| In China, with the development and utilization of mineral resources and the exhaustion of high-grade mineral, exploitation of low-grade mineral resources got more and more attention. However, there were still some problems in flotation of low-grade mineral: the more collector, the lower grade and recovery. The main purpose of the paper: reducing collector’s dosage and enhancing concentrate’s grade and recovery. Gold mines was chosen as research object, gold occurrence state was analysed through technological mineralogy at the first time. Then the most optimum conditions was confirmed from single-factor experiments. It provided date supporting for open circuit test and closed-circuit test. Mechanism between collector and ore was studied by infrared spectroscopy. It provided theoretical basis for sorting.Process mineralogy studies indicated that the gold grade of ore was 2.14 g/t, and sulfur grade was 1.28%, Pyrite was the main gold-bearing mineral, and the ore type was low sulfur gold-bearing ore. Native gold was the main gold minerals. Phase analysis showed that 70% of the gold was in sulfides, and the rest was in the gangue. Pro-gold pyrite iswas relatively fine, so flotation was more suitable for separation.In flotation, single-factor method was used, the main factors which were explored were the slurry PH, sodium sulfate dosage and different collector dosage. The results of single factor showed that the sodium carbonate dosage was 100 g/t, copper sulfate dosage was 200 g/t; the composite collectors were PAX and Dithiophosphate BA. Then exploring the ratio and dosage of composite reagents. PAX: Dithiophosphate BA =3:1, and the composite reagents dosage was 100g/t.The open-circuit experiment carried out according to the results of single factor experiment.The principle process of open-circuit test was one roughing, three selected and four scavenging. The concentrate grade was 19.30 g/t, and recovery was 52.61%. Tailings grade was 0.45 g/t, and recovery was 6.47%.The principle process of closed-circuit test was one roughing, three selected and two scavenging. The concentrate grade was 18.40 g/t, and recovery was 79.72%. Tailings grade was 0.50 g/t, and recovery was 20.28%.The flotation effect was better than using single collector, and collector dosage reduced 50 g/t. The optimal dosage of single collector was 150 g/t, and composite collector was 100 g/t. The flotation effect of composite collector was better, and dosage reduced 50 g/t.Infrared analysis showed that PAX was branched chain organic, perhaps contained aromatic ring and nitrocellulose. SIBX was straight chain organic, perhaps contained amine or unsaturation. Dithiophosphate BA was unsaturated branched chain organic, perhaps contained C=C, C≡N, C=O, C-P-O-,-P-S-. The ore perhaps contained-OH, NH4+, CO32-, Al2O3, Si-O, Ti O3.Infrared analysis between ore and collector showed that Dithiophosphate BA was in physical and chemical adsorption, and PAX was in chemical adsorption. So PAX had better selectivity than that of Dithiophosphate BA, and concentrate grade was higher. Composite collector and ore was not only in physical adsorption, chemical adsorption, but also in co-adsorption. Therefore, composite collector had more surface adsorption than single collector. It would be have good flotation indicators, reduce the dosage of collector, and reduce the cost of beneficiation. |
PDF Full Text Request