摘要
Malachite,being highly hydrophilic and difficult to be floated conventionally,is usually beneficiated by sulfidation flotation in industry.However,the complex crystal structure of malachite leads to the formation of various fracture surfaces with distinct properties during crushing and grinding,resulting in surface anisotropy.In this study,we explored the surface anisotropy of malachite and further investigated its sulfidation mechanism from the coordination chemistry perspective,considering the influence of the Jahn-Teller effect on malachite sulfidation.Computational results reveal that the penta-coordinated Cu ions on the malachite(201)and(010)surfaces exhibit stronger activity compared to those on the malachite(201)surface.Additionally,the tetra-coordinated structure formed by HS^(−)adsorption on the malachite(010)and(201)surfaces is more stable,with more negative adsorption energy,compared to the hexa coordinated structure formed by HS−adsorption on the(201)surface.The sulfidized malachite surface has an additional pair ofπelectron and smaller HOMO(highest occupied molecular orbital)-LUMO(lowest unoccupied molecular orbital)gap with xanthate molecules,causing strongerπbackbonding with xanthate.This study provides new insights into the surface sulfidation mechanism of malachite and offers a theoretical reference for the design of targeted flotation reagents.
孔雀石是一种亲水性很强、难以常规浮选的矿物,工业上常用硫化浮选法对其进行选矿。然而,孔雀石的晶体结构复杂,在破碎和磨矿过程中会形成不同性质的解离面,导致表面各向异性。本文研究了孔雀石的表面硫化的各向异性,并考虑到Cu—O八面体的Jahn-Teller效应对孔雀石硫化的影响,从配位化学的角度进一步探究了孔雀石的硫化机理。计算结果表明,孔雀石(201)和(010)表面的五配位铜离子活性比孔雀石(201)表面的五配位铜离子更强。与孔雀石(201)表面吸附HS^(-)后形成的六配位结构相比,孔雀石(010)和(201)表面吸附HS-后形成的四配位结构更稳定,具有更强的负吸附能。硫化孔雀石表面具有额外的一对π电子以及和黄药分子更小的HOMO-LUMO带隙,可以与黄药分子形成更强的反馈π键。研究结果为孔雀石的表面硫化机理提供了新的见解,并为浮选药剂靶向设计提供了理论参考。
基金
Projects(52074356,U22A20170)supported by the National Natural Science Foundation of China
Project(2022YFC2904503)supported by the National Key R&D Program of China
Project(2023SK2061)supported by the Special Fund for the Construction of Hunan Innovative Province,China
Project(2023CXQD002)supported by the Innovation-driven Project of Central South University,China
Project(2022RC1183)supported by the Science and Technology Innovation Program of Hunan Province,China
Project(kq2009005)supported by the Changsha Science and Technology Project(Changsha Outstanding Innovative Youth Training Program),China
Project supported by the High-performance Computing Centers of Central South University,China。
