Multistage Gravity Beneficiation of Rutile in a Tar-Free Sand Residue

Abstract

This study reports on the concentration of rutile in the sand recovered from tar sand in Ondo State in Nigeria. The tar-free sand residue, approximately 90 % of which passes through a sieve with a pore size of 355 μm, was subjected to sieve analysis as well as sequences of panning gravity pre-concentration and shaking-table concentration at a slurry density of 25 % solids to improve the rutile content. The sand residue recovered in addition to the panned pre-concentrate and shaking table concentrates were also subjected to reflected light microscopy as well as transmitted light microscopy, counting using ImageJ software and X-ray fluorescence spectroscopy. The micrographs obtained showed that the samples contain rutile, dark-brown in color, interlocked with the major silica content and the content of rutile estimated by ImageJ software increased in the pre-concentrate from 7.90 % to 19.23 % in the final concentrate. X-ray fluorescence spectroscopy also showed that the rutile content increased in the pre-concentrate from 1.43 % to 31.02 % in the final concentrate. Therefore, the rutile content was successfully increased by the cheap gravity techniques of panning and shaking tables.