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. Preheated FGDs with temperatures between 25 and 150 °C and durations between 0 and 24 h were used to replace …
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What is desulfurization gypsum. 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 dihydrate (CaSO 4.2H 2 O).. How desulfurization gypsum comes
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Flue-gas desulphurization (FGD) gypsum is a highly prevalent industrial by-product worldwide, which can be an excellent alternative to natural gypsum due to its high content of CaSO 4 ·2H 2 O. The preparation of α …
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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.
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Based on laboratory trials, the composition of raw materials in LC3 was decided as 50% clinker, 31% Calcined clay, 15% limestone and 4% gypsum. All major raw materials were procured from the state ...
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Flue gas desulfurization gypsum (FGDG) is an industrial by-product generated during the flue gas desulfurization process in coal-fired power plants. ... cement produced with FGDG calcined at 200 °C and with a 3.5% content of SO 3 showed the maximum strength. ... (Oriza sativa L.) growth and yield using desulfurized gypsum in the west of ...
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The invention belongs to the technical field of building materials, particularly relates to an expanded polystyrene particle heat-preservation building block using non-calcined desulfurized gypsum as a main cementing material and a preparation method thereof. The expanded polystyrene particle heat-preservation building block is composed of the desulfurized gypsum, …
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The results show that the mechanical properties and volume stability of the composite cementitious system can be improved by adding appropriate amount of calcined …
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Calcined a 100 °C for 6 h: 1.10 1.175 [108] FGD panel: Calcined at 140 °C for 30 h: 1.332 – 1.354 [107] Gypsum-FGDG binder ... it is essential to develop quality control measures to ensure that FGD gypsum meets the necessary standards for different applications. Another challenge is the transportation and storage of FGD gypsum, which can be ...
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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 properties of desulfurized …
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The invention belongs to the technical field of building materials, and particularly relates to a non-calcined desulfurized gypsum hydraulic composite gel system. The non-calcined desulfurized gypsum hydraulic composite gel system is prepared from desulfurized gypsum, ore slag powder, metakaolin, calcined gangue, calcined clay, diatomite, cement, sodium silicate, magnesium …
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Desulfurized gypsum is used primarily in construction, agriculture, the chemical industry, ... Its setting time and standard consistency should be tested by the "GB/T 9776-2008 Building Gypsum" standard. The gypsum hardness test is performed by the national standard "GB/T 17669.3–1999." And the specifics of are setting time as follows ...
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Employing the sintering FGD gypsum, ferric oxide, and graphite carbon as raw materials, the effects of the carbon content, reaction time, and molar ratio of CaO to Fe 2 O 3 …
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Firstly, crushing and grinding natural gypsum, wherein the fineness can be controlled between 80 and 200 meshes; the desulfurized gypsum can be directly calcined without crushing and grinding, but the desulfurized gypsum is ensured not to have agglomeration, rolling balls and too much moisture when entering a fluidized bed furnace;
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Zhao Feng-qing8) has studied the mixing of water repellent agents that are prepared by granular blast furnace slag, high calcium fly ash and some additives with calcined desulfurized gypsum; …
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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 gypsum.The other one is …
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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 …
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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 …
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The invention relates to a calcined desulfurized gypsum composite cementing material insulation board with a heat reflection coating and a preparation method thereof, wherein the insulation board comprises the following components: 100 parts of calcined desulfurized gypsum, 40-70 parts of metakaolin, 20-50 parts of volcanic slag powder, 10-30 parts of gneiss powder, 2-6 …
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Desulfurized gypsum (DG) presents significant challenges in recycling with the rapid development of industrialization. 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 and those containing natural gypsum (NG) in terms of hydration, …
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The binders used in this study included granulated blast furnace slag (GBFS), steel slag (SS) and desulfurized gypsum (DG). ... mold (40 mm × 40 mm × 160 mm) and compacted with a vibrating table. Finally, the specimens were covered in the standard curing room with a relative humidity of 90 % and a temperature of 20℃ until the measured ages ...
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2.4 Test methods 2.4.1 Macro-performance testing. The standard consistency water consumption, initial and final setting time and 2 h/adiabatic-flexural and compressive strength of modified phosphogypsum were tested in accordance with "Building Gypsum" (GB/T9776-2008). According to "Gypsum-based self-levelling mortar" (JC/T1023-2021), the 30 …
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Effects of slag, high-calcium fly ash, desulfurized gypsum, calcined desulfurized gypsum and sodium sulfate on early age autogenous shrinkage of cement pastes, long terms of desiccation shrinkage ...
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Desulfurized building gypsum (DBG) has great application potential and can be used to produce lightweight plastering gypsum (LPG). In this work, DBG was modified by adding different proportions of ...
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The obtained semi-aqueous desulfurized gypsum was the original desulfurized gypsum, which was placed in an oven at 180 °C and dehydrated for 2 h under synchronous heating with the box. ... Based on the standard GB20472-2006, the 1-d flexural strength was 6.3 MPa, the 3-d flexural strength was 6.6 MPa, the 1-d compressive strength was 35.8 MPa ...
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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 systematically evaluated. The …
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Results show that the addition of calcined FGD gypsum and active calcium aluminate is able to improve the early compressive strength but using more FGD gypsum and …
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At present, several research teams have investigated many research areas pertaining to the improvement of the water-resistance of gypsum. Zhao Feng-qing 8) has studied the mixing of water repellent agents that are prepared by granular blast furnace slag, high calcium fly ash and some additives with calcined desulfurized gypsum; this was aimed at preparing a waterproof …
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