The utilization of solid wastes (SWs) as a potential resource for backfilling is not only conducive to environmental protection but also reduces the surface storage of waste. Two types of SWs, including fly ash (FA) and desulfurized gypsum (DG), were used to prepare cementitious backfilling materials for underground mined-out areas. …
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 …
Current study proposes an effective way to modify the properties of super-sulfated cement (SSC) paste and mortar with preheated flue gas desulfurization (FDG) gypsum at different temperatures and durations, and different sulfate compositions. …
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).
The Role of Cellulose Ether in Controlling Hydration Heat of Desulfurized GypsumCellulose ether is a widely used additive in the construction industry due to its ability to control the hydration heat of desulfurized gypsum. This article aims to explore the effect of cellulose ether on the hydration heat of desulfurized gypsum and its role in
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 …
Concrete/cement and asphalt production. Natural gypsum can be used in concrete production as a replacement for calcium ... FGDG plays a major role in soil …
The production of flue gas desulfurization gypsum poses a serious threat to the environment. Thus, utilizing gypsum-based self-leveling mortar (GSLM) stands out …
Prior to its use in cement, FGD gypsum needs to be dehydrated. 109 According to these studies, the results showed that (a) as the heat treatment temperature increased, the concrete setting time decreased and (b) cement produced with FGD gypsum calcined at 200°C and showed a maximum strength at a 3.5% SO 3 content.
The Portland cement-fly ash-desulfurized gypsum composite solidifier brings the dredged soil to have higher strength and good resistance to dry-wet cycles [24]. Titanium slag is the residue after the titanium extraction from high titanium-type blast furnace slag. Currently, there are 80 million tons of titanium slag in China, with an annual ...
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 mass ratio of MgO to MgSO 4 ·7H 2 O is 2.61:1, CA was taken as 0.5 % of the mass of MgO. FGDG was used as an external admixture, with 0 %, 15 %, 18 …
Geopolymer is an emerging green cementitious material that can be used to stabilize dredged clay (DC) as construction materials. This paper presented an …
mass ratio of composite phase change material to desulfurization gypsum was 1:3. Li et al. [19] modified desulfurized gypsum insulation materials by using hydrogen peroxide as the ing agent, and glass fibers were added to improve their thermal properties. The corresponding results showed that the minimum thermal …
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 concrete. And the smaller the particle size of desulfurized gypsum, the better the mechanical properties of cement mortar. The compressive and flexural tests show that the cement mortar with …
The influence of the mixture of desulfurized gypsum and natural gypsum on the setting time of cement It can be seen from Figure 5 that the setting time tends to decrease with the increase of the ...
DOI: 10.1016/j.conbuildmat.2022.128718 Corpus ID: 251521813; Effects of flue gas desulfurization gypsum incorporation and curing temperatures on magnesium oxysulfate cement @article{Li2022EffectsOF, title={Effects of flue gas desulfurization gypsum incorporation and curing temperatures on magnesium oxysulfate cement}, …
Effect of curing temperature on the reaction kinetics of cementitious steel slag-fly ash-desulfurized gypsum composites system. Author links open ... used grinding steel slag powder with a size of 0–5 mm to produce composite cement with strength classes of 42.5 and 32.5 of European Standard EN 197–1. The content of steel slag …
The weighed fly ash, desulfurized gypsum, cement and silt are poured into the mixer for dry mixing for about 1 min. Next, pour half of the weighed water and stir for 30 s, followed by adding the remaining water and mixing for about 3 min to create a desulfurization gypsum–fly ash fluidized lightweight soil slurry. Pour the slurry into a test ...
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 …
The influences of desulfurization gypsum on the properties of both Magnesium oxychloride cement (MOC) pastes and MOC abrasive tools were investigated in this study. By incorporating desulfurization gypsum in the MOC pastes, the compressive strength of MOC paste improved slightly. With 5% gypsum addition, the flexural strength of MOC pastes …
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 ...
Delayed AFt formation is more significant in systems with a mass ratio lower than 4:1 for aluminate cement to FGD gypsum. Recently, water-resistant binders using 20–40 % FGD gypsum along with FA and Portland cement ratios of 1:3, 2:3, and 3:3 were prepared by Wansom et al., [84]. Generally, gypsum dissolves on water treatment, and …
In order to explore the influence of the types of waste gypsum on the properties of alkali slag cement, fluorogypsum (FG) and flue-gas desulfurization (FGD) gypsum were comparatively …
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
PVAF played a better role than BF in crack resistance and toughening, hence contributing more. When the content of PVFA and BF increased to 0.5% and 0.75%, …
The experimental study of the cement-fly ash-desulfurized gypsum mortar system has explored the composition of cement, FA, and FGD through experiments [4]. The cement content is initially set at 10%-20% of the cementitious material, and FA is added. The amount is 10% to 60%, and the FGD is 20% to 70%; ...
of desulfurized gypsum conforms to the concept of green and low-carbon development. Therefore, full research on the comprehensive performance of desulfurized gypsum in ... The chemical composition of P.II.52.5 Portland cement, FGD gypsum, and fly ash (wt/%). Item CaO SiO2 Al2O3 Fe2O3 MgO SO3 TiO2 K2O Portland cement …
The GSLM benchmark mix ratio was determined as follows: 94% of desulfurization building gypsum, 6% of cement, 0.638% each of water reducer and retarder, 0.085% each of HPMC and deer ...
Gypsum, which is used for retarding the setting of cement is obtained from the mines at Ghaba in Wilayat Adam. Three Kilns and Four Cement grinding mills allow flexibility to produce various types of cement. The process control is fully computerized and handled by highly qualified and experienced personnel. ... Oman Cement has a range of top ...
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 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 …
The effects of desulfurized gypsum, heat-treated desulfurized gypsum and hydrogen peroxide modified desulfurized gypsum on the setting time of Portland cement were studied. The results showed that when the content of desulfurized gypsum after 80 °C heat treatment was 4% of Portland cement, the initial setting time was …
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 …