Shear flocculation and carrier flotation of fine hematite

Abstract

Enhancement of particle size by particle aggregation is one of the methods that can be used to improve recovery during the flotation of fine particles. This paper describes the results of two such processes, shear flocculation and carrier flotation, for enhancing the flotation of fine hematite. The shear flocculation of fine hematite particles with sodium dodecyl sulfate (SDS) collector was investigated as a function of the agitation rate of the suspension. The flotation separation of hematite and quartz is enhanced by this technique. In a second aspect of this investigation, pre-conditioned coarse hematite particles were added to the ore suspension to act as carrier particles for the fine hematite. The combined pulp is agitated to promote the coating of the reagentized coarse hematite with the fine hematite. Carrier flotation not only increase the recovery and grade of the hematite concentrate, but also cut the pre-flotation conditioning period by two-thirds over the flocculation/flotation process where no carrier particles were present.