Abstract: Based on the crystallization of AlCl₃·6H₂O in the acid-leaching filtrate of gangue，the activity coefficients model of Bromley-Zemaitis in software OLI can be used to predict the solubilities of AlCl₃·6H₂O in different systems，such as HCl， NaCl，KCl，and H₂O，under the conditions of different temperatures（10~70 ℃） and concentrations（0~17 mol/kg）.Meanwhile predicting values were compared with the literature ones.Results showed that in the solutions of H₂O，NaCl，and KCl， temperature and solution concentration had little influence on the solubility of AlCl₃·6H₂O，and so did the temperature in the solution HCl.But with the increase of the concentration of HCl，the solubility of AlCl₃·6H₂O reduced sharply.The predicting values were similar to the literature ones.It demonstrated that the activity coefficients model of Bromley-Zemaitis in software OLI could be used to predict the solubilities of AlCl₃·6H₂O in the above mentioned 4 systems.It could provide phase equilibrium prediction for industrial crystallization AlCl₃·6H₂O.

Key words: AlCl₃·, 6H₂O；solubility；activity coefficients model of Bromley-Zemaitis