六偏磷酸钠在镍黄铁矿/蛇纹石浮选体系的作用研究

Effect Mechanism of SHMP on Flotation System of Pentlandite and Serpentine

通过矿物浮选试验、动电位测试及Zeta电位分布、扫描电镜观测等研究手段,考察了六偏磷酸钠在蛇纹石/镍黄铁矿浮选分离体系中的作用,分析了六偏磷酸钠对矿物颗粒间的分散作用机理。结果表明,在镍黄铁矿/蛇纹石浮选体系中,蛇纹石的存在降低了镍黄铁矿的回收率,而加入六偏磷酸钠使镍黄铁矿的浮选环境得到改善,回收率上升。机理研究表明:在一定pH值范围内,蛇纹石与镍矿铁矿表面荷电相反,蛇纹石可通过静电作用与镍矿铁矿发生“异相凝聚”而罩盖在其表面,从而降低镍矿铁矿表面的疏水性能,导致其可浮性下降;六偏磷酸钠可以使蛇纹石的表面电位由正变负。此时,蛇纹石和镍矿铁矿之间的电性相同,两者之间由静电吸引变为静电排斥,从而减弱蛇纹石在镍矿铁矿表面的附着,消除蛇纹石对镍黄铁矿的抑制作用,提高镍黄铁矿的浮选回收率。

The dispersion effect of sodium hexametaphosphate(SHMP)on flotation system of serpentine-pentlandite was investigated and the mechanism was studied by flotation experiments,Zeta potential,and SEM measurement.The results showed that the hetero-aggregation between serpentine and pentlandite results in the attachment of serpentine slimes on pentlandite surface and changed the surface characteristics of pentlandite,thus decreased the pentlandite flotation recovery.However,the pentlandite flotation recovery was increased by adding SHMP.The mechanism studies demonstrate that the serpentine particles coat on the pentlandite surface by hetero-aggregation because the surface electrical properties of serpentine and pentlandite are same in a certain pH range.It reduces the hydrophobicity of pentlandite surface and decreases the flotation recovery of pentlandite.The hetero-aggregation between pentlandite and the particles of serpentine can be eliminated by adding SHMP.Because the addition of SHMP significantly changes the surface electrical properties of serpentine,and makes electrostatic attraction convert into electrostatic repulsion between pentlandite and the particles of serpentine,thereby improving the flotation recovery of pentlandite.