PRECIPITATION CONDITIONS OF CHEVREUL'S SALT FROM SYNTHETIC AQUEOUS CuSO4 SOLUTIONS

In this study, synthetic aqueous CuSO4 solution was prepared at various concentrations. Chevreul's salt was precipitated by passing SO2 through these solutions. Chevreul's salt, a mixed valence copper sulfite, Cu2SO3CuSO32H2O, was characterized by XRD and SEM. The effects of parameters such as initial solution concentration, SO2 feeding rate, reaction time, and initial solution pH on precipitation of Chevreul's salt were investigated. 2n factorial experimental design and orthogonal central composite design methods in the precipitation experiments were used. It was observed that the effective parameters on the precipitation of Chevreul's salt were initial solution concentration, SO2 feeding rate, and initial solution pH. The optimum conditions obtained for maximum copper precipitation were: initial solution concentration 1.14M, SO2 feeding rate 329.35L.h.-1, reaction time 25min, and initial solution pH 8.5. Constant parameters chosen at the initial stage of the reaction were: temperature 62C, stirring speed 600rpm, and reaction pH 3 (Calban et al., 2006). Under these optimum conditions, the percentage of precipitated copper from synthetic aqueous CuSO4 solutions was 99.95.