R31 filter aid enhances filtration of fine hematite concentrate particles

Abstract R31 filter aid containing macromolecular long-chain organic compounds with carboxyl, sulfonic, amide groups was used to improve the filtration of fine hematite concentrate in this study. The carboxyl, sulfonic and amide groups adsorbed on the surface of hematite concentrate particles. The macromolecular long-chain organic compounds flocculated fine hematite concentrate particles to increase the apparent particles size. The H+ ions ionized by carboxylic acid and sulfonic groups compressed hydration film of hematite concentrate particles. The hydrophobic groups in the organic matter decreased the surface wettability of fine hematite concentrate particles. Thinner hydration film and less wettability decreased the water adhesion on surface of hematite concentrate particles. The dehydration rate of filter cake increased from 1.82 × 10−3 ml∙cm2∙s−1 to 3.20 × 10−3 ml∙cm2∙s−1 with a 75.82% increase, when the mass concentration of R31 filter aid increased from 0 to 1800 g/t, and the filter cake moisture content decreased from 19.88% to 17.72%.