微细粒级氧化锌矿物氯-氨耦合催化硫化机理研究

In the mineral processing industry, there is no breakthrough in the areas of sulfidization - amine method for the recovery of zinc oxide ore in decades. This method has hitherto failed to be applied in the industrial flotation of zinc oxide ore. The main reason is that, slime has seriously affected the sulfidization - amine processing, resulting in the deterioration of flotation indexes. Compared with the sulfidization - amine flotation, the influences of slime on sulfide - xanthate flotation are much smaller. In order to avoid the influences of the undesirable slime as much as possible, Innovative flotation method for the recovery of zinc oxide ore effectively is therefore studied. In the present project, microfine smithsonite, which is one of main oxidized zinc minerals in the slime is served as the raw material. Density functional approach is employed to calculate the factors during the sulfidization-treated processing of smithsonite, such as the substitution reaction energy between sulfur ion andcarbonate ion, electron transfer, density states, etc, in order to analyze the molecular orbital factors of sulfidization surface of smithsonite. Also, solution chemistry calculation, thermodynamics and reaction equilibrium constant calculations are conducted to study the effects of chlorine and ammonia and sulfur ion concentrate on the sulfidization-treated processing. Catalyzed - sulfidization mechanism of four elements coupled with "sulfur-ammonia-zinc-carbonate ion" in system of smithsonite surface is studied through sulfidization by adding high concentrate of sulfur ions, coupling catalyzed- sulfidization with sodium chloride and ammonium hydroxide addition and catalyzed-sulfidization with inorganic ammonia salt addition. Meanwhile, the steady state model of catalyzed-sulfidization on the smithsonite surface is established. X-ray photoelectron spectroscopy (XPS), raman spectroscopy (RS) and surface potential detection are employed to characterize surface properties of the sulfidization-treated smithsonite. Furthermore, the surfaces property differences of zinc sulfide mineral before and after sulfidization are analyzed. Adsorption capacity of advanced xanthate and contact angle of mineral surfaces are detected to investigate hydrophobicity differences of the smithsonite surfaces before and after catalytzed sulfidization. Finally, factors affecting the processing of chlorine-ammonia coupling catalyzed- sulfidization are investigated through laboratory flotation tests of Halimond tube and hanging trough flotator. Based on research results of the present project, the innovative prototypes named "couplying catalyzed-sulfidization of microfine zinc oxide mineral by adding chlorine and ammonia- Xanthate flotation" can be formed, moreover, the theoretical basis for practical applications of this innovative prototypes can be obtained.

几十年来，氧化锌矿的回收一直没有突破硫化—胺法的范畴，而该方法却受到矿泥的严重影响。与硫化—胺法相比，硫化—黄药浮选受矿泥的影响要小得多。本项目以矿泥中的微细粒级菱锌矿为代表，通过密度泛函计算分析影响矿物表面硫化的分子轨道因素；通过溶液化学和反应平衡常数计算，研究氯氨组份、硫离子浓度对硫化过程的影响；通过高浓度硫离子硫化、氯-氨耦合催化和无机铵盐催化等方式，深入研究菱锌矿硫化体系中硫-氨-锌-碳酸根的四元耦合催化机制，建立菱锌矿表面催化硫化稳态模型；通过光电子能谱、拉曼光谱、表面电位等手段对菱锌矿硫化表面进行表征，分析与硫化锌矿物表面硫化前后的性质差异；检测高级黄药在矿物表面的吸附量和表面接触角，表征催化硫化前后矿物表面黄药吸附层的疏水性差异，通过浮选实验，研究氯-氨耦合催化的影响因素，形成微细粒级氧化锌矿物的氯-氨耦合催化硫化—黄药浮选新技术原型，并为该新技术原型的实际应用提供理论依据。

几十年来，氧化锌矿的回收一直没有突破硫化—胺法的范畴，而该方法却受到矿泥的严重影响。与硫化—胺法相比，硫化—黄药浮选受矿泥的影响要小得多。本项目以矿泥中的微细粒级菱锌矿为代表，开展了微细粒级氧化锌矿物氯-氨耦合催化硫化机理研究。密度泛函计算结果表明：铵根离子和硫离子共吸附的吸附构型相对稳定。菱锌矿催化硫化过程中铵根离子与锌离子发生强烈的络合作用。溶液化学和反应平衡常数计算结果表明：氯化钠（0.5×10-3 mol/L）和氨水（2.0×10-3 mol/L）的添加，促使菱锌矿表面与硫氢根离子置换反应的趋势增强，从而催化菱锌矿表面硫化。锌铵络合物的生成促进了菱锌矿表面的溶解，催化了更多闪锌矿沉淀物的生成。菱锌矿催化硫化后表面结构与性质的研究结果表明：菱锌矿表面的硫化物由单一硫化物和多硫化物组成。多硫化物主要以S2-碎片峰的形式存。氯化钠和氨水的添加，增加了矿物表面硫含量（S2p含量由3.37%增加到4.69%），同时促使单一硫化物向多硫化物的转变（S2p3/2中多硫化物由22.58%增加到29.74%）。飞行时间二次离子质谱仪检测结果表明：氯化钠-氨水的添加使得样品表面硫化层的厚度由15.32 nm增加到29.20 nm，从而改善矿物表面的疏水性。氯-氨催化硫化后菱锌矿对黄药的吸附量为94.45%，一次解析后，吸附量为63.35%。氯-氨的催化硫化作用不仅提高了菱锌矿对黄药的吸附量，而且还增加了黄药在菱锌矿表面吸附的稳定性。不同组元体系下菱锌矿浮选试验结果表明：在最佳药剂用量下，添加Cl-、NH4+组分后菱锌矿回收率提高了近26个百分点。人工混合矿（含锌约为17%）经一次分选后，浮选精矿中锌品位约为35%，回收率约为77%。因此，在小型实验室中实现了微细粒级菱锌矿与脉石矿物的分离和富集。形成了“微细粒级氧化锌矿物氯-氨耦合催化硫化黄药浮选”新技术原型，并为该技术原型的实际应用提供理论依据。