Flotation of quartz from quartz-feldspar mixtures by the HF method

Flotation experiments performed on a quartz-feldspar mixture demonstrate that quartz can be floated selectively from feldspars in diluted solutions of hydrofluoric acid (HF) simply by the aid of a frother. High grades and good recoveries were obtained for both quartz and feldspars. A feldspar concentrate of 99.9% at a recovery of 95.6% was produced. No further cleaning of the quartz concentrate (95.4% quartz at a recovery of 88.6%) was attempted. Feldspar impurities in the quartz concentrate is believed to be particles entrained in the froth, non-liberated quartz-feldspar particles, in addition to feldspar particles with sufficient hydrogen terminated silicon sites. (C) 2016 Elsevier Ltd. All rights reserved.