Abstract：Aluminum hydroxide was prepared by solventing-out method using methanol and water in the decomposition of sodium aluminate. The solubility of Al2O3 and Na2O in methanol-water solvent with different mass ratios of methanol was investigated at 30℃. In addition, the effects of mass ratio of methanol and reaction temperature on decomposition process of sodium aluminate hydrate were studied, and the obtained product was characterized by XRD, IR, SEM techniques, particle size distribution and purity analysis. The results showed that the solubility of Al2O3 and Na2O decreased with the increase of methanol mass ratio to solvent, its effect on solubility of Al2O3 was more remarkable, increasing the molar ratio of sodium aluminate significantly up to a peak value when the mass ratio of methanol was 0.8. The decomposition rate of sodium aluminate hydrate reached to 80%~90% in 1~3 h when the mass ratios of methanol to solvent were 0.5~0.8, while the rate would slightly decrease with the increase of temperature. The product was identified as bayerite with integrated IR peaks at 30℃, and it transformed to gibbsite when the temperature was higher. The prepared aluminum hydroxide consisted of pure and uniform tabular particulates with average 100 nm in thickness and 1 mm in diameter.
2008, Vol. 8 
