Inorganic polymers were synthesized from dehydroxylated aluminosilicate clay (metakaolinite) condensed with sodium silicate in a highly alkaline environment. The thermal treatment of aluminosilicate materials causes changes in their structure with an increase in the amorphous phase. For that kind of structural change XRD analysis is not appropriate, so those changes are currently assessed by in...

In-situ alumina-zirconia composite bodies were fabricated by heat treatment of gibbsite-zircon-kaolinite mixture at 1450℃. The current research investigated crystallization behavior and mechanical properties of the mentioned mixture in the presence of 5 wt.% MgO as an additive. X-ray diffraction (XRD) results showed that alumina, zirconia, and magnesium aluminosilicate were crystallized during ...

We investigated arsenate (As(V)) reactivity and surface speciation on amorphous aluminosilicate mineral (synthetic allophane) surfaces using batch adsorption experiments, powder X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). The adsorption isotherm experiments indicated that As(V) uptake increased with increasing [As-(V)]0 from 50 to 1000 microM (i.e., Langmuir type adsorptio...

A simple, processable precursor to mullite can be synthesized in quantities of 100 g in a few hours by direct reaction of silica, aluminum hydroxide, and triethanolamine in ethylene glycol. To delineate a processing window whereby precursor shapes can be transformed into mullite, the chemical and phase microstructural evolution of this precursor on pyrolysis to selected temperatures in air is f...

The hydration behaviour of Ca3Al2O6, Ca12Al14O33 and CaAl2O4 with added amorphous silica at 40, 65 and 90 1C has been studied for periods ranging from 1 to 31 days. In hydrated samples crystalline phases like katoite (Ca3Al2(SiO4)3 x(OH)4x) and gibbsite, Al(OH)3, were identified, likewise amorphous phases like Al(OH)x, calcium silicate hydrates, C–S–H, and calcium aluminosilicate hydrates, C–S–...

Brown corundum dust is a solid waste produced during the preparation of brown with bauxite as raw material. The has relatively high gallium content; therefore, it great value to recover from this kind dust. In paper, range analysis and characterization methods, including XRD, XRF, SEM-EDS, EPMA, were used determine occurrence gallium. It was found that mainly present in potassium-rich phase, wr...

Geopolymers are a class of X-ray amorphous alkali aluminosilicate gel binder materials with potential applications in a wide range of areas. In particular, geopolymers can provide significant improvements over traditional Portland cement technology in applications requiring resistance to acid or salt attack, or thermal stability at temperatures up to 1000°C. The quasi-zeolitic nature of some of...

There is some ambiguity regarding the fate of Mg during alkali activation Mg-rich precursors within broader field activated materials (AAMs). The present work addresses this issue by studying reaction products in AAMs synthesized from (Na-Mg) aluminosilicate glasses. Here, instead magnesium silicate hydrate (M-S-H) phase, exclusively forms an amorphous (AMS) phase. Compared to M-S-H, AMS a more...