BHA浮选锡石体系中锌组分活化机理的量子化学计算研究

Quantum Chemistry Calculation Study on Activation Mechanism of Zinc Component in BHA Flotation Cassiterite System

锌的生物毒性和环境影响远小于铅,以锌替代铅组分活化锡石的浮选研究具有重要意义。利用Material Studio软件中CASTEP模块探明了在苯甲羟肟酸(BHA)浮选体系中锌组分活化锡石表面的机理。计算结果表明:锡石(110)面上O(顶位)原子活性较强,可作为药剂吸附位点。以Zn(OH)^(+)为代表的锌组分均可在锡石(110)面上以不同形式与O(顶位)原子位点间发生吸附作用,形成Zn—O键;且在双桥形式吸附中,生成的Zn—O键稳定性更好。在BHA浮选锡石体系中,BHA以双键O原子与锡石(110)面的Sn直接吸附,未形成螯合吸附,吸附稳定性差;然而,加入Zn(OH)^(+)对锡石(110)面作用后,BHA分子中双键O原子和—OH基团与Zn原子作用形成稳定的五元环螯合结构,提高了BHA在锡石(110)面的吸附能力和稳定性。

The biological toxicity and environmental impact of zinc are much smaller than that of lead,and its ability to replace the lead component in activating cassiterite is of great significance.The mechanism of zinc component activation on the surface of cassiterite in the benzohydroxamic acid(BHA)flotation system was explored using the CASTEP module in Material Studio software.The calculation results indicate that the O(top position)atom on the cassiterite(110)surface has strong activity and can be used as the reagent adsorption site.Zinc components represented by Zn(OH)^(+)can adsorb with O(top position)atomic sites in different forms on the cassiterite(110)surface,forming Zn—O bonds;In the double bridge form of adsorption,bond of Zn—O has better stability.In the BHA flotation cassiterite system,BHA directly adsorbs onto Sn atoms on the(110)surface of cassiterite through double bond O atoms,without forming chelating adsorption,resulting in poor adsorption stability.However,after the addition of Zn(OH)^(+)to the surface of cassiterite(110),the double bond O atoms and—OH groups in the BHA molecule interact with Zn atoms to form a stable five membered ring chelating structure,which can improve the adsorption ability and stability of BHA on the cassiterite(110)surface.