The structural, thermal, and mechanical properties of Moroccan gypsum rocks sampled from the Agadir and Safi regions was studied in order to suggest the use of natural gypsum materials for sustainable building and …
The compressive strength of the sample with 10 % content is the highest at 28 d, which is 84.6 MPa. ... in industrial production, a certain proportion of natural gypsum is often added during the grinding process of SAC clinker ... [28] studied the hydration rate of SAC mixed with gypsum and anhydrous gypsum respectively, and found that gypsum ...
Subsequently, the DTG curves of all pastes enter a stable dehydration interval from 150 °C to 400 °C, without distinct weight loss peaks, corresponding to slow water loss of various hydration products (He et al., 2018) and dehydration of hemihydrate gypsum to anhydrous gypsum (Pritzel et al., 2022). The weight loss ranking of pastes within ...
With natural anhydrite (type II anhydrous gypsum) from Hanshan Country of Anhui Province as major raw materials, the preparation and application of anhydrous plaster gypsum are investigated.
Therefore, this study used a novel apparatus (Shi et al. 2012) to measure the solubility of gypsum from 0 to 40 °C and 1 to 1450 bar in the presence of 0–4 mol NaCl/kg H 2 O.
Natural gypsum is the most common sulfate on our planet, which is widely used in construction due to its excellent astringent properties, environmental friendliness, thermal and fire resistance, accessibility in nature and low price. ... Anhydrous gypsum is thermoinert up to 1200 °C [8] and 1300 °C [17]. ... Effect of graphene-based additives ...
The patent discloses a method for preparing high-strength anhydrous gypsum from calcium sulfide slag, which comprises the steps of adding the calcium sulfide slag, a calcium source, an activating agent and a silicon-aluminum source into a drying and scattering machine to obtain dry materials, adding the dry materials into a counter-current dryer for dehydration, then cooling …
[Chang, et al 2005] Investigated by Mum et al in 2006 shows by promoting hydration of GBFS by adding activator, a small quantity of commercial slacked lime, anhydrous gypsum, and limestone powder were applied as activators and filler, sharply increases early compressive strength than that without activator added.
High-strength gypsum∥ type anhydrite powder production line-Linyi Huihang Machinery Co., Ltd. -Type II anhydrite powder belongs to high-strength gypsum powder, also known as high-temperature gypsum, which is calcined in a rotary kiln at high temperature (≥650℃). Type II anhydrous gypsum powder has a long setting time,
Strong retarding performance. It can provide required setting time for gypsum mortar at low dosage, with minimal influence on the dry strength of the gypsum. The setting time changed steadily and linearly with dosage increasing. Lime has no …
Preparation of α-calcium sulfate hemihydrate with high mechanical strength from natural fibrous gypsum in KCl-mediated glycerol-water solution. 2024, Construction and Building Materials ... The addition of maleic acid to the salt solution was found to foster anhydrous gypsum formation. In contrast, succinic acid can decrease the crystals ...
The molecular weight of anhydrous gypsum is 136.14 and for the dihydrate 172.17. Thus if you calculate that you need x grams of the dihydrate you will only need x*136.14/172.17 grams of the anhydride. ... Gamma-anhydrous easily reacts with water to return to its natural state of gypsum. Beta-anhydrous DOES NOT REACT WITH WATER. If very …
Anhydrous gypsum produced higher optimum compressive strength as compared with di-hydrate gypsum. An increase in SO3 content from gypsum contributed to strength development at early ages but reduced its …
Figure 6b shows the compressive strength experiments, where both DG and natural gypsum were mixed and used together. The compressive strength of the mortar with 2.1% DG and 1.4% natural gypsum was greater than that of the other mixes. The performance of cement prepared by mixing DG and natural gypsum was better than that of cement …
In order to study the physical and mechanical properties of gypsum rock samples in three states (natural, high-temperature dehydration and hydration time), natural gypsum rock was put into high-temperature condition of 220°C for dehydration treatment, and then the high-temperature dehydrated gypsum rock was treated with different hydration time, and the …
Gypsum, a naturally occurring mineral with the chemical formula CaSO4·2H2O, exhibits several important chemical properties that contribute to its versatility and usefulness in various applications. Here are some key chemical properties of gypsum: 1. Hydrated Structure:Gypsum is a hydrated …
What effect does cement have on the properties of natural anhydrous gypsum-based self-leveling mortar? Jul 06, 2020. 1. The mixed cementitious material forms ettringite during the hydration process. ... In addition to further improving the strength, its purpose is to reduce the alkalinity, resulting in stable volume conditions for the ...
Utilize natural gypsum raw materials An annual output of 60,000 tons of construction gypsum production line program. First, the design basis 1. Environmental Protection Law of the People 's Republic of China (Revised in 1989); 2. Law of the People 's Republic of China on Prevention and Control of Atmospheric Pollution (revised in 2000);
CaS04.1/2 H20 is the final product which you can use it to produce gypsum board other gypsum product. After calcining, CaSO4.1/2H2O is widely used in paper faced gypsum board and gypsum block and painting gypsum powder and model. Natural gypsum generally includes dehydrate gypsum and anhydrous gypsum.
1 Natural anhydrous gypsum mixed 3.7%; 2 Natural anhydrous gypsum mixed 0.0%. Based on Table 2, a sludge with a high content of SiO 2 Al 2O 3, used as a raw material for the development of an ESA, includes 60 70% moisture. It also contains chemical components such as SiO 2 (25 46%), Al 2O 3 (25 38%), and Fe 2O 3 (2 5%). When organic impurities ...
The anhydrous Portland cement (CEM I) used in this study was characterised by TGA-DTG analysis (Fig. 14). DTG curve shows four peaks. A first peak at around 125 °C, which can be attributed to the decomposition of gypsum (3.4 %) or the presence of a little free water. The amount of gypsum is slightly lower than that given in the technical sheet.
At calcination temperatures above 350℃, type III anhydrous gypsum transforms into type II anhydrous gypsum or natural anhydrite characterized by dense and stable crystalline phase with...
The natural gypsum powder includes anhydrous gypsum and CaS04.2H2O, if you want to commercialize the gypsum powder, you should adopt the CaS04.2H2O, after removing part of water by heating, it will become CaS04.1/2 H20.
This study explored the production of a medium–low strength α-hemihydrate gypsum (α-HH) from phosphogypsum using an autoclaved method. The influence of slurry …
Preparation of anhydrous from red gypsum and effect of high strength gypsum on its properties 779 gypsum products have stable performance because they have same hydrate (gypsum, CaSO4·2H2O). There is currently limited work reported on the CaSO4 II from red gypsum and activator of high strength gypsum. Moreover, the underlying mechanism
The compressive strength and porosity of natural anhydrite-based cementitious materials are related and the relationship satisfies R = R 0 exp (-BP). Natural anhydrite-based …
Another type of slag-containing cement is a supersulfated cement consisting of granulated slag mixed with 10 to 15 percent hard-burned gypsum or anhydrite (natural anhydrous calcium sulfate) and a few percent of portland cement. The strength properties of supersulfated cement are similar to those of portland cement, but it has an increased ...
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 …
Linyi Huihang Machinery Co., Ltd. was established in 2005 and is located in the Economic Development Zone of Pingyi County, Shandong Province (the company was formerly known as Pingyi Xingping Machinery Factory: established in 1993).The company's leading products are the research and development, manufacturing, installation, commissioning and product production …
The results show that the main components of natural gypsum minerals were gypsum dihydrate (71%), dolomite (27%) and potassium chloride (2%). The hydration of high …
The active ingredient is recovered by gradual precipitation during the production of anhydrous gypsum by leaching TG (Chen et al., 2021). ... The addition of 10% TG to clinker results in mechanical strength comparable to that of natural gypsum (Gázquez, 2012). Mixed specimens of TG and ground granulated blast furnace slag ...
According to GB/T 9776 − 2008 "Calcined gypsum", the compressive strength of 7 days of the cemented short-columnar α-HH was about 6.35 MPa, which it meets the strength requirements for ...
The findings reveal a notable reduction in the Length/Diameter ratio (L/D ratio) of α-HH crystals, diminishing from 17.79 to 0.96, in response to the incremental introduction of …
(strength) gypsum. One of the reasons plaster continues to be used in dentistry (orthodontic) ... Type III calcium sulfate has good solubility compared to natural anhydrous. The anhydrous sample weight obtained reached constant room conditions for 12 hours. The mass yield increases from 7 to 7.5 %, 6.6 % is the theoretical value for the ...
The present invention relates to a biodegradable resin composition comprising a biodegradable polymer resin pulverized to a size of 300 to 600 μm and modified natural anhydrite, and a method for preparing the same. In the present invention, in order to solve the problem that the physical properties of the master batch (M / B) are not uniform due to the problem of dispersibility and ...
Flue gas desulphurization gypsum (FGD gypsum) is an industrial byproduct generated during the desulphurization and purification processes of power plant flue gas emissions [1].This byproduct is primarily comprised of calcium sulfate dihydrate (CaSO 4 ·2H 2 O, DH), along with minor impurities and a high moisture content. With an abundance of coal-fired …
At calcination temperatures above 350℃, type III anhydrous gypsum transforms into type II anhydrous gypsum or natural anhydrite characterized by dense and stable crystalline phase with potential ...
According to the amount of crystalline water, gypsum can also be categorised into dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum. Hemihydrate gypsum can be further classified as alpha-gypsum and beta-gypsum [26], which are considerably different in physical performance. The alpha-gypsum is well crystallised and has high strength ...
