Enhance Cyanide Recovery by UsingAir‐Sparged Hydrocyclone

Human health and environmental concerns dictate that industrial processes be improved or replaced. Recovery or recycling is an important activity that allows cyanide residue from the industrial processes to be re‐used, reducing its production cost and disposal problems. In this regard, the air‐sparged hydrocyclone (ASH) has been used as a reactor for the treatment of cyanide solutions for cyanide recycling by acidification/volatilization using the Mexican modification of the Mills‐Crowe process. Aqueous cyanide‐ion concentration can be reduced from 250 ppm to below 20 ppm in the ASH with recoveries greater than 80 % in a single stage.     

SFG and DFG investigation of Au(111), Au(210), polycrystalline Au,Au–Cu and Au–Ag–Cu electrodes in contact with aqueous solutions containing KCN and 4-cyanopyridine

We report on potential-dependent in situ SFG and DFG spectroscopy carried out at Au(111), Au(210), polycrystalline Au, Au–Cu and Au–Ag–Cu electrodes in contact with aqueous solutions containing CN⁻ and 4-cyanopyridine (4CP). Spectroelectrochemical work was complemented by cyclic voltammetry. The chief stress has been placed on systematising and quantifying the interaction between 4CP and CN⁻ and the attending effects on the vibrational and electronic structures of the interface. The voltammetric behaviour of the investigated electrodes, modified by the addition of 4CP to the CN⁻ electrolyte, denote changes in the CN⁻ adsorption characteristics and effects of the adsorbed CN⁻ layer on the electrodic reactivity of 4CP. The differences among the investigated electrodes can be explained in terms of their respective degrees of atomic packing or with alloying effects on the stability of adsorbed CN⁻. The potential-dependent spectra have been analysed quantitatively with a model for the second order non linear susceptibility accounting for vibrational and electronic effects. The spectral changes induced by addition of 4CP denote interaction of the aromatic with the electrode through the CN⁻ monolayer. The non-resonant contribution yields information on the effects of 4CP on the fine structure of the bound electron density of states.     

Suppression of photo-induced dilation in cyanide treated hydrogenated amorphous silicon films

Effects of cyanide (CN) treatment with hydrogenated amorphous silicon (a-Si:H) films have been investigated. The decrease of ΔV/V was observed in cyanide treated a-Si:H films and the successive thermal annealing at 200°C after CN treatment induced the further reduction of the ΔV/V. XPS spectra show the indirect evidence that the cyanide species is present within 10 nm from the hydrogenated amorphous silicon surface. The results of CN treatment with a-Si:H solar cells are demonstrated.     

金回收技术的研究

银洞坡金矿选一厂氰化浸出过程中存在着金浸出率低、泡沫外溢造成的金的流失和氰化尾渣含泥高严重影响氰化尾渣综合回收等主要问题。针对这些难题,提出并研究了磨矿与药剂组合的新工艺,使浮选金精矿品位由39 43g/t提高到53 19g/t,金浮选-氰化浸出总回收率由80 92%提高到90 54%;解决了所存在的三大难题。     

甘肃某难处理金精矿的预处理与生产实践

针对甘肃某含砷、含锑难处理金精矿,采用"浸锑—两段焙烧"脱锑、脱砷,然后进行氰化提金的流程。考察了浸锑条件和焙烧条件对脱锑、脱砷的影响。试验结果表明,在优化后条件下,含砷、含锑难处理金精矿的脱砷、脱锑率分别达到78.59%、93.8%,然后通过氰化浸出工艺提金,金的回收率可从48%提高到92.3%。     

云南某金矿氰化尾渣中铁回收工艺改进试验研究

针对云南某金矿氰化尾渣铁回收过程中存在磁铁矿回收率偏低的问题,进行了磨矿细度、磁感应强度、脱泥磁选的试验研究。结果表明,现场原矿磨矿粒度过细是导致磁铁矿回收率偏低的主要原因,磨细后磁铁矿主要损失在褐铁精矿中。对现场获得的褐铁精矿进行的实验室弱磁选试验结果表明,能从褐铁精矿中获得产率约为8%的磁铁矿,磁铁矿中铁的总回收率可提高15%左右。试验结果应用于现场生产,对现场工艺流程进行改进,将褐铁粗精矿引流至弱磁精选进一步回收磁铁矿,磁铁精矿中铁回收率提高了13.92%,总铁回收率提高了11.23%,吨矿价值提高了55.31元,不仅可实现资源的综合利用回收,同时可为企业增效创收。     

福建某金银矿山氰化厂设计中的问题探讨

福建某金银矿山是以银为主的金银矿,原矿银品位为128．87g／t,金品位为0.72g／t。设计采用浮选精矿氰化、锌粉置换法提金工艺。我们针对氰化厂设计中的工艺和工艺参数选取进行了分析探讨,对今后的工作具有一定的指导意义。     

几座移动式选金厂的生产效果

三年前,地矿部矿产综合利用研究所研制成功移动式选金装置,并设计建成了一些移动式选金厂,取得了良好结果。本文介绍了几个处理量为10—50t/d移动式选金厂的运行状况,着重讨论了所处理的矿石性质、工艺流程及获得的生产技术指标或设计指标。     

过氧化氢在氰化浸金工艺中的应用

本文综述了过氧化氢辅助浸金工艺的发展现状。进行了两个矿样的小型试验。结果表明,使用过氧化氢辅助浸金,可缩短浸出时间,提高金的浸出率。     

氧化金矿石强化氰化浸出的试验研究与工业实践

针对某氧化金矿石的特性,提出采用"过氧化钙强化氰化浸出工艺"进行处理,实验室研究获得最佳浸出条件为:浸出物料细度-74μm占93%,浸矿浓度为35%,NaCN用量为4 kg/t,石灰用量8 kg/t,过氧化钙(CaO2)用量为4kg/t,木质素磺酸钙(SAA)用量为1 kg/t,矿浆pH值为12.3左右。过氧化钙强化氰化浸出工艺的工业生产实践表明,与原工艺相比,金、银的浸出率明显提高,经济效益十分明显。