六偏磷酸钠抑锌浮铜分选过程中的微量热动力学机理

Microcalorimetric Study of the Hexametaphosphate on Flotation Separation of Chalcopyrite and Sphalerite

在单矿物浮选试验的基础上,结合微量热法和吸附量测试研究了六偏磷酸钠对黄铜矿和闪锌矿的作用效果,旨在从热动力学角度阐释六偏磷酸钠的抑制作用机理,为铜锌硫化矿的高效浮选分离提供依据。浮选试验结果表明:pH=9时,浓度为2×10^(-4) mol·L^(-1)的六偏磷酸钠对黄铜矿与Cu^(2+)活化后的闪锌矿有较好分离效果,与不添加六偏磷酸钠相比,黄铜矿浮选回收率由95.15%小幅降至90.77%,而Cu^(2+)活化后的闪锌矿浮选回收率则由85.13%大幅降低至28.51%。微量热测试结果表明,乙硫氮在黄铜矿和Cu^(2+)活化后的闪锌矿表面吸附过程的表观活化能分别为36.95 kJ·mol^(-1)和57.28 kJ·mol^(-1),经六偏磷酸钠作用后,乙硫氮在两种矿物表面吸附的表观活化能分别升高了13.07%、37.08%,而表观活化能差值则显著升高了80.72%。这表明乙硫氮更容易在黄铜矿表面吸附,六偏磷酸钠可以显著增大乙硫氮在Cu^(2+)活化后的闪锌矿表面的吸附难度,而对乙硫氮在黄铜矿表面的吸附影响较小,从而扩大两者的可浮性差异,吸附量测试结果也支持了这一结论。

Based on the flotation test of copper-zinc sulfide ore,the effect of sodium hexametaphosphate on chalcopyrite and sphalerite was investigated by combining microcalorimetry and adsorption amount test,aiming to explain the inhibition mechanism of sodium hexametaphosphate from the perspective of thermodynamics and provide a basis for the efficient flotation separation of copper-zinc sulfide ore.The results showed that the concentration of 2×10^(-4) mol/L sodium hexametaphosphate at pH=9 had a good separation effect on chalcopyrite and Cu^(2+)activated sphalerite,and the flotation recovery of Cu^(2+)activated sphalerite was reduced from 85.13%to 28.51%,and the recovery of chalcopyrite was reduced from 95.15%to 90.77%.Before the action of sodium hexametaphosphate,the apparent activation energy Ea of sodium diethyldi thiocarbamate with chalcopyrite and Cu^(2+)activated sphalerite were 36.95 kJ/mol and 57.28 kJ/mol,respectively;after the action of sodium hexametaphosphate,the apparent activation energy Ea of sodium diethyldi thiocarbamate adsorbed on the surface of chalcopyrite and Cu^(2+)activated sphalerite increased by 13.07%and 37.08%,respectively,which increased the apparent activation energy of sodium diethyldi thiocarbamate on the surface of Cu^(2+)activated sphalerite and Cu^(2+)activated sphalerite.The adsorption difficulty of ethionite on Cu^(2+)activated sphalerite surface was increased by 13.07%and 37.08%,respectively,which increased the difficulty of ethionite adsorption on Cu^(2+)activated sphalerite surface,while it had less effect on ethionite adsorption on chalcopyrite surface.