金矿非氰化浸金研究进展

随着易处理金矿石资源枯竭,含砷、含碳、高硫、超细颗粒金矿石已成为金矿开采的重点,这些难处理金矿通过常规氰化浸金等方法浸出效果差,由于氰化物有剧毒,会危害人体健康,并严重污染生态环境。非氰化法浸金因具有环保、浸出速率快、效率高等优点受到了广泛关注。在综述了硫代硫酸盐法、甘氨酸法、卤素法、石硫合剂法、碘化焙烧工艺、硫脲浸出法和非水溶液浸金7种非氰浸金方法的浸金原理及其在难处理金矿方面的最新研究进展的基础上,讨论了非氰浸金方法存在的浸出剂昂贵、浸出液中金回收困难、浸出体系复杂、浸出剂性质不稳定及消耗量大等问题,并对非氰浸金技术的发展方向进行了展望。      

非氰浸金技术的研究及应用现状

由于氰化物具有剧毒性,故采用氰化法处理含金矿石时,对环境的污染比较严重。同时,对于复杂金矿石的氰化浸金效果差的问题,许多学者试图研究更理想且能够替代氰化提金的非氰浸出剂。非氰浸金法具有无毒性或毒性比氰化物小、浸出速度快和对某些杂质的适应性强等优点,使得该方法备受青睐。阐述了非氰浸金技术的研究进展及其应用现状,重点分析了硫脲法、硫代硫酸盐法、多硫化物和石硫合剂法、卤素及其化合物法,以及各方法的浸金工艺和优缺点,提倡开发更有效的无毒非氰浸金工艺,实现高效、环保且适合工业生产的目的。     

非氰提金技术研究进展

随着难处理金矿的占比不断增加以及人们对环保问题的日益重视，氰化法受到了技术和环保两方面的制约，非氰方法成为金、银提取的必然趋势。非氰方法包括湿法工艺和火法工艺两大类。系统介绍了湿法非氰方法中卤素法、硫脲法、硫代硫酸盐法、硫氰酸盐法和环保提金剂的原理及发展状况；火法非氰方法主要介绍了具代表性的高温氯化焙烧工艺和造锍捕金工艺，其适用对象分别为铁含量高的含金物料和含砷、硫、碳等难处理金精矿。通过综合分析得出贵金属提取的重要趋势是火法—湿法工艺结合，即先通过火法充分富集贵金属，再利用湿法工艺高效回收。     

非氰浸金技术发展现状及应用前景

氰化法浸金尽管应用广泛,但其浸出剂氰化物有剧毒,使用不当会严重污染环境和危害人身安全。而非氰浸金技术具有浸出速度快,杂质影响小,低毒甚至无毒等优点,已成为目前黄金湿法冶炼领域一项重要研究课题。总结了硫脲法、硫代硫酸盐法、卤素法、多硫化物法、石硫合剂法和生物法等主要非氰浸金技术研究现状,分析了其浸金机理及优缺点,并对非氰浸金技术尤其是硫代硫酸盐浸金应用前景进行了展望。     

无氰浸金技术在我国的研究应用现状

非氰药剂近年来在我国某些难浸金矿选冶提金工业化应用生产,不但提高了金的回收率,而且有利于矿山环境保护。经研究试验,只要合理采用无氰浸出提金技术工艺,该类金矿仍可达到较好的经济技术指标。     

难选金矿浸出工艺的研究及评价

高龙金矿经全泥氰化法、硫脲法、硫代硫酸盐法浸出试验,金浸出率分别达到94.6%、97.6%和93.9%;渣含金各为0.27g/t、0.12g/t、0.30g/t。建立的金浸出率数学模型,查明了诸影响因素与金浸出率之间的关系。以1g黄金的生产成立本为目标函数,利用复合形法进行的技术经济综合寻优证明,在诸浸出方案中炭浸法有较好的技术经济指标,且较成熟,可作为扩大实验及工业实验的推荐流程。     

某金矿石的石硫合剂法浸金研究

本文研究了石硫合剂法对陕西省某金矿难浸金矿石浸金的适应性。研究结果表明：采用石硫合剂法处理该矿石可获得较好的浸出指标。     

某难处理复杂金精矿高效循环回收金银试验研究

针对国外某金矿产出的难处理复杂金精矿,采用细磨—氰化法、焙烧—氰化法处理,金浸出率分别为26.99%、79.97%,回收效果不理想,同时其他有价元素难以得到有效综合回收,造成资源浪费。研究了高效回收该金精矿中有价元素金、银的工艺技术,结果表明：采用添加钠盐二级焙烧—酸浸—浮选,金银精矿浸出—氰渣循环焙烧及浮选尾矿氰化工艺,在最佳条件下,氰渣金品位为1.78 g/t、银品位为54.10 g/t,金总回收率达到96.29%、银总回收率达到92.01%;且尾渣铁品位达到63.20%,可作为制备高质量炼铁球团矿的原料,实现了金精矿资源的高效综合回收。     

置换法回收硫代硫酸盐浸金液中金的研究进展

氰化法是目前黄金企业生产普遍采用的方法,但氰化法浸金对产金区生态环境影响较大,尤其是对地下水污染严重,现场操作人员的安全风险较高,在一些国家和地区氰化法提金已受到限制使用。硫代硫酸盐体系因其对环境影响小、无毒、安全、浸金速率快以及能处理氰化法难处理的含铜含碳难冶炼矿石等优点,已被认为是目前最有望取代氰化法浸出及回收金的浸出剂。但由于硫代硫酸盐提金工艺试剂消耗量大以及缺乏一种有效回收金的方法,导致该法一直未能应用于工业生产。从相关文献可知,硫代硫酸盐浸金液中回收金的方法较多,其中置换法是目前能有效回收金的方法之一,且研究较多。在综述硫代硫酸盐提金机制的基础上,概述了锌、铜、铝、铁以及其他金属置换法回收金的机制、研究现状和存在的问题,提出了今后的研究方向,为硫代硫酸盐的大规模应用研究提供一定的科学理论参考。     

金矿石处理方法研究现状及进展

随着环保要求日益严格与金矿资源品位逐渐下降，非氰提金技术与难处理金矿石预处理技术受到广泛关注，如何高效、绿色地提金成为目前冶金工业的研究热点之一。总结了近年来金矿石浸出技术及难处理金矿石预处理技术的现状及进展，并通过分析各方法的作用机理对比了其优缺点，为金矿提金技术的发展及推广应用提供参考与借鉴。     

Developments in Gold Leaching: A Literature Survey

The gold industry has seen intense activity in the areas of exploration and metallurgy'in recent years. Many developments have taken piace through which ore bodies that were once considered uneconomical to exploit are becoming economical grade. Even the traditional cyanidation process has been modified during the course of time to make it more economical and efficient. Developments such as heap leaching, in-situ leaching, carbon-in-pulp (CIP), carbon-in-leach (CIL) resin-in-pulp (RIP), and pretreatment of refractory ores have already made an impact on gold industries. Research and development work is also being carried out on less toxic, more efficient lixiviants which may eventually replace the toxic cyanide, solving the disposal problem currently facing the industry. This paper aims at summarizing the developments in the extraction of gold using conventional, as well as unconventional, lixiviants. Some developments in the area of gold recovery from pregnant solutions have also been briefly discussed.     

Dissolution Chemistry of Gold and Silver in Different Lixiviants

Cyanide has been recognized for a long time as a powerful lixiviant for gold and silver, forming very stable cyano complexes with both metals. While cyanide is very effective in leaching free milling ores, there are certain classes of gold and silver ores (i.e., carbonaceous, pyritic. arsenical, manganiferous, cuperferous) that are considered refractory to conventional cyanidation dissolution. Recently there has been considerable effort directed towards new and improved reagents for leaching these difficult-to-treat ores and concentrates. A large portion of this effort has been devoted to finding alternative lixiviants that might compete with conventional cyanidation. Furthermore, there is a general interest in developing non-toxic environmentally safe substitutes for cyanide.

There are a number of reagents that form stable complexes with gold and silver e.g., thiourea, thiosulfate, halides, malononitrile, acetonitrile and polysulfides. The chemistry of gold and silver dissolution using alternative lixiviants is discussed in this paper. Special emphasis is given to the application of Eh-pH diagrams to interpret the dissolution behavior.     

含锑难处理金精矿加压氧化法制备焦锑酸钠的工艺研究

锑及其化合物是重要的战略物资,焦锑酸钠被广泛应用于玻璃行业。锑金矿是难处理金矿的一种,直接氰化浸出时金的浸出率极低,需要进行预处理后才能提取金。针对某矿山含锑较低的难处理金精矿的特点,并结合目前难处理金矿的各种预处理方法的优缺点,研究确定了该类难处理金精矿适宜采用先回收锑再回收金的思路,即以含锑难处理金矿为原料,采用硫化钠浸出法优先分离锑,使锑以硫代亚锑酸钠形式进入滤液,然后采用加压氧化新工艺以焦锑酸钠产品的形式回收锑,氧化后的滤液经过净化和浓缩结晶后产出硫代硫酸钠产品,脱除锑后的浸出渣用细菌氧化预处理,最后用氰化法从细菌氧化渣中提取金,从而实现难处理金精矿中锑、硫、金的综合回收。     

Hydrometallurgy of precious metals recovery

The hydrometallurgical process for the treatment of gold and silver ores remained unchanged for the first 70 years of this century, and consisted essentially of leaching in cyanide solution followed by solid-liquid separation, with the solid residues being washed as efficiently as possible, and the leach liquor being treated by zinc cementation to recover the precious metals. White this process is generally extremely efficient and fairly cheap, it does have limitations in the treatment of low-grade ores and certain complex ore types. For example, ores with a high content of clay or other soft, fine minerals are usually difficult to filter, and losses of soluble gold or silver in the residues can be unacceptably high. In other situations, where the precious metal host rock contains high concentrations of sulphides such as pyrite or arsenopyrite, for example, or base-metal oxides or carbonates, the traditional process often suffers from poor gold recovery (due to encapsulation of the precious metals in the sulphides) or high cyanide consumption, or both of these. Whereas these occurrences were fairly rare (or were avoided!) in the first half of this century, they are now assuming great importance, and each year a higher percentage of world gold production derives from sources such as these.A number of new hydrometallurgical processes have been developed and implemented in the gold industry in the last 20 years, and these have transformed gold processing into a chemical “high tech” industry, and have allowed increasingly complex ore types and progressively lower grades of ore to be treated economically. As a result, in a period when gold production might have been expected to decline, world-wide production has almost doubled over the two decades.This paper describes the traditional cyanidation and zinc cementation processes, but focuses on the new developments in the industry. In particular, new leaching technologies such as heap leaching for low-grade ores and pressure leaching for refractory sulphide ores are discussed, as well as the carbon-in-pulp and carbon-in-leach processes that have effectively replaced filtration and countercurrent decantation on almost every gold plant built since 1980. Some emerging technologies such as bacterial leaching and resin-in-pulp are also discussed briefly.     

加压氰化法提取贵金属的研究进展

氰化法是处理金矿较为成熟的工艺。加压氰化过程通过强化反应动力学,可实现难浸金属的高效浸出,在贵金属湿法提取冶金领域是一新兴技术。分别介绍了加压氰化法处理难浸金矿、失效汽车催化剂、含铂族金属矿物等方面的研究工作及其最新进展。对我国云南大理地区低品位铂钯硫化矿的浮选精矿,采用传统火法造锍熔炼技术工序繁冗、能耗高、污染严重、贵金属易分散损失,经济上难以创效。而采用加压氰化全湿法新工艺,不但贵金属及铜镍等有价金属回收指标高,而且该工艺工序少、周期短、能源低、污染小,为开发利用我国低品位原生铂矿资源提供了一条新技术思路。     

重金属强化氰化浸金的动力学研究

本文以难浸硫化物金精矿、氧化物金矿和易浸硫化物金精矿为对象,进行了重金属强化浸金的技术及动力学研究。单独添加重金属时,对于氧化物金矿和易浸硫化物金精矿具有一定的强化效果,但对难浸硫化物金精矿强化作用并不明显。重金属和过氧化氢协同强化时,三种金矿的浸出速率都显著提高。动力学研究结果表明,采用重金属和过氧化氢协同强化时,降低了表观活化能,提高了氰化钠的表观反应级数。     

某高砷难溶金矿石浸出特性试验研究

采用超细磨、边磨边浸和强化碱浸等工艺方法考察了某高砷型难溶金矿石的浸出特性。其结果表明,超细磨、边磨边浸和强化碱浸工艺均能有效提高金的浸出率。矿样超细磨至-37μm占99.7%时,金的氰化浸出率从23.7%提高到73.6%,金的非氰化浸出率从18.5%提高到66.9%;在同样磨矿细度条件下进行边磨边浸,而后再继续浸出,金的氰化浸出率进一步提高到82.4%,金的非氰化浸出率提高到72.9%;在同样磨矿细度条件下进行碱浸预处理,碱浸6~9 h金的氰化浸出率为88.3%~87.5%,碱浸9~12 h金的非氰化浸出率为89.7%~90.2%。     

青海某难浸金矿的工艺矿物学研究

青海某金矿石中含金5.2×10^-6,硫1.82%,砷1.01%,锑0.73%,铁4.19%,实验室直接氰化浸出时金回收率不足50%,属于典型的含砷锑难浸金矿。为查明影响金浸出的矿物学因素,采用X射线衍射仪（XRD）和扫描电镜（SEM-EDS）,并结合传统的光学显微镜对该难浸金矿中金的赋存状态及主要载金矿物的嵌布特征进行了研究。结果表明：该矿石中金的赋存状态主要有3种,即可见自然金（明金）、硫化矿物包裹金和脉石矿物包裹金。其中,可见自然金占比较低,仅为42.87%,主要嵌布在辉锑矿、毒砂和石英等矿物颗粒间或裂隙中;硫化矿物包裹金占比为46.83%,主要以显微、次显微金或固溶体的形式赋存于毒砂、辉锑矿和黄铁矿等硫化矿物中;脉石矿物包裹金占比为10.3%,主要以显微、次显微金或微细粒包裹体的形式赋存于石英、长石和方解石等脉石矿物中或矿物颗粒间。由此可知,自然金占比低、硫化矿物包裹金和脉石矿物包裹金含量高是造成氰化浸出时金回收率低的主要原因,工艺矿物学研究结果为该金矿的合理开发利用提供了重要参考。