Research on degradation mechanisms of recycled building gypsum
— The recycled dihydrate gypsum was much easier to grind than the natural gypsum ores, resulting in larger SSA and VF of the recycled hemihydrate powders. (2) The remarkable increase in the WR of the recycled hemihydrate powders were mainly ascribed to the deteriorated PSD, the large SSA and VF, the poor sphericity of particles. ...
Preparation of α-hemihydrate gypsum from phosphogypsum in recycling
— Herein, the feasibility of recycling use of electrolyte solution (CaCl 2 solution in this study) in α-HH preparation from PG was studied in laboratory and pilot scale tests. The properties (CaCl 2 concentration, pH value and impurity concentration) of the CaCl 2 solution in each recycle were analysed. The characteristics (crystal morphology, …
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Salalah International Gypsum Co. L.L.C., or SIG in short, is the leading natural gypsum producer & exporter from Sultanate of Oman. We are located at Salalah in the Dhofar governorate, which is the southernmost …
Techno-economic impact assessment of recycled gypsum …
— In contrast, Jiménez-Rivero and García-Navarro (2017b) tested gypsum plasterboards with different content of RG (17-28%) and found out that 86% of samples met the mechanical requirements for ...
Gypsum Manufacturer & Supplier Oman|Marble, Limestone …
GMC is one of largest manufacturer of Gypsum in GCC sourcing most of raw materials from Oman itself. GMC also engages in production of Limestone, Marbles.
Oman retains crown as world's biggest gypsum …
— Gypsum shipments from the Sultanate of Oman, currently the world's biggest exporter of the industrial mineral, are projected to grow exponentially over the next decade as consumption rebounds in key …
Management of end-of-life gypsum in a circular economy
— Gypsum products are well suited for a circular economy, because the raw material calcium sulfate dihydrate can repeatedly change its properties through a reversible hydration reaction. However, quality postconsumer recycled gypsum can only be obtained when gypsum products are properly managed during the end-of-life stage, provided that …
Effect of citric acid on properties of recycled gypsum plaster …
— Citric acid increases the fluidity of recycled gypsum plaster. •. Retarding effects are higher with high content of the admixture. •. Mechanical properties are …
Calcium sulphate hemihydrate hydration leading to gypsum
— The hydration of calcium sulphate hemihydrate (CaSO 4 ·0.5H 2 O) leading to the crystallization of gypsum (calcium sulphate dihydrate – CaSO 4 ·2H 2 O) has been the subject of several investigations over a long period and a vast amount of data is widely distributed throughout in the literature. In this review article an overall picture of the …
Application of the Industrial Byproduct Gypsum in Building …
— The industrial byproduct gypsum is a general term for byproducts discharged from industrial production with calcium sulfate as the main ingredient. Due to the high number of impurities and production volume, the industrial byproduct gypsum is underutilized, leading to serious environmental problems. At present, only …
Research on degradation mechanisms of recycled building gypsum
— The results showed that the recycled dihydrate gypsum was much easier to grind than the natural gypsum ores, resulting in deteriorated particle size distribution, large specific surface area and ...
Comparative Analysis of Recycled Plaster Composition …
— Plaster is primarily used as a building material obtained by the calcination of gypsum. Its rapid setting time (time for the mixture to solidify) and the low quality of labor generate a large amount of nonused material. Due to its solubility in water, wasted gypsum cannot be disposed of in the environment, and its recycling process is encouraged. In …
Dehydration Pathways of Gypsum and the Rehydration …
— The dehydration products of gypsum under different temperature and water vapor pressure were investigated by thermodynamic theory. Additionally, the rehydration mechanism of soluble anhydrite was also studied by Monte Carlo (MC) simulations. The thermodynamic calculation results reveal that the dehydration mechanism of gypsum …
Preparation of alpha-calcium sulfate hemihydrate from FGD gypsum …
— Chemical adsorption was formed between O of KAP, Ca²⁺ and O of dihydrate gypsum (0 2 0) surface (OKAP- Ca²⁺-Osurf) in the presence of Ca²⁺, thus KAP can be stably adsorbed on the ...
Experimental Study and Mechanism Analysis of Preparation …
— 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 CaSO4·2H2O. The preparation of α-calcium sulfate hemihydrate is a high-value pathway for the efficient use of FGD gypsum. Here, a dynamic method, or an improved …
Future Asian gypsum demand and supply trends: Oman
— Gypsum resources are abundant in Oman, especially around the port of Salalah. With domestic demand set to grow only slowly, the potential for exports to the …
Preparation of calcium sulfate from recycled red gypsum to …
— Red gypsum (RG) is an industrial waste generated from the titanium dioxide process produced. For the low-cost and high-benefit utilization of RG, calcium sulfate (CaS) was prepared from recycled RG. Rod-like gypsum crystals with a rough surface, uniform size, 1 µm in diameter and 5 µm in length, were obtained, when the as-prepared CaS …
Sustainability of gypsum products as a construction material
— Natural gypsum, shown in Fig. 25.1, is the most common raw material for production of binders.It is a soft mineral, attributed to sedimentary rocks, normally grey or with no colour, with a humidity of about 8–10%. Gypseous stone, a denser modification of gypsum that is composed of gypsum and sandy and clayey stone, is normally used to …
Recycling, reusing and environmental safety of industrial by …
— Hansen et al. [14], [107] studied the effect of recycled gypsum content (0–20 %) on the unconfined compressive strength of fly ash composite recycled gypsum (from waste drywalls) cementitious materials. The study found that the 90-day compressive strength of concrete with 5 % gypsum content was the highest, which was 45.2 MPa.
How to Clarify the Water in Your Pond with Recycled Gypsum
Treating Your Pond with Gypsum. Gypsum (CaSO4) is a water soluble mineral found in fertilizers, drywall, and plaster. Recycled gypsum is available in a variety of particle sizes for easy application. Since gypsum is pH neutral, it will not affect the water pH when added to your pond the way some aluminum sulfate treatments can.
Environmental Evaluation of Gypsum …
— Gypsum is widely used in the construction sector, and its worldwide consumption has been increasing for several decades. Depending on the lifetime of the used gypsum products, an increase of …
recycled gypsum wallboard with Chiyoda Ute
— The Japanese wallboard producer Chiyoda Ute Co., Ltd. and its partners have developed a patented gypsum recycling process that allows the production of wallboard with up to recycled content, bringing the prospect of true resource circularity to the global gypsum sector. ... Above: Table 1 - Japanese gypsum dihydrate …
α-calcium sulfate hemihydrate preparation from FGD gypsum in recycling
— The effects of salt solution recycling on the transition of α-HH from FGD gypsum were investigated by a comparison with that in laboratory scale, focusing on the dehydration rate of FGD gypsum, the crystal morphology, chemical composition and mechanical strength of the products. α-HH could be transformed from FGD gypsum in …
α-calcium sulfate hemihydrate preparation from FGD gypsum in recycling
DOI: 10.1016/J.CEJ.2011.09.033 Corpus ID: 96659014; α-calcium sulfate hemihydrate preparation from FGD gypsum in recycling mixed salt solutions @article{Guan2011calciumSH, title={$alpha$-calcium sulfate hemihydrate preparation from FGD gypsum in recycling mixed salt solutions}, author={Baohong Guan and Li Yang and …
Formation of α-Hemihydrate Inside of a Gypsum …
— Gypsum (calcium sulfate dihydrate) is one of the most used inorganic binding materials in the world. During calcination, calcium sulfate subhydrates are formed and, for technical reasons, are mixed with water to form dihydrate again. Therefore, the dehydration process of gypsum and the rehydration of hemihydrate were investigated. This …
How to Clarify the Water in Your Pond with …
Treating Your Pond with Gypsum. Gypsum (CaSO4) is a water soluble mineral found in fertilizers, drywall, and plaster. Recycled gypsum is available in a variety of particle sizes for easy application. Since gypsum …
Gypsum Powder | Oman CHEMICAL
Gypsum has many application. some of as below : Drilling Fluids : The chemical CaSO4, which occurs naturally as the mineral anhydrite. Gypsum is the dihydrate mineral form, CaSO4·2H2O. Anhydrite and gypsum (commonly called gyp) are found in the subsurface and drilling even small stringers of these minerals can upset a freshwater or seawater mud.
Production and resource utilization of flue gas desulfurized gypsum …
— Desulfurization gypsum is mainly produced in the wet desulfurization process, and its main component is calcium sulfate dihydrate. Desulfurization gypsum has the same properties as natural gypsum ...
Gypsum Supplier & Wholesale in Oman (Spec, …
Gypsum is one of the primary construction materials that has been used for thousands of years that abundantly found in the solid crust of the Earth in relatively thick layers that is extracted from mines and utilized. Calcium …
Tri-calcium phosphate (ß-TCP) can be artificially synthesized …
Calcium phosphate is known as a major component of biological hard tissues. This study aimed to produce calcium phosphate by recycling kneaded surplus gypsum. β-dihydrate gypsum was derived from commercial dental β-hemihydrate gypsum, which was mechanically powdered and mixed with the liquid component of a commercial zinc …
Insight into the influences of β-hemihydrate and dihydrate gypsum …
— Dihydrate gypsum was provided by China National Pharmaceutical Industry Corporation ltd. The chemical compositions of CAC, β-hemihydrate, and dihydrate are listed in Table 1 ; their specific surface areas were calculated to be …
Comparative Analysis of Recycled Plaster Composition …
— Chandara et al. performed thermogravimetric tests to quantify the compounds present in two gypsum samples in the form of dihydrate—one natural and one wasted from ceramic molds—and XRD tests for phase identification. They found 91.28% of dihydrate, …
Understanding gypsum in 3 diagrams
— Gypsum is one of the most widely-used building materials in the world. It is applied in several interior building uses, including in wallboard. Normally, calcium sulphate dihydrate (CaSO 4 •2H 2 O) is used as a raw material and a subhydrate such as hemihydrate (CaSO 4 •0.5H 2 O) or anhydrite (CaSO 4) is produced. The subhydrate is …
Estimation of gypsum hemihydrate content in recycled …
— recycled gypsum dihydrate is almost the same as that (2.326 g/cm. 3) of the reagent gypsum dihydrate, and the. density (2.660, 2.662 g/cm. 3) of the recycled gypsum.