Research on Low Alkali Flotation Process of a Copper Mine in Hubei

Copper ore in Hubei contains 0.67% copper and 0.012% molybdenum. The high-alkaline copper-molybdenum mixed flotation process was used on site which caused problems such as high lime consumption and difficult wastewater treatment. Through the use of combined collectors and adjustment of ore slurry potential, under the conditions of lime and calcium peroxide dosages of 400 g/t respectively, and the dosage of butyl xanthate + ethyl sulfoxide (mass ratio 1:1) was 80 g/t (at this time, the pH of the pulp is 10.5, and the potential of the pulp is 177.4 mV). A rough concentrate with a copper grade of 14.4%, a recovery rate of 88.42%, a molybdenum grade of 0.16%, and a recovery rate of 58.3% was obtained. When sulfhydryl agents were added together with collectors, a gold recovery increases from 55% to 68% when the dosage is increased from 0 g/t to 40 g/t, an increase of 13%; the silver recovery increases from 66 % to 68%, an increase of 2%. Ultraviolet adsorption capacity tests show that under the same conditions, 0.34 mg of combined collector could be absorbed on per gram of copper pyrite surface, which was higher than 0.2 mg of single butyl xanthate and 0.28 mg of single ethyl disulfide, which enhanced the collection effect. Using a closed-circuit process of one roughing, one cleaning and two scavenging, the bulk concentrate with a copper grade of 19.555%, recovery of 96%, and a molybdenum grade of 0.32%, recovery of 56.25% was obtained. Compared with the field high alkaline flotation process, the copper grade and recovery of concentrate increased under low alkalinity flotation conditions.