The desulfurized gypsum treated with hydrogen peroxide can improve the stability of cement. When the proportion of desulfurized gypsum and natural gypsum is 1:1 and the …
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Effect of using sugar and gypsum as a retarder on concrete properties in Omani weather. Niger. J. Technol. Dev., 20 (2023), pp. 9-14, 10.4314/njtd.v20i1.1264. ... Study on desulfurized gypsum used as cement retarder. IOP Conference Series: Earth and Environmental Science, IOP Publishing (2021), Article 032048. Crossref View in Scopus Google Scholar
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The aim of this paper is to investigate the possible displacement of natural gypsum (CaSO4·2H2O) in cement with an alternative setting retarder, such as the industrial by-product derived from ...
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The retarding effect of protein retarder on phosphorus building gypsum (PBG) and desulfurization building gypsum (DBG) was investigated, and the results show that protein retarder for DBG can effectively prolong the setting time and displays a better retarding effect, but for PBG shows a poor retarding effect. Furthermore, the deterioration reason of the retarding …
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Cement clinker minerals, mineral powder, and active calcium aluminate were dissolved in water to produce Al(OH) 4− and OH − after water was added to the Portland cement-fly ash-calcined FGD gypsum-calcium aluminate composite quaternary cementitious system. The desulfurized gypsum also dissolved SO 4 2− and Ca 2+ rapidly. When these ions ...
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According to statistical data, in 2020, the desulfurized gypsum emissions of China reached about 147 million ton, which increased to more than 161 million ton in 2021 and continues increasing . Gypsum can be used as a cement retarder or as a building material in products such as gypsum wallboard or gypsum ceiling . However, because of technical ...
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Desulfurized building gypsum (DBG) has great application potential and can be used to produce lightweight plastering gypsum (LPG). ... By adding sawdust, retarder, and water-retaining agent, the ...
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The gypsum desulfurized in power plants is only a primary product and needs to be reprocessed. However, as a kind of waste, we must rationalize resources and can do many things such as: cement retarder, building gypsum powder, paper …
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The invention discloses a desulfurized gypsum retarder, a preparation method and application thereof in sulphoaluminate cement, wherein the method comprises the following steps: the temperature of the rotary kiln is reduced from 300 ℃ to 400 ℃, the temperature reduction process is divided into a plurality of temperature reduction sections, the desulfurization gypsum is …
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Natural gypsum can be used in concrete production as a replacement for calcium aluminate cement (CAC), opening the possibility of replacing the natural gypsum with FGDG in this application with success, even though some studies have reported a reduction of compressive strength and water solubility when compared to conventional cement mixtures ...
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Compared with natural gypsum, the retarding effect of desulfurized gypsum on Portland cement is more significant at the same dosage. The desulfurized gypsum treated with …
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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 …
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Technical feasibility for use of FGD gypsum as an additive setting time retarder for Portland cement. J. Mater. Res. Technol. (2018) Y. Zhang et al. Study on the performance of FGD gypsum-metakaolin-cement composite cementitious system. Constr. Build. Mater. ... Moreover, the solid waste desulfurized gypsum is used as a sulfate activator. The ...
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The desulfurization gypsum are widely utilized in cement retarder, building material, embedment and neutralizer or regulator of soil in agriculture [3, 4]. At same time, decomposing of desulfurization gypsum or Phosphogypsum to producing ( {text{CaO}} ) and ( {text{S}}{{text{O}}_2} ) is another promising utilization method for cement as ...
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The invention relates to a cement using desulfurized lime as a retarder. Powdery desulphurization waste residue "desulfurized lime" with the SO3 mass fraction of 16-19%, obtained after lime desulphurization of energy dissipating enterprises adopting coal and natural gas as main energy, is used as the retarder; and a mixture composed of granulating slag, fly ash, limestone, …
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In this study, different amounts of cement were used as reinforcement materials in desulfurized building gypsum-based self-leveling mortar to investigate the working …
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After many grinding mixture ratio tests in laboratories,the paper studies the effect on ordinary cement and slag cement of desulfurized gypsum as cement retarder,instead of raw gypsum.The result shows that the cement is strengthened,finer with normal setting time and no adverse effects.It is suggested that desulfurized gypsum granulators be used in cement plants,which …
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FGDG can be used as an ingredient in cement, in the production of asphalt, and as a set retarder in concrete and grout. The primary land application of FGDG is its use as a soil amendment and as a fertilizer in agriculture. ... growth and yield using desulfurized gypsum in the west of Songnen ... Rantis G, Tsimas S Alternative calcium-sulfate ...
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Chandara et al. (2009) successfully used DG to replace natural gypsum as cement retarder. Boonserm et al. (2012) used DG as an additive to effectively improve the strength development of geopolymer mortars. ... Production and resource utilization of flue gas desulfurized gypsum in China - a review. Environ. Pollut., 288 (2021), Article 117799.
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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.
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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).
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Synthetic gypsum can be a substitute for natural gypsum and as cement admixtures, gypsum-based plasters, drywalls and more [18]. ... It was found that STPP acted as a retarder in hydration of gypsum and the addition of 0.3 wt% STPP increased setting time more than 5 times, while with adding of 0.4 wt% SS as hydration accelerator, the setting ...
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Flue gas desulfurization gypsum (FGDG) is an industrial byproduct produced by limestone-gypsum wet desulfurization to treat SO 2 produced by thermal power plants and coal-fired plants, whose main component is CaSO 4 ·2H 2 O. In wet desulfurization, 1 t of SO 2 produces about 2.7 t of FGDG [1], [2].Some 130 million tons of FGDG were produced in 2019, …
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Synergistic effect of red mud, desulfurized gypsum and fly ash in cementitious materials: Mechanical performances and microstructure. Author links open overlay panel Yaguang Wang a, Xiaoming Liu b, ... which is often used as a retarder in cement-based materials, with a dosage generally less than 3%. When the sulfate content in cement is high ...
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This paper describes replacing natural gypsum with FGD gypsum as cement retarder, the influence on the working performance, compressive strength and admixture adaptability of concretes, which were ...
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Desulfurization-gypsum-based composite cementitious materials were prepared by adding certain proportions of sulfoaluminate cement, mineral powder quick lime, retarder, and water reducer into the original desulfurization gypsum and semi-hydrated desulfurization gypsum. Based on the Box–Behnken design of the response surface methodology (RSM), regression …
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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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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 investigated. Moreover, the action mechanisms of FG and FGD gypsum on the properties of alkali slag cement were analyzed. The results show that both the FG and FGD …
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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 sawdust, retarder, and hydroxypropyl methylcellulose (HPMC) water-retaining agent to prepare LPG. When the sawdust content is greater than 9% and less than …
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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 136min, and the final setting time was 196min, …
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Flue gas desulfurized gypsum (FGDG) is an industrial by-product discharged from thermal power plants, smelters, and large-scale enterprise boilers. ... At present, FGDG is mainly used as building materials, such as cement retarder (Tzouvalas et al., 2004), gypsum panel products (Koralegedara et al., 2019), and other structural materials (Jiang ...
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The invention relates to a method for producing a cement retarder from desulfurized gypsum instead of natural gypsum. The method comprises the following steps: the first step: the desulfurized gypsum is maintained at a temperature of 5-25 DEG C, the second step: the desulfurized gypsum is dried by adding a homogeneous substance as binder 20-30 wt% per …
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Desulfurization gypsum uses and properties – take it as cement retarder What is desulfurization gypsum Desulfurization gypsum, also known as FGD gypsum (flue gas desulfurization gypsum), is an industrial by-product …
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In cement applications, FGD gypsum can be used as a retarder in cement production. FGD gypsum has a low impurity concentration and is a suitable substitute for …
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Study on desulfurized gypsum used as cement retarder, Jianmei Zhou
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