Selective Flotation And First-principles Study On Copper-Molybdenum Ore

Flotation separation of copper-molybdenum surfide ores is difficult, due to its properties of complex composition, serious associated phenomenon, low grade, etc. So copper-molybdenum separation has drawed researchers’increasing attention. In this test some basic studies have been carried out, in order to provide references for the follow-up researchers.The flotation tests show that different reagents could have influences upon chalcocite and molybdenite’s flotation behavior. Different pH tests using butyl xanthate, O-isobutyl-N-ethoxycarbonyl thionocarbamate (Z-200), kerosene as collectors respectively indicated that chalcocite and molybdenite had good flotability in pH range, and that molybdenite’s flotability was better than that of chalcocite. Butyl xanthate and Z-200had good catching ability for both chalcocite and molybdenite, while kerosene had better selectivity. Sodium sulfide’s collector-removal test showed that adding some sodium sulfide, it could remove collectors. The solution chemistry calculation of sodium sulfide showed that HS-played a major role in the collector-removal process. The depressant test showed that the mercaptoacetic acid had higher inhibition for chalcocite than molybdenite. Mercaptoacetic acid’s solution chemistry calculation showed that HSCH2COO-played a major role in the depressant test.In real ore tests, butyl xanthate and Z-200were adopted in the copper-molybdenum mixed flotation as combined collector with a grinding fineness of66.12%(-0.074mm). Sodium sulfide was added used to remove the hydrophobic substance contained in the ore and then added mercaptoacetic acid to depress chalcocite and kerosene to collect molybdenite, which could separate copper and molybdenum. The results of middling regrinding closed-circuit tests showed that the final grade of copper and molybdenum concentrate could reach28.43%and48.66%respectively, with respective recovery rates of90.10%Cu and76.13%Mo, achieving the expected flotation effect.In order to better understand chalcocite, molybdenite and the action principle between minerals and reagent, research has been conducted with the first principle theory by using the soft of Materials Studio5.5to study the electronic structure of chalcocite and molybdenite. The results showed that different electronic structure properties (energy band structure, density of states, Mulliken population value, charge density, etc.) of chalcocite and molybdenite would directly impact on the flotation performance of chalcocite and molybdenite. By studying the chemical frontier orbital energy, the surface energy of minerals, and the adsorption energy of minerals and reagent, it could know that the acting force between mercaptoacetic acid and minerals was stronger than the other reagents, which proved that it is highly feasible to use mercaptoacetic acid to depress chalcocite in copper-molybdenum separation.