Beneficiation of oxide ores using dense medium cyclones. A simulation study

Recent investigations of particle behavior and segregation phenomena in a cyclone underline that little is known about particle distribution within a heavy medium separation. For this purpose, density profiles in a heavy medium cyclone (HMC) is measured with techniques such as computational fluid dynamics (CFD) in combination with discrete element modelling (DEM), electrical resistance tomography (ERT), X-ray tomography, particle dynamics analyzer (PDA) etc. Along with these modern efforts of determining the performance of HMC, traditional methods depending on empirical inferences based on experimental data are still important and in progress. The aim of this research was to investigate the possibility of using HMC for the concentration of problematic ores which are not coarsely aggregated. Towards this purpose, current empirical methods were applied to experimental data which were derived from float-sink tests of selected heavy minerals and Fe, Mn, and Cr ore samples. Low density difference between particles made the enrichment difficult using other gravity methods like jigs and shaking tables. After determining physical and mineralogical properties of the samples, appropriate size fractions were prepared for float-sink tests. Combination of sodium polytungstate and tungsten carbide powder were used to prepare non-toxic heavy liquids with density up to 3.5 g/cm3. Using the sink-float test results and existing empirical models for high-density DMC plants simulations were performed. The results of the simulations followed by experimental studies showed that HMCs are applicable to process Fe, Mn, and Cr ores with acceptable grade and recovery