Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for preparing α-hemihydrate gypsum from flue gas desulfurization gypsum

A technology for desulfurized gypsum and hemihydrate gypsum, which is applied in the field of preparation of gypsum-based building materials, can solve the problems of slow dehydration and crystal conversion rate of gypsum, high required pressure, poor controllability of α-hemihydrate gypsum composition and morphology, etc. Achieving the effects of good morphology and size uniformity, low cost and high density

Active Publication Date: 2021-03-30
宁波金泽新型建材有限公司
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Some α-hemihydrate gypsums have been synthesized by this method and some good results have been obtained, but the obtained α-hemihydrate gypsum has poor composition and shape controllability, requires high pressure, and the rate of gypsum dehydration and crystal transformation is slow etc., limiting its further application

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for preparing α-hemihydrate gypsum from flue gas desulfurization gypsum
  • A method for preparing α-hemihydrate gypsum from flue gas desulfurization gypsum
  • A method for preparing α-hemihydrate gypsum from flue gas desulfurization gypsum

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Weigh 0.085 mol of sodium chloride, 0.2 mmol of disodium edetate and mix them uniformly in 30% glycerin-water solution, then add 50 g of flue gas desulfurization gypsum into it to make a slurry. The temperature of the slurry was maintained at 90°C by means of heat conduction oil, stirred at a constant speed for 2h, and transferred to a 100mL reactor with a reaction temperature of 100°C and a reaction time of 2h. After the reaction, the reaction kettle was naturally cooled to room temperature, and the product was centrifuged, washed with water and ethanol three times in sequence, and then placed in a vacuum drying oven at 60°C for 12 hours in vacuum to obtain light yellow powder α-hemihydrate gypsum.

Embodiment 2

[0031] Weigh 0.085 mol of sodium chloride, 0.2 mmol of disodium edetate and mix them uniformly in 30% glycerin-water solution, then add 50 g of flue gas desulfurization gypsum into it to make a slurry. The temperature of the slurry was maintained at 90°C by means of heat conduction oil, stirred at a constant speed for 2h, and transferred to a 100mL reactor with a reaction temperature of 120°C and a reaction time of 2h. After the reaction, the reaction kettle was naturally cooled to room temperature, and the product was centrifuged, washed with water and ethanol three times in sequence, and then placed in a vacuum drying oven at 60°C for 12 hours in vacuum to obtain light yellow powder α-hemihydrate gypsum.

Embodiment 3

[0033] Weigh 0.085 mol of sodium chloride, 0.2 mmol of disodium edetate and mix them uniformly in 30% glycerin-water solution, then add 50 g of flue gas desulfurization gypsum into it to make a slurry. The temperature of the slurry was maintained at 90°C by means of heat conduction oil, stirred at a constant speed for 2h, and transferred to a 100mL reactor with a reaction temperature of 140°C and a reaction time of 2h. After the reaction, the reaction kettle was naturally cooled to room temperature, and the product was centrifuged, washed with water and ethanol three times in sequence, and then placed in a vacuum drying oven at 60°C for 12 hours in vacuum to obtain light yellow powder α-hemihydrate gypsum.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
specific surface areaaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method for preparing alpha-hemihydrate gypsum from flue gas desulfurization gypsum. The method comprises the following process steps that (1) little sodium chloride and little ethylene diamine tetraacetic acid are weighed and are uniformly mixed in a glycerinum-water solution; then, 50g of flue gas desulfurization gypsum is added; slurry is prepared; (2) the temperature of the slurry is maintained to be 90 DEG C through heat conducting oil; uniform speed stirring is performed for 1 to 3h; the slurry is transferred to a 100mL reaction kettle, wherein the reaction temperature is 100 to 160 DEG C, and the reaction time is 1 to 3h; (3) after the reaction is completed, the reaction kettle is naturally cooled to room temperature; the product is centrifugated and is sequentially cleaned for three times by water and ethanol; the product is put into a vacuum drying chamber; vacuum drying is performed for 12h at 60 DEG C; faint yellow powder alpha-hemihydrate gypsum isobtained. The prepared alpha-hemihydrate gypsum has the characteristics that the crystal form is good; the cost is low; the control is easy; the repeatability is high; the large scale production can be realized; wastes are utilized, and the like. The CaSO4 content of the alpha-hemihydrate gypsum is greater than 92 percent; the alpha-hemihydrate gypsum completely conforms to the standard of European building material chemistry association and belongs to high-quality gypsum.

Description

technical field [0001] The invention relates to the technical field of preparation of gypsum-based building materials, in particular to a method for preparing α-hemihydrate gypsum by using waste flue gas desulfurization gypsum from power plants. Background technique [0002] Environmental pollution and energy crisis are already hot issues today. With China's rapid development, the discharge of industrial waste has also increased, especially flue gas desulfurization gypsum, which restricts economic development. At present, there are many ways to convert flue gas desulfurization gypsum, such as: retarder for cement products, calcined mold products, building materials, etc. Among them, it is widely used as a building material, because gypsum is one of the three major cementitious materials, especially α-hemihydrate gypsum is considered to be the most sustainable building cementitious material. [0003] After more than 20 years of extensive and in-depth research, the production...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C04B11/032C04B11/26C04B11/024
CPCC04B11/024C04B11/032C04B11/264
Inventor 兰明轩
Owner 宁波金泽新型建材有限公司