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1.
ROBERT W. CRANDALL 《Mineral Processing and Extractive Metallurgy Review》2013,34(1-4):307-322
Government policy towards the metals industries should be based upon a careful analysis of “market failure,” those instances in which private markets fail to provide the appropriate signals to market participants. These include environmental effects, neighborhood effects, large scale economies, and national defense considerations. In most traditional metals industries, the scale economies in production are not large enough relative to the U.S. market to warrant serious policy concern. Nor are national defense considerations important in most of the “nonstrategic” metals. The principal concerns for government policy in the metals industries are therefore the environmental controls and neighborhood effects, the effects of sudden changes in metals industries upon other activity in nearby locations. 相似文献
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BERNARD A. GELB 《Mineral Processing and Extractive Metallurgy Review》2013,34(1-4):183-193
The recent decrease in oil prices should benefit metals producers by reducing costs of production—through lower energy prices—and increasing the demand for metals— through income and substitution effects. It is difficult, however, to predict a substantial return to the earlier relative role of metals: Real energy prices are still well above their levels of 20 years ago; the duration and extent of the oil price decrease is highly uncertain; petroleum generally is not a very important energy input in metal production; other energy prices probably will not decline as much as oil prices; and the effects of the oil price decrease on currency exchange rates and inflation rates are complex and difficult to predict in general and for individual countries. 相似文献
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A.K. SURI 《Mineral Processing and Extractive Metallurgy Review》2013,34(1):287-302
Abstract Refractory metals belonging to the Group IV to VIA of the periodic table have assumed very important role in variety of high-tech applications. Extraction of these metals so far has been accomplished mainly from primary and byproduct sources. Depletion of primary sources, non-availability of the sources of these metals in certain countries, relatively large applications and greater emphasis on environmental preservation have led to increased awareness in using secondary sources of these metals. Use of secondary sources in fact makes a better economic source particularly for these high value metals This paper is based on extensive studies carried out in the Materials Group of BARC on the recovery of refractory metals such as tungsten, molybdenum, niobium, tantalum, vanadium and zirconium from a variety of secondary sources available within the country. Major objective has been to develop processes which can be operated even on a small scale with variable grade of the source using indigenously available equipment 相似文献
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为探究南京市郊某污灌区环境治理效果、小白菜中重金属健康风险及其根际土壤重金属超标情况,采用靶标危害系数及体外模拟法对研究区小白菜重金属健康风险进行评估,利用农用地土壤污染风险管控标准(试行)(GB 15618—2018)对比小白菜根际土壤重金属超标情况。结果显示,Cd在小白菜根际土壤中最小值达到0.95mg/kg,最大值达到了1.14mg/kg,平均1.05mg/kg,超过农用地土壤污染风险管控标准。对于成人和儿童,其THQ的最大值从大到小排序为Cu>Pb>Cr>Cd>Zn,小白菜对成人及儿童的HI值分别为6.75×10-3和5.76×10-3,两者均小于1,表明使用该模型评估得出小白菜中重金属对暴露人体造成的健康影响不明显。成人通过食用研究区小白菜日均摄入Pb、Zn、Cu和Cd的含量范围依次为337~430、3 294~3 025、359~540及288~483mg。儿童通过食用研究区小白菜日均摄入Pb、Zn、Cu和Cd的含量范围分别为221~282、1 985~2 162、235~354及189~317mg。综上所述,重金属生物可给量均未超过每周可耐受摄入量值,证明食用污灌区小白菜不存在重金属健康风险。与前次研究相比(采样时间相隔七年),相关部门对该区域环境治理取得了很好的效果,但还应注意Cd在土壤及小白菜中的迁移及富集。 相似文献
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DAVID A. GULLEY 《Mineral Processing and Extractive Metallurgy Review》2013,34(1-4):1-9
The changing nature of the world metals industry was the subject of a three-day meeting of experts from around the world. The conference, held in May, 1986 and sponsored by the United States Bureau of Mines and the Henry Krumb School of Mines of Columbia University, included sessions on: the current status of the industries; changes in metals demand; changes in metals supply and trade; implications for the private sector; and implications for the public sector. The article introduces the issues raised at the Arden House Conference. 相似文献
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Large amounts of non-ferrous slags containing Co, Ni, and Cu are produced and stockpiled by metallurgical industries. These industries also produce sulphur dioxide, an air pollutant. Using sulphur dioxide as a leaching reagent to leach the valuable metals from slag would reap both economical gains and environmental benefits. Extraction of these metals using aqueous sulphur dioxide (SO2(aq)) is being carried out in our group. 相似文献
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俄罗斯有色金属矿产资源及有色冶金工业 总被引:1,自引:0,他引:1
韩丕兰 《有色金属材料与工程》2010,31(2):94-97,99
介绍了俄罗斯有色金属矿产资源的分布、储量概况及有色金属冶金工业现状,分析了这些矿产资源的开发利用情况。 相似文献
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This article is devoted to one important issue in the development of rare and precious metals industry— analytical control (AC). The current state, importance, problems, and prospects of the development of AC as an integral part of the production of rare and precious metals and quality assurance of products are considered. Modern methods of AC—atomic-spectral, mass-spectral, X-ray fluorescent, combined, and rational fields of their application—are characterized. It is shown scientific-and-technical progress is inextricably associated with a cardinal increase in a nomenclature of materials based on rare and precious metals and an increase in requirements for their quality. This will require the development of new methods of AC and improving existing ones, standardizing them, and metrological support. To carry out this work, it is necessary to attract research organizations of the Russian Academy of Sciences, universities, branch institutes with research laboratories that have survived the dissolution of the Soviet Union, and activate factory science. It is necessary to effectively use the achievements of advanced analytical laboratories abroad and participate in international comparative trials. At the same time, special attention is paid to unsolved problems—a scientifically justified formulation of requirements for new types of products based on rare and precious metals; the development and metrological assessment of sampling techniques; the development of high-quality metrological support for the AC of production of rare and precious metals; improving analytical methods; standardizing analytical methods; the accreditation of analytical laboratories; and the education and training of highly qualified analytical chemists. 相似文献
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It is a challenge to apply coupled hydrodynamic, sediment process, and contaminant fate and transport models to the studies of surface water systems. So far, there are few published modeling studies on sediment and metal transport in rivers that simulate storm events on an hourly basis and use comprehensive data sets for model input and model calibration. The United States Environmental Protection Agency (USEPA) in 1997 emphasized the need for credible modeling tools that can be used to quantitatively evaluate the impacts of point sources, nonpoint sources, and internal transport processes in 1D/2D/3D environments. A 1D and time-dependent hydrodynamic, sediment, and toxic model, within the framework of the 3D Environmental Fluid Dynamics Code (EFDC), has been developed and applied to Blackstone River, Mass. The Blackstone River Initiative (USEPA) in 1996, a multiyear and multimillion-dollar project, provided the most comprehensive surveys on water quality, sediment, and heavy metals in the river, and served as the primary data set for this study. The model simulates three storm events successfully. The river flow rates are well calculated both in amplitude and in phase. The sediment transport and resuspension processes are depicted satisfactorily. The concentrations of sediment and five metals (cadmium, chromium, copper, nickel, and lead) during the three storm events are also simulated very well. Numerical analyses are conducted to clarify the impacts of contaminant sources and sediment resuspension processes on the river. While point sources are important to sediment contamination in the river, other sources, including nonpoint sources from watershed and bed resuspension, were found to contribute significantly to the sediment and metals in the river. Point sources alone cannot account for the total metals in the river. The model presented in this paper can be a useful tool for studying sediment and metals transport in shallow rivers and for water resource management. 相似文献
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JOHN G. MYERS 《Mineral Processing and Extractive Metallurgy Review》2013,34(1-4):105-120
Input-output simulation of the 1960-84 period for the U.S. permits an evaluation of the factors that affected the metals industries. Technical change, measured by coefficient change, was a major depressing factor on metals production, more important than rising imports in many instances. Ores were most depressed after 1972, followed by metals. Metal products, on the contrary, experienced above average growth, but there was much diversity among product types. Export demand for ferrous ore and metal fell sharply during the 1974-84 period, while nonferrous ores and metals showed little net change. Exports of metal products were generally strong. 相似文献
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有色金属矿产资源是国家发展建设的重要物质基础,广泛应用于建筑、工业、农业、军工等各行各业,是一种关键的战略资源。经济的迅速发展对资源提出了更大的要求,如何充分利用有色金属矿产资源,实现有色金属矿产资源开发循环经济的发展显得尤为重要。本文从有色金属开发循环经济的意义入手,阐述了有色金属矿产循环经济的原则,指明了有色金属矿产循环经济发展的主要技术方向,以及相应的政策措施,以期能够为有色金属矿产资源开发发展循环经济的深入发展提供借鉴。 相似文献
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有色金属的强化方法 总被引:5,自引:0,他引:5
邓安华 《有色金属材料与工程》2000,21(4):187-194
概述了有色金属几种主要的强化方法,并对各种强化方法的强化机制、影响强化效果的因素、强化特点以及在工业上的应用作了简单的介绍。 相似文献
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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。 相似文献
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R. L. Smith 《Metallurgical and Materials Transactions B》1983,14(4):519-529
Over the past quarter century, public support for heavy industries has eroded and the United States has moved into a post-industrial era. Among those industries most heavily affected have been those involved in the first part of the materials cycle—exploration, mining, and smelting. Loss of public support has resulted in pejorative government regulations. Unless public attitudes and government actions are modified, the first part of the materials cycle will not survive as a major domestic industry. The health of those industries involved in the remainder of the materials cycle depends in large part upon the development and utilization of new technology and the ability of industrial leaders to marshal public support for their endeavors. 相似文献
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Risk assessment of exposure to sources of radiation is an important tool for national governments in regulating radionuclide emissions and thus reducing radiation doses for the general public. For this reason radiation doses from sources throughout The Netherlands have been analyzed. For sources with well-defined locations and doses that were thought to vary significantly throughout The Netherlands, radiation dose maps were produced. Average dose values were calculated or derived from the literature for doses considered to be evenly distributed throughout the country or for which no information on the geographical distribution of dose was available. Emission, dispersion, and individual dose were modeled for each source using various pathways and exposure routes. Indoor radon and gamma radiation from building materials generate the highest dose values. The highest human induced radiation doses for industries of which the doses showed to be geographically distributed are found in the cement industry, elemental phosphorus production, phosphoric acid production, and iron and steel production. Radiation dose from some of these sources has a very local peak and decreases rapidly with distance. The elemental phosphorus production causes relatively high radiation doses throughout a large part of The Netherlands. Cumulation of doses from various sources occurs, but these are often masked by doses from a few large industries. 相似文献
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J. W. Evans 《Metallurgical and Materials Transactions B》1995,26(2):189-208
This article treats some electrometallurgical and electromagnetic aspects of the production of metals, but it opens with an
examination of whether there is ldelectricity”(i.e., vitality) in the primary metals industries, particularly within the United States of America. That question is examined
in terms of the economics of two examples: aluminum and zinc. Then, three examples are provided of potential improvements
in the production of metals arising from industrial and university research: use of new electrode materials in Hall-Héroult
cells to reduce energy consumption in aluminum smelting, the fluidized bed electrowinning of copper and other metals, and
the employment of electromagnetic forces in metals processing, particularly electromagnetic casting. The article concludes
with observations on the paucity of United States support for research and development (R & D) in primary metals production,
compared with that of other industrial activities and of other nations, and suggests a prognosis for the future of academic
research and teaching in extractive and process metallurgy. 相似文献
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Solid-state amperometric sensor for the In-situ monitoring of slag composition and transport properties 总被引:2,自引:0,他引:2
Open-circuit potential (OCP) measurements with zirconia-based sensors have been used for several decades in the metals industries
to determine the oxidation state of high-temperature melts. Although amperometric techniques are known to provide additional
kinetic and compositional analysis of the system, they have not been utilized by the metals industries to the same extent.
In this work, three different amperometric techniques were examined to monitor high-temperature slags by utilizing zirconia-based
sensors. Applied direct current (DC) potential steps and impedance frequency sweeps at fixed applied DC potentials were shown
to clearly distinguish between slags having the same oxidation state but different quantities of FeO
x
in low concentrations. The techniques were also shown to reveal information on the transport properties, slag structures,
dissociable oxide type, and buffering capacity of the slag to a given oxidation state. The third technique, coulometric titration,
was shown to easily differentiate between slags containing different quantities of FeO
x
in larger concentrations. The ion-selective membrane properties of the zirconia allowed the coulometric titration to proceed
at current efficiencies near 100 pct. This may be useful in developing technology for the recovery of metals from oxide waste
streams. 相似文献