塩酸溶液中におけるアルミノケイ酸塩の溶解(第2報)溶解速度と溶解量

抄録

The dissolution behavior of aluminosilicates was different according to the mixing ratio of Na₂SiO₃ to AlCl₃ which had been used to synthesize the samples. When the mixing ratio was below 1.5, the samples, being aluminum silicates, were insoluble even in strong acid solution, but above 2.0, the samples, being sodium aluminosilicates, were easily soluble. When the mixing ratio was increased from 1.5 to 2.0, the pH value, at which the half amount of aluminosilicates was dissolved, increased rather suddenly. As for the samples synthesized at a constant pH, those obtained in strong alkaline solution were the most soluble irrespective of the mixing ratio. Solubility of the ones synthesized in a weak alkaline solution was not high and the value was little affected by the mixing ratio. Dissolution of sodium and aluminum from sodium aluminosilicates followed the rate equations of the first order. When sodium and aluminum were dissolved, linear relations were obtained between log k_Na vs. pH and log k_Al vs. pH of the suspension, and both k_Na and k_Al were the higher, the lower the pH of the suspension was. From these relations, it has been concluded that k_Na/k_Al≒20 at each pH of the suspension.