蛇纹石及六偏磷酸钠对硼镁石浮选的影响

摘要

为提高硼镁石浮选回收率,使用六偏磷酸钠减小蛇纹石对浮选的不利影响.通过浮选试验、zeta电位测试、傅里叶红外光谱分析、XPS分析及DLVO理论等手段,研究蛇纹石粒度、含量以及六偏磷酸钠(SHMP)对硼镁石浮选的影响,并对矿物颗粒间的相互作用以及六偏磷酸钠的作用机理进行分析.结果表明,蛇纹石与硼镁石颗粒间易发生团聚作用,且蛇纹石粒度对硼镁石浮选结果影响十分显著.与粗粒级蛇纹石相比,粒径小于38μm的蛇纹石能显著降低硼镁石的回收率.加入SHMP后,蛇纹石对硼镁石浮选的不利影响得到明显减弱.机理研究表明,SHMP能影响蛇纹石与硼镁石矿物表面电荷,从而阻碍颗粒间团聚的发生,使矿物颗粒在矿浆中呈良好的分散状态,有利于硼镁石的浮选.此外,SHMP通过氢键与化学吸附作用于蛇纹石表面,并生成一种络合物使蛇纹石的可浮性降低.%Sodium hexametaphosphate (SHMP) was used to minimize the adverse effect of serpentine for improving ascharite recovery.The effects of particle size and content of SHMP,and serpentine on ascharite flotation process were investigated through flotation,zeta potential tests,FT-IR analysis,XPS analysis and DLVO theory.Particles interaction and mechanism of SHMP were also discussed.It was found that aggregation between serpentine and ascharite particles easily happened,and the particle size of serpentine had a profound impact on the ascharite recovery.In particular,the fine serpentine with size less than 38 μm had the greatest contribution to the deterioration of ascharite flotation performance.After SHMP treatment,the adverse effect of serpentine was significantly reduced.The mechanism of SHMP showed that it could alter the surface charges of serpentine and ascharite to prevent severe interparticle aggregation,which resulted in a well-dispersed pulp and benefited ascharite flotation process.The adsorption of SHMP on serpentine was due to hydrogen bonding and chemical adsorption,resulting in the formation of complex on serpentine surface to decrease its floatability.