chemical equation dehydration of gypsum

chemical equation dehydration of gypsum

Dehydration Pathways of Gypsum and the Rehydration

Their experimental results reveal that gypsum dehydration proceeds through only a single CaSO 4 2H 2 O → γ-CaSO 4 step when the ambient water vapor pressure is less than 26664 Pa; however, a two-step process of CaSO 4 2H 2 O → β-CaSO 4 0.5H 2 O → γ

From atom level to macroscopic scale: Structural mechanism of gypsum ...

2022年4月1日 The first step is dehydration: heated to 100–200 °C, gypsum (CaSO 4 2H 2 O) releases water as vapor [1, 2] and, depending on temperature and water vapor partial

Gypsum hydration: a theoretical and experimental study

2019年12月3日 1. Ultrasonic results indicate gypsum hydration reaction consists of two stages: the dissolution of hemihydrate in the first stage and the nucleation and

Dehydration Pathways of Gypsum and the Rehydration Mechanism

2019年4月26日 In the high-temperature and low water vapor pressure region, gypsum dehydrates to form γ-CaSO 4 in a single-step process (CaSO 4 2H 2 O → γ-CaSO 4 );

The dehydration process of gypsum under high pressure

2017年8月29日 It is worth noting that the process of dehydration of gypsum to anhydrite involves a change in specific volume (gypsum: 74.5 cm3/ mol; bassanite: 52.8 cm3/mol;

The dehydration process of gypsum under high pressure

2011年9月30日 It is worth noting that the process of dehydration of gypsum to anhydrite involves a change in specific volume (gypsum: 74.5 cm 3 /mol; bassanite: 52.8 cm 3

Fast in-situ X-ray scattering reveals stress sensitivity of gypsum ...

2021年5月24日 The dehydration of gypsum to hemihydrate has been studied for decades because it is an important model reaction for understanding fluid-triggered earthquakes,

Kinetics of Gypsum Dehydration - Springer

2017年8月25日 Abstract. The kinetics of gypsum dehydration in non-isothermal conditions with constant heating rate as well. in quasi-isotherm, quasi-isobar regime, was

Dehydration‐induced damage and deformation in

2012年3月10日 The large compaction and the absence of strain localization in the deformation test suggests that dehydrating rocks maybe seen as soft inclusions and could thus induce ruptures in the

CaSO4*2H2O = CaSO4 + H2O - Balanced Chemical Equation

CaSO4*2H2O = CaSO4 + H2O is a Decomposition reaction where one mole of Gypsum [CaSO 4 2H 2 O] decomposes into one mole of Calcium Sulfate [CaSO 4] and two moles of Water [H 2 O] Reaction Type. Decomposition. ... To balance a chemical equation, enter an equation of a chemical reaction and press the Balance button. The balanced equation will ...

Plaster of Paris Formula, Properties Application

Explore Plaster of Paris – its chemistry, manufacturing process, applications, safety aspects, and environmental impact. Introduction to Plaster of Paris. ... It is formed by the partial dehydration of gypsum, a mineral composed of calcium sulfate dihydrate (CaSO 4.2H 2 O).

Gypsum Properties, Formation, Uses and

2023年9月9日 Complete Dehydration: If gypsum is heated to higher temperatures and for an extended period, it loses all its water content, transforming into anhydrous calcium sulfate (CaSO4), commonly known

The thermal dehydration of synthetic gypsum - ScienceDirect

1995年12月20日 The main dehydration of the calcium sulphate dehydrate part of synthetic gypsum occurs between 95 and 170°C (heating rate 5°C min −1) and seems to proceed via a process with an activation energy of 392 ± 100 kJ mol −1 for α-values between 0 and 0.1. For α-values between 0.1 and 0.7, the reaction can be described by a first-order ...

Calcium Sulfate Dihydrate - an overview ScienceDirect Topics

In addition, synthetic gypsum is recovered via flue-gas desulfurization in some coal-fired electric power plants and used interchangeably with natural gypsum in some applications. 19.2.1 Definition of gypsum. Gypsum is a sulfate mineral composed of calcium sulfate dihydrate and has the chemical formula CaSO 4 2H 2 O. It exists as massive ...

Novel approach to thermal degradation kinetics of

2020年3月26日 dehydration of gypsum into bassanite was carried out by a two-dimensional JMA mechanism, while the second process, attributed to the complete dehydration of gypsum, was performed according to a three-dimensional JMA. ... Gypsum of chemical formula CaSO 4 2H 2O, also called calcium sulfate dihydrate, is a versatile

Fast in-situ X-ray scattering reveals stress sensitivity of gypsum ...

2021年5月24日 The dehydration of gypsum to hemihydrate has been studied for decades because it is an important model reaction for understanding fluid-triggered earthquakes, and due to the global use of plaster ...

Dehydration Pathways of Gypsum and the Rehydration

2019年4月26日 Thermodynamic Data for CaSO 4 2H 2 O, β-CaSO 4 0.5H 2 O, and H 2 O (g) Thermodynamics is a rigorous theory and is widely used in chemistry, materials science, metallurgy, and other fields. The large number of thermodynamic calculations used in this work is very helpful for determining the gypsum dehydration pathways.

Gypsum board reaction kinetics at elevated temperatures

2012年2月10日 The equations that are presented define the composition of the gypsum boards, the energy that is absorbed/produced during gypsum board heating and the reaction kinetics parameters (Arrhenius parameters and reaction model) for three main reactions: evaporation of free moisture content, dehydration of chemically bound water and crystal

Dehydration behavior of FGD gypsum by simultaneous TG

2010年10月26日 The dehydration behavior may vary significantly among different gypsum types, such as natural gypsum and many kinds of chemical gypsums [6, 23, 25, 26]. Differences in crystalline characteristics (i.e., size, habit, amount of defects) and impurities appear to be the most important factors resulting in discrepancies of dehydration

Thermal behaviour and kinetics of dehydration of gypsum in

2009年1月11日 Thermal behaviour and kinetics of dehydration of gypsum in air have been investigated using in situ real-time laboratory parallel-beam X-ray powder diffraction data evaluated by the Rietveld method. Thermal expansion has been analysed from 298 to 373 K. The high-temperature limits for the cell edges and for the cell volume, calculated using

A 4D view on the evolution of metamorphic

2017年7月31日 Gypsum dehydration has proven to be analogous to reactions involving silicate minerals 18 but is much more suitable for synchrotron study since it completes in hours rather than years and

The Dehydration Kinetics of Gypsum in a Fluidized Bed Reactor

2000年10月1日 THE DEHYDRATION KINETICS OF GYPSUM IN AFLUIDIZED BED REACTOR S. R. CAVE and R. G. HOLDICH (AFFILIATE)Department of Chemical Engineering, LoughboroughUniversity, UKM easurements have been made of the rate of dehydration of desulphurized gypsumwith particle diameters in the range of 35±67 m m

Structural evolution of gypsum (CaSO42H2O) during thermal dehydration ...

2022年12月6日 The volumetric thermal expansion coefficient of gypsum is 1.31 × 10–4 K–1. The site occupancy of Ow in β-hemihydrate continuously decreases from 0.8 and reaches approximately 0.5 at ...

The dehydration process of gypsum under high pressure

2011年9月30日 The effects of pressure on the dehydration of gypsum materials were investigated up to 633 K and 25 GPa by using Raman spectroscopy and synchrotron X-ray diffraction with an externally heated diamond anvil cell. At 2.5 GPa, gypsum starts to dehydrate around 428 K, by forming bassanite, CaSO4 hemihydrate, which completely

Structural evolution during the dehydration of gypsum

2009年6月1日 The dehydration of pure and waste gypsums has been examined using in situ synchrotron angle-dispersive X-ray diffraction. Pure gypsum was studied under a number of defined environments; various ...

(PDF) Scrutinizing Gypsum Board Thermal Performance at Dehydration ...

2011年3月1日 the first two stages of gypsum thermo chemistry (Equations (1) and (2)) by gradually heating up the samples with a low heating rate up to 300 8 C. For this purpose a special ‘sample-holding ...

Thermo-poro-mechanics Modelling of Gypsum Dehydration

2017年7月12日 The governing equations are integrated numerically using the finite element method. The obtained results show a significant correlation between gypsum dehydration and creation of fluid pathways. The proposed model can be generalised to describe the effects of dehydration in other minerals carrying water in their crystal

Dehydration Pathways of Gypsum and the Rehydration

2019年4月4日 Over the past decades, many studies have proposed the existence of various subhydrates with a general chemical formula of CaSO 4 nH 2 O, where the numerical value of n ranges from 0 to 0.67. 25,28 If the dehydration product CaSO 4 nH 2 O occurs upon the heating of gypsum, then the dehydration reaction of gypsum can be

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