Impact of the grinding conditions on the particle properties and flotation of a scheelite ore

Milling and flotation operations are typically studied separately in the literature, although it is well-established that the grinding environment is a determining factor on the flotation performance. This study aims at evaluating the effect of grinding conditions on the discharge particle properties and the subsequent flotation responses in the specific case of semi-soluble salt-type minerals. Three different ores were used as case studies: a scheelite (low-grade), an apatite (medium-grade) and a fluorite (high grade) ore. All three ores were dry-milled, wet-milled, and wet-milled in presence of depressants down to a particle size distribution specific to each ore, and the mill discharge was then floated under pre-established conditions in an Outotec mechanical cell. The concentrates and tailings of flotation tests were characterized with a Mineral Liberation Analyzer (MLA). This article presents the comparative results of the flotation tests conducted on the scheelite ore based on particle properties including size, composition, liberation, association, entrainment and shape.