羟基钙(CaOH^(+))在铜砷分离中对毒砂抑制机理的DFT研究

The DFT study on the inhibition mechanism of arsenopyrite by hydroxyl calcium(CaoH^(+))in the copper:-arsenic separation process

黄铜矿与毒砂浮选分离中,Cu^(2+)总是不可避免地活化毒砂,使其混入铜精矿产品中,从而降低产品的质量。石灰作为毒砂的有效抑制剂,其有效成分为CaOH^(+)。本研究采用密度泛函理论(DFT),分析CaOH^(+)对毒砂的抑制机理。DFT计算结果表明,CaOH^(+)能够使Cu^(2+)离开毒砂表面,削弱其活化作用;毒砂表面的Fe^(2+)和Cu^(2+)失去的电子对与CaOH^(+)的LUMO+1轨道形成反馈π键,导致Fe、Cu的活性被CaOH^(+)降低,从而对毒砂形成强抑制作用。这表明无论毒砂是否被Cu^(2+)活化,CaOH^(+)均能吸附在其表面,达到抑制效果。

In the flotation separation process of chalcopyrite and arsenopyrite,arsenopyrite was inevitably activated by Cu^(2+),and then was mixed into the copper concentrate product whose product quality was thus reduced.Lime is an effective inhibitor of arsenopyrite,with its acitve component of CaoH^(+).In this investigation,the inhibition mechanism of CaOH^(+)on arsenopyrite has been analysed using the Density Dunctional Theory(DFT).The DFT calculation results show that the CaOH^(+)can cause Cu^(2+)leave the surface of arsenopyrite,and weaken the activation capacity of Cu^(2+).The lost electron pairs of Fe^(2+)and Cu^(2+)on the surface of arsenopyrite formed a feedbackπbond with the LUMO+1 orbital of CaOH^(+),resulting in the reduction of the activity of Fe and Cu by CaOH^(+).Thus,CaOH^(+)has strong inhibiton effect on arsenopyrite.This phenomenon suggests that CaOH^(+)could be adsorbed on the surface of arsenopyrite to achieve its inhibition effect on arsenopyrite,whether arsenopyrite was activated by Cu^(2+)or not.