金属离子对一水硬铝石和高岭石浮选行为的影响

Influence of metal ions on floatability of diaspore and kaolinite

通过一水硬铝石和高岭石纯矿物的浮选试验和动电位测定,研究不同种类的金属离子对一水硬铝石和高岭石浮选行为的影响。研究结果表明:Na+和K+对这2种矿物的可浮性和表面电位影响很小;Ca2+和Mg2+对一水硬铝石可浮性影响不大,却显著活化了高岭石的浮选,特别是在碱性范围内,高岭石的浮选回收率从40%提高到了90%以上;Ca2+和Mg2+显著降低了2种矿物表面的电位绝对值,但基本不改变2种矿物的等电点。Al3+和Fe3+对2种矿物可浮性和表面电性的影响行为不同,Fe3+对一水硬铝石和高岭石的可浮性影响不大;当pH=4～8时,Al3+对高岭石抑制作用相当明显,形成一个低谷;Al3+增加了一水硬铝石和高岭石表面的Zeta电位,使一水硬铝石的等电点由7.2变为8.5,高岭石的等电点则由4.8变为9.0。

The influences of several metal ions on the flotation of diaspore and kaolinite were investigated by flotation experiments and measurement of zeta potential. The results show that there are little influences of Na^＋ and K^＋ on the flotability and zeta potentials of diaspore and kaolinite. Ca^2＋ and Mg^2＋ also show little influences on the flotability of diaspore, but they can activate the flotation of kaolinite especially during the alkaline pH region, and the flotation recovery of kaolinite is raised from 40% to 90%. The absolute values of Zeta potential of both minerals are reduced to a very low value close to zero both in the presence of Ca^2＋ and Mg^2＋, but the isoelectric points （IEPs） of both minerals are not changed almost. Al^3＋ and Fe^3＋ have different effects on the flotability and Zeta potentials of the both minerals. There is a little effect of Fe^3＋ on the flotability of the both minerals. However, the depression effect of Al^3＋ on the flotation of kaolinite is very obvious and a valley point of the flotation is formed during the pH region of 4 to 8. A13＋ can increase the Zeta potentials of kaolinite and diaspore, and the IEP of diaspore shifts from 7.2 to 8.5, and that of kaolinite also shifts from 4.8 to 9.0.