It is now well accepted and demonstrated that calcium silicate, calcium aluminate and calcium sulfo aluminate (ettringite, AFm) phases exhibit a good capability to fix metals and metalloids. Unfortunately the role of minor phases and especially calcium-ferric aluminate phase, shorthand C4AF is not well defined. In other systems like in soils or sediments iron phases play a key role in the fixat...

calcium aluminates (ca) are the most important hydraulically setting cements used for preparing refractory castables, because they develop high strength at very early ages after placements.  the anhydrous phases of this kind of cements are ca, ca2 and traces of c12a7 and alpha-alumina. the major hydraulic phase in all of the ca cements including ciment fondue is ca. once hydrated, it starts to ...

the major hydraulic phase in all the calcium aluminate cements including ciment fondue is ca (caal2o4). once hydrated, it starts to form the hexagonal crystals of cah10 and c2ah8 that depending on the time and temperature of hydration convert to the cubic crystals of c3ah6 and ah3. the nature, sequence, crystallinity and microstructure of hydrated phases of commercial refractory calcium alumina...

Early-age hydration with neutral or alkaline (0 M to 8 M) solutions was studied in calcium sulfoaluminate clinker (CSA) using isothermal conduction calorimetry, X-ray diffraction (both continuous and discontinuous, i.e., after detaining isopropanol) infrared spectroscopy. Hydration 0.1 NaOH observed be similar water. At the next highest concentration (1 M), however, reaction rate slower, due pr...

The purpose of this study was to evaluate the physical properties and hydration evolution of calcium aluminate cement (CAC) compositions containing an advanced dispersant. The compressive strength, dimensional change, apparent porosity and quantitative X ray diffraction analysis (XRD) of the cement pastes were carried out over 1-15 days of curing (with the samples immersed in distilled water) a...

Partial replacement and co-hydration of calcium aluminate cement (CAC) with ladle slag was investigated in this study as a pathway valorizing the reducing economic cost CAC. The impact on physical microstructural properties were analysed using different techniques such mechanical strength test, freeze-thaw, sulfate attack, XRD, SEM etc. Thermodynamic modelling used to predict phase assemblages ...

The objective of this paper is to investigate the use calcium aluminate cements as alternative within context nuclear waste stabilization by solidification. Using an external 60Co source, effect γ-radiation on H2 gas production one cement-based materials (cement “Ciment Fondu”) and its stable hydrates, was studied. amount produced these cement pastes found be much lower (up five times less) tha...

A large amount of wet-discharged fly ash has caused serious harm to the ecological environment, so utilization received attention. This paper analyzes formation products ash–lime system under autoclave process by X-ray diffraction (XRD) analysis and thermogravimetric–differential thermal (TG-DSC) analysis. The hydrothermal reaction product generation was quantitatively analyzed using hydrochlor...