塩酸水溶液中におけるモリブデン酸の溶解度ならびに酸沈法によるモリブデン酸の回収
1980 年 96 巻 1104 号 p. 91-96
詳細
1980 年 96 巻 1104 号 p. 91-96
Precipitation of molybdic acid from aqueous molybdate solutions with the addition of hydrochloric acid was investigated through the solubility measurements of molybdic acid in hydrochloric acid solutions and the precipitation experiments of molybdic acid from artificial aqueous molybdate solutions.
The solubility of molybdic acid in an aqueous hydrochloric acid solution is greatly increased with the increase in the concentration of hydrochloric acid in the range of 0.01-3mol/l. A small increase in the solubility of molybdic acid with temperature elevation was observed. Solubility of molybdic acid in a hydrochloricacid solution containing sodium chloride or ammonium chloride decreases to some extent.
The precipitation of molybdic acid from artificial aqueous molybdate solutions is sometimes greatly influenced by the presence of certain electrolytes. Particularly, the presence of sulphates or the co-existence of sulphates and sodium chloride causes the decrease in molybdic acid precipitation. Because of the sensitive response of the molybdic acid precipitation to the concentration of hydrochloric acid, the careful control of acid addition is important to achieve a better precipitation.
