碳酸根对方解石浮选速率的影响及机理研究

通过方解石单矿物浮选试验,研究了不同浓度碳酸根离子以及矿浆pH值对方解石浮选速率的影响,结果表明:加入1.5mmol/L碳酸根离子时,方解石完全上浮的时间由原来的2min缩短至30s,浮选速率显著提高,而pH值对其浮选速率无显著影响.利用ζ-电位测定、溶液化学计算以及颗粒间相互作用原理,探讨了碳酸根离子影响方解石浮选速率的作用机理,结果表明:碳酸根离子在方解石表面发生静电吸附,生成碳酸钙沉淀,中和了颗粒表面电性,方解石颗粒间的静电排斥力减小,颗粒间的两种吸引力即范德华作用力和疏水作用力占主导地位,颗粒相互吸引靠拢产生聚沉,颗粒更易于向气泡附着,使得方解石浮选速率显著提高.

Effects and action mechanism of CO3^2- on flotation rate of calcite

The effects of different concentrations of CO32-and pH values on flotation rate of calcite were studied through pure mineral flotation tests.The results show that the floating time for calcite was completely shortened from 2 min to 30 s at CO32-concentration of 1.5 mmol/L.The flotation rate increased significantly while pH value had no obvious influence on it.The action mechanism was studied using Zeta-potential measurement,solution chemistry calculation and interaction principle of particles.The results show that CO32-adsorbed by static was at the surface of calcite in form calcium carbonate deposition which then neutralized the surface electricity.The repulsive force between calcite particles decreased.The Van der Waals force and hydrophobic interaction played dominant roles.The particles attracted each other and agglomerated,which caused the particles to be adsorbed to the bubbles,thus increasing the flotation rate.