process of hemihydrate gypsum

Microstructure and mechanical properties of β …

2009-8-20 · A process for producing alpha-hemihydrate gypsum from dihydrate gypsum includes feeding a slurry comprising the dihydrate gypsum and water into a heating tube, heating the heating tube at a temperature effective to generate steam and pressure from the water, wherein the steam and pressure are effective to convert the dihydrate gypsum to the alpha-hemihydrate gypsum, and withdrawing the …

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Alpha hemihydrate

2017-11-6 · Abstract: The effects of Na +, Mg 2+, Al 3+ and Fe 3+ ion concentrations on the crystal morphology of calcium sulfate hemihydrate whiskers formed via a hydrothermal method have been studied. In the presence of Al 3+ concentrations higher than 1×10 − 3 mol/L the whiskers were significantly shorter and thicker and the presence of Mg 2+ and Fe 3+ resulted in shorter whiskers.

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The α

Kelley, Southard and Anderson1 have shown that the thermodynamic properties of calcium sulphate hemihydrate depend on whether the hemihydrate is produced from gypsum calcined in a …

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Gypsum hydration: a theoretical and experimental study

ABOUT US. John Wing is president of the consulting firm John Wing, PE, LLC. Decades of service to the phosphate industry involved consulting, process design, project management, technical service, process development, & production supervision.

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11.16 Gypsum Manufacturing

2016-7-21 · However, the process is costly because a long grinding time is required for the gypsum ore. Xu, Li, Luo, and Xiang (2011) reported on the formation of CaSO4 ·0.5H2 O whiskers from CaCO3 -bearing desulfurization gypsum via the acidi?cation-hydrothermal route

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JP2002249317A

Autoclave‐Free Formation of α‐Hemihydrate Gypsum. ... gypsum produced in the wet limestone-gypsum flue gas desulfurization process not only encroaches on lands but also causes serious ...

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process of hemihydrate gypsum

2018-7-7 · Gypsum samples prepared with various water to gypsum ratios and containing two polymer admixtures – HEMC or PVAC (in weight fraction 1%) were studied by DSC in setting and mechanical experiments. Results are shown graphically and discussed. A difference between the effect of both admixtures on the process of gypsum – calcium hemihydrate ...

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PROCESS FOR PREPARING GYPSUM HEMIHYDRATE

Once it has been washed, the remaining alpha hemihydrate is mixed with the sulfuric acid, under conditions in which the alpha hemihydrate is unstable and recrystallized like gypsum, producing a co-crystallized and unattacked gypsum with a low P 2 O 5 content. The main characteristics of the process are : high phosphoric acid content;

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Determination of Calcium Sulfate Dihydrate and …

In order to expand the utilization methods of desulphogypsum and meet the increasing need of α-hemihydrate gypsum, this paper studies the reasonable autoclave process of α-hemihydrate gypsum made from desulphogypsum.

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New Development in Dihydrate -Hemihydrate processes: …

A process for producing alpha-hemihydrate gypsum from dihydrate gypsum includes feeding a slurry comprising the dihydrate gypsum and water into a heating tube, heating the heating tube at a temperature effective to generate steam and pressure from the water, wherein the steam and pressure are effective to convert the dihydrate gypsum to the alpha-hemihydrate gypsum, and withdrawing the alpha ...

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α-hemihydrate gypsum 的翻译结果--cnki翻译助手

to obtain the gypsum binder (α-hemihydrate gypsum) characterized by good physical-mechanical properties in the process of dehydration of dihydrate gypsum under hydrothermal conditions. 2 12 223242 5262 2 Θ, [deg] Relative intensity, u.a. DDDD D D D D D D D D D D D D D D D Fig. 1. X-ray diffraction pattern of the raw materials (FGD gypsum ...

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IJC’S EXPERIENCE WITH HEMIHYDRATE PROCESS

2017-10-11 · resulting alpha-hemihydrate developed at various ratios and had different properties, depending on the acid solution concentration and the gypsum/acid solution mixing ratio. An alpha-hemihydrate composed of smooth, compact, acicular monocrystals, which according to reference data promises the best utilitarian aspect, was obtained using 20 wt.% acid

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process of hemihydrate gypsum

High-strength α-plaster of Paris can be produced by dehydrating gypsum dihydrate partially in aqueous salt solution. Single factor test was employed to investigate some factors effecting the compressive strength of hydratedα-plaster of Paris which was made by ...

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process of hemihydrate gypsum

The new treatment process works well with synthetic gypsum by reducing the water demand with increasing treatment time. Note that once again the process resulted in a reduction in both the soluble anhydrite content and the residual gypsum content, turning both into hemihydrate.

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Gypsum boards from waste material: a cost effective …

According to the different preparing methods, it can change to α hemihydrate gypsum or β hemihydrate gypsum. 根据制备工艺的不同,可获得α型半水石膏或β型半水石膏。 短句来源 With arthogonality experiment method and SEM, TG-DTA, the properties of α hemihydrate gypsum and the factors of influence on them were studied, and the optimum condition of autoclave technology ...

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