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.     

碳中和背景下中国钢铁行业低碳发展路径

钢铁行业的低碳转型对于我国实现碳达峰碳中和目标具有至关重要的作用,有必要提前研究"双碳"目标下中国钢铁行业的发展路径及技术路线图。本文回顾了中国钢铁行业发展的历史趋势;归纳了钢铁行业实现低碳发展的主要技术选择;基于文献调研汇总了近年来关于中国钢铁行业低碳发展路径的相关研究,并总结了不同研究对钢铁未来低碳路径中关键参数的判断,包括粗钢产量、废钢资源量、电炉炼钢比例、低碳技术应用、能耗强度、二氧化碳排放等,同时分析了不同研究得出的普遍认识和主要差异。在研究中我们也简要分析了中国钢铁转型路径与全球钢铁转型路径之间的异同。基于上述分析,本文提出了"双碳"目标下中国钢铁行业发展路径的研究需求。     

Based on material flow analysis: Value chain analysis of China iron resources

Iron is an important basic resource for national economic development in China. It is of great strategic importance for the sustainable development of China's economy to study the utilization and circulation status of iron resources. In this paper, using the material flow and value chain analysis method, we quantitatively analyzed the value flow of iron resources in China. According to the value chain and price theory of element M, a value stream diagram of iron resources corresponding to the substance flow chart was plotted. Based on the previous material flow analysis result of iron resources, the diagram quantitatively depicted the value of the circulating flow of iron resources in China in 2011. The results show that by recycling materials, the value of the circulating flow of iron resources can bring considerable economic benefits to both producers and consumers. In the production stage, the expenditures of the entire economic system was reduced by 91.77 billion RMB by circulating iron and the income increased by 95 billion RMB by recycling home scrap, which was generated in the crude steel production stage. In the use stage of iron and steel products, the recycling of old scrap enabled the entire economic system to recover 370.78 billion RMB. It should be noted that analysis within a single framework of physical and economic characteristics of iron resources in the economic system can further extend the research chain of substance flow and value flow at the macro level, enhancing the economic value of substances flow research. In addition, by tracking and depicting the value flow cycle of elements, the improvement potentials and the value situations can be determined to provide useful information for conducting processing and technological innovation for waste minimization.     

Challenges and political solutions for steel recycling in China

The circular economy is an essential component of China's sustainable development. To promote the recycling of end-of-life products, the government has adopted various policies. Steel scrap is an important resource for steelmaking. Yet, the Chinese iron and steel industry uses less scrap to produce new steel compared to other large steelmaking countries. This article examines the reasons, why steel recycling is still relatively weak in China and what measures the government takes to improve the situation. We found that limited availability of scrap, high scrap prices, inadequate steelmaking capacities, industry fragmentation and unclear responsibilities for manufacturers are the main obstacles for steel recycling in China. The government is trying to improve steel recycling through tax incentives, import facilitation, support for supply, industry reorganization, and recycling parks, but with modest results.     

Trends and development of steel demand in China: A bottom–up analysis

With economic development, the Chinese steel industry has rapidly expanded over the past three decades. However, this expansion has resulted in many problems, such as increasing energy consumption and excessive environmental pollution. Therefore, it is important to analyze the future steel demand in China. This study presents changes in steel production and apparent steel consumption in the years 1998–2010. Steel is mainly consumed by construction, machinery, automobiles, shipbuilding, railways, petroleum, household appliances and containers, and these nine industries are analyzed separately using stock based models. The study suggests steel demand in China will rise from 600 million t in 2010 to a peak of 753 million t in 2025, and then gradually decrease to 510 million t in 2050. The construction industry is the largest steel consumer, although its share of total steel demand will decrease in the future. Steel demand in automobile manufacturing, by contrast, will increase rapidly before 2035, and its share will increase from 6.0% in 2010 to 19.0% in 2050. Sensitivity analysis on the four major impact factors such as saturation levels, lifetime distributions, GDP and urbanization rate shows that saturation levels of different products greatly affect long-term and short-term steel demands, while GDP and lifetime distributions, especially the lifetime distribution of buildings, mainly affect the short-term and long-term steel demands, respectively.     

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.     

The material resources for the iron and steel industries

The future supplies of iron ore, coking coal and ferrous scrap are discussed. There is no likelihood of the resources of iron ore being exhausted until well into the twenty-first century. Coking coal, on the other hand, is in shorter supply but it is being eked out by blending with non-coking coal and by making blast furnaces more efficient. Briquettes made completely from non-coking coal will play a part in iron making in the future. To ensure greater flexibility in steel making, hydrocarbons are being considered as possible substitutes for coal. Scrap has always played an important part in steel making and the amount recycled is increasing every year. But more effort is needed, for example, to ensure that the steel in car scrap is fully utilised and that refuse is efficiently recycled. Steel making increasingly demands the scrap to have few impurities and to be in uniform sized pieces. A cryogenic method of preparing such scrap is described. A futuristic way of extracting iron, non-ferrous metals and other saleeable by-products from refuse, by using redundant blast furnaces, is also discussed.     

Potential CO2 emission reduction for BF–BOF steelmaking based on optimised use of ferrous burden materials

Currently, the blast furnace (BF) to basic oxygen furnace (BOF) is the dominant steel production route in the steel industry. The direct CO₂ emission in this process system exceeds 1 t of CO₂/t of crude steel produced. Different ferrous burden materials, for instance iron ore and scrap, can be used in various proportions in this steelmaking route. This paper analyses how energy use, conversion costs, and CO₂ emissions can be influenced by the use of different ferrous burden materials when producing crude steel. An optimisation mixed integer linear programming (MILP) model has been applied for analysis. By the use of the optimisation model, it is possible to highlight some issues of special importance, such as best practices to increase production at low conversion cost, or best practices to increase production at low CO₂ emission. It is found out that more benefits will be gained when using the system-oriented analysis to the steelmaking process. Furthermore, a comprehensive view of the trade-offs between the objectives of Cost and CO₂ can provide useful information for decision makers to generate strategies under the future emission trading.     

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.     

The influence of iron flow on iron resource efficiency in the steel manufacturing process

An iron resource efficiency is proposed to define a measure of the natural iron resources saved in the steel manufacturing process. A simplified iron flow diagram is presented for the steel manufacturing process. The influences of various deviations in iron flow from the simplified iron flow diagram on iron resource efficiency are analyzed. The relationships between iron resource efficiency of unit processes and the final product are also discussed. As an example, data from a steel plant are used to analyze the influence of iron flow on its iron resource efficiency of finial product in the steel manufacturing process, the influence of iron resource efficiency of unit process on iron resource efficiency of the final product, and give some measures to improve the iron resource efficiency of the steel manufacturing process.     

Comprehensive Study Regarding Greenhouse Gas Emission from Iron Ore Based Production at the Integrated Steel Plant SSAB Tunnplåt AB

During the years 2001–2002, a comprehensive study regarding CO₂ emissions related to the steel production for the integrated steel making production route, was carried out. The study was financed by SSAB and carried out by a research group with members from SSAB, MEFOS and LTU. The aim was to study the emissions from the existing system and how these could be influenced by process changes and by process modifications. The calculations were made using a global spreadsheet model for calculating the CO₂ emissions, developed from an existing Energy and Process Integration model of the same system. The calculated cases included the existing BF/BOF route as well as integration of other processes, e.g., an electric arc furnace, DR processes, COREX and a new future smelting reduction process concept (Sidcomet). All new existing alternative ore based process technologies would increase the specific CO₂ emission from the system. A technology transfer to scrap based metallurgy would significantly decrease the emission level, but is not feasible for SSAB, due to the future product mix and the structure of scrap availability. In a 5–20 year perspective, the existing steel making process route with the use of magnetite ore for pellet production has the lowest specific CO₂ emission. In a long-term perspective, 20–50 years, alternative process routes, e.g., based on H₂ and DRI, could be of interest. Studies on such changes are, however, big projects and should be carried out as joint European and/or international efforts.     

Long-term perspectives on world metal use—a system-dynamics model

In this paper, a system dynamics model is described, which simulates long-term trends in the production and consumption of metals (i.e. iron/steel and an aggregate of metals of medium abundance) in relation to impacts such as ore-grade decline, capital and energy requirements and waste flows. This metal model can be of assistance in exploring the issue of sustainability of metal resource use. Application of the model to historical trends shows it to be fairly capable of reproducing the long-term trends in the 1900–1990 period, among others on the basis of two intensity of use curves applied to 13 world regions. For future trends, a set of perspective-based long-term scenarios has been constructed that represent the major paradigms in resource use. These scenarios highlight some of the uncertain factors in the relation between economic growth, metal resource exploitation and use, and energy and environmental consequences. They also indicate that apparently similar metal flows in society may be the result of quite different and sometimes contrary assumptions on metal demand, production patterns and resource base characteristics. Such analyses contribute to a more open and transparent discussion on the issue at hand by adding quantitative explications to qualitative views.     

Time-series analysis of global zinc demand associated with steel

This study aimed to analyze the global-scale substance flow of zinc associated with steel in order to discuss the sustainable use of zinc resources in the future. The relationship between the demand for steel and zinc was characterized in terms of zinc intensity for galvanized steel and the percentage of galvanized steel that accounts for the total steel demand. Zinc consumption for steel was divided into end uses according to the statistics on steel. Zinc demand in the future was forecasted with three scenarios for zinc intensity. Future steel demand was estimated using the stocks-drive-flows model, in which the demand is determined by the change in stock. The growth of in-use stock of galvanized steel in the future was estimated by considering economic growth on the basis of the transition of in-use stock of galvanized steel in the past. The cumulative zinc demand for galvanized steel up to the year 2050 was compared with the zinc reserves. It was found that the global average recovery rate of zinc was estimated at approximately 20% by the dynamic substance flow analysis for zinc. It is hoped that the recovery rate will increase. Even if zinc intensity is continuously reduced according to an experience curve based on technological development, a large portion of the current reserves will be consumed for galvanized steel. It was concluded that technological development in reducing zinc intensity will play a significant role in zinc resource conservation.     

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.     

Seaborne iron ore trade in the 1990s

This paper discusses how world steel production and seaborne iron ore trade have grown since 1950. The role of steel production forecasts in determining investment in the iron ore industry is examined. Forecasts for world steel production and the demand and supply of seaborne iron ore in the 1990s are presented. It is predicted that world steel production will increase by 64 million tons between 1991 and 2000. This increase will be located principally in the developing countries and China. The corresponding increase in seaborne iron ore trade will be approximately 55 million tons. Expansion projects will be located mainly in Australia and Brazil, but no greenfield iron ore projects will be undertaken. By the end of the decade, the demand for seaborne iron ore will be equal to its supply.     

The USSR, China, India and the world metals industry to 2010

Remarkable changes are occurring within the economies of the USSR, China and India that are influencing mineral industry activities. These three countries account for a major share of world minerals production and consumption. Their domestic reforms may ultimately have a serious impact on the global mining industry. This paper examines the present status of the Soviet, Chinese and Indian mineral industries, and forecasts conditions to 2010. Long-term characteristics analysed include industrial production, intensity of use, consumption, mine and plant expansion and trade policy. Six metals are highlighted in the study – aluminium, copper, lead, nickel, steel and zinc.     

Assessing the potential of yield improvements, through process scrap reduction, for energy and CO2 abatement in the steel and aluminium sectors

Targets to cut 2050 CO₂ emissions in the steel and aluminium sectors by 50%, whilst demand is expected to double, cannot be met by energy efficiency measures alone, so options that reduce total demand for liquid metal production must also be considered. Such reductions could occur through reduced demand for final goods (for instance by life extension), reduced demand for material use in each product (for instance by lightweight design) or reduced demand for material to make existing products. The last option, improving the yield of manufacturing processes from liquid metal to final product, is attractive in being invisible to the final customer, but has had little attention to date. Accordingly this paper aims to provide an estimate of the potential to make existing products with less liquid metal production.Yield ratios have been measured for five case study products, through a series of detailed factory visits, along each supply chain. The results of these studies, presented on graphs of cumulative energy against yield, demonstrate how the embodied energy in final products may be up to 15 times greater than the energy required to make liquid metal, due to yield losses. A top-down evaluation of the global flows of steel and aluminium showed that 26% of liquid steel and 41% of liquid aluminium produced does not make it into final products, but is diverted as process scrap and recycled. Reducing scrap substitutes production by recycling and could reduce total energy use by 17% and 6% and total CO₂ emissions by 16% and 7% for the steel and aluminium industries respectively, using forming and fabrication energy values from the case studies. The abatement potential of process scrap elimination is similar in magnitude to worldwide implementation of best available standards of energy efficiency and demonstrates how decreasing the recycled content may sometimes result in emission reductions.Evidence from the case studies suggests that whilst most companies are aware of their own yield ratios, few, if any, are fully aware of cumulative losses along their whole supply chain. Addressing yield losses requires this awareness to motivate collaborative approaches to improvement.     

基于资源价值流转的电解铝企业循环经济综合评价与实证分析

循环经济作为一种经济发展模式的革命，其发展水平的科学定量评价一直是循环经济基础理论问题之一。本文根据资源流转平衡原理，以企业资源的物质流转路线为基础，通过描绘和追踪其生产流程过程的资源投入、消耗、产出及废弃的价值信息，从投入、消耗与循环、输出三环节构建循环经济评价指标体系，采用AHP＆MLR综合评价方法对电解铝企业循环经济的发展状况作了实证研究，从而为其及相关企业资源流转价值的时空转移、循环经济的发展提供一种有效的评价手段。     

钢铁企业雨水资源的应用前景分析

钢铁企业是用水大户，节约工业新水量、降低吨钢耗新水指标已经成为钢铁企业节能减排的重要任务之一。雨水作为一种重要的淡水资源，日益受到钢铁企业的重视。开发利用雨水资源是钢铁企业摆脱有限水资源束缚、可持续发展的重要出路之一。本文从实际情况出发，对钢铁企业雨水资源应用的前景和需要解决的问题作了初步的分析。     

Chinese resource security policies and the restructuring of the Asia-Pacific iron ore market

This paper reviews the restructuring of the Asia-Pacific iron ore market in the wake of the rise of the Chinese steel industry. Prior to the 2000s, this market was characterised by two key features—high firm-level concentration on both the producer and consumer sides, and price determination through annually negotiated benchmark pricing between Australian mining and Japanese steel firms. However, owing to rapid growth in the Chinese steel industry and its emergence as the region's principal iron ore consumer, the Asia-Pacific iron ore market has been dramatically restructured during the last decade. This process has been accelerated since 2005 by Chinese governmental resource security policies, which have sought to address current record high iron ore prices through the use of foreign investment to sponsor new market entrants and the formation of an import cartel amongst the Chinese steel firms. This paper evaluates how these policies have driven restructuring in the Asia-Pacific iron ore market, through an analysis of the growth of China's steel industry, Chinese resource security policies aimed at lowering iron ore import costs, and their effects upon the regional market's ownership structure and price determination mechanisms. It argues that while Chinese investment and cartelisation policies have catalysed significant changes to the ownership and pricing structures of the Asia-Pacific iron ore market, they have carried only mixed benefits for the Chinese steel industry's resource security.