هل ستصبح شريكنا القادم ؟
In this study, Temperature Programmed Decomposition (TPD) and Sequential Chemical Extraction (SCE) were applied to FGD gypsum to identify the Hg species in it. The FGD gypsum samples were collected from seven coal-fired power plants in China, with Hg concentrations ranging from 0.19 to 3.27μg/g.
WhatsApp: +86 18221755073
Semantic Scholar extracted view of "Fate of mercury in flue gas desulfurization gypsum determined by Temperature Programmed Decomposition and Sequential Chemical Extraction." by Zhen-wu Zhu et al. ... {Zhu2016FateOM, title={Fate of mercury in flue gas desulfurization gypsum determined by Temperature Programmed …
WhatsApp: +86 18221755073
The iron and calcium elements can be reused as iron-making raw materials, but the sulfur element in the gypsum is required to be removed as it has a harmful effect on the properties of iron. Herein, the influence of carbon and pyrite on the desulfurization behavior of red gypsum is systematically investigated by high-temperature decomposition.
WhatsApp: +86 18221755073
the application of temperature-dependent thermal properties under natural fire especially for the cooling phase. 2 | STATE OF THE ART 2.1 | Thermal decomposition of gypsum plasterboards In general, gypsum plasterboards consist of a porous solid core of primar-ily calcium sulfate dihydrate CaSO 4 2H 2O between two layers of paper.
WhatsApp: +86 18221755073
Abstract. The decomposition of CaSO 4 · 2H 2 O under the conditions of TA consists of two consecutive reactions, firstly CaSO 4 · 0.5H 2 O then CaSO 4 III being …
WhatsApp: +86 18221755073
and/or mass loss rate as a function of time and/or temperature (see Fig. 1 for an example). 0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 0 200 400 600 800 1000 / ° C)) Temperature ( °C) Fig. 1. Example of TGA mass and mass loss rate curves (Type C gypsum board heated at 20 °C/min). ARRHENIUS-RATE THERMAL DECOMPOSITION KINETICS
WhatsApp: +86 18221755073
The temperature at which the gypsum binder (calcium sulfate hemihydrate) is industrially produced, between 80 and 180 °C, is often mentioned in the literature …
WhatsApp: +86 18221755073
Gypsum plaster is considered a sustainable binder, produced by the calcination of gypsum (calcium sulfate dihydrate: CaSO4∙2H2O) in a dry process at temperatures that range from 125 °C to 180 °C (Borrachero et al., 2008; Gartner, 2009).
WhatsApp: +86 18221755073
It is important to know the characteristics of gypsum before using it. The thermal characteristics of gypsum produce the following thermal changes. 60~150°C …
WhatsApp: +86 18221755073
$$text{The decomposition of gypsum to Plaster of Paris is as follows:-}$$ $$ 373,K $$ $$ CaSO_4. 2H_2O xrightarrow{bigtriangleup} CaSO_4 . 1/2H_2O $$
WhatsApp: +86 18221755073
This paper describes the influence of high temperatures on some physical and mechanical properties of gypsum mixtures. Two gypsum mixtures were designed, first one was composed of gypsum and citric acid and the second one contained standardized sand also. The samples were exposed to temperatures from 50°C to 1000°C.
WhatsApp: +86 18221755073
This was mainly due to water being driven from the gypsum matrix at temperatures up to about 300 °C and gases (such as CO 2 and SO 2) from the decomposition of relevant minerals at higher treatment temperatures being released. …
WhatsApp: +86 18221755073
Due to microwave heating and calcium ferrite formation, the decomposition temperature of FGD gypsum decreased to around 800°C in air atmosphere. Based on the XRD patterns and SEM images, the ...
WhatsApp: +86 18221755073
The structure and composition of the gypsum at elevated temperatures were studied by means of scanning electron microscopy, X-ray diffraction (XRD) and thermogravimetry (TG). The gypsum paste samples were heated to the temperatures from 50 to 1000 °C. The changes in the structure of gypsum were in good accordance with …
WhatsApp: +86 18221755073
Due to microwave heating and calcium ferrite formation, the decomposition temperature of FGD gypsum decreased to around 800°C in air atmosphere. Based on the XRD patterns and SEM images, the ...
WhatsApp: +86 18221755073
However, in the reducing atmosphere with different CO content, the CaSO 4 begin to decompose at temperature about 800°C, which was much lower than that of the pure reactive CaSO 4, about 970°C .The reason is the impurities in the phosphogypsum, such as SiO 2, Al 2 O 3 and Fe 2 O 3, reacts as catalyst to reduce the initial decomposition ...
WhatsApp: +86 18221755073
The process of decomposition reaction between flue gas desulfurization (FGD) gypsum and anthracite is complex, which depends on the reaction conditions and atmosphere. In this study, thermogravimetric analysis with Fourier transform infrared spectroscopy (TGA-FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) …
WhatsApp: +86 18221755073
This would tend to increase the decomposition temperature[7]. Such problems can be avoided by using a fluidized bed reactor, where temperature homogenit.v and high mass and heat transfer rates can be obtained. 3.2 Gypsum decomposition Gypsum (CaSO~. 2H20) becomes anhydrous at temperatures above 160: CaSOa" …
WhatsApp: +86 18221755073
Phosphogypsum (PG) is not only a solid waste discharged from the phosphate fertilizer industry, but also a valuable resource. After high-temperature heat treatment, it can be decomposed into SO2 and CaO; the former can be used to produce sulfuric acid, and the latter can be used as building materials. In this paper, the catalytic …
WhatsApp: +86 18221755073
An overall powdery/blurry effect on the crystal surfaces can be observed. The changes in structure and composition of the gypsum matrix at high temperatures detected in this work were in agreement ...
WhatsApp: +86 18221755073
Herein, the influence of carbon and pyrite on the desulfurization behavior of red gypsum is systematically investigated by high-temperature decomposition. In the absence of carbon, a small amount of anhydrite (CaSO4) phase is decomposed after sintering at 1200 °C for 2 h.
WhatsApp: +86 18221755073
Thermal decomposition of PG in air generally occurs at very high temperatures exceeding 1400 C. [27] PG can also decompose in a reducing …
WhatsApp: +86 18221755073
Gypsum is a naturally occurring mineral that has been used by humans for various purposes for thousands of years. It is a versatile mineral with a wide range of applications in construction, agriculture, industry, and even art. ... If gypsum is heated to higher temperatures and for an extended period, it loses all its water content ...
WhatsApp: +86 18221755073
The direct decomposition temperature of CaSO 4 is extremely high (Dewing and Richardson, 1959; Liu et al., 2007), which causes a severe sintering of CaO, resulting in the reduced activity of CaO ... It was discovered that the reaction efficiency of gypsum decomposition was high between 1050 °C and 1075 °C.
WhatsApp: +86 18221755073
Due to the above chemical properties, the decomposition of gypsum occurs at higher temperature ranges than plaster of Paris or hemihydrate samples. For the former, at high heating rates, decomposition occurs from 100 to about 300 °C, with overlapped peaks of the two steps .
WhatsApp: +86 18221755073
Toxic elements can be immobilized by the glassy slag, which has high stability . The reductive decomposition behaviors of gypsum residue have been studied by many researchers (Fang et al., 2020 ...
WhatsApp: +86 18221755073
Besides, it could be reasonably expected that mercury in FGD gypsum might be released in the gas phase during the calcination process of wallboard production, based on the release curves of FGD gypsum samples from TPD, even though the temperature in the industrial process (about 160°C) is lower than the peak temperature of the …
WhatsApp: +86 18221755073
The temperature at which the gypsum binder (calcium sulfate hemihydrate) is industrially produced, between 80 and 180 °C, is often mentioned in the literature [14,15,16,17].However, dehydration from gypsum to basanite (CaSO 4 ·0.5H 2 O) starts at a much lower temperature. The dehydration temperature depends on the …
WhatsApp: +86 18221755073
Fate of mercury in flue gas desulfurization gypsum determined by Temperature Programmed Decomposition and Sequential Chemical Extraction Zhu, Z.; Zhuo, Y.; Fan, Y.; Wang, Z. Journal of Environmental Sciences 43: 169-176
WhatsApp: +86 18221755073
Coordinated disposal of FGD gypsum and power plant concentrated brine via preparation of α-hemihydrate gypsum. Materials Today Sustainability, Volume 25, 2024, …
WhatsApp: +86 18221755073
