Investigation into shanghai comprehensive utilization of fly ash and desulfurized slag. May 2007 ... the crystallization of ettringite is stronger in fly ash cement with calcined gypsum than in ...
WhatsApp: +86 18221755073
In order to improve the early strength of fly ash blended cement concrete under steam curing conditions, fly ash was partly substituted by calcined flue gas desulfurization (FGD) gypsum and active ...
WhatsApp: +86 18221755073
The effective and safe use of FGD gypsum in agricultural land is still debated in some countries even though its effectiveness in soil management has been reported in many studies. Thus, the changes in the levels of soil salinity, alkalinity, crop yield, and other physicochemical properties in different soil types and crops after …
WhatsApp: +86 18221755073
The XRD patterns of FGD gypsum with different CaO addition calcined at 140 °C and 200 °C are respectively presented in Fig. 2 (a) and (b). It can be seen from Fig. 2 that the patterns containing CaO addition are very similar, and their main diffraction peaks can be attributed to orthorhombic bassanite (CaSO 4 ·0.5H 2 O, JCPDS: 33-0310), …
WhatsApp: +86 18221755073
According to Leiva et al. (2010), gypsum panels of FGDG passed the European standards for physiochemical (density, moisture content, water adsorption …
WhatsApp: +86 18221755073
Abstract. As a relatively fast-setting building material, desulfurized gypsum is difficult to use. Citric acid, sodium gluconate, and sodium tripolyphosphate were used to design and prepare a desulfurized gypsum paste containing single or combined retarders. The effects of the retarder type and content on the setting inhibition and mechanical …
WhatsApp: +86 18221755073
Calcium-based desulfurization by-products can be divided into two categories: desulfurization gypsum and desulfurization ash. Desulfurization gypsum is …
WhatsApp: +86 18221755073
The calcined gypsum produced by the calcination of desulfurized gypsum can be widely used in gypsum based building materials, which has great economic and social environmental benefits. By calcining the desulfurized gypsum with the addition of KAl(SO4)2, the calcined gypsum was obtained.
WhatsApp: +86 18221755073
Then, the undisturbed desulfurization gypsum is calcined in an oven at 180 • C for 2 h, sealed and aged for 5-7 d to obtain the semi-hydrated desulfurization gypsum [2]. The chemical components ...
WhatsApp: +86 18221755073
Home ›› Anti Dumping Cases ›› Anti-dumping investigation concerning imports of Calcined Gypsum Powder originating in or exported from Iran, ... Oman, Saudi Arabia and UAE. Case No. : 6/45/2020-DGTR. Product : Calcined Gypsum Powder. Country : Iran, Oman, Saudi Arabia and UAE.
WhatsApp: +86 18221755073
The undisturbed desulfurization gypsum after screening was calcined at 180 °C for 2 h and sealed at room temperature for about 7 d to form semi-hydrated desulfurized gypsum. Fig. 1 shows the microscopic morphology and X-ray diffraction (XRD) diagram of desulfurization gypsum. The quicklime was taken from Yibin …
WhatsApp: +86 18221755073
The system diagram of reducing gypsum in the multi- stage and multi-atmosphere fluidized beds. Diagrammatize: 1 raw material; 2 pelleter; 3 adhesion material; 4 drying process; 5 circulating fluidized bed heater; 6 cyclone separator; 7 J type valve; 8 circulating fluidized bed reactor; 9 tubular air preheater; 10 dust collector; 11 draft fan; …
WhatsApp: +86 18221755073
This content was downloaded from IP address 158.46.161.126 on 17/03/2020 at 17:12
WhatsApp: +86 18221755073
DOI: 10.1016/j.conbuildmat.2023.131840 Corpus ID: 258997305; Effects of hybrid fibers on properties of desulfurized gypsum-based composite cementitious materials @article{Lv2023EffectsOH, title={Effects of hybrid fibers on properties of desulfurized gypsum-based composite cementitious materials}, author={Fangtao Lv …
WhatsApp: +86 18221755073
Gypsum is a naturally occurring mineral that has been used by humans for various purposes for thousands of years. ... From the Greek name for the mineral, but more especially for the calcined mineral. Association: Halite ... Gypsum deposits are common in several Middle Eastern countries, including Iran, Oman, and Saudi Arabia. Desert ...
WhatsApp: +86 18221755073
Purpose For an alkaline–saline region in Northwest China, we examined the responses of soil microbial communities to flue gas desulfurization gypsum by-products (FGDB), a new ameliorant for alkaline–saline soils. In 2009 and 2010, we collected soils from 0–20 cm and 20–40 cm depths along an experimental FGDB gradient (0, 0.74, …
WhatsApp: +86 18221755073
With steel slag and desulfurized gypsum as main raw material,mixed appropriate amount slag and compound addition a little of activator,and based on orthogonal test,we explored the slag dosage,the proportion of the combined admixture activator and the desulfurized gypsum dosage impact on the performance of clinker-free cementing material,such as …
WhatsApp: +86 18221755073
In order to improve the early strength of fly ash blended cement concrete under steam curing conditions, fly ash was partly substituted by calcined flue gas desulfurization (FGD) gypsum and active calcium aluminate. The effect of the composition and curing condition on the workability, mechanical property, and volume stability was …
WhatsApp: +86 18221755073
Flue gas desulfurized gypsum (FGD gypsum), mainly originates from thermal power plants, smelters, and large-scale enterprise boilers. This article reviews the production in China and the latest beneficial utilizations of FGD gypsum. China is a large coal-consuming country and has always had serious SO 2 emissions. Therefore, the …
WhatsApp: +86 18221755073
Desulfurization gypsum (Flue gas desulfurization gypsum, FGD gypsum for short) is a by-product of desulfurization in coal-fired plants. Its main component is calcium sulfate …
WhatsApp: +86 18221755073
If the desulfurized gypsum is calcined at a temperature of 185°C, when it is calcined for 1.5 hours, it can effectively achieve the mechanical properties required by the general building gypsum powder itself, and the desulfurized gypsum is calcined at a temperature of 235°C. ... In addition, with the requirement of standard consistency, the ...
WhatsApp: +86 18221755073
Calcined gypsum as a low-energy material can be produced with advantage from the waste FGD gypsum by its dehydration at the temperatures of 110–150 °C. The …
WhatsApp: +86 18221755073
DOI: 10.1016/j.conbuildmat.2021.124910 Corpus ID: 240532385; Preparation of high-performance building gypsum by calcining FGD gypsum adding CaO as crystal modifier @article{Hao2021PreparationOH, title={Preparation of high-performance building gypsum by calcining FGD gypsum adding CaO as crystal modifier}, author={ng Hao and …
WhatsApp: +86 18221755073
The decomposing of gypsum is commonly calcined in the rotary kiln. Because of the stability of ( {text{CaS}}{{text{O}}_4} ), it consumes large quantities …
WhatsApp: +86 18221755073
Chen [] made statistics on the main physical phases of CDA from steel plant sintering machines and coal-fired power plants, and the results are shown in Table 2.Among the many components, CaSO 3 contains the highest percentage, which is generated by the reaction between SO 2 and lime in the flue gas. The CaCO 3 content is also higher …
WhatsApp: +86 18221755073
Calcined gypsum as a low-energy material can be produced with advantage from the waste FGD gypsum by its dehydration at the temperatures of 110–150 °C. Then, β-form of calcined gypsum is formed according to the equation (1) CaSO 4 · 2 H 2 O → CaSO 4 · 1 / 2 H 2 O + 1 1 / 2 H 2 O.
WhatsApp: +86 18221755073
1. Introduction. Flue gas desulfurization (FGD) gypsum is a by-product of the wet FGD process of coal-fired power plants (Chen et al., 2001).Its main content is CaSO 4 or a mixture of CaSO 3 and CaSO 4.To meet clean air standards, almost all coal-fired power plants are required to be equipped with a desulfurization facility to remove SO 2 …
WhatsApp: +86 18221755073
Two different processes of the dehydration of calcium sulfate dihydrate are commonly employed. One is the dry method in which β-gypsum is produced by the calcination of gypsum at the atmospheric pressure and temperatures between 120 and 180 °C []; the product is known as stucco, kettle stucco, plaster, plaster of Paris, or calcined …
WhatsApp: +86 18221755073
The undisturbed desulfurization gypsum after screening was calcined at 180 °C for 2 h and sealed at room temperature for about 7 d to form semi-hydrated desulfurized gypsum. Fig. 1 shows the microscopic morphology and X-ray diffraction (XRD) diagram of desulfurization gypsum. The quicklime was taken. Results and …
WhatsApp: +86 18221755073
Semidry desulfurization and wet desulfurization in a furnace are usually used in the circulating fluidized bed boiler in the power production of thermal power plants, and these two approaches lead to high calcium content in the fly ash and bottom slag of circulating fluidized beds and produce abundant flue-gas desulfurized (FGD) gypsum …
WhatsApp: +86 18221755073