我国废有色金属拆解利用再生产业发展现状

阐述了我国废金属拆解利用产业发展现状及存在的主要问题,提出了应对废金属拆解再生产业加强政府引导、加强回收体系建设、研发推广先进技术和改善税收政策等对策建议。     

Tracking effective measures for closed-loop recycling of automobile steel in China

Closed-loop recycling of steel in automobiles is particularly difficult because of the low tolerance for impurities and the use of composites of various types of steel products. Technologies that reduce impurities or increase impurity tolerance must be developed and introduced to the steel recycling system at the appropriate time. This study evaluated the feasibility of closed-loop recycling in the automobile industry in China. Material pinch analysis combined with dynamic modeling of the life cycle of steel sheets used in the manufacture of automobiles was employed to estimate the amount of steel sheet scrap available for closed-loop recycling and the amount of copper contamination in the scrap. The results indicate that by 2050, more than half of the old steel sheet scrap generated annually will have to be down-cycled because of its high copper contamination. However, scenario analyses of three types of technologies for mitigating the problem of copper contamination showed the potential for increasing the amount of old scrap used in closed-loop recycling. In particular, improving copper tolerance in the steel production process could be effective both now and in 2050.     

Dynamic material flow analysis of zinc resources in China

Zinc is one of the most widely applied nonferrous metals in China. Study on the applications and recurrent situation of zinc resources is of great strategic importance for the sustainable development of China's economy. In this paper, a dynamic material flow analysis (MFA) method has been adopted to analyze quantificationally zinc resources in China, as well as to analyze and predict the quantity of zinc product scrap and their recycling situation. The weighted average method was applied to calculate average lifetimes of six major zinc products in China. The average lifetimes of battery, zinc oxide, zinc die-casting alloys, zinc material products, galvanized zinc and brass are 0.17, 5.3, 11.1, 12, 21 and 30 years, respectively. Assuming the lifetime of zinc product group obeys the Weibull distribution and the consumption of zinc products varies linearly with time, the future consumption and scrap generation of zinc products will increase continuously. It is expected that they would increase from 49% to 76% during 2004–2020, respectively. Assuming the recycling rate remains unchanged with time, the zinc old scrap index, both the theoretical and actual values, would continue increasing in China. The values are expected to reach 0.402 and 0.076 by 2020, respectively. Therefore, the regeneration resource of depreciated zinc is actually insufficient in China. According to the scenario analysis, the actual value of old scrap indexes is positively correlated with the recycling rate of zinc products. Because galvanized products are the largest consumption area of zinc products in China, the influence of their recycling rate on old scrap index is obviously larger than other zinc products. Through the analysis, this paper suggests that the increase of the recycling rate of zinc products could not only improve to a certain degree China's relative shortage of zinc resources, but greatly relive the supply pressure of zinc in the world.     

Historical evolution of anthropogenic aluminum stocks and flows in Italy

Dynamic stocks and flows analysis was applied to the anthropogenic aluminum cycle in Italy in order to detect and quantify metal flows and in-use stocks over the years 1947–2009. The model utilized a top-down approach, including data for production, consumption, loss, and trade flows of aluminum. Seven end-use markets were considered, namely buildings and construction, transportation, consumer durables, machinery and equipment, electrical engineering, containers and packaging, and miscellaneous appliance types. The results of this dynamic stocks and flows analysis model quantified the contemporary anthropogenic reservoirs (or in-use stocks) of aluminum at about 320 kg per capita, mainly embedded within the transportation and building and construction sectors. Cumulative in-use stock represents approximately 11 years of supply at current usage rates (about 20 Mt versus 1.7 Mt/year), implying significant potential for recycling in the future as this stock comes out of use. Flow analysis revealed that Italy imports mainly unwrought aluminum and exports final products, while the main material losses occur during alumina refining and collection of old scrap: specifically, containers and packaging have the highest old scrap generation rate, but for the lowest recovery rate (50%). Increasing support to collection of scrap and initiatives oriented to aluminum recovery specifically would allow Italy to increase its reliance on domestic material, and may also allow a decline of the country import-dependence on primary sources. The dynamic stocks and flows model created here provides a quantitative historical record of the aluminum required by Italian society during important periods of development and provides guidance for future decision-making around the use of domestic secondary resources.     

Secondary copper recovery

Following a brief review of the economics of copper recycling, the technical details of secondary copper recovery are given, from classification and sampling of scrap through to the production of blister copper ready for electrolytic refining.     

Metals recycling in the United States

Twenty-two metals for which secondary recovery is important, in terms of quantity and/or value, were compared and ranked for rate and efficiency of recycling, and availability of recycled metal. In general, their recycling rates trended upward over the period 1970–1993. Iron, aluminum, copper, gold, platinum, and lead accounted for most of the value of all secondary metal produced, while iron and steel dominated in terms of quantity produced and exported. The factors most influential on recycling rates are profitability, public support, organization of infrastructure, sortability, legislative support, and scrap purity. The share of supply accounted for by secondary metals is expected to surpass that of primary metals sometime in the next decade.     

Environmental consequences of recycling aluminum old scrap in a global market

Nowadays, aluminum scrap is traded globally. This has increased the need to analyze the flows of aluminum scrap, as well as to determine the environmental consequences from aluminum recycling. The objective of this work is to determine the greenhouse gases (GHG) emissions of the old scrap collected and sorted for recycling, considering the market interactions. The study focused on Spain as a representative country for Europe. We integrate material flow analysis (MFA) with consequential life cycle assessment (CLCA) in order to determine the most likely destination for the old scrap and the most likely corresponding process affected. Based on this analysis, it is possible to project some scenarios and to quantify the GHG emissions (generated and avoided) associated with old scrap recycling within a global market. From the MFA results, we projected that the Spanish demand for aluminum products will be met mainly with an increase in primary aluminum imports, and the excess of old scrap not used in Spain will be exported in future years, mainly to Asia. Depending on the scenario and on the marginal source of primary aluminum considered, the GHG emission estimates varied between −18,140 kg of CO₂ eq. t⁻¹ and −8427 of CO₂ eq. t⁻¹ of old scrap collected. More GHG emissions are avoided with an increase in export flows, but the export of old scrap should be considered as the loss of a key resource, and in the long term, it will also affect the semifinished products industry. Mapping the flows of raw materials and waste, as well as quantifying the GHG impacts derived from recycling, has become an essential prerequisite to consistent development from a linear toward a circular economy (CE).     

Quantification of Chinese steel cycle flow: Historical status and future options

China is the largest steel producer and consumer around the world. Quantifying the Chinese steel flow from cradle to grave can assist this industry to fully understand its historical status and future options on production route transformation, capacity planning, scrap availability, resource and energy consumption. With the help of the systematic methods combined dynamic MFA (material flow analysis) with scenario analysis, the Chinese steel cycle during the first half of the 21st century was quantified and several thought-provoking conclusions were draw. In the past decade, lots of pig iron or molten iron was fed into EAF (electric arc furnace) and the scrap usage of EAF fluctuated slightly. Thus, the real scrap-EAF route share is much lower than the EAF production share. On the other hand, we reconfirmed that the scrap supply in China will rise significantly in the future. Meanwhile, the secondary production route share will grow sharply and exceed primary production share before or after 2050 depending on our options. The scrap recycling rate and construction's lifetime play a vital role in this trend. In the end, an intensive discussion on production capacities’ adjustment and energy and resource consumption was conducted and relative policy suggestions were given. It is worth noting that scrap usage is crucial to future energy saving and emissions reduction of Chinese steel sector and its energy consumption might peak as early as 2015.     

Long-term global availability of steel scrap

Primary steelmaking involves CO₂-intensive processes, but the expansion of secondary steel production is limited by the global availability of steel scrap. The present work examines global scrap consumption in the past (1870–2012) and future scrap availability (2013–2050) based on the historical trend. The results reveal that (i) historically, the consumption of old scrap has been insufficient compared with the amounts of discarded steel, and (ii) based on historical scrap consumption, the future availability of scrap will not be sufficient to satisfy the two assumed cases of steel demand. Primary steelmaking is expected to remain the dominant process, at least up until 2050. Under the reference-demand case of 2.19 billion tons in crude steel production by 2050, the total production of pig iron and direct reduced iron could reach 1.35 billion tons. Consumption of old scrap could reach 0.76 billion tons. Because the availability of scrap will be limited in the context of the global total, it is important to research and develop innovative low-carbon technologies for primary steelmaking and to explore their economic viability if we are to aim for achieving large reductions in CO₂ emissions from the iron and steel industry.     

The contemporary European silver cycle

This paper examines the 1-year anthropogenic stocks and flows of silver as it progresses from extraction to final disposal on the European continent. The primary flows of silver include production, fabrication and manufacturing, use, and waste management. A substance flow analysis (SFA) was used to trace the flows and inventory data, and mass balance equations were used to determine the quantity of flows. The results reveal that Europe has a low level of silver mine production (1580 Mg Ag/year) and instead relies on silver imports and the recycling of scrap in production and fabrication. In the year 1997, Europe imported 1160 Mg Ag of ore concentrate and 2010 Mg Ag of refined silver, and recycled 2750 Mg Ag of new and old scrap. There is a net addition of 3320 Mg Ag/year into silver reservoirs at the use stage. This is the result of a greater amount of silver entering the system from manufacturing than is leaving the system into waste management. The waste flow with the highest content of silver is municipal solid waste, which contains 1180 Mg Ag/year. In total, 62% of all discarded silver is recycled and 38% is sent to landfills. The results of this study and other element and material flow analyses can help guide resource managers, environmental policy makers, and environmental scientists in their efforts to increase material recovery and recycling, address resource sustainability, and ameliorate environmental problems.     

Economic and policy instrument analyses in support of the scrap tire recycling program in Taiwan

Understanding the cost-effectiveness and the role of economic and policy instruments, such as the combined product tax-recycling subsidy scheme or a tradable permit, for scrap tire recycling has been of crucial importance in a market-oriented environmental management system. Promoting product (tire) stewardship on one hand and improving incentive-based recycling policy on the other hand requires a comprehensive analysis of the interfaces and interactions in the nexus of economic impacts, environmental management, environmental valuation, and cost-benefit analysis. This paper presents an assessment of the interfaces and interactions between the implementation of policy instruments and its associated economic evaluation for sustaining a scrap tire recycling program in Taiwan during the era of the strong economic growth of the late 1990s. It begins with an introduction of the management of the co-evolution between technology metrics of scrap tire recycling and organizational changes for meeting the managerial goals island-wide during the 1990s. The database collected and used for such analysis covers 17 major tire recycling firms and 10 major tire manufacturers at that time. With estimates of scrap tire generation and possible scale of subsidy with respect to differing tire recycling technologies applied, economic analysis eventually leads to identify the associated levels of product tax with respect to various sizes of new tires. It particularly demonstrates a broad perspective of how an integrated econometric and engineering economic analysis can be conducted to assist in implementing policy instruments for scrap tire management. Research findings indicate that different subsidy settings for collection, processing, and end use of scrap tires should be configured to ameliorate the overall managerial effectiveness. Removing the existing boundaries between designated service districts could strengthen the competitiveness of scrap tires recycling industry, helping to reduce the required levels of product tax and subsidy. With such initial breakthroughs at hand to handle the complexity of scrap tire recycling technologies, there remains unique management and policy avenues left to explore if a multi-dimensional solution is to be successful in the long run.     

The effects of higher energy prices and declining ore quality: Copper—aluminium substitution and recycling in the USA

An econometric model of the US copper and aluminium industries is simulated to evaluate the impact that higher energy prices and declining ore quality will have on copper–aluminium substitution and recycling in the USA in the next decade. The unique features of the model described here include the calculation of elasticities of substitution between copper and aluminium from the production functions of the using sectors, the use of statistical (not engineering) cost functions for both the primary and the secondary industries, and the explicit consideration of ore- quality deterioration as primary production progresses.     

Recycling opportunities in the UK for aluminium-bodied motor cars

The purpose of this paper is to review, and draw attention to, issues raised by the recycling of wrought aluminium from motor cars, even though the time horizon for significant arisings of such aluminium scrap is in the order of 20 years from now. Recycling of specific grades of wrought aluminium will be viable only when a means of positively identifying different types of scrap is available. A solution must be reliable, rapid, and low-cost; probably used in conjunction with a vehicle shredder. Such a system of identification will eliminate the need for costly hand-dismantling and segregation. Simple segregation of cast and wrought alloy will, however, be essential when wrought aluminium from car bodies dominates the scrap arisings. Such segregation will produce two high-value scrap products. The first of which will be similar to the A380 casting alloy specification, maintaining the current supply of this scrap, and the second will be a composite of wrought alloys. These issues are relevant to the aluminium scrap industry, which will have to accommodate future changes in the composition of the scrap it receives, and the motor industry, which may adopt in-house recycling of wrought alloy in order to offset the high purchase cost of aluminium.     

On modelling the global copper mining rates,market supply,copper price and the end of copper reserves

The world supply and turnover of copper was modelled using simple empirical estimates and a COPPER systems dynamics model developed for this study. The model combines mining, trade markets, price mechanisms, population dynamics, use in society and waste as well as recycling, into a whole world system. The degree of sustainability and resource time horizon was estimated using four different methods including (1) burn-off rates, (2) peak discovery early warning, (3) Hubbert's production model, and (4) COPPER, a system dynamics model. The ultimately recoverable reserves (URR) have been estimated using different sources that converge around 2800 million tonne, where about 800 million tonne have already been mined, and 2000 million tonne remain. The different methods independently suggest peak copper mine production in the near future. The model was run for a longer period to cover all systems dynamics and delays. The peak production estimates are in a narrow window in time, from 2031 to 2042, with the best model estimate in 2034, or 21 years from the date of writing. In a longer perspective, taking into account price and recycling, the supply of copper to society is estimated to run out sometime after 2400. The outputs from all models put focus on the importance of copper recycling so that society can become more sustainable with respect to copper supply.     

Dynamic material flow analysis of steel resources in Korea

Material flow analysis (MFA) is an evaluation technique that systematically identifies the flows and stocks of materials within predefined spatial and temporal boundaries. In this paper, the steel resources in Korea are investigated using dynamic MFA. Iron ore and steel scrap are added as raw material components during the production processes of steel, which is then used in a variety of product groups such as construction products, transportation equipment, machinery/metal products, electrical/electronic devices, and other products through fabrication and manufacturing processes. When such product groups are discarded, they are either recycled or landfilled. With consideration for the lifetimes of various product groups in conjunction with steel resource flows in Korea, dynamic MFA is conducted on the flows of steel stock change and annual scrap generation. By 2020, these two flows are expected to increase by as much as 40% and 30%, respectively, compared to 2008, with transportation equipment, in particular, envisaged to experience high growth. At the current recycling rate, however, it will be hard to meet future scrap demand. According to the scenario analysis, 100% of this future scrap demand can be supplied domestically if the recycling rate is increased to over 70% for all product groups, except construction products and transportation equipment, which already have high recycling rates. By 2020, the reduction in scrap importation costs is projected to offer a financial gain of 2.3 billion dollars.     

Management of used lead acid battery in China: Secondary lead industry progress,policies and problems

The amount of used lead acid batteries rises along with the rapid development of battery manufacture in China. The battery manufacture and recycling industry has developed sharply in these recent 5 years. The annual production of secondary lead from used lead acid batteries in China increased rapidly to 1.5 million tonnes (MT) in 2013, making china the world's largest secondary lead producer. Secondary lead enterprises are mainly located in the middle and eastern regions of China, with a legal production capacity of 3 MT/year. Environmental pollution problems began to happen frequently from 2009. After 2011, the government began to put in efforts to promote pollution control, eliminate outdated production capacity, support advanced production and technology innovation research, and has achieved remarkable results. However, the main existing problems are that the proportion of secondary lead production is only 30% of the total lead production, no formal recycling network has been established and the overall level of industrial technology and equipment is outdated. Compared with developed countries, this paper predicts that, secondary proportion will reach 44% in 2015 and 60% in 2028. Finally some countermeasures are given to the recycling mode and technology promotion.     

Modeling methods for managing raw material compositional uncertainty in alloy production

Operational uncertainties create disincentives for use of recycled materials in metal alloy production. One that greatly influences remelter batch optimization is variation in the raw material composition, particularly for secondary materials. Currently, to accommodate compositional variation, firms commonly set production targets well inside the window of compositional specification required for performance reasons. Window narrowing, while effective, does not make use of statistical sampling data, leading to sub-optimal usage of recycled materials. This paper explores the use of a chance-constrained optimization method, which allows explicit consideration of statistical information on composition. The framework and a case study of cast and wrought production with available scrap materials are presented. Results show that it is possible to increase the use of recycled material without compromising the likelihood of batch errors, when using this method compared to conventional window narrowing. This benefit of the chance-constrained method grows with increase in compositional uncertainty and is driven by scrap portfolio diversification.     

National benefits,local costs? Local residents' views on environmental and social effects of large‐scale mining in Chingola,Zambia

This study examined the environmental and social effects of large‐scale mining in Chingola, Zambia. Data was collected through semi‐structured interviews with 164 residents living close to Zambia's largest open pit mine, key informants and desk analysis of secondary data. Quantitative data was analysed using the chi‐square test, one sample T‐test and two sample Z‐proportions test, while qualitative data was analysed using content analysis. Results show that the residents reported being most affected by sulphur dioxide air emissions and noise pollution due to the proximity of the copper smelter and heavy moving machinery to their residences. The residents received domestic water containing rust and copper ore particles from the water utility company which draws raw water from the mine. Although the mine was a source of employment for locals, over 4,000 jobs (representing a 33% decrease) have been lost over a period of 4 years, negatively affecting the local economy. Mine management attributed the job losses to high production costs and mechanization of mining processes. The residents perceived the job losses to have led to crime, alcohol abuse and prostitution among youths as well as a general increase in poverty levels. Analysis of air emissions data from the mine found elevated levels of dust, cadmium, copper and lead pollutants. Key informants from Nchanga Mine reported implementing bioremediation to reduce soil contamination by the heavy metals and recycling SO₂ to produce sulphuric acid. The study recommends an increase in social corporate responsibility from the mine management to ensure residents derive more substantive benefits from their proximity to the mine.     

Exploration and discovery of Australia's copper,nickel, lead and zinc resources 1976–2005

Examination of copper, nickel, lead and zinc (base metals) exploration expenditure and discovery in Australia over the period 1976–2005 reveals some significant trends. Australia's base metal resource inventory grew substantially as a consequence of successful exploration over the period, both through addition of resources at known deposits and new discoveries, notably a small number of very large deposits that underpin the resource base. In 2005, Australia had the world's largest economic demonstrated resources (EDR) of nickel, lead and zinc, and the second largest EDR of copper. Growth in nickel resources has been especially strong owing to discovery of large laterite resources in the late 1990s. Resource life, in average terms based on current EDR and production, is approximately 30 years for lead and zinc, 40 years for nickel sulphide (120 years for all nickel EDR) and 50 years for copper. Despite this success, major increases in production over the period (copper, nickel and zinc output increasing 3–4 fold, lead output doubling) and a fall in discovery rates during much of the 1990s means that resource life for lead and zinc is lower and nickel sulphide comparable now to that in 1976; only the resource life of copper has grown substantially over the period. Current published ore reserves are sufficient for at least 15 years operations at current production levels, but only a small number of the largest deposits currently being mined are likely to still be in production in 20 years. However, several mines have substantial inferred resources that may allow production beyond current mine reserves and there is a substantial number of undeveloped deposits that may provide the foundation for extended or new mining operations. The discovery record is strongly cyclical with resource growth for all the base metals punctuated by the discovery of giant (world-class) deposits each decade: these underpin current and future production. Recent higher metal prices and renewed interest in base metals, especially nickel, has reversed a 10 year decline in base metal exploration attended by reduced rates of discovery and resulted in record expenditure, new nickel, copper and zinc discoveries, and increased resources at a number of existing deposits, notably the Olympic Dam copper–uranium–gold deposit. With the exception of the Prominent Hill copper–gold and West Musgrave nickel–copper deposits, most of the recent discoveries, especially zinc (-lead) deposits, are of small tonnage (some of high grade). Nevertheless, these new discoveries have helped stimulate further exploration and also highlight the potential for further discoveries in little-explored provinces, especially those under regolith and shallow sedimentary cover.     

Some observations on copper yields and ore grades

The paper examines trends in the average copper content of mined ores over the years. It has tended to decline over the long term, but by no means evenly. US averages are not typical of global averages, at least in the past four decades. Those have been both higher, and less volatile than in the US. One reason for falling averages is a change in the type of deposit mined, with a rise in the share of relatively low grade porphyry deposits. The different nature of their deposits is reflected in marked differences in grades between the different continents. African and Australian average grades are higher than the global average, and changes in the share of Central Africa in global output have affected the global average grade. Yields are have been consistently lower in North America than elsewhere, and Latin American average grades have trended downwards, reflecting both the ageing of mines and the rising share of production from porphyry deposits. Typically the yield of mines declines over time as mining proceeds. The average copper content of ore deposits is usually below the average yield of the ore accessed in the early years of production. The initial grades of new mines have not declined over the past forty years, and there has been no perceptible tendency for the average grade of porphyry deposits brought into production to decline over time. There is no apparent correlation between average grade and deposit size, but mine operators tend to exploit economies of scale to offset low grades. The relationship between the annual percentage yields (the head grade) and the reserve grades of deposits is not static. In recent years head grades have fallen closer to reserve grades. The relationship may be affected by movements in metal prices. Although the evidence about the influence of prices is not clear-cut, it does suggest that prices and cut-off grades may be inversely related. As many ores contain other valuable metals besides copper, copper yields will sometimes be subordinated to the extraction of these other metals. Copper equivalent grades have not moved in the same way as copper grades alone.