Evaluation for the beneficiability of yellow silica sands from the overburden of lignite mine situated in Rajpardi district of Gujarat, India

Abstract

A representative feed sample of Yellow sand was wet-sieved in order to recover the desired fractions for glass making. The mass percentage of (–600 +300) μm and (–300 +125)μm fraction was found to be 44.2 and 55.8% (ratio 1:2.26).Hence, this ratio which satisfies the size specifications for glass making sand, was maintained for all the down stream processing studies. The chemical analysis of the ‘wet sieved desired fractions for Yellow sand’ (WSDFy) i.e., mixture of –600 +300μm and –300 +125μm fractions, showed that the material does not satisfy IS specifications since it still contains 0.41% iron. WSDFy analysed 95.8% silica, 0.41% Fe2O3, 0.25% TiO2 and 0.3% Al2O3. In order to further value add WSDFy, the same was subjected to attrition followed by magnetic separation. Tests at optimum conditions gave a non-magnetic fraction (sand product) which analysed 98.5% silica with 0.08% Fe2O3, 0.05% TiO2 and 0.2% LOI. This is found matching with IS specifications for Grade III sand only