Effect of Particle Size on Reverse Flotation of Quartz from Hematite using Dodecylamine in Alkaline Media

The effect of particle size on the reverse flotation of quartz from hematite was examined in alkaline media (pH-10), where both quartz and hematite were negatively charged whereby neither heterocoagulation nor slime coating took place.Results obtained are as follows.1) In the case of coarse particles system (149-210μm for both quartz and hematite) fairly good separation of quartz was obtained.2) Reverse flotation of quartz became difficult (both recovery and grade of quartz decrease) with decreasing the particle size: For intermediate particles system (44-53μm) the flotation results were tolerable, but for fine particles system (-10μm) no satisfactory results were obtained because of the concurrent flotation of hematite, though the recovery of quartz was improved as compared to that in acidic media.3) In the system consisting of coarse quartz and fine hematite, no reverse flotation of quartz was achieved, which may be due to the lack of collector (DAA) concentration for quartz'flotation as a result of adsorption of DAA onto surfaces of hematite fine particles.4) With the system consisting of fine quartz and coarse hematite no difficulty existed with the reverse flotation of quartz.