Effects of particle size and particle interactions on scheelite flotation

Effects of size distribution (particle size and content of fine fraction (<10 μm)) on scheelite flotation were studied using flotation tests and theoretical calculations. The results show that particle size influences the scheelite recovery and the performance of combined reagents. The scheelite recovery is lowered by adding fine particles (<10 μm) into the pulp containing coarse particles. Extended DLVO (EDLVO) theory confirms that the fine fractions (<10 μm) could interface with the coarse fractions. The interaction energy and fluid forces are relative to the particle size, which might explain why the fine fractions influence the scheelite flotation. The highest recovery of scheelite using combined reagents as collector and optimum ratio of combined reagents were determined by scheelite particle size and reagent performance. However, the optimum adding order was only determined by reagent performance, which has nothing to do with particle size.