How will biomining be applied in future？

This paper reviews the current status of commercial biomining operations around the world, identifies factors that drive the selection of biomining as a processing technology, describes challenges to exploiting these innovations, and concludes with a discussion of biomining＇s future. Biomining is commercially applied using engineered dumps, heaps and stirred tanks. Overcoming the technical challenges of lowering costs, processing low-grade, low-quality and complex ores and utilizing existing capital investments at mines requires better understanding of microbial activities and innovative engineering. Surmounting biomining commercial challenges entails improved mining company/biomining innovator cooperation and intellectual property control.     

Research progress in biohydrometallurgy of rare metals and heavy nonferrous metals with an emphasis on China

In the past decade, progress in the field of biohydrometallurgy had been significant. A total of 17 novel biomining microorganisms were discovered, and eight copper heap bioleaching plants and 11 gold biooxidation plants were established or expanded. In this review, it was summarized the physiological properties of the newly isolated biomining microorganisms and three novel microbial ecological methods for studying microbial community dynamics and structure. In addition, biohydrometallurgy research on rare metals such as uranium,molybdenum, tellurium, germanium, indium, and secondary rare metal resources, as well as heavy nonferrous metals such as copper, nickel, cobalt, and gold has been reviewed, with an emphasis on China. In future, further studies on bioleaching of chalcopyrite, rare metals, secondary resources from waste, and environmental pollution caused by resource utilization are necessary.     

BiohydrometaUurgy applied to exploitation of black shale resources:Overview of Bioshale FP6 European project

Bioshale project, co-funded by the European Commission （FP6 programme）, started in October 2004 and finished in October 2007. The main objective of this project was to define innovative biotechnological processes for ＂eco-efficient＂ exploitation of black shale ores. The black shale ores contain base, precious and high-tech metals but also high contents of organic matter that handicap metal recovery by conventional techniques. Three world class black shale deposits were chosen as targets of the R＆D actions. These include one deposit that existed under natural conditions （Talvivaara, Finland）, one currently in process （Lubin, Poland） and one after mining （Mansfeld, Germany）. The main technical aspects of the work plan can be summarized as follows： evaluation of the geological resources and selection of metal-bearing components; selection of biological consortia to be tested for metal recovery; assessment of bioprocessing routes, including hydrometallurgical processing for metals recovery; techno-economic evaluation of new processes including social and environmental impacts. An overview of the main results obtained by the 13 European partners （from 8 countries） involved in this completed research programme is given in this work.     

Energy-Efficient and Low-GHG-Emission “Thiometallurgy”

Extractive metallurgy has used free or combined sulfur as both the raw material and the energy material in carrying out economical manufacture of several metals in millions of tons per year quantities over the past century. This has controlled carbon emissions in an unintentional fashion and out of necessity as the ores in many cases have been sulfides to start with. And the benefits of heat generation by the sulfides reacting with oxygen in the process steps have avoided the use of carbon as a fuel in providing the reaction temperatures. In this article, we will show the inherent benefits of “thiometallurgy,” which uses sulfur in the extraction of metals in alleviating CO₂ and water vapor–greenhouse gas (GHG) emissions, as well as its ability to provide a cost-effective energy material solution. Such solutions are not only applicable to existing base metal production but, as the authors will show, also are applicable to newer processes in the production of other metals and chemicals, such as alkaline earth metals, titanium, and to an extent aluminum in an indirect fashion. Iron ores can also be treated with thiometallurgy to meet the ULCOS criterion of ultra-low carbon dioxide steel being studied in Europe. The concept of generating “thiopower” as an alternative energy approach is also introduced by the authors.     

Recycling lead to recover refractory precious metals

Lead recycling has many benefits. For example, it provides an alternative to virgin lead, thereby avoiding the environmental impacts of primary lead smelting. In addition, as with other secondary metal operations, it consumes less energy at a lower cost than primary production. An emerging process has been evaluated in which these attributes are leveraged to process refractory precious metals ores. Direct cyanidation of refractory gold and silver ore yields poor gold and silver recoveries. In fact, some ores are simply not amenable to direct cyanidation. The process described in this paper consists of smelting lead-bearing material together with argentopyrite concentrate that contains precious metals. Sodium carbonate is used as a fluxing agent and scrap iron is used as a reductant. The reaction product is molten lead bullion enriched with the precious metals. Smelting recoveries of both silver and gold can be as high as 98%. For more information, contact J.R. Parga, Instituto Tecnológico de Saltillo, Depto. Metal-Mecánica, Av. Venustiano Carranza, Saltillo, Coahuila, 25280, Mexico. jrparga@fenix.its.mx.     

Modifying organic coatings to provide corrosion resistance—Part III: Organic additives and conducting polymers

Part I of this article has outlined the conditions under which corrosion can occur and the approaches for preventing or controlling corrosion attack. One of the approaches is to use protective coatings to prevent the corrosive environment from reaching and reacting with the substrate metal. These coatings may be organic or inorganic in composition, or a combination of both. In this article the focus has been on organic coating systems and how they may be modified to provide better corrosion resistance through the use of additives.Inorganic additives traditionally have been used to improve the stability and corrosion resistance of paint systems, and these are discussed in Part II of this article. Barrier coatings incorporate particles or lamellae to effectively increase the diffusion pathway of corrosive ions to the metal surface and delay corrosion attack. Reactive particles may be incorporated into coatings to react with the corrosive ions and prevent them from reaching the metal/coating interface. Some additives facilitate the oxidation of the metal surface and passivate it, preventing corrosion from occurring. Sacrificial additives are metals, such as zinc, that corrode preferentially to the metal substrate and protect it by an electrochemical (galvanic) action. Other additives may dissolve slowly and provide an inhibiting action to protect the metal. Examples of each of these types of additive have been provided, along with some recent developments.In Part III of this article, a similar discussion is provided, but the additive chemicals are organic compounds, many of which enable more environmentally compliant coatings to be formulated. In addition, the relatively recent research on the use of conducting polymers (organic metals) to protect metal surfaces is discussed. Some polyaniline-based additive packages are now available commercially in small quantities. The use of self-assembling monolayers to provide thin barrier films with corrosion protection properties is a new area of research on organic coatings with tailored properties.Finally, it should be remembered that, for these types of coatings to be accepted in industry and commerce, they must be robust systems, available in sufficient quantities at an acceptable price, and provide equivalent or better performance in the field. The ancillary equipment used to apply them also must be available. This may require the modification of currently available equipment or the development of the new equipment appropriate to the coating system being offered for sale.     

Biotechnology for the extractive metals industries

Biotechnology is an alternative process for the extraction of metals, the beneficiation of ores, and the recovery of metals from aqueous systems. Currently, microbial-based processes are used for leaching copper and uranium, enhancing the recovery of gold from refractory ores, and treating industrial wastewater to recover metal values. Future developments, emanating from fundamental and applied research and advances through genetic engineering, are expected to increase the use and efficiency of these biotechnological processes.     

The activox® process: Growing significance in the nickel industry

Metal-market analysts project a global nickel supply gap which will be filled by further high-pressure acid leach treatment of laterite ores and the commercialization of hydrometallurgical refineries to recover nickel from sulfide ores. The Activox® process is one such hydrometallurgical technology developed to recover a range of base and precious metals from sulfide ores and concentrates. The combination of ultrafine grinding and oxidative leaching extracted and enabled the recovery of 96.2% nickel, 88.3% cobalt, and 82.9% copper in the 310 kg/h Tati Hydrometallurgical Demonstration Plant.     

Microbial community structure and function in sulfide ore bioleaching systems

The severe current situation facing to minerals processing is that the most minerals are characterized by low-grade, being complex and very hard to deal with. It is necessary to find a new way to solve these questions. Nowadays, biohydrometallurgy draw more and more attention because of its simple process, low cost and kindness to environment. However, the lack of suitable bacteria and hard research on the mechanisms between the bacteria and ores or bacteria in gene level result in the low efficiency and poor yield of the target metal in bioleaching. Therefore, the understanding of the microbial community structure and function in the bioleaching systems is very important for the optimization of microbial community by controlling the operating conditions in bioleaching systems, thus enhancing the leaching rate. A review is given on the achievements and progress related to the study on microbial community structure and function in sulfide ore bioleaching systems made in our research group.     

印度Sukinda铬铁矿区水样的重金属污染、理化性质和微生物的评价(英文)

分析了Sukinda铬铁矿采石场及其邻近区域水样的重金属污染及理化性质和微生物含量。铬铁矿的水样含有高浓度重金属,其浓度顺序为Cr>Fe>Zn>Ni>Co>Mn,然而该地区的地下水除了Fe以外并没有受到重金属污染。矿井水样的理化参数与正常水的有差别。与相邻矿水样相比,矿井水样含有一些低浓度的微生物种群,包括细菌、真菌和放线菌。金属浓度与相关的理化参数显示了他们之间有正、负响应,而金属浓度和微生物种群之间表现出了负的相关性。从铬铁矿废水中纯化出来的菌株对铬和其他的重金属以及抗生素表现出高的耐受性,可作为重金属污染的指示剂。     

Emerging SOM technology for the green synthesis of metals from oxides

This article is intended to demonstrate that the environmentally sound solid-oxide-membrane (SOM) technology is an emerging process that can efficiently synthesize metals and alloys directly from their oxide ores with minimum feed-material preparation and produce oxygen gas or water vapor as the major byproduct. To demonstrate the proof-of-concept and economic viability, this article will focus on the synthesis of magnesium metal. The current production methods for magnesium are either metallothermic reduction (magnetherm process) at thig temperatures (1,600°C) involving expensive metal reductant (FeSi) or electrolysis from a halide electrolyte bath that requires extensive and expensive feed-material preparation. Both these techniques are also energy intensive, have low yield and generate large quantities of waste reaction products harmful to the environment. In the SOM process, the oxide reduction is electrochemical and has efficiencies close to 100%. It will be shown that unlike the current metallothermic and the electrolytic processes, the SOM process has the potential to be more economic and less energy intensive, and its process products are environmentally benign. The results reported in this article for magnesium synthesis are also applicable for environmentally sound production of other high-energy-content metals that are produced by less-efficient techniques that result in environmentally harmful reaction products. To date, in addition to magnesium, the SOM process has been used to produce silicon, chromium, and iron, along with alloys from their respective oxides dissolved in appropriate solvents. For more information, contact U.B. Pal, Boston University, Manufacturing Engineering Department, 15 St. Mary’s Street, Boston, MA 02446; (617) 353-7708; e-mail upal@bu.edu.     

Treatment of copper ores and concentrates with industrial nitrogen species catalyzed pressure leaching and non-cyanide precious metals recovery

Today, with a stringent economic and environmental climate prevailing in the copper business, there is increased interest in evaluating new processing alternatives for production. Hydrometallurgical pressure oxidation of copper concentrates is one of the more viable approaches, and several technological candidates have emerged. Of these, an overlooked but, ironically, the first industrially proven methodology utilized nitrogen species catalyzation in the oxidizing pressure-leach system to produce copper via solvent extraction/electrowinning. Given its advantages, this may prove to be a feasible process alternative for the future. In this article, the history of the system and its application to copper concentrates and ores will be outlined. In particular, a non-cyanide methodology for effective recovery of precious metals from chalcopyrite concentrates will be discussed. For more information, contact C.G. Anderson, Montana Tech, the Center for Advanced Mineral and Metallurgical Processing, Room 221 ELC Building, Butte, Montana, 59701; (406) 496-4794; fax (406) 496-4512; e-mail CAnderson@mtech.edu; www.mtech.edu/camp.     

贵金属复合材料的成就与展望:(II)贵金属复合材料体系

贵金属及其合金作为组元材料,可与其他金属、陶瓷、碳、化学化合物、金属间化合物以及聚合物结合,构成贵金属复合材料。在贵金属复合材料中,贵金属及其合金可作为基体材料,为纤维状或颗粒状的其他材料强化;亦可以涂层、纤维和颗粒等形式作为功能相材料分布在其他基体材料中。本文是“贵金属复合材料的成就与展望”系列文章的第二部分,总结了贵金属复合材料的种类,包括层状复合、纤维复合和颗粒复合材料;列举了贵金属复合材料的主要体系及其应用;讨论了一些贵金属复合材料的结构特征及其今后研究的新课题。     

贵金属深加工的废水处理方案

金银等贵金属实现其工业用途的前提是对其进行深加工，在深加工过程中产生的大量含酸、碱、重金属和氰化物的废水对环境造成的危害已经成为社会极为关注的问题。本文对这类废水的来源和常用处理方法进行了论述，提出一套适合于以金银作为深加工对象的废水处理方案，在保证充分回收贵金属的前提下，合理地使废水中的氰化物、重金属、酸和碱得到有效的处理。本文案具有经济、简便和实用的特点。     

Preferential sulfation of nickel and cobalt in lateritic ores

Pilot plant operations have confirmed the validity of a process for the recovery of nickel and cobalt from the ores of laterite deposits, the world’s largest known reserves of these metals.     

稀土元素在金属材料中的作用与机理

该文作者从１９６１年开始进行稀土元素在铁基、镍基、铜基、铝基等约百个２～４元金属溶液体系的热力学、相平衡及在２０多个金属材料（包括稀土－铁超磁致伸缩材料）中的作用与应用研究，该文依据作者所在科研组的研究成果并参考一些文献，说明了稀土元素在金属材料中的作用和机理     

Effect of Low-Melting Metals (Pb,Bi, Cd,In) on the Structure,Phase Composition,and Properties of Casting Al–5% Si–4% Cu Alloy

The effect of low-melting metals (Pb, Bi, Cd, In) on the structure, phase composition, and properties of the Al–5% Si–4% Cu alloy was studied using calculations. Polythermal sections have been reported, which show that the considered systems are characterized by the presence of liquid regions and monotectic reactions. The effect of low-melting metals on the microstructure and hardening of base alloy in the cast and heat-treated states has been studied.     

Application of high velocity impact welding at varied different length scales

Three complementary impact welding technologies are described in this paper. They are explosive welding, magnetic pulse welding, and laser impact welding, which have been used to provide metallurgical bonds between both similar and dissimilar metal pairs. They share the physical principle that general impact-driven welding can be carried out by oblique impact but are used at different length scales from meters to sub-millimeter. The different length scales require different kinds of systems to drive the process, and the scales themselves can give different weld morphologies. Metallographic analysis on cross-sections shows a wavy interface morphology which is likely the result of an instability associated with jetting, which scours the surfaces clean during impact. The normalized period and amplitude of the undulations increase with increasing impact energy density. Microhardness testing results show the impact welded interface has a much greater hardness than the base metals. This can lead to weldments that have strengths equal to or greater than that of the weakest base material.     

Sulfide smelting using Ausmelt technology

Over the past decade, Ausmelt has been developing the top submerged lancing process for the smelting of sulfidic ores to recover such metals as copper, lead, silver, tin, antimony, and nickel as well as for separation of minor elements such as arsenic, antimony, and bismuth. Development has taken place in Ausmelt’s pilot plant in Dandenong, near Melbourne, Australia. A number of projects have proceeded to commercial-scale operation. This paper reviews developments at both the pilot and commercial scales.