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。     

Review of Recovery of Platinum Group Metals from Copper Leach Residues and Other Resources

Porphyry copper and mixed copper-gold sulfide deposits contain varying amounts of precious (gold and silver) and platinum group metals (PGMs). Currently, milling and froth flotation is the most common processing route for the treatment of high-grade base metal sulfide ores. During this process, the precious metals and PGMs are also concentrated and represent a possible opportunity for the beneficiation of these metals to increase the overall economic value of the ore. Although not yet commercialized, the high temperature pressure oxidation (POX) of copper concentrates provides an alternative processing route to traditional smelting technology. With increasingly aggressive air quality standards and rising upstream processing costs for smelting, hydrometallurgical processing options become progressively attractive. The treatment of POX residues for the recovery of precious metals has seen significant attention and multiple processing routes have been developed on various scales. Extraction and beneficiation of PGMs from copper concentrate POX residue has garnered significantly less attention and mechanistic questions remain to be answered. Based on a review of the processing options for PGM ores and concentrates, hydrometallurgical processing routes for the extraction of PGMs from copper concentrate POX residues are envisioned.     

贵金属二次资源的回收利用与展望

阐明了贵金属二次资源的回收利用的意义以及废料的主要来源,对贵金属二次资源的预处理方法以及金银铂钯等贵金属的回收利用方法等进行阐述,比较了目前国内外贵金属二次资源回收贵金属的处理技术,分析了相关行业存在的问题,并对贵金属二次资源的回收利用进行了展望。     

Plasma Technology in Extractive and Process Metallurgy

Thermal plasma technology may be useful for a broad range of applications in extractive and process metallurgy. Plasma technology is being used in the melting/remelting and refining of metals/alloys and scrap. Plasma technology may also be potentially useful in the benericiation of complex ores, treatment of wastes, reduction of oxides, the generation of value added products, and the recovery of precious metals from waste products. This paper gives an overview of thermal plasma applications in the field of extractive and process metallurgy.     

黑龙江鸡东五星铂钯铜镍矿床的铂钯元素赋存规律

五星铂钯铜镍矿床位于敦密断裂南东侧的兴凯地体内,矿床内不仅含有铜镍钴矿体,同时含有贵金属铂钯矿体。通过对铂钯元素在岩石、矿石及矿体中的物相分配、赋存规律的研究,发现矿体中贵金属钯铂主要以2种形式赋存,即矿物相及类质同像,且类质同像又分为硫化物中的类质同像、造岩矿物及氧化物中的类质同像。研究表明,钯铂主要以矿物相存在,硫化物中的类质同像次之,造岩矿物及氧化物中类质同像的赋存形式较少。     

Formation of the metal and energy-carrier price clusters on the world market of nonferrous metals in the postcrisis period

The laws of formation of price clusters are revealed upon statistical processing of the data on changing the quotation prices of nonferrous and precious metals, oil, black oil, gasoline, and natural gas in the postcrisis period from January 1, 2009 to November 1, 2013. It is found that the metal prices entering in the price cluster of nonferrous metals most strongly affect the formation of the nonferrous metal price and that the prices of precious metals and energy carriers correct the exchange price of the metal to some extent but do not determine its formation. Equations are derived to calculate the prices. The results of calculation by these equations agree well with the real nonferrous metal prices in the near future.     

Recovery Problems in Gold Ore Processing with Emphasis on Heap Leaching

The present paper briefly describes the methods of gold ore processing and the associated problems are grouped into mineralogical, chemical and physical. The processing of low grade gold ores by heap leaching is an important technological development. But a major drawback in heap leaching process is low recovery of the precious metals. The problems that generally lead to a low gold recovery and the possible solutions are discussed.     

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.     

New Alternative To Cyanidation: Biocatalyzed Bisulfide Leaching

Abstract

Metallurgists have long sought cost-effective techniques for recovering precious metals from their ores. They are increasingly called upon to design processes for ores refractory to conventional recovery techniques. Adding environmental costs (including site remediation) to the total cost of mining has also stimulated a search for alternative to conventional processes. This paper describes progress in development of an alternative to cyanidation, bisulfide leaching, for extracting gold, silver from refractory ores and concentrates. While bisulfide leaching can be implemented abiolically, significant benefits accrue from its practice as a bioprocess integrating precious-metals liberation and extraction steps. Bisulfide leaching appears to offer advantages over the traditional cyanidation process, including lower reagent costs and toxicity as well as an ability to leach “preg-robbing” ores and other ores not amenable to cyanidation. Bisulfide leaching may also offer advantages over cyanidation for selective dissolution of precious metals from base-metal concentrates.     

关于金银浸出时电化学催化

提出了金银等贵金属在氰化等浸出过程中原电池抑制和催化作用的机理,首次提出了控制被矿物脉石包裹的金银粒子表面上的电位,使金表面上有利于阳极溶解过程,同时使氧的阴极还原集中于包裹的矿物脉石及其产物表面上。因而既提高了贵金属浸出速度,又阻碍或抑制了矿物脉石的溶解,从而降低了试剂的消耗。这种电化学催化新工艺,原则上适用于所有氧化还原浸出过程,特别适用于难用常规氰化处理的顽固金矿或金精矿。     

Nickel sulphide smelting and electrorefining practice: A review

Nickel in the form of cathodes, rounds, powders, and salts is well recognized as a useful commodity in domestic industries and/or export. It is shipped as concentrates, mixed sulphides, and ferronickel. Today, there are only a limited number of major and minor producers of this important metal, which is employed worldwide in a multitude of commercial and residential applications. Traditionally, nickel and associated metal values are recovered from ore feedstock by proven mineral processing, smelting, and refining processes. Typical host minerals contain other base metals, such as copper, cobalt, and noble metals consisting of gold, silver, and OPMs (otherprecious metals). Although sulphide-bearing ores such as those found in Canada and Russia will likely serve as a long-term source of this nonferrous material, the future trend is expected to involve laterite processing, which represents about 70% of the world's known nickel resources. The authors are aware of seven nickel refineries (ie, electrorefining) on a global basis dedicated to the production of class I primary nickel products. The supply and demand of pure and high-grade nickel products during the past decade has been erratic and subject to wide fluctuations in delivered price. This article describes theestablished industrial processes for recovery of nickel originating from sulphidic sources. Details of smelting and refining practice are provided for the three largest nickel producers. For completeness, other extractionprocesses involving a mixed sulphide, pellets from the carbonyl process, nickel powders, and briquettes are noted in the compendium of nickel processing practice, which includes pyrometallurgical principles. This paper lists the 47 pyrometallurgical operations worldwide which are mainly dedicated to the production of class II nickel products (nickel oxide products and utility nickel), nickel matte, and granules. The theme of the nickel biography is to provide a full extractive metallurgy synopsis rather than the reader reviewing numerous authors.     

有色金属冶炼过程中主金属价态变化规律

对传统矿物之重金属、轻金属、稀有金属、贵金属冶炼以及电子垃圾在金属提炼过程中主金属价态发生的变化规律进行了归纳整理，并绘制成图形。结果表明，轻金属和稀有金属的冶炼过程价态变化基本对应Z字形，相对不活泼的重金属冶炼过程的价态变化呈凹字形，贵金属的冶炼过程价态变化呈凸字形。我们认为，这些基本规律的存在，跟各元素的金属活泼性直接相关。以上规律的梳理，可以对开展城市矿产资源的循环再生新思路、新方法探索起到一定的助益和参考。      

An Integrated Biotechnological Approach to Gold Processing - An Indian Experience

Abstract

The role of biotechnology in different facets of gold extraction metallurgy is illustrated with respect to biogenesis of gold ore deposits, biobenefication, bioliberation and bioenvironmental control. The use and commerical potential of this technology are discussed with reference to the mining and processing of Hutti gold ores. A microbial survey of the Hutti gold mines revealed the ubiquitous presence of various autotrophic and heterotrophic bacteria, fungi and yeast of relevance in gold processing. The possible roles played by different indigenous microorganisms in the formation, conversion and transport of gold along with various associated minerals have been brought out. Similarly, the role of Thiobacillus ferrooxidans in the flotation beneficiation of gold-bearing sulphides and in enhancing gold recovery from refractory sulphide ores and concentrates has been demonstrated. Direct gold solubilization could be achieved by Bacillus spp. Various fungi and yeast were found to be useful in the biosorption of gold and other base metals from cyanide effluents. It could thus show that biotechnology could be beneficially utilized in different stages of precious metal processing spanning from mining to waste disposal.     

Recovery of Silver and Gold from Cyanide Solution by Magnetic Species Formed in the Electrocoagulation Process

Cyanidation is the predominant process by which gold and silver are recovered from their ores in metallurgical operations, and it is recognized that the Carbon in Pulp, the Merrill–Crowe, the Ion Exchange, and Solvent Extraction processes are used for concentration and purification of gold and silver from cyanide solutions. Among other available options for recovery of precious metals from cyanide solutions, Electrocoagulation (EC) is a very promising water and wastewater electrochemical technique that does not require high concentrations of silver and gold in cyanide solutions to yield excellent results. In this work, an introduction to the fundamentals of the EC process is given, followed by the conditions and results of the EC test run for removal of precious metals from cyanide solutions, and finally the characterization of the solid products formed during the EC process with X-ray Diffraction, SEM, and Transmission Mossbauer Spectroscopy. Results suggest that magnetite particles and amorphous iron oxyhydroxides are present (Lepidocrocite and Gohetite). With the EC process, the achieved removal efficiency of silver and gold from cyanide solutions, within 5 min, exceeded 99%.     

On Prospects of Electric Pulse Disintegration from Energy Balance Standpoint

Abstract

Although electric pulse disintergration possesses a number of advantages over mechanical means of comminution (efficient liberation of monominerals from polymineral rocks, high purity of products, no metal contaminants), a serious drawback putting a limit to its commercial use is its energy inefficiency.

Calculations of energy consumption in terms of increased surface area of fragments resulting from disintergration indicated that specific consumption of energy in electric pulse disintegration is within 0.00135–0.00067 Wh/cm². To disintegrate a cube with 4 cm side down to ? 2 + 0 mm size requires work amounting to 20 kWh/t as compared to 3–10 kWh/t of commercial and 15–17 k Wh/t of laboratory mechanical facilities.

Analysis of energy distribution proved that the total electrical efficiency of electric pulse disintegration is as low as 0.01–0.08 of the amount consumed from power supply main. Specific energy consumption per 1 cm² of increased surface area is 0.4–0.5 J.cm^-2.     

贵金属配合物在医药领域中的应用

简要综述了贵金属抗癌配合物的发现、临床应用、抗癌机理及研究现状,着重介绍了11类铂配合物的最新研究进展,指出了应用中尚须解决的问题,并展望了铂、金、银、锇、钌、铑、钯、铱等贵金属配合物在医药领域的应用前景。     

铝土矿选矿脱硅的研究现状及进展

论述了我国铝土矿资源状况与特点,指出了铝土矿选矿脱硅的重要性,并从化学选矿脱硅和物理选矿脱硅两方面介绍了铝土矿选矿脱硅的研究现状与进展,在此基础上指出了铝土矿选矿脱硅的研究方向.     

Research and Development Activities for the Recovery of Gold From Alkaline Cyanide Solutions

The use of autotrophic and heterotrophic microorganisms in the solublisation of gold from refractory sulphides and oxide ores is discussed. Basic microbiological characteristics of the leaching bacteria are outlined. Reaction mechanisms in the biooxidation of gold-bearing arscnopyrite and pyrite an: illustrated with special reference of Thiobacillus ferrooxidans. Biological and engineering factors influencing biooxidation for the liberation of gold are critically examined. Available reactor designs as welt as pilot-plant operations are brought out. The utility of heterotrophs in the direct leaching of gold is also evaluated. The role of biosorption in the recovery of precious metals from solutions and in environmental control is also examined. The potential of biomineral technology for processing gold-bearing ores and concentrates in the Indian context is highlighted.     

Processing mineral raw materials in Siberia: ores of molybdenum,tungsten, lead and gold

Problems related to the processing of mineral raw materials from Siberia (i.e. molybdenum-, tungsten-, lead- and gold-containing ores and concentrates) are reviewed. It is shown that hydrometallurgical methods for processing such raw materials are more advantageous than pyrometallurgical ones. For example, hydrometallurgical treatment of molybdenum and tungsten concentrates can be used industrially. Studies have shown that the recovery and concentration of molybdenum and tungsten from leach solutions can be effectively carried out using macroporous anion exchangers. Other studies show that nitric acid/iron(III) solutions are most efficient for leaching lead from lead sulfide concentrates. Metallic lead as well as lead-containing compounds can be produced by electrolysis of lead nitrate leach solutions. These solutions also provide a hydrometallurgical method for the oxidation of pyrite and arsenopyrite in gold-containing raw materials prior to the recovery of gold by complex-forming reactants. Salt decomposition of sulfides and dissolution of gold by non-cyanide complex-forming reagents can be used also for the recovery of gold from refractory arsenopyrite concentrates. Hydrometallurgical technologies recover about 93–98% of metals. Moreover, it is quite easy to improve production efficiency by modifying the design of the industrial equipment and by preventing the formation of environmentally harmful products.     

REVIEW OF AGGLOMERATION PRACTICE AND FUNDAMENTALS IN HEAP LEACHING

ABSTRACT

This article reviews agglomeration practices for precious metal and copper heap leaching. Both industries prefer drum to conveyor agglomeration, particularly for clayey ore or ore having a high fines content. Precious metal heap leaching operations opt for cement in a dosage from 2.5 to 10 kg cement/t of ore (5–20 lb/ton) added to a cyanide solution. Copper ores are agglomerated with water and up to 40 kg sulfuric acid/t of ore (80 lb/ton) without binder. The agglomerate physical characteristics, with the exception of their strength, can be measured precisely and automatically. The impact of agglomeration on the in situ physical characteristics of the heap, other than the observable ponding and slumping, is not understood well. The most substantial benefits of agglomeration include up to 90% metal recovery from poorly permeable ores, shorter leach cycles, extra metal recovery from already-leached tailings, and better environmental heap closure.