Investigation Of Flotation For Fine Columbite-Tantalite

Ta and Nb possess the superiorities of high melting point, good ductibility, low vapor tension, causticity-resistant and high thermal conductivity and so on. They are the important raw materials of electronic, atomic, space navigation, steel and chemical industry, etc. The demands of Ta and Nb are keeping increasing tendency with steady steps in the world. Gravity seperation is the most important process for columbite-tantalite ore disposal, but it is low recovery in the gravity seperation of columbite-tantalite and affects the technical index and economic benefit of concentrating plants. Recent years, the investigation of the columbite-tantalite flotation reagents has been greatly done by the mineral processing researchers in the domestic and overseas. Thereinto, the fatty acids, arsonic acids, phosphonic acids, hydroximic acids, cation collectors are the efficient collectors. However, as a result of high reagents expenses and environment pollution, they are not applied very well. Accordingly, it is important for investigation of the columbite-tantalite flotation technics and reagents.Based on the summary of the columbite-tantalite ore mineral processing technology in the domestic and overseas , the single minerals flotation and the choice of the flotation reagents have been done. The results indicats that benzylhydroximic acid has high collected ability for columbite-tantalite at pH6.0~10.0 . By means of benzylhydroximic acid plus WT2 compound collector, it make the technical index and flotation reagents adaptability high and the flotation reagents expense low, also bring the coopration function of 1+1>2.Combining the nation "ten five" technology project and Xiangning project, the investigation of the Xianning columbite-tantalite has been made. When the feed contains 0.029% Ta2O5, flotation concentrate of Ta2O5 is 0.882% and the recovery is 88.45%. In virtue of magnetic-flotation-gravity, the flotation concentrate can be separated to obtainTa-Nb-W concentrate containing 13.53% Ta2O5, and a recovery of 78.94% relativeflotation feed, this result surpasses greatly the demand of "the investigation of the flotation flowsheet and reagents of fine columbite-tantalite ore in Xiangning" and the nation "ten five" technology project.Lastly, by means of the dissolve chemistry of benzylhydroximic acid, UV spectrophotometer, IR spectrophotometer, X-ray diffractometer and adsorption capacity, it is deeply investigated the action mechanism between benzylhydroximic acid and columbite-tantalite. According to the crystal structure characteristic of columbite-tantalite, we discuss what the active center of columbite-tantalite is and the relation between benzylhydroximic acid molecular structure and its collected ability . The results of the dissolve chemistry of benzylhydroximic acid indicate that benzylhydroximic acid ion and molecule adsorb together on the minerals at pH 6.0-10 which reach the adsorption capacity maximum. The test results of the IR spectrophotometer indicating: at pH5~6, Mn2^ of the columbite-tantalite surface chelated with Benzylhydroximic acid to form five ring chelate matter. Becase the bond length Mn ?O is bigger than Ta桹, manganese ions on columbite-tantalite fractured surface expose easily to act with benzylhydroximic acid ion. so, Mn + is thought as primary flotation active center.