铅离子协同苹果酸抑制滑石可浮性的机理研究

Inhibition Mechanism of Lead Ions Synergized with Malic Acid on Talc

滑石是辉钼矿等金属硫化矿的常见共生矿物,天然疏水性极好。为阐明煤油作捕收剂时铅离子及苹果酸对滑石浮选行为的影响机理,进行了滑石的单矿物浮选实验,并采用ζ电位、XPS和FTIR等测试方法对药剂在滑石表面的吸附机理进行了研究。结果表明,当pH值为8、Pb^(2+)浓度为1.0×10^(-4) mol/L^(-3)时,1.0×10 mol/L的苹果酸对滑石的抑制作用最为显著,此时滑石的回收率为54.60%,与没有添加抑制剂时相比降低了32.50个百分点。与仅添加苹果酸时相比降低了11.66个百分点。溶液中铅离子的羟基络合物Pb(OH)_(2)、Pb(OH)_(3)^(-)和具有强烈亲水性的C_(4)H_(4)O_(5)^(2-)吸附在滑石表面,二者的共同作用使滑石的表面电位负向增大,不利于煤油的吸附。苹果酸根离子侵蚀滑石表面并与滑石表面的活性点Mg结合生成亲水性的苹果酸镁,可明显提高滑石的亲水性,使其接触角由64.27°改变为39.87°,本研究对含滑石型矿物的高效浮选分离具有一定的参考意义。

Talc is a common co−occurring mineral of metal sulfide ores such as molybdenite,with excellent natural hydrophobicity.To elucidate the mechanism of flotation behavior of talc under the action of Pb ions and malic acid when kerosene is used as a collector,single mineral flotation tests of talc were carried out,and the adsorption mechanism of the reagents on the surface of talc was investigated byζ−potential,XPS and FTIR.The results showed that the inhibition of talc by 1.0×10^(−3) mol/L malic acid was the most significant when the pH was 8 and the Pb^(2+)concentration was 1.0×10^(−4) mol/L.The recovery of talc was 54.60%,which was 32.50 percentage lower than that without inhibitors and 11.66 percentage lower than that of malic acid alone.The hydroxyl complex of lead ions in solution,Pb(OH)_(2),Pb(OH)_(3)^(−)and C_(4)H_(4)O_(5)^(2-)with strong hydrophilicity could be adsorbed on the surface of talc,and their combined effects shifted the surface potential of talc negatively,which was unfavorable to the adsorption of kerosene.Malate ions eroded the talc surface and reacted with the active Mg ion site on talc surface to generate hydrophilic magnesium malate,which could significantly improve the hydrophilicity of talc and change its contact angle from 64.27°to 39.87°.The research can provide significant reference for the efficient flotation separation of talc−containing minerals.