Removal of iron from quartz sands: A study by column leaching using a complete factorial design

Abstract The aim of the work was to decrease the iron content of ferrous quartz sands by fixed-bed column leaching with recycling of the leaching solutions in order to attain a product suitable for industrial use. Dissolution of iron was achieved by treating the sands in an acid medium with a reducing agent (oxalic acid) to convert Fe III into Fe II . The factors assumed to affect dissolution of iron, such as temperature, oxalic acid concentration, pH and flow-rate, were studied with a 2 4 full factorial design in order to assess the main effects and the interactions among the factors. Removal of 46.1% iron gives a product containing 0.0163% Fe 2 O 3 which is fit for industrial applications.