Growth of covellite crystal onto azurite surface during sulfurization and its response to flotation behavior

In this work,the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated.Filed emission scanning electron microscopy-energy dispersive X-ray spectroscopy(FESEM) and X-ray diffraction(XRD) studies confirmed that the sulfurization of azurite is not limited to the mineral surface,but rather penetrates into the bulk to form covellite crystal(synCuS),creating favorable conditions for the stable adsorption of xanthate and greatly promoting the azurite flotation.Additionally,as demonstrated by X-ray photoelectron spectroscopy(XPS) and time of flight secondary ion mass spectrometry(TOF-SIMS) analyses,a redox reaction occurred during this process,and Cu(Ⅱ) onto the mineral surface was reduced to Cu(Ⅰ).Correspondingly,reduced S^(2-) was oxidized to(S_(2))^(2-),(S_n)^(-2),and even to deeper oxidation state S~0,(S_(x)O_(y))^(n-) and SO_(4)^(2-).Excess sodium sulfide strengthens copper sulfide to form onto the azurite surface,and provides enough raw material for crystal copper sulfide to grow,resulting in the formation of "flake-like" covellite with a better crystallinity.However,the floatability of azurite decreased dramatically under this condition,because the generated massive colloidal copper sulfide in flotation pulp deteriorates the flotation environment,resulting in a decreased effective adsorption of collector onto azurite surfaces.

Role of ammonium sulfate in sulfurization flotation of azurite:Inhibiting the formation of copper sulfide colloid and its mechanism

In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of colloid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was restored.After adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite surface.The nucleation rate was reduced,and the growth of copper sulfide crystal was improved.Covellite(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of copper sulfide products onto the mineral surface.Therefore,the generated copper sulfide colloid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.

复杂氧化铜矿浮选活化剂研究进展

铜因其优异的物理化学性能而在工业中得到广泛应用。目前,随着硫化铜资源的枯竭,氧化铜资源的开发利用逐渐成为研究的重点。氧化铜矿作为铜金属的最主要来源之一,其有效回收的关键是活化过程。然而由于易选铜矿物的逐渐减少,且现存氧化铜矿资源呈现出氧化率高、矿物组成复杂、易泥化等特点,致使选别过程较为困难。经典的硫化-黄药浮选法无法满足目前复杂氧化铜矿资源的选别要求。此外,活化剂作用于矿物表面的机理以及对活化产物晶体结构的解释不明确,在一定程度上制约了氧化铜矿分离理论和方法的发展。近年来,针对复杂难选的氧化铜资源,多种新型活化剂或者组合活化剂已见诸报端,在一定程度上解决了复杂氧化铜矿难选的问题。本工作通过梳理近年来氧化铜矿活化剂发展脉络,重点综述了新型活化剂以及新型活化方法的应用及活化机理,旨在丰富氧化铜矿高效浮选理论体系,为生产实践提供参考。

滇东某多金属氧化铅锌矿高效回收选矿工艺

对滇东某多金属氧化铅锌矿采用先铅后锌的工艺浮选,浮选流程均为两粗一精一扫.结果表明,矿石中有价元素为铅、锌、银,铅主要赋存于白铅矿和铅矾中,锌主要赋存于菱锌矿和异极矿中,银以伴生形式存在,目的矿物嵌布粒度较细.浮选所得铅精矿铅品位为61.45%,铅回收率为86.41%,银品位为451.58 g/t,银回收率为66.73%,含锌3.68%;锌精矿锌品位为42.32%,锌回收率为90.63%,含铅1.39%.两性捕收剂R（144）对锌的捕收能力和选择性比十二胺、十八胺和二者混合胺更好.