heated autoclave with a slurry pump, and at the same time start the agitator and open the steam valve to heat the autoclave heat up.

[0037] ②When the temperature of the autoclave rises to about 105°C, open the vent valve to discharge the air, continue to heat up to the required temperature, and keep it for the set time.

[0038] ③ After the constant temperature is over, open the vent valve to release the air, and when the pressure in the autoclave drops to less than 0.1MPa, put the α-hemihydrate gypsum slurry in the autoclave into the thermal insulation storage tank for standby.

[0039] ④ According to the requirements of the production speed of the product, put the slurry in the thermal insulation storag...

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Abstract

Disclosed is a method which uses desulfurization dihydrate gypsum to prepare alpha-type semi-hydrated gypsum slurry, comprising the following steps: getting the power plant desulfurization dihydrate gypsum; mixing the power plant desulfurization dihydrate gypsum with water to form slurry with concentration between 10% and 50%; adding a crystal modifier into the slurry, wherein, the crystal modifier can be succinate, sodium succinate or succinate magnesium, and the dosage of the crystal modifier takes up 0.5 to 8 per mille of the mass of the desulfurization dihydrate gypsum; heating the slurring with crystal modifier to 120-160 DEG C and preserving the slurry for 1 to 4 hours so as to get the alpha-type semi-hydrated gypsum slurry. An alpha-type semi-hydrated gypsum product preparation method comprises the following steps: taking the alpha-type semi-hydrated gypsum slurry as the raw material, and then directly pouring the slurry into a mold through centrifugal or vacuum dehydration without drying, so as to obtain gypsum blocks or other alpha-type semi-hydrated gypsum products.

Description

technical field [0001] The invention belongs to the building material preparation technology, in particular to a method for preparing α-type hemihydrate gypsum slurry and gypsum products by using desulfurized dihydrate gypsum. Background technique [0002] Desulfurization gypsum is a waste produced during flue gas desulfurization in thermal power plants. If it is not utilized, it will cause secondary pollution to the environment. Desulfurization gypsum is a useful industrial resource, but there is still a lack of effective comprehensive utilization at present. The full use of desulfurized gypsum has comprehensive effects such as energy saving and environmental protection. The energy consumption of gypsum production is 1 / 3 of that of lime and 1 / 4 of that of cement. Fireproof, it is the best green, energy saving, environmental protection and healthy wall material. [0003] Domestic desulfurization gypsum mainly produces β-type hemihydrate gypsum (ie construction gypsum), wit...

Claims

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Application Information

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IPC IPC(8): C04B11/26
CPCC04B11/264
Inventor 秦鸿根李岗段珍华唐修仁
Owner SOUTHEAST UNIV
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