绿泥石/蛇纹石聚集分散及抑制行为研究

Interactions and Depression of Chlorite and Serpentine

通过浮选试验、沉降试验和Zeta电位测试,研究了绿泥石和蛇纹石的聚集分散及抑制行为,并对其机制进行了分析。浮选试验结果表明:六偏磷酸钠对绿泥石和蛇纹石不具有抑制作用;羧甲基纤维素是绿泥石的有效抑制剂,但不会影响蛇纹石的浮选。蛇纹石和绿泥石共存时,单独使用六偏磷酸钠或羧甲基纤维素均不能抑制蛇纹石和绿泥石混合矿的浮选,而同时使用六偏磷酸钠和羧甲基纤维素能够抑制蛇纹石和绿泥石混合矿的浮选,六偏磷酸钠和羧甲基纤维素共同作用下,混合矿浮选回收率从31.4%降低到8.7%。Zeta电位测试和沉降试验结果表明,绿泥石的等电点p H约为4.5,蛇纹石等电点p H约为11.8,在硫化铜镍矿浮选常用的弱碱性p H区间,蛇纹石与绿泥石表面电性相反,容易发生异相凝聚。异相凝聚使不能被羧甲基纤维素抑制的蛇纹石罩盖在绿泥石表面,影响了羧甲基纤维素对绿泥石的抑制作用。加入六偏磷酸钠可以改变蛇纹石表面电位,分散绿泥石与蛇纹石混合矿,消除蛇纹石对羧甲基纤维素抑制绿泥石的影响。

The interactions and depression of chlorite and serpentine were investigated through flotation experiments,sedimentation tests and Zeta potential measurements. The flotation results showed that calgon had no depression effect on chlorite and serpentine flotation. The carboxymethyl cellulose（ CMC） was an effective depressant for chlorite flotation but it did not affect the serpentine flotation.The use of calgon or CMC alone could not depress the flotation of chlorite and serpentine mixed ore. However,using calgon and CMC together could depress the mixed ore flotation. The results of sedimentation tests and Zeta potential measurements showed that the isoelectric point（ IEP） p H of chlorite was about 4. 5 and that value of serpentine was 11. 8. In weak alkaline p H range that was commonly used in copper-nickel sulfide ore flotation,the surface electrical potentials of chlorite and serpentine were opposite,causing hetero-aggregation between serpentine and chlorite. The hetero-aggregation causing the formation of serpentine slime coating on chlorite surface,which would interfere with the depression effect of CMC on chlorite flotation. The addition of calgon compensated the positive charge on the serpentine particle and its Zeta potential was rendered negative. When the serpentine surface was negatively charged,repulsive interaction energy generated and serpentine slimes dropped off from the surface of chlorite,thus the adverse effect of serpentine slime on the depression of carboxymethyl cellulose on chlorite was eliminated.