Grobler, J.D., Exxaro Resources, South Africa; Bosman, J.B., PESCO, South Africa
In a gravity separation device, particle shape, size and density all play a role. The combination of these determines where each individual particle reports to in the viscous fluid, where particle crowding (solids to water ratio) also plays a role. To understand the performance of gravity separation devices in the heavy mineral industry, these particle characteristics need to be measured. There are various challenges in analysing particle density and particle size simultaneously for the purpose of quantifying gravity separator performance, not to mention particle shape. These analytical challenges include the high cost of high-density sink-float fractionation, toxicity of high-density sink-float media, inability of sink-float media to fractionate at densities greater than 4.0 g/cm3, and the time-intensive nature of these fractionations. The use of the detailed particle-by-particle output from Qemscan® particle mineral analyses (PMA) as a fast and cost-effective alternative is evaluated. The size and density outputs from the Qemscan® were employed to characterize the performance of a heavy mineral spiral concentrator as an example. Critical analytical requirements are to be addressed before the Qemscan® output data can be utilized. © The Southern African Institute of Mining and Metallurgy, 2011.
Analytical challenge; Gravity separation; Gravity separator; Heavy minerals; High costs; High-density; Individual particles; Mineral analysis; Output data; Particle characteristics; Particle densities; Particle shape; Performance; Performance evaluation; QemSCAN; Viscous fluids; Water ratio; Cost benefit analysis; Fractionation; Separators; Silicate minerals; Zinc ore treatment; Mineral industry