Mr. Zhifeng Zhang

Abstract:

The lead complex of benzohydroxamic (Pb-BHA), as an effective collector, has realized the mixed flotation of wolframite and scheelite to a certain extent. The Pb-BHA complex can be adsorbed on the surface of wolframite and scheelite by bonding with the O on the surface of tungsten minerals through the lead ion in the structure. However, current research cannot explain the detailed difference between wolframite and scheelite in flotation behavior and kinetic, and it is of great significance for the design of corresponding reagents and the development of efficient flotation flowsheets in actual ores. In this paper, the flotation behavior and kinetics of two tungsten minerals under the Pb-BHA system are systematically studied. The flotation rate constant K for scheelite(0.20) is higher than wolframite(0.16), which is the reason why the tungsten minerals lost in the actual tailings are mainly wolframite. Subsequently, the internal reasons for the difference in their flotation behaviors are analyzed through adsorption experiments, solution chemical analysis, and quantum chemical calculation. The quantum chemical calculation showed that the ΔE(|EHOMO(mineral)-ELUMO(Pb-BHA)|) for wolframite is lower than scheelite but the adsorption capacity of Pb-BHA on scheelite surface is higher than wolframite. The contradiction is further explained by the different interaction characteristics between water molecules and mineral surfaces. The pre-hydration degree of two tungsten mineral surfaces affects the adsorption of Pb-BHA, further influencing the hydrophobicity of the two mineral surfaces.