Effect And Inhabitory Mechanism Of Depressant On Flotation Of Fluorite And Calcite

Abstract:with exhaustion of the fluorite ore resources in our country, exploitation and utilization of the high-calcium fluorite has been regarded as an important project in fluorine industry. It is very difficult to separate fluorite and calcite by flotation method, which is because the physical and chemical properties of them are similar to each other. In order to solve this problem, the flotation behaviors of fluorite and calcite and the selective inhibition mechanism of organic inhibitor tannin to calcite have been studied systematically in this paper, which is through the means of single mineral flotation test, surface wettability test, potentiodynamic test, infrared spectral analysis, and solution chemistry calculation.The results of single mineral flotation test show that the selectivity and pH applicable range of tannin is better than other inhibitors like water glass,calgon, sodium tripolyphosphate,CMC and sodium humate when using DW-1as collector. Under neutral and weakly alkaline conditions, tannins can significantly enhance the surface hydrophilicity of calcite and restrain calcite selectively.The mechanism research results show that chemical adsorption and physical adsorption are both detected on the interfaces of tannin-fluorite and tannin-calcite. There are direct Ca-0chemical bond, activation Ca-O chemical bond, hydrogen bond and electrostatic attraction between phenolic hydroxyl group of tannin molecular and surface particles of calcite. Under ideal conditions, there is a mutual transformation between fluorite and calcite, in which the critical transformation pH is8.5. calcite grows on the fluorite surface when pH>8.5, while fluorite grows on the calcite surface when pH<8.5. In addition, there is an intimate relationship between the mineral surface transformation and concentration of solvent ions. When [F-]2/[CO32-]<10-2.06, calcite grows on the fluorite surface. When [F-]2/[CO32-]>10-2.06, fluorite grows on the calcite surface.Multi-metal associated fluorite ore from Shizhuyuan is used in the real ore separation test. Through the process of "preferential flotation of fluorite and then mixed flotation of scheelite and wolframite", the fluorite concentrate and mixed crude concentrate of wolframite and scheelite are obtained. The operation recovery of fluorite concentrate is66.21%which belongs to FC-93level, while it contains CaF293.69%, WO30.40%and CaCO30.37%. The mixed crude concentrates of wolframite and scheelite contains WO35.54%whose operation recovery is68.22%.