A selective flotation of cassiterite with a dithiocarbamate-hydroxamate molecule and its adsorption mechanism

N-[(3-hydroxyamino)-propoxy]-N-octyl dithiocarbamate (OAHD) was designed as cassiterite flotation collector. AFM clearly showed that OAHD assembled on cassiterite surfaces to generate innumerable nano-aggregates. The FTIR and XPS recommended that the adsorption of OAHD was related to forming the [GRAPHICS] and [GRAPHICS] configurations in the surface OAHD-Sn(IV) complexes, which improved the hydrophobicity, decreased the surface energy and hydrophilicity index, and realized an effective flotation enrichment of cassiterite particles. In addition, the dithiocarbamate group might act as a hydrophilic group for calcite flotation, while as a chelating group for cassiterite flotation, which rendered OAHD to return the lower flotation recovery of calcite than octyl hydroxamic acid, and the excellent collecting properties towards cassiterite.