Unconventional column flotation of low-grade gold fine particles from tailings

摘要

This work shows results obtained in the treatment of gold bearing tailings, using H1C, high intensity conditioning in combination with a modified "enriching" flotation cell named C3P, or three-product column. This cell has shown to yield, in all cases, clean, high grade concentrates because it separates selectively the froth rejected particles (drop-back or third product) and uses two washing water inputs. In a tailing sample, where gold was liberated, concentrate recoveries were of the order of 15 percent Au, with grades higher than 160 g t~(-1) Au and enrichment ratio of the order of 120. With low gold grades (0.15- 0.4 g t~(-1) Au) and a poor liberation, this 3pc cell was able to produce a product (12 percent gold recovery) with the quality of a rougher flotation concentrate (13 g t~(-1) Au). These results could not be attained in the conventional column cell operating under similar conditions. H1C, as a feed pre-trcatment assisted the column flotation performance enhancing selectivity, recovery and process kinetics. Mass transfer and interfacial phenomena in columns and in HIC (gold-gold particle and gold-carrier particle interactions) were used to explain results obtained. Potential practical applications of this HIC-3PC-flotation scheme in the treatment of the valuable flotation tailings are discussed.