Hydration products of calcium silicates and calcium aluminates often are difficult to identify by X-ray methods. In this study the hydration products of the aluminate phase especially under the influence of additional chloride ions were studied. Special X-ray measurement conditions must be applied for accurate identification including 1. In situ control of relative humidity 2. Exclusion of CO2 ...

Mineral wools are the most common insulation materials in buildings worldwide. However, mineral wool waste is often considered unrecyclable because of its fibrous nature and low density. In this paper, rock wool (RW) and glass wool (GW) were studied as alkali-activated material precursors without any additional co-binders. Both mineral wools were pulverized by a vibratory disc mill in order to ...

Experimental work has been performed to investigate the precipitation mechanism of aluminum hydroxide phases from sodium aluminate/sodium carbonate pregnant solutions by carbon dioxide gas purging. Such result leaching calcium aluminate slags with solutions, in accordance Pedersen process, which is an alternative process for alumina production. The concentration ions solution revealed as a key ...

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...

Calculation of chemical equilibria involving a liquid requires a full knowledge of chemical potentials (or activities) of all the oxide components present in the liquid phase. This is a rigorous requirement compared to that for solid compounds, where only total free energies need to be known in order to calculate their stabilities relative to other compounds; obviously the difference stems from...

We apply density functional theory and the augmented spherical wave method to analyze the electronic structure of V2O3 in the vicinity of an interface to Al2O3. The interface is modeled by a heterostructure setup of alternating vanadate and aluminate slabs. We focus on the possible modifications of the V2O3 electronic states in this geometry, induced by the presence of the aluminate layers. In ...

Stabilization efficiencies of spinel-based construction ceramics incorporating simulated nickel-laden waste sludge were evaluated and the leaching behavior of products investigated. To simulate the process of immobilization, nickel oxide was mixed alternatively with gamma-alumina, kaolinite, and hematite. These tailoring precursors are commonly used to prepare construction ceramics in the build...