Hydration mechanism and sintering characteristics of hydratable alumina with microsilica addition

Add time:08/15/2019    Source:sciencedirect.com

Hydratable alumina is potential for the application in refractory industry as one of Ca-free binders, but it is greatly limited because of the excess hydration of rho-alumina (ρ-Al2O3). In this study, hydration mechanism and sintering characteristics of hydratable alumina with different microsilica addition are researched, via the rheological, hydration, and morphological characteristics of ρ-Al2O3–SiO2–H2O system during aging are analyzed using various techniques. Boehmite (AlOOH) initially appears and increases in content after 1 h aging at the setting temperature of 30 °C and relative humidity of 80%. As the addition of microsilica increases from 0 wt% to 8 wt%, the SiO2 coating combines with the boehmite gel and efficiently suppresses the hydration reaction, resulting in decrease of relative hydrated densities from 5.42% to 4.27% and increase of zeta potential from −10.1 mV to −21.3 mV. Further, the thus-formed SiO2-AlOOH gels cover the surface of hydratable alumina particles, connect with each other, and get distributed homogeneously around hydratable alumina particles to harden, thus inhibiting the further hydration. This is reflected by the high-temperature X-ray diffraction and the final sintering microstructures. Overall, these results indicate that the 6 wt% addition of microsilica makes hydratable alumina promising for application as a kind of controlled binders.

We also recommend Trading Suppliers and Manufacturers of hydrate (cas 16657-47-9). Pls Click Website Link as below: cas 16657-47-9 suppliers

Prev:Synthesis of 2-bromo-1-aryl-1H-indenes via a Ag(I) promoted domino 2π-electrocyclic ring-opening/4π-electrocyclization reaction of 1,2-diaryl substituted gem-dibromocyclopropanes
Next:Full Length ArticleDeveloping a new hydrate (cas 16657-47-9) saturation calculation model for hydrate (cas 16657-47-9)-bearing sediments)