The utilization of desulfurized building gypsum as raw material for gypsum-based self-leveling mortar (GSL) is limited by its low strength and poor water resistance. ... crystal morphology, and pore structure were also analyzed. Cement significantly improved the fluidity of slurry. Moreover, the compressive strength and softening coefficient of ...

2. When desulfurization gypsum is used as a cement retarder to prepare cement, the cement has a larger specific surface area than the natural gypsum during the same grinding time. The grindability of desulfurized gypsum is better than natural gypsum, and the desulfurized gypsum itself is a fine powdery material.

The main utilization method of FGD gypsum is still used in construction materials (Ye et al., 2019). As an auxiliary material or instead of natural gypsum, it can be widely used in concrete, walls, concrete, etc. It is the best way to use desulfurized gypsum in large quantities, but its economic value is relatively low (Pedreno-Rojas et al., 2020).

Tens of millions of tons of desulfurized gypsum can be produced in China every year. Desulfurization gypsum is used as an admixture to replace part of cement in.

when the amount of cement is 18%, the softening coefficient of desulfurized building gypsum is 0.71, and the water resistance is better[5]. Research by Butakova et al. found that adding a certain amount of cement and silica fume into gypsum can improve its water resistance, and the softening coefficient has been increased from 0.33 to 0.50[6].

In this study, desulfurized building gypsum was modified by adding different amounts of 42.5R ordinary Portland cement to prepare qualified GSL. The mechanism of different cement content was systematically studied through experimental test and theoretical analysis.

the limestone gypsum flue gas desulfurization process, 2.7 ton of desulfurized gypsum can be generated for each 1 ton of SO2 removed [3]. A 300 MW coal-fired thermal power unit discharges about 30,000 ton of desulfurized gypsum every year (assuming 1.0% sulfur in coal) [4]. A substantial amount of desulfurized gypsum is generated as a by-product

Flue gas desulfurized gypsum (FGDG) is an industrial by-product discharged from thermal power plants, smelters, and large-scale enterprise boilers. It is produced when sulfur is removed from flues gases in the flue gas desulfurization (FDG) system, and the formation processes are shown by the following equations (Liu et al., 2021).

The utilization of desulfurized building gypsum as raw material for gypsum-based self-leveling mortar (GSL) is limited by its low strength and poor water resistance. The objective of this study was to improve. comprehensive properties of GSL and prepare qualied desulfurized building gypsum-based self-leveling

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 ...

The false setting is when cement stiffens prematurely in a few minutes after adding water. Some variables could cause false setting in CPI-S-32 Portland cement, for example, alkali concentration ...

Li et al. [12] showed that by adding desulfurized gypsum to concrete with a large amount of slag, the loss rate of early compressive strength of concrete was improved, the hydration reaction rate ...

Desulfurization gypsum, also known as FGD gypsum (flue gas desulfurization gypsum), is an industrial by-product gypsum obtained by desulfurization and purification of flue gas generated after combustion of sulfur-containing fuel (coal, oil, etc.), and its composition is calcium sulfate … See more

In this study, the potential of using desulfurized gypsum (DG), phosphogypsum (PG), gypsum dihydrate (G), and calcium carbide slag (CS) in the production of supersulfated cement (SSC) was investigated. The effects of various types of gypsum and their dosages on the performance and hydration process of SSC were thoroughly examined.

Why Gypsum is Added to Cement? Gypsum is added to cement for several essential reasons: 1. To Prevent Flash Setting. Cement undergoes hydration when mixed with …

In this paper, coal gangue, carbide slag and desulfurized gypsum (DG) were used as raw materials to calcine the all-solid-waste-based belite sulphoaluminate cement (BSAC), …

An innovative approach suggests using titanium slag and flue gas desulfurized gypsum as substitutes for Portland cement for soil solidification. This study systematically evaluates the effects of titanium slag-flue gas desulfurized gypsum-Portland cement composite (TS-FGD-OPC composite) solidifier on the performance of solidified soils.

Li et al. [12] showed that by adding desulfurized gypsum to concrete with a large amount of slag, the loss rate of early compressive strength of concrete was improved, the hydration reaction rate ...

The production of cement is a highly energy-intensive process, which consumes 3.0 % of the world's annual energy output and releases roughly 8.0 % of the global CO 2 emissions [1], [2], [3].To meet the carbon neutral goal and alleviate global energy crisis, developing a green and low-carbon approach for cement production is urgently required.

To explore the feasibility of DG as a sulfate source in producing limestone calcined clay cement (LC3), this study investigates the differences between LC3 samples containing DG …

The main purpose of adding gypsum in the cement is to slow down the hydration process of cement once it is mixed with water. The process involved in hydration of cement is that, when the water is added into cement, it starts reacting with …

Magnesium oxychloride cement (MOC) prepared by using magnesium chloride and light calcined magnesia has been widely used as decorative materials, refractory materials and adsorbing materials.

A comparison between Fig. 12 (III) and Fig. 12 (VI) reveals that the presence of cement improves the heat release performance of A1 (PO is obtained by adding a small amount of cement to A1). Compared to A1, cement introduces additional C 3 S, C 2 S, C 3 A, and C 4 AF, accelerating the formation of hydration products and dissolution of reactants.

The results show that adding desulfurized gypsum, which accounts for 6% to 8% of the total mass of the cementitious material, has no adverse effect on the workability and can significantly...

The results show that adding desulfurized gypsum, which accounts for 6% to 8% of the total mass of the cementitious material, has no adverse effect on the workability and can significantly …

Study on desulfurized gypsum used as cement retarder Jianmei Zhou* School of Chemistry and Chemical Engineering, Inner Mongolia University of ... The desulfurized gypsum is modified by adding 1% of the mass of desulfurized gypsum with hydrogen peroxide, dried and ground for standby. According to GB / T 1346-2001, determine the standard brick ...

The semi-hydrate content of desulfurized gypsum is adjusted as a natural plaster substitute for producing gypsum board, wallboard [107].The modified treatment of desulfurized gypsum with cement, inorganic waste, straw fiber and other wastes can be used to manufacture high-insulation and compression-resistant wall materials [108].Desulfurized gypsum is incorporated into the …

The compressive strength of the modified cement was significantly improved by adding fly ash to MOSC [21]. Wu et al., (2015) [22] found that the compressive strength of cement could be increased to 80 MP after 28 days of curing by adding 0.5 wt% phosphoric acid or potassium dihydrogen phosphate by weight of magnesium oxide to MOSC. In addition ...

The production of flue gas desulfurization gypsum poses a serious threat to the environment. Thus, utilizing gypsum-based self-leveling mortar (GSLM) stands out as a promising and effective approach to address the issue. β-hemihydrate gypsum, cement, polycarboxylate superplasticizer, hydroxypropyl methyl cellulose ether (HPMC), retarder, and deer were …

Research has found that adding 5–10% of desulfurized gypsum can enhance the strength of geopolymers. ... desulfurized gypsum, cement clinker, and slag as the cementitious composite. Table 4 describes the test protocol, where a total of 27 groups were set up. The cement–mortar ratio was 1:4 and the slurry concentration was 74%.