Influence of calcination temperature on hydration behavior, …

The results show that the increase in calcination temperature resulted in higher anhydrite content, and CPG showed similar chemical and mineral compositions at …

Materials | Free Full-Text | Experimental Study and …

As shown in Figure 3, the HH phase began to appear as the temperature reached 140 °C, and there was no characteristic diffraction peak of DH when the …

Preparation, Characterization, and Formation Mechanism …

Calcium sulfate hemihydrate whiskers were synthesized successfully via one-step hydrothermal crystallization method using phosphogypsum at 130 °C for 240 min with an initial slurry mass fraction of 2.5wt%. The phase compositions, microstructures, thermal properties and molecular structures of asprepared samples were analyzed by …

Caractérisation structurale multi-échelles de la calcination et de …

Le gypse (CaSO4·2H2O) est la matière première du plâtre. Il est chauffé entre 100 et 200 °C pour obtenir par déshydratation partielle l'hémihydrate (CaSO4 · 1 2H2O) qui, mélangé à de l ...

Mechanism of calcination modification of phosphogypsum and …

The calcination might eliminate the adverse effect of harmful impurities, and with the increase of calcination temperature and time, the removal effect was enhanced. Moreover, during calcination, the gypsum phase was transformed to β-hemihydrate and III-anhydrate, which has strong hydration activity.

CaSO4

La température et le temps nécessaire dépendent de la pression partielle de l'eau. Des températures de 170 ° C sont utilisés dans la calcination industrielle, mais à ces températures l'anhydrite commence à se former. ... (vapeur) Le minéral est en fait partiellement déshydraté : hémihydrate de sulfate de calcium ou de gypse ...

Calcination

Calcination: Roasting: Calcination is the process in which the ore of the metal is heated to a high temperature in the absence or limited supply of air or oxygen. Roasting is the process in which the ore is heated to …

Formation of -Hemihydrate Inside of a Gypsum Crystal …

Because hemihydrate formation is endothermic, energy is consumed by dehydrating the outer layers of the gypsum crystal. In this case, the inner part of the …

Calcium Sulfate Hemihydrate

When heated at about 160 °C, gypsum is converted in its hemihydrate form (CSH) which is used in plaster of Paris. The chemical reaction responsible for the setting and hardening …

Caractérisation structurale multi-échelles de la calcination et de …

Le gypse (CaSO4·2H2O) est la matière première du plâtre. Il est chauffé entre 100 et 200 °C pour obtenir par déshydratation partielle l'hémihydrate (CaSO4 · 1 2H2O) qui, mélangé à de l'eau, se dissout tandis que des cristaux de gypse précipitent pour former une matrice résistante. Ce cycle qui paraît simple est compliqué par l'existence d'autres phases dans …

The Mechanism of the First Hydration-Dehydration Cycle of …

One of the major findings from this study was that the properties of the generated hemihydrate and dihydrate after the 1st reaction cycle were based on several factors …

Influence of calcination temperature on hydration behavior, …

The results show that the dehydration of PG to β-hemihydrate gypsum depends on calcination temperature and time. ... With the best calcination temperature of 800 °C, gypsum plaster showed a ...

calcination temperature

Viele übersetzte Beispielsätze mit "calcination temperature" – Deutsch-Englisch Wörterbuch und Suchmaschine für Millionen von Deutsch-Übersetzungen.

Influence of calcination temperature on hydration behavior, …

Modern building gypsum obtained under controlled calcination conditions at low temperature (i.e., 135–180 °C), in contrast, is generally of high purity and contains …

Investigation of Solid-State Reactions Using Variable Temperature …

Purpose. The object of this study was to demonstrate the applicability of variable temperature X-ray powder diffractometry (XRD) to investigate solid-state reactions using aspartame as a model compound. Methods. Aspartame exists as a hemihydrate (ASH) under ambient conditions and converts to aspartame anhydrate (ASA) at ∼130°C. ASA …

N AIM g /A 1 Microchimica .Acta, 'C 0 ti A Reactivity of …

Centre d'Etude de l'Energie Nucleaire, Mol-Donk, Belgium. ... hemihydrate with 60 gm. of water, held in a Dewar ... temperature of calcination is raised this reaction

Traduction de "INTO ALPHA-HEMIHYDRATE" en français

Traductions en contexte de "INTO ALPHA-HEMIHYDRATE" en anglais-français avec Reverso Context : PROCESS FOR CONVERTING CALCIUM SULPHATE DIHYDRATE INTO ALPHA-HEMIHYDRATE

Calcination parameters on phosphogypsum waste recycling

The calcination at low temperatures transforms phosphogypsum (PG) waste in a material with binder properties. This study evaluated two parameters of PG calcination: kiln residence time (1 h, 2 h, and 5 h) and temperature (120 °C, 150 °C, and 200 °C). The main objective was to find adequate calcination conditions considering PG …

Translation of "alpha-hémihydrate de" in English

Translations in context of "alpha-hémihydrate de" in French-English from Reverso Context: alpha hémihydrate de sulfate de calcium et procédé de fabrication d'alpha-hémihydrate de sulfate de calcium

Thermal analysis of calcium sulfate dihydrate sources used to …

The temperature of the hemihydrate transition for LPdce-08 is 151.7 °C at a DTA value of ‐37.567 μV with a heat change of about ‐179.2 μV/mg and the temperature of the hemihydrate transition for LPdce-10 is 148.8 °C at a DTA value of ‐37.544 μV …

Translation of "alpha-hémihydraté" in English

Translations in context of "alpha-hémihydraté" in French-English from Reverso Context: en vue de former du gypse dur, procédé caractérisé en ce que le gypse bêta-hémihydraté est transformé directement en gypse alpha-hémihydraté, à une température supérieure à la température de calcination de 95 º c, en ce que le gypse dur est retiré du post-réacteur

Influence of α-Calcium Sulfate Hemihydrate on Setting, …

As previously mentioned, soluble gypsum calcium sulfate hemihydrate can easily absorb moisture and thus accelerate the rate of expansion and hardening. Figure …

Influence of calcination and GGBS addition in preparing β-hemihydrate …

As the calcination temperature increased, the peak of CaSO 4 ·2H 2 O became weaker and even diminished. When the calcination temperature was increased to 140 °C, a weaker CaSO 4 ·2H 2 O peak was observed in the calcined PG, compared to the peak of other phases, suggesting that a large portion of dihydrate PG had been …

Energies | Free Full-Text | Influence of the Calcination Temperature …

The paper assesses the influence of the calcination temperature of synthetic gypsum binder on the binding properties of innovative gypsum pastes, as well as on masonry and plastering mortars. The calcination process of gypsum binder was carried out at four different temperatures ranging from 170 to 190 °C. The specimens for testing …

calcination de réglage de température de gypse temps

Caractérisation structurale multi-échelles de la calcination et de . Le gypse (CaSO42H2O) est la matière première du plâtre. Il est chauffé entre 100 et 200 °C pour obtenir par déshydratation partielle l'hémihydrate (CaSO4 1 2H2O) qui, mélangé à de l'eau, se dissout tandis que des cristaux de gypse précipitent pour former une matrice résistante.

The dihydrate‐hemihydrate transformation in gypsum

Il est chauffé entre 100 et 200 °C pour obtenir par déshydratation partielle l'hémihydrate (CaSO4 · 1 2H2O) qui, mélangé à de l'eau, se dissout tandis que des cristaux de gypse ...

Formation of -Hemihydrate Inside of a Gypsum Crystal …

Because hemihydrate formation is endothermic, energy is consumed by dehydrating the outer layers of the gypsum crystal. In this case, the inner part of the crystal should not reach the temperature, which is necessary for the formation of -HH. The formation of beta-hemihydrate is an endothermic reaction as well.