Based on flotation tests of a low-grade copper sulfide ore, a processing technique was developed, composed of flash flotation of Cu, Cu-S bulk flotation, and Cu-S separation after regrinding of roughing concentrate from bulk flotation. Effects of factors on flotation were also explored, including grinding fineness, flotation reagent, regrinding fineness of roughing concentrate from bulk flotation. Ammonium dibutyl dithiophosphate was used as the collector for Cu in the flash flotation, a combination of ammonium dibutyl dithiophosphate and butyl xanthate as the collector for Cu-S bulk flotation, lime as a sulfur depressant, and terpineol oil as a frother. With grinding fineness of -0.074 mm 60% and regrinding fineness of -0.045 mm 70%, a closed-circuit test for the raw ore assaying 0.40% Cu and 2.45% S produced a bulk copper concentrate grading 19.49% Cu at 87.68% recovery, and a sulfur concentrate grading 48.65% S at 35.11% recovery. It is concluded that efficient separation and enrichment of copper and comprehensive recovery of sulfur from this low-grade copper ore can be actualized by this technique.

low-grade  /  copper sulfide ore  /  flotation  /  flash flotation  /  bulk flotation  /  Cu-S separation  /  copper concentrate  /  sulfur concentrate