Behaviour of different particle size fractions in the flotation of calcite from wollastonite and microcline

Abstract

Entrainment experiments as well as flotation experiments were carried out on the calcite rich wollastonite-microcline ore from Jokkmokk, Sweden, in a 1.35 L laboratory cell. Entrainment experiments show that it could be an important contributor to the flotation of slime sized calcite from wollastonite and microcline. This, along with the probable excess consumption of the collectors by the finer particles at the expense of the coarser particles, led to low selectivity and, thereby, low grades and recoveries in normal flotation. The use of split flotation led to significant improvements in selectivity and also showed the possibility of reducing the consumption of collectors by over 25%. Calcite recoveries of 90% at grades of 90% CaCO 3, are possible in all the fractions except in the −10 μm fraction.