The solubility of AlCl//3 in pure water was 31. 09 and 31. 77 wt-pct at 25 degree and 85 degree C, respectively, and decreased to 10 and 0. 1 wt-pct when 20. 3 and 37 wt-pct hydrochloric acid (HCl) were added in solution. The equilibrium constant for the solubility of hexahydrate, activities, and activity coefficients of AlCl//3 and H//2O were calculated. The results were useful in leaching nonbauxitic ores. Simultaneous solubilities of AlCl//3, FeCl//3, KCl, and NaCl in solutions of HCl-H//2O were also determined and their effects on the purity of AlCl//3 multiplied by (times) 6H//2O crystallized from mixed salt solutions are briefly discussed.