二氧化锰对黄铜矿浸出行为的影响

黄铜矿常压浸出存在浸出缓慢等问题。当溶液中存在MnO_2时,由于矿物接触间的原电池效应为黄铜矿的氧化提供更多途径,从而为提高黄铜矿浸出率带来可能。分别研究了在H_2SO_4溶液和H_2SO_4-Fe_2(SO_4)_3溶液中,MnO_2对黄铜矿浸出行为的影响。结果表明,添加MnO_2能够促进黄铜矿的浸出,在浸出过程中,MnO_2迅速分解。黄铜矿在浸出过程中会形成一种缺金属钝化层,这种钝化层附着在黄铜矿表面,阻碍溶液与黄铜矿的接触,阻碍了黄铜矿的浸出。     

黄铁矿促进黄铜矿微生物浸出影响因素

采用摇瓶实验,以氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,At.f)浸出黄铁矿-黄铜矿,重点研究了基础培养基、矿物配比和粒度组成等因素的影响.黄铁矿能促进黄铜矿的微生物浸出,以采用无Fe 9K培养基效果较好,它对应铜浸出率是9K培养基的1.68倍;采用宽粒级矿物时铜浸出效果较好,且铜浸出率与黄铁矿和黄铜矿的质量比有关,当质量比为2:2时铜浸出率最高可达45.58%;黄铁矿含量大小是影响铜浸出率高低的实质,当质量比小于等于5:2时以At.f菌的氧化作用为主,当质量比为10:2时以硫化矿间的原电池效应为主.浸渣的X射线衍射分析表明,采用无Fe 9K培养基时浸渣中生成的钝化物黄钾铁矾较少,故黄铁矿可以很好地替代9K培养基中的FeSO₄,并能与黄铜矿形成原电池效应,从而促进铜的浸出.      

硫代硫酸盐浸出金矿石中硫化物和二氧化锰的相互作用

在氨浸出体系和氨性硫代硫酸盐浸出体系中，研究了黄铁矿或黄铜矿和二氧化锰之间的相互作用。在氨性溶液和氨性硫代硫酸盐溶液中，有二氧化锰存在时，黄铁矿和黄铜矿的溶解速度得到提高。二氧化锰提高硫化物浸出作用适用于从黄铁矿精矿和硫化矿石中用硫代硫酸盐浸出金。在用硫代硫酸盐浸出硫化物包裹型金矿石过程中，加入少量的二氧化锰可改善金浸出动力学，并提高金的总浸出率，并且几乎不影响硫代硫酸盐的消耗。     

石煤中钒酸浸出工艺研究

通过对陕西某地石煤钒矿的物相和化学成分分析, 依据矿物的特点确定用H_2SO_4溶液作为浸出剂从石煤钒矿中浸出钒. 实验主要研究了H_2SO_4浓度、浸出温度、液固比、浸出时间对石煤钒矿中钒的浸出率的影响. 结果表明, 在一定范围内钒的浸出率随H_2SO_4浓度及浸出温度的升高、浸出时间的延长而提高; 得出的较优条件为H_2SO_4浓度6.0 mol·L~(-1)、浸出温度95 ℃、液固比为3∶ 1、浸出时间5 h, 可以使钒的浸出率达到93.83%.     

H_2O_2-Fe_2(SO_4)_3-H_2SO_4体系中辉铜矿的浸取研究

以H_2O_2和Fe_2(SO_4)_3为氧化剂、NaCl为助浸剂,在H_2SO_4溶液中浸出辉铜矿中的铜。结果表明,在反应温度85℃,反应时间180 min,H_2O_2、Fe_2(SO_4)_3、NaCl、H_2SO_4浓度分别为0.2、0.25、0.5、0.5mol/L的条件下,铜浸出率可达94.33%。采用XRD和EDS等手段对不同反应时间浸出残渣进行了表征与分析,初步揭示了辉铜矿浸取反应历程。     

用堆浸—液体—凝胶萃取联合流程从含铀磷酸盐砂岩中回收铀的研究：Ⅰ—堆浸

在所研究的矿石中,铀不形成独立的矿物,而是存在于磷灰石晶格中。工作中所使用矿样的铀含量在0.045—0.048％之间。堆浸最早采用pH1.7的Fe_2(SO_4)_3/H_2SO_4溶液进行试验,但是结果不理想。后改用具有中等酸度的含有低浓度HNO_3的硫酸溶液进行试验。浸出过程分为溶解和冲洗两个不同阶段。本文研究了溶解阶段影响铀的回收率和酸耗的因素,并确定了回收铀的最佳条件。     

某超基性岩硫化铜镍矿中钴的物相分析

本矿区的钴,经过用各种研究手段证实,是替换镍黄铁矿中的镍而呈类质同象状态存在,也就是说它主要分布于镍黄铁矿中。这一结论还有必要通过化学物相分析来证实。 本文采用本区的主要硫化物——镍黄铁矿(紫硫镍铁矿),黄铜矿,磁黄铁矿(纯度均大寸90％)来作试验,然后将其应用于原矿各类矿石中钴的物相分析。经试验表明,各种溶剂对本区各种矿物的选择溶解情况为:5％H_2SO_4+HF能很好地溶解硅酸盐矿物和磁铁矿而不溶解硫化物;盐酸能较好地溶解磁黄铁     

黄铁矿表面XPS分析与生物浸出机制研究

黄铁矿的溶解过程受表面化学反应控制,表面性质的变化是影响溶解动力学的关键因素。X射线光电子能谱技术(XPS)是研究矿物溶解过程先进的表面分析技术,可分析矿物表面5 nm范围内化学组成的变化,为解释矿物溶解机制和动力学提供可靠的数据指导。本文采用XPS分析了常温下黄铁矿生物浸出过程中矿物表面的变化,黄铁矿表面主要由含Fe和含S的两种化合物组成。其中,含Fe化合物主要为FeS_2、针铁矿、硫酸盐、高铁络合物;含S化合物主要为FeS_2、硫酸盐、半胱氨酸、多硫化合物。研究表明,黄铁矿的溶解与表面硫的氧化密切相关(从S_2~(2-)氧化至SO_4~(2-)),黄铁矿溶解过程首先是Fe-S键断裂,在细菌、溶氧等氧化剂的作用下,Fe~(2+)和S_2~(2-)迅速被氧化,化学反应界面逐步内扩至黄铁矿本体,最后铁氧化物或氢氧化物型氧化产物稳定存在于未反应的黄铁矿表面。黄铁矿的生物浸出遵循硫代硫酸盐机制,间接浸出和直接浸出机制同时存在,浸出过程中形成稳定的铁氧化物或氢氧化物型氧化产物,在一定程度上加快了表面电子传递速率,促进了黄铁矿电化学氧化溶解。     

黄铜矿生物浸出中钝化现象研究进展

随着矿产资源的日益贫化，传统的矿物加工及其后续的火法冶炼技术在处理矿物时存在不少弊端，生物浸出技术以其反应温和、对环境友好、能耗低、流程短等优点被各国广泛研究。常温生物堆浸技术业已在硫化铜矿（次生）的开采中实现大规模商业化应用，效果良好。但是，在铜资源主体一黄铜矿的生物浸出研究中，研究者发现常温菌难以获得较高的浸出速率，即所谓的钝化现象，以黄钾铁矾钝化，硫层钝化，多硫化物钝化3种现象最为普遍。为了防止黄铜矿生物浸出过程中钝化现象的产生，提出了Ag^＋催化、Fe^2＋和Cu^2＋催化、嗜热嗜酸菌浸出等有效措施。本文介绍了国内外生物湿法冶金工作者在黄铜矿生物浸出过程中钝化方面的研究进展。     

物理——化学法研究含Ni、Co、和Cu针铁矿的浸出

据荷兰《湿法冶金》报道,印度坎普尔工学院采用物理和化学的综合研究方法,在含Ni、Co和Cu的针铁矿的浸出及纯针铁矿的浸出方面进行比较。他们使用H_2SO_4溶液(0.5M,50℃)和H_2SO_3溶液(SO_21.5％,20℃)进行浸出。搅拌速度900r/m,持续时间达20—100min,     

Morphology of chalcopyrite leaching in acidic ferric sulfate media

Two-dimensional computer simulations based on percolation theory were used to explain the morphology associated with atmospheric chalcopyrite leaching in acidic ferric sulfate solution. The aim of this study was to understand the differences in observed morphology between chalcopyrite residues leached with and without pyrite in the leach environment. The study of chalcopyrite morphology is of interest because there are no records of similar investigations available. Simulations showed high copper extractions from chalcopyrite when surface atoms were mobile leading to agglomeration of like atoms and the formation of highly porous mineral structures. High degrees of surface mobility are associated with active anodic behavior. The simulated morphology was consistent with previously observed residue morphology from chalcopyrite leach experiments in the presence of pyrite. Thus it was found that the enhanced recoveries and peculiar morphology observed during pyrite catalyzed leaching are attributable to active anodic behavior. Conversely, the simulations also showed that the recovery of copper was low when surface atoms were effectively locked in place resulting in mineral passivation. The simulation morphology obtained in this case was also consistent with experimental results of chalcopyrite leached without the presence of pyrite which have shown non-porous film like product layers.     

从锂离子二次电池正极废料—铝钴膜中回收钴的工艺研究

根据锂离子二次电池正极废料－铝钴膜原料中LiCoO2的性质,提出了LiCoO2在硫酸、双氧水体系中的分解反应为：2LiCoO2 3H2SO4 H2O2→Li2SO4 2CoSO4 4H2O O2↑确定从中回收铝、钴的工艺流程为：碱浸→酸溶→净化→沉钴。碱浸液中的铝用硫酸中和制取化学纯氢氧化铝,回收率94．84％;钴以草酸钴的形式回收,产品质量达到赣州钴钨有限责任公司的草酸钴产品标准,直收率95．75％。每处理1t铝钴膜废料可获纯利4．56万元。     

Reactivity comparison of Australian chalcopyrite concentrates in acidified ferric solution

The leaching of chalcopyrite from several Australian chalcopyrite concentrates by the reaction CuFeS₂ + 4 Fe(III) + Cu(II) + 5 Fe(II) + 2 S⁰ obeyed parabolic kinetics in acidified nitrate solution between 25 and 40°C. The chalcopyrite reactivity was dependent on the mineral composition of the concentrate: the presence of pyrite accelerated the reaction markedly, but sphalerite and bismuthinite slowed it slightly. Galvanic interaction between minerals cannot account for this change: instead, the associated minerals must influence the rate determining diffusion of the lattice elements within the chalcopyrite crystal.     

The leaching of copper from sulphur activated chalcopyrite with cupric sulphate in nitrile-water mixtures

If chalcopyrite is roasted with sulphur at 400–450°C pyrite and idaite or bornite are produced. Bornite plus pyrite are also prepared by roasting a 1:1 mixture of chalcopyrite and covellite. These copper-iron sulphides were leached with acidified aqueous cupric sulphate solutions containing acetonitrile or hydracrylonitrile and the results are compared with leaching with acidified cupric chloride in brine. The nitrile route has the advantage of a less corrosive sulphate medium for subsequent copper recovery processes.Bornite appears to be the most attractive product from the roasting of sulphur and chalcopyrite because much of its copper can be readily leached. Iron reports to the solution only in the latter stages of extraction. Up to 80% of the copper in this bornite is leached with CuSO₄/RCN/H₂O at 60°C. Copper is recovered from the resulting cuprous sulphate solution by electrowinning with inert anode. The products are copper cathodes and cupric sulphate, which is recycled. The leach residue may be used to reactivate further chalcopyrite or is leached of its copper by established routes.     

痕量钴的浸出工艺研究

研究了痕量钴浸出试验的工艺条件。正交试验结果表明酸度对钴浸出率的影响最大,其次是反应时间,最后才是反应温度,且酸度对浸出率的影响远大于反应时间和反应温度。硫酸浓度和反应温度的提高有助于浸出率的提高,在温度100℃、酸度45%、反应时间3 h时,钴浸出率达到91.56%。在酸过量的情况下,提高酸的加入量对浸出率影响不大。     

镉车间铜渣中有价金属铜的回收

试验表明 ,在pH <1的硫酸溶液中加入经自然风干后的铜渣和FeSO4 进行堆浸 ,经过 34天二个阶段的自然堆浸作业 ,铜渣中Cu的浸出率可达到 90 %以上 ,该工艺在技术上是可行的     

高硫碳酸锰矿与软锰矿直接浸出实验

传统电解锰生产中,软锰矿需要经过还原焙烧将其中的Mn4+还原为Mn2+才能被稀硫酸浸出制得MnSO4溶液。利用高硫碳酸锰矿中的硫铁矿成份和浸出时产生的具有还原性的H2S和溶液中的Fe2+,可以直接浸出软锰矿中的Mn4+。经过多次实验对比,总结出了较理想的高硫碳酸锰矿与软锰矿的配矿比,既有利于高硫碳酸锰矿在浸出时产生的H2S的利用吸收,减少尾气中的H2S,给尾气处理减轻负担,又有利于保持较高的浸出率,可为高硫碳酸锰矿和软锰矿的直接浸出提供参考。     

Galvanic interaction between chalcopyrite and pyrite during bacterial leaching of low-grade waste

The bacterial leaching of a low-grade chalcopyrite waste rock in a lixiviant containing thermophilic, Sulfolobus-like microorganisms at 60°C and a lixiviant containing Thiobacillus ferrooxidans at 28°C has been compared with the leaching in sterile lixiviant in terms of copper solubilized in elapsed time and the conversion of $\text{Fe}{}^{\mathrm{3+}}\text{Fe}{}^{\mathrm{2+}}$. Bacterial action has been shown to drastically increase the ratio $\text{Fe}{}^{\mathrm{3+}}\text{Fe}{}^{\mathrm{2+}}$ with elapsed time of leaching. Direct observations of the associated pyrite and chalcopyrite surface corrosion, utilizing scanning electron microscopy, showed that during the leaching of these sulfides as separate, non-contacting phases, the pyrite corroded more rapidly than the chalcopyrite in both sterile and inoculated media. This effect was more pronounced at elevated temperature and in the presence of bacteria. When the pyrite and chalcopyrite were in contact, the resulting galvanic interaction caused the chalcopyrite to corrode more rapidly than the pyrite, which was effectively passivated. The leaching of chalcopyrite is thereby enhanced in contact with pyrite. This effect is accelerated in the presence of bacteria. The corrosion of chalcopyrite was also markedly enhanced as a result of the oxidation of elemental sulfur (formed during the reaction) to sulfuric acid. This reaction was also accelerated by bacterial catalysis. The important implications of the enhanced chalcopyrite corrosion by galvanic interaction in the leaching of low-grade chalcopyrite waste and other galvanic-contact regimes involving metal sulfides are identified and discussed.