Kinetic comparison of sulphide mineral flotation performance in the cyclone underflow and overflow streams of an industrial concentrator

摘要

Comparison of the flotation kinetics of liberated pyrite particles in a flash flotation cell and a first rougher column has been performed resulting in the development of a mathematical relationship which takes the form: k_(fi)~2 = k_(ci) * m_(Ri). This relates the first order rate constants of the flash flotation machine (kf) and the rougher flotation column (k_c) for each size class (i) in the floatable size range, using the mass recovery (mR) of each size class within the flash flotation machine. This relationship was further refined to include all size classes and takes the form: k_c * m_R = 0.001 In k_f~2 + 0.008.The mass recovery in the flash flotation machine was used to normalise the data, allowing for the considerable differences in both feed properties and operating strategy to be accounted for. The flash flotation cell receives cyclone underflow material as its feed, while the rougher receives cyclone overflow material. The flash flotation machine on this particular circuit recovers predominantly fast floating well liberated particles, with a minimal froth depth and short residence time; while the rougher column has a very deep froth and long residence time. The ability to relate these two very different unit operations via particle specific properties provides impetus for further investigation into the methods we use to analyse flotation data. The similarities in the rate constants of both machines for the size range -106 + 38 μm are also of interest for the possibility of mill discharge (cyclone feed) flotation. The rougher column receives the fine split of the cyclone feed, while the flash flotation machine receives the coarse split, if a single machine could be used to recover all these particles in a single stage it would result in considerable cost savings to the industry via decreased plant footprint and operating costs, most notably via reduced water and reagent consumption.