Role of sulphates in cement clinkering: The calcium silicosulphate phase
β Scribed by Y.B. Pliego-Cuervo; F.P. Glasser
- Publisher
- Elsevier Science
- Year
- 1978
- Tongue
- English
- Weight
- 263 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0008-8846
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β¦ Synopsis
Calcium silicosulphate is reported to have the chemical composition Cas(SiO,)2(SO,). However, the synthetic product prepared in air at IIO0Β°C contains 0.46 wt % H20.
It is not known how the water is present in the structure; assuming it to be OH-, the formula is CasSi2SO~.88(OH)0.2~. This water is essential as silicosulphate cannot be synthesized in a dry atmosphere: moreover samples prepared in moisture-containing atmospheres decompose to Ca2SiO, and CaSO, upon reheating in dry atmospheres containing S02 and 02.
β’ Β° β’
El sulfosilicato de calcio se ha reportado con una composlclon qu{mica Cas(SiO,)2(SO,). Sin embargo, el producto sint~tico preparado en aire a llO0 Β° contiene el 0.46% de H20 en peso.
No se conoce como est~ el agua en la estructura : suponiendo que sea como OH-la f6rmula es : CasSi2SO11.ss(OH)o.2,. El agua es esencial para su sintesis, el sulfosilicato no puede ser preparado en atm6sfera seca; a~n m~s muestras obtenidas en atm~sferas h~medas se descomponen en Ca2SiO, y CaSO, por recalentamiento en atm6sferas secas que contienen S02 y 02.
π SIMILAR VOLUMES
The CaO-rich portions of the systems CaO-A~203-SiO2-K2SO,, CaO-AC203-K2SO,-CaSO,, CaO-A~203-SiO2-K2SO,-CaSO, and CaO-A~203-Fe203-CaSO,-K2SO, have been studied experimentally. Schemes are presented showing phase assemblages compatible at subsolidus temperatures. Melting commences at about 825Β°C in as
Crystallization of a liquid similar to that present in Portland cement at clinkering temperatures has been studied. Its composition (in wt %) is CaO = 54.8, A~203 = 22.7, Fez03 = 16.5, Si02 = 6.0. Prolonged crystallization or slow cooling yields the equilibrium phases: C3A, ferrite close to C,AF, an