STATISTICAL INTERPRETATION OF FLOTATION KINETICS FOR A COMPLEX SULFIDE ORE

Kinetic flotation models were applied to data from tests with reactive gases (hydrogen and sulphur dioxide) on a complex sulphide ore. The m odels were evaluated by statistical techniques, after non-linear regre ssion on the model parameters. It is found that a first order model wi th rectangular distribution of floatability fits the test data very we ll. Statistical tests on copper, silver and lead kinetic data show tha t reactive gases have a greater influence on silver mineral flotation compared to copper-lead minerals. Sulphur dioxide generally gives high er ultimate silver recoveries than sodium bisulphite, and the magnitud es depend on the interactions between the modifiers and the flotation gases (5% H-2, N-2 and air). Correlation analysis suggests that silver flotation is probably determined by the floatability of a separate mi neral such as tetrahedrite. Multivariate analysis on pulp chemistry da ta reveals that the pulp pH is the most significant variable among the pulp chemistry data, provided the grinding is iron-free. The pH effec t is attributed to the addition of sulphur dioxide. After autogenous o r non-reducing grinding, the naturally-occurring variations in redox l evels are too small to influence the flotation results, despite the te sts being made with a complex sulphide ore.