An agglomeration study of sulphide minerals using zeta potential and settling rate. Part II: sphalerite/pyrite and sphalerite/galena

Zeta potential and agglomeration were studied in Part I for galena and pyrite in the presence of Ca, Pb and Fe(II) ions, and each other. In Part II, the study is extended to sphalerite in the presence of Ca, Pb and Fe(II) ions, and in the presence of galena or pyrite. ded ions consistently increased the iso-electric-point (iep). The maximum agglomeration did not correspond to the iep for sphalerite alone or with Ca ions but increased with pH. An attractive hydrophobic force is suggested. For Pb and Fe(II) ions, maximum agglomeration did occur close to the iep. Lead ions promoted agglomeration while Fe(II) had a minor dispersing effect. With the mixtures of sphalerite with either pyrite or galena, maximum agglomeration corresponded to the zeta-potential of the two minerals approaching zero. For equal sized particles at least, homo- and hetreocoagulation appear to occur. sults are compared to those in Part I and some observations on the relevance of these observations to flotation selectivity are offered.