A survey has been conducted on a refractory gold (pyrite) concentrator which utilises flash flotation on the cyclone underflow stream and a flotation column on the cyclone overflow stream. Both cells are considered to be performing a first rougher operation on their respective streams. A comparison of the size and nature of the target mineral for flotation (pyrite) in the concentrates from both these unit operations has shown that they both recover predominantly liberated pyrite in the fine and intermediate size classes (-150 mu m). The flash flotation machine on this particular circuit recovers 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. To date no comparison of a flash flotation cell and a column cell has been published in the literature and the results presented here are the first of their kind to the best of the authors' knowledge. Analysis of the liberated pyrite recovery data has culminated in the development of a mathematical relationship which takes the form: k(fi)(2) proportional to kci * m(Ri). This relates the first order rate constants for liberated pyrite in the flash flotation machine (k(f)) and the rougher flotation column (k(c)) for each size class (i) in the floatable size range (+38/-150 mu m), using the mass recovery (m(R)) of each size class within the flash flotation machine. To account for the considerable differences in both feed properties and operating strategy of the two flotation machines, the rate constant data was normalised using the mass recovery of the total solids to concentrate by the flash flotation machine, allowing a relationship to be developed. The ability to relate these two very different unit operations via particle specific properties provides impetus for further investigation into the methods used to analyse flotation data. The similarities of both the properties of the recovered pyrite particles and the rate constants of both machines for the size range +38/-106 mu m 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. (C) 2016 Elsevier Ltd. All rights reserved.