Flotation performances of polymorphic pyrrhotite

The floatability of different crystalline structures of pyrrhotite (monoclinic and hexagonal) was studied. It is shown that the floatability of monoclinic and hexagonal has obvious difference, and that the flotation recovery of monoclinic pyrrhotite is larger than that of hexagonal pyrrhotite using different collectors. When butyl dithiophosphate is used as the collector, the recovery is larger than that by sodium butyl xanthate and sodium diethyl dithiocarbamate. At the pH values ranging from 6 to 9, monoclinic pyrrhotite can be floated well, and the flotation recovery is higher than 90%. Monoclinic and hexagonal pyrrhotites are more easily activated by Cu²⁺ in acidic conditions than in alkaline conditions. But Cu²⁺ cannot activate hexagonal pyrrhotite using sodium diethyldithiocarbamate as the collector. By the measurement of contact angle, it is indicated that monoclinic and hexagonal pyrrhotites float well and are easily activated by Cu²⁺ when dithiophosphate is used as the collector. Using sodium diethyl dithiocarbamate as a collector, the relationship between potential and pH range for pyrrhotite flotation is established. At pH 5, the optimal potential range for flotation of monoclinic pyrrhotite is about 125–580 mV (vs SHE), with the maximum flotation occurring at about 350 mV (vs SHE); the optimal potential range for flotation of hexagonal pyrrhotite is 200–580 mV (vs SHE), with the maximum flotation occurring at about 300 mV (vs SHE).     

Bioleaching of sphalerite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans cultured in 9K medium modified with pyrrhotite

Elective culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in 9K medium modified with pyrrhotite was studied. Bioleaching of flotation concentrate of sphalerite by the selected bacteria was carried out. The results show that the microorganisms cultured by pyrrhotite are a mixture of Acidithiobacillusferrooxidans and Acidithiobacillus thiooxidans, of which the capability to oxidize ferrous to ferric irons is enhanced by the high mass ratio of Fe to S in pyrrhotite. Three pyrrhotite samples were separated into various parts with corresponding S/Fe ratios by magnetic separation and were used to culture the elective bacteria as the substrate. The association of the cultures could provide a more rapid and complete oxidation of sphalerite than that of bacteria cultivated by conventional methods.     

苯乙烯膦酸体系中细粒金红石的疏水絮团浮选（英文）

通过浮选试验、动电位测试、显微镜观测、激光粒度分析、吸附量测定和DLVO理论研究细粒金红石在苯乙烯膦酸(SPA)体系中的絮团浮选行为。单矿物浮选试验结果表明,苯乙烯膦酸对细粒金红石的絮团浮选具有良好的诱导作用;同时,溶液pH值、剪切力(搅拌速率)和搅拌时间均对絮团浮选效果有一定影响。动电位测试发现,随着SPA的加入,等电点及电位均负向移动,表明矿物与药剂之间主要发生化学吸附。激光粒度分析表明,在搅拌速度为1800 r/min和1000 mg/L SPA时,金红石颗粒的尺寸最大。此外,通过显微镜观测和浮选试验证明絮团的产生有利于细粒金红石的浮选。综上可得,SPA通过化学吸附作用能有效诱导细粒金红石的疏水絮团并增大其颗粒尺寸。最后,通过DLVO理论计算进一步验证SPA与金红石颗粒之间主要发生化学吸附作用,进而促进絮团产物的形成。     

黄原酸钾盐介质中黄铁矿的电化学行为Ⅱ:疏水性产物双黄药的吸附及其稳定性研究

利用恒电位和恒电流的电化学研究方法 ,研究了黄原酸钾溶液中黄铁矿表面的电化学行为。研究表明 ,随着pH值提高 ,电极表面的双黄药吸附层变薄 ;双黄药在黄铁矿电极表面的还原动力学方程式表明 ,高碱条件下 (pH=11.0) ,双黄药易于还原解离。     

DFT research on activation of sphalerite

Activation of sphalerite ZnS, (Zn, Fe)S, (Zn, Cu)S were carried out using the density functional theory (DFT) method. The electronic structures and related properties of three kind of zinc sulfide compounds were investigated. In addition, the relation between electronic structure and flotation behavior was discussed. The results show that, ZnS has a broader band gap than (Zn,Cu)S and (Zn,Fe)S do, and it has low electrochemistry activity to react with flotation collectors to render the surface hydrophobic. When the Zn atom in ZnS is replaced by Cu atom,the band gap will be reduced, and the top valence band will be occupied by Cu 3d orbit, thus it is beneficial to the interaction between mineral surface and collector.     

我国金属矿山废石资源化综合利用现状与发展

随着社会的发展,我国对矿产资源的需求日益增加,矿山废石的大量堆积不仅造成矿产资源的严重浪费,而且占据大量土地,还会带来严重的安全问题和环境污染。针对我国矿山废石堆存量大、增长快、废石种类及成分复杂、废石资源化综合利用率低等特点,本文总结了矿山废石的危害和现行的处理及利用方式,详述矿山废石用于回收有价金属及进一步的废石回填、覆土造田、制造建筑材料等主要处理方式的特点、发展及应用情况,并归纳展望矿山废石未来可能研究发展的重点方向,提出矿山废石资源化利用的可行性建议。指出矿山废石的资源化综合利用的跨区域集聚处理、多领域多产业协同处理和分类分段处理是日后研究的关键。确定矿山废石堆存量以及成分、粒度、有价金属的含量是矿山废石综合利用的重要前提。制定合理方案对矿山废石进行分类分段处理是提高矿山废石综合利用率的重要步骤。     

硫砷铜矿、蓝辉铜矿与铜蓝表面选择性氧化浮选分离研究

针对蓝辉铜矿、铜蓝和硫砷铜矿开展了表面选择性氧化浮选分离研究,并通过矿物表面接触角变化及XPS表面分析,阐明了3种矿物表面选择性氧化反应机制。结果显示,氧化剂次氯酸钙和高锰酸钾均可有效抑制蓝辉铜矿和铜蓝上浮,但对硫砷铜矿可浮性无影响; 在丁铵黑药作用下,硫砷铜矿和蓝辉铜矿接触角均达到90°,经次氯酸钙氧化后,蓝辉铜矿接触角降至15°~30°,硫砷铜矿接触角仍高于86°; XPS分析结果表明,次氯酸促进了蓝辉铜矿表面的氧化,硫元素被氧化为SO₄^2-,以CuSO4形式覆盖在矿物表面,增加了表面亲水性,而硫砷铜矿表面As、Cu和S元素并未发生明显的氧化反应,矿物表面维持较高的疏水性。次氯酸钙实现了蓝辉铜矿与硫砷铜矿表面选择性氧化,强化了两者的浮选分离。     

细粒锡石的电解浮选及碰撞粘附机理(英文)

为了研究细粒锡石电解浮选中颗粒气泡间的相互作用,分析不同粒级锡石的浮选回收率和锡石颗粒与氢气泡的碰撞机理。浮选实验在一个单泡电解浮选装置中进行,实验结果表明,10μm,10～20μm,20～38μm和38～74μm粒级的锡石分别与50～150μm,约250μm,约74μm和约74μm尺寸的气泡相匹配,可以获得较好的浮选回收率。因此,颗粒和气泡的大小直接影响锡石的浮选回收率。利用碰撞、粘附和捕集模型进行碰撞、粘附、分离和捕集几率的计算。理论计算结果发现碰撞几率随着颗粒尺寸的减小以及气泡尺寸(150μm)的增大而显著降低。有效的碰撞有利于粘附几率的增加,从而有利于提高浮选回收率。