金属离子对滑石浮选行为的影响及机理研究

滑石常存在于硫化矿中影响硫化矿浮选精矿的质量。为了解金属离子对滑石浮选行为的影响和作用机制，考察了Ca²⁺、Mg²⁺、Cu²⁺、Fe³⁺对滑石纯矿物浮选、滑石表面ζ电位及滑石与气泡之间诱导时间的影响。结果表明：Ca²⁺、Mg²⁺、Cu²⁺、Fe³⁺均可在滑石表面形成吸附；Ca²⁺对滑石可浮性影响不大；添加Mg²⁺后，当pH＞10时，滑石可浮性降低；添加Cu²⁺后，滑石在pH=4~10范围被抑制，并且在pH值为6左右时Cu²⁺对滑石抑制作用最强；Fe³⁺在pH=3~9的范围内能够抑制滑石，并且在pH值为7左右时对滑石抑制作用最强。溶液化学计算结果表明，溶液中的金属络合离子可以改变滑石的表面电位，而氢氧化物沉淀吸附在滑石表面会降低滑石的可浮性。静电作用能计算结果表明：当pH值低于氢氧化物的零电点时，金属离子形成的氢氧化物沉淀会特定地吸附于滑石表面，产生多相凝聚，导致滑石表面亲水性增强，可浮性降低；当pH值大于氢氧化物的零电点时，凝聚现象减弱，滑石表面疏水性增强，可浮性提高。试验结果对含滑石硫化矿中滑石的抑制和分离有一定的指导作用。

Influence and Mechanism of Metal Ions on Flotation Behavior of Talc

Talc easily is reported to reduce concentrate grade as a common gangue mineral in complex sulphide ores. The influences and mechanism of several metal ions( Ca2+、Mg2+、Cu2+、Fe3+) on the flotation of talc were investigated by flotation experiments of single talc,measurements of Zeta potential and induction time,calculation of solution chemistry and electrostatic interactions. The results show that Ca2+,Mg2+,Cu2+and Fe3+can adsorb on the surface of talc. Ion like Ca2+shows no significant influence and Mg2+can depress flotation of talc at higher pH values (pH>10). Flotation of talc can be depressed at pH 4~10 while adding Cu2+ and the inhibition is strongest when pH=6. Similarly,flotation of talc can be depressed at pH 3~9 while adding Fe3+ and the inhibition is strongest when pH=7. Solution chemistry calculations confirm that the Zeta potential of talc can be changed through the adsorption of metal ion complexes onto the surfaces of talc and the recovery of talc decreases due to precipitation of hydroxide. The calculations of electrostatic interactions indicate the hydrophobic surfaces of talc become hy-drophilic and talc flotation is depressed within certain pH range due to hetero-coagulation of the metal hydroxides on surfaces of talc. The flotation recovery of talc can rise again when pH>PZC of metal hydroxides. The experiments play an instructive role for depressing and separation talc from sulphide ores contain talc.