Dissolution kinetics of celestite (SrSO4) in HCl solution with BaCl2

Leaching of celestite (SrSO4) in hydrochloric acid solution with BaCl2 was investigated to produce SrCl2 in solution, which is the main source for SrCO3. The effects of variables such as stirring speed, BaCl2 and HCl concentrations, and temperature and particle size, and also the presence of NaCl in the leaching solution were studied. The leaching was modeled according to the shrinking core model. The activation energy for the leaching process in 8.25 × 10− 3 M BaCl2 solution equilibrated with 0.5 M HCl was found as 68.8 kJ mol− 1. This value reveals that the dissolution of celestite is a chemical reaction controlled process. In agreement with the model, the reaction rate is inversely proportional to the particle size and increases as 0.73, 0.70 and 0.19 powers of the H+, Cl− and Ba2+ concentrations, respectively.