Ab initio quantum mechanical calculations were performed on Al(OH)3, Al(OH)4, NaAl(OH)4 and related species with varying numbers of explicit water molecules to elucidate the structural, spectral and energetic properties of the possible species. We find that Al(OH)3 reacts with H2O in the gas-phase with an exoergicity of 24.1 kcal/mol to produce Al(OH)3H2O, which has shorter Al-OH distances, lar...

The continuous casting tundish is the last metallurgical reactor where molten metal flows before solidifying in mold. A covering powder can be used for improving steel cleanliness; this case it named ‘active slag’. objective of work to evaluate, laboratory, effect three kinds powders on cleanliness a SAE 1055 modified - Ca-aluminate, Ca-Mg-aluminate, and an Al-silicate powder, analysing their i...

The fast loss of fluidity sodium silicate-activated slag (SS-AAS) systems have been widely studied in the literature. In this study, rheology these cements has correlated with evolution reaction products formed over time. For purpose, a combination experimental characterization techniques, to study pore solution composition and microstructure SS-AAS pastes thermodynamic calculations applied. in...

Co-Mo/γ-Al2O3 catalysts with different pore shapes were synthesized for the ex situ upgrading of extra heavy oils by hydrodesulfurization (HDS), hydrodemetallization (HDM), and hydrodeasphaltization (HDA). The using aluminum oxides that prepared various methods. It was found product obtained thermochemical activation gibbsite leads to formation slit-shaped pores in oxide, while application hydr...

This study evaluated the effect of different types of filler in a resin-based pit and fissure sealant on fluoride release, recharge, and lactic acid neutralization. Resin-based sealant was incorporated with 5% w/w of the following fillers: calcium aluminate cement (CAC), synthesized mesoporous silica (SI), a CAC and SI mixture (CAC+SI), glass-ionomer powder (GIC), and acetic acid-treated GIC (G...

The addition of active seed for increasing the precipitation rate leads to formation fine Al(OH)3 particles that complicates separation solid from mother liquor. In this study, enhanced coarse sodium aluminate solution using agglomerated was investigated. Aluminum salt (Al2(SO4)3) were used at initial process. About 50% obtained when these agglomerates as a in amount 20 g L−1 25 °C within 10 h....

DETERMINATION OF SILICA OXIDE iron ores usually are found in intimate association with sllica and phosphorus compounds. heir quantitative separation and purification sometimes present difficult problems to the chemist. Silicic acids may represent various degrees of dehydration. They are exceedingly weak, but combine with metallic oxides and form some of the most stable , oxides in nature, the s...

The compositions and molecular structures of anhydrous and hydrated cements are established by using advanced solid-state nuclear magnetic resonance (NMR) spectroscopy methods to distinguish among different molecular species and changes that occur as a result of cement hydration and setting. One- and two-dimensional (2D) solid-state (29)Si and (27)Al magic-angle spinning NMR methodologies, incl...