Scrap Consumption Research Articles

Carbon emissions in China's steel industry from a life cycle perspective: Carbon footprint insights

China is the most important steel producer in the world, and its steel industry is one of the most carbon-intensive industries in China. Consequently, research on carbon emissions from the steel industry is crucial for China to achieve carbon neutrality and meet its sustainable global development goals. We constructed a carbon dioxide (CO2) emission model for China's iron and steel industry from a life cycle perspective, conducted an empirical analysis based on data from 2019, and calculated the CO2 emissions of the industry throughout its life cycle. Key emission reduction factors were identified using sensitivity analysis. The results demonstrated that the CO2 emission intensity of the steel industry was 2.33 ton CO2/ton, and the production and manufacturing stages were the main sources of CO2 emissions, accounting for 89.84% of the total steel life-cycle emissions. Notably, fossil fuel combustion had the highest sensitivity to steel CO2 emissions, with a sensitivity coefficient of 0.68, reducing the amount of fossil fuel combustion by 20% and carbon emissions by 13.60%. The sensitivities of power structure optimization and scrap consumption were similar, while that of the transportation structure adjustment was the lowest, with a sensitivity coefficient of less than 0.1. Given the current strategic goals of peak carbon and carbon neutrality, it is in the best interest of the Chinese government to actively promote energy-saving and low-carbon technologies, increase the ratio of scrap steel to steelmaking, and build a new power system.

International comparison of impurities mixing and accumulation in steel scrap

AbstractThe accumulation of impurities in the recycling of steel impacts the quality of secondary steel. Understanding impurity levels is crucial in the context of the proliferation of circular economy policies, expected high recycling rates, and growth of scrap consumption. By assuming the accumulation of impurities to be equal worldwide, the understanding of the extent and variation of the mixing and accumulation was limited in previous studies, and the factors influencing those variations were not considered. This is a first cross‐national comparison of impurity accumulation in recycled steel. In this study, the copper, tin, nickel, chromium, and molybdenum content was analyzed in over 500 samples of electric arc furnace rebars from China, Japan, Vietnam, Ukraine, and the Netherlands (representing northwestern Europe) with an optical emission spectrometer. The impurity content in rebars represents the content of impurities accumulated in steel scrap in the countries studied. The measured content of impurities was then used to determine the factors influencing the accumulation of those impurities. It was revealed that the recycling technology, the presence of a market for recovered metals, the quality of the material input, steelmaking practices, and the management of byproducts derived from a legislative or economic context played a role in the impurities content. By communicating on scrap chemical content, the collaboration between the recycling and steel industries could be enhanced in terms of matching the demand and supply and facilitating an increase in the scrap share in steelmaking.

Effects of flaxseed cake fortification on bread shelf life, and its possible use as feed for Tenebrio molitor larvae in a circular economy: preliminary results.

Bread represents a significant share of food waste worldwide. The extension of the bread shelf life together with innovative systems of food waste treatment might decrease waste biomass decay, the need for transportation, and the need for storage. In recent years, insects have been selected as a valuable tool for food waste treatment owing to their capability to transform low-value food waste into biomass with high nutritional value. Bakery wastes can be used profitably for this purpose. This work had two objectives: (i) to measure the impact of flaxseed cake fortification on bread shelf life depending on the leavening agent (baker's yeast vs sourdough); (ii) to evaluate the possible reuse of the stale bread fortified with flaxseed cake for Tenebrio molitor rearing. Our results showed that fortification seemed to slow the hardening rate of bread, particularly if baker's yeast was used. The time necessary for mold to appear in sourdough bread doubled (from 2 to 4 days). The addition of flaxseed cake to the recipe determined an increase of its scrap consumption by T. molitor larvae. We also observed a significant increase in the body mass of the T. molitor larvae fed with bread obtained with the brewer's yeast with respect to larvae fed with the sourdough. Taken together, these preliminary data can indicate that sourdough bread fortified with 5% of flaxseed cake can represent a promising tool to reduce food waste and to recycle bread scraps by a novel zero-waste approach. © 2021 Society of Chemical Industry.

ТЕХНОЛОГІЧНИЙ АНАЛІЗ ЕФЕКТИВНОСТІ ЕКСПЛУАТАЦІЇ ПЕРИКЛАЗО-ВУГЛЕЦЕВИХ ВОГНЕТРИВІВ В КОНВЕРТЕРАХ МАЛОЇ ЄМНОСТІ

The aim of this study is to establish the functional relationships between different groups of factors of production and the stability of the lining of small-volume converters. At the stage of development of world metallurgy, the oxygen-converter process is the most popular way of producing structural steel. Its main difference is high productivity, which is determined by the duration of maintenance-free periods of smelting units. Under the current conditions, it is possible to increase productivity and reduce the cost of steel production in converters by increasing the stability of refractory linings. Thus it is relevant and necessary to assess the factors influencing the stability of the lining and the search for rational technological conditions for its operation. A statistical analysis over a five-year period of the work of two 50-ton converters with top blowing, which was lined with periclase carbon heat-treated refractories, was conducted. It was established that the dependences of the lining stability on the consumption indicators of charge materials are extreme: the consumption of hot metal at the level of 920-930 kg/t of steel corresponds to the lowest indicators of the lining stability; scrap consumption at the level of 200 - 220 kg/t of steel and lime consumption at the level of 70-75 kg/t of steel correspond to the best working conditions of the lining. Regarding the chemical composition of processed hot metal, the best working conditions of the lining correspond to the content of silicon in it at the level of 0.80-0.85% of the mass and manganese - 0.50-0.60% of the mass. Researches shown that in order to more accurately interpret the impact of certain factors on the stability of the lining of oxygen converters, it is necessary to group factors by organizational and production characteristics and conduct a detailed analysis in each of the groups. According to the results of correlation and regression analysis, the equation was obtained, which allows to predict the stability of the lining of converters with a capacity of 50 tons. The resulting equation can be used in industrial conditions to predict the stability of the lining.

Review of the Energy Consumption and Production Structure of China’s Steel Industry: Current Situation and Future Development

China produced 49.2% of the world’s total steel production in 2017. From 1990 to 2017, the world’s total steel production increased by 850 Mt, of which 87% came from China. After 30 years of rapid expansion, China’s steel industry is not expected to increase its production in the medium and long term. In fact, the industry is currently in the stage of industrial restructuring, and great changes will arise in production structure and technical level to solve pressing issues, such as overcapacity, high energy intensity (EI), and carbon emission. These changes will directly affect the global energy consumption and carbon emissions. Thus, a review of China’s steel industry is necessary to introduce its current situation and development plan. Therefore, this paper presents an overview of the Chinese steel industry, and factors involved include steel production, production structure, energy consumption, technical level, EI, carbon emission, scrap consumption, etc. In addition, four determinants are analyzed to explain the EI gap between China and the world’s advanced level. In addition, comparison of steel industries between China and the world, development plans for energy savings, and emission reduction are also included in this paper to give readers a clear understanding of China’s steel industry.

Characteristic Features of the Gas Injection Process in Oxygen Converters That Use Iron-Containing Slag Produced During Steel Smelting

We describe the characteristic features of the steel smelting process in the 160-metric-ton converters at EVRAZ Consolidated West Siberian Metallurgical Plant JSC for the case where 10–50% of the solid metal charge consists of ferrous converter-slag waste products. Information on the chemical composition of the slag materials and the metal and slag components of the slag/scrap mixture was combined with the scrap consumption rate to quantitatively estimate the change in fundamental process statistics. The parameters of the traditional oxygen-injection process for the 160-metric-ton converters were compared against those for the technology to be discussed in this paper. Both the decrease in the concentration of non-ferrous-metal impurities and the required impurity removal levels at the exit from the converter are specified. The oxidative metal refining production data for the 160-metric ton converters at EVRAZ Consolidated West Siberian Metallurgical Plant JSC and the cost reductions from slag/metal scrap usage indicate that the process is economically promising.

Recycling as a Strategic Direction to Improve Efficiency of Steel Industry in the Russian Federation

The article discusses the issue of increasing the efficiency of the Russian steel industry taking into consideration the requirements of the concept of sustainable development. To solve this problem the author reviews the practices of metal scrap collection and recycling at the leading enterprises of the North America, Europe and the forecast of metal recycling development in the world economy up to the year 2050. This part of the survey shows that technologies of metal scrap and other types of industrial waste recycling could result in considerable economy of different types of resources. The great benefit of using metal scrap recycling technologies by the companies in the United States and the European Union is new jobs creation and improvement of environmental conditions. Taking into account the mentioned benefits of using recycling technologies in steel industry the author analyzes the forecast information and concludes that the further development of steel industry may lead to two times increase in metal scrap collection and recycling by the middle of the XXI century. Companies of the Chinese People Republic, countries members of NAFTA and Japan will prevail in the regional structure of metal scrap consumption. The article also states that the system of metal scrap collection and recycling in the Russian Federation will have to be recreated on the qualitatively new foundation. The most important distinctive feature of a new system still under creation from the former one is that before all the enterprises engaged into metal scrap collection had made part of a single concern and operated as a branch of steel industry. In this regard the Russian Federation faces the problem of re-creation of institutional foundation of metal scrap collection and recycling as well as creation of mechanisms to manage this industry efficiently. This in turn will require the development of legal, regulatory, organizational, economic and scientific support.

Development of converter operation technology using ironbearing concentrates and clinker-steel cakes

Technological process of steel production in converters using clinker-steel cakes and iron-bearing concentrates of “EVRAZ ZSMK” JSC slag processing unit ensuring liquid-phase reduction of iron from oxides is designed. Developed technology allows implementation of iron-containing materials recycling, reduces consumption of scrap, increases liquid metal yield, improves environmental safety in the region.

Retrospective and Prospective Analysis on the Trends of China’s Steel Production

AbstractEconomic development has contributed to the rapid expansion of China's steel industry during the past two decades, which has resulted in numerous problems including increased energy consumption and excessive environmental pollution. This study examines changes in crude steel production, steel scrap consumption, energy consumption, CO2emissions and steel stocks per capita from 2000 to 2014. Scenario analysis based on QGT equation is provided to accurately assess China's steel demand. Under three different scenarios, the peak of steel production and the variation trend of energy consumption, CO2emissions, steel stocks per capita and steel scrap are analyzed from 2010 to 2030. Based on Chinese situation, the most reasonable variation trend of China's steel production is proposed, which will increase from 626.7 Mt in 2010 to approximately 914 Mt in 2020, then gradually decrease to about 870 Mt in 2030. Steel stocks per capita will increase from 3.8 t/cap in 2010 to 8.09 t/cap in 2020 (the inferior limit of completing industrialization), then reach 11.46 t/cap in 2030 and stabilize. The peaks of energy consumption and CO2emissions in steel industry are expected to reach 505.37 Mtce and 1444.1 Mt in 2020, respectively. The scrap ratio is expected to reach 0.36 by 2030, when steel scrap resources will be relatively sufficient. This paper can provide corresponding theoretical basis for the government to make decision-making of macro-control.

Forecast of steel demand and the availability of depreciated steel scrap in China

Economic development has contributed to the rapid expansion of the Chinese iron and steel industry during the past two decades, which has resulted in numerous problems including increased energy consumption and excessive environmental pollution. Steel scrap as an important resource in the steelmaking process is attracting greater attention for its energy efficiency, low carbon emissions, and cyclic regeneration. This study examines changes in crude steel production, steel scrap consumption per ton steel, and steel scrap consumption from 1980 to 2012. A modified IPAT model, which can quantitatively and directly evaluate the influence level of environment, economy, population, technology and national policy on future steel production, is adopted to forecast Chinese steel production from 2010 to 2030. In 2020, the value of steel production and steel stocks per capita are expected to reach 901 million tons and 8.01 tons, respectively. Improved steel-scrap usage will decrease the demand on natural resources and lessen the overall environmental impact. According to steel production forecasts, the calculated scrap ratio will continue to increase from 2020 to 2030 in China, the value of which is expected to reach 0.366 by 2030. Otherwise, two major challenges expected to emerge within the next 20 years are discussed in detail. Finally, several policy suggestions are provided regarding the regulation of steel production and the integrated recycling scrap utilization.

PREDICTION OF METAL TURNOVER ON SEPARATE STAGES OF ITS MOVEMENT

The role of the iron turnover in the economy can not be overestimated. To understand the processes of iron motion you need to know the proportion of metal used in the process of its production and distribution. Need to think of a complex structure intraindustrial relationships, establish proportions not only in the form of the most common indicators such as output, exports and imports of steel, but also how these parameters interact with each other. Knowledge of these flows will allow successfully predict metal fund, and to make long-term balance sheets of scrap. Interbranch balance (MOB) – economic-statistical model, which characterizes the inter-industry production linkages in the economy, as well as the connection between the release of products in the same industry and the cost of resources used up all the other sectors in the provision of this release. MPS is made as to the value and natural forms. In this article, the author of an original method, adapted to the needs of the calculation and analysis of the movement of steel between the individual stages of its production and consumption, based on the method-output tables and matrices «input-output» Leontiev. Also presented a method to predict the flow of metal in the individual stages of its circulation in the economy, depending on the projected volumes of final consumption of steel products in order to determine the forecast balances education and consumption of steel scrap.

FUND FERROUS METAL RUSSIA (METHOD AND RESULTS OF CALCULATIONS)

In this article presents and substantiates methods of estimation in-use stocks of iron (bottom-up and top-down approaches) and proposes the approach, based on them and also considering contemporary Russian economic conditions. The significance of this issue is that for last decade there has been a tendency of increasing both the share and volume of producing steel by EAF-process in world and in Russian ferrous metallurgy. As a result, the consumption of ferrous scrap has been increasing constantly. Thus, there is a necessity of studying the sources of its formation. And considering that more than 50 % of scrap generation is obsolete scrap, released from in-use steel stocks, it is crucial to analyze them.

Russian electrosmelting and predicted demand for metal scrap

The scrap consumption in the electrosmelting of steel in Russia is predicted. Data regarding the introduction of electric arc furnaces in 2013 and the construction of mini mills relying primarily on metal scrap in the period up to 2020 are derived from official Russian sources. The production of electrosteel will continue to expand as a result of the shutdown of open-hearth furnaces and the introduction of new electrosmelting shops in Russia.

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.

KTH Steel Scrap Model – Iron and Steel Flow in the Swedish Society 1889–2010

KTH Steel Scrap Model calculates material flows of iron and steel in the Swedish society based on statistics, mass balance and mass flow analysis and industry knowledge. The material flows of iron and steel were calculated for external scrap consumption, internal scrap, domestic steel scrap arising and net flow of iron and steel into the Swedish society. Model output on external steel scrap consumption and domestic steel scrap arising was compared to an earlier analysis done by Jernkontoret for the timeline 1980–2009. The results show that mass balance calculations are area wise corresponding to consumption figures based on trade statistics. In addition the difference in trend is assumed to be mainly due to stocking effect. Furthermore it is shown that mass balance and mass flow models could be used as a tool to calculate apparent scrap consumption based on crude steel production figures by process type.

Environmental life-cycle comparisons of steel production and recycling: sustainability issues, problems and prospects

Abstract This paper reports on historical analysis of the steel industry in which crude steel production trends are quantified for the period from 1950 to 2006. On the basis of this analysis, the future production of steel for the world is estimated using regression analysis. The historical analysis shows that the world steel production increased from 187 Mt to 1299 Mt in that period. In addition, the paper also reports on historical (1950–2006) steel scrap consumption and was compared with crude steel and electric arc furnace (EAF) steel production. Since 1950, scrap consumption by steel industry worldwide has been growing at 12% per annum whereas the EAF share of steel production has been increasing at 66% per annum. Furthermore, since 1987 iron ore prices have increased at 24% per annum whereas scrap prices have grown by 13% per annum. From the analysis on environmental benefits of steel recycling, it was established that there are numerous advantages of scrap utilisation. The major environmental benefits of increased scrap usage comes from the very fact that production of one tonne of steel through the EAF route consumes only 9–12.5 GJ/tcs, whereas the BOF steel consumes 28–31 GJ/tcs and consequently enormous reduction in CO 2 emissions. In addition, a discussion on various alloying elements in steel and their presence in residual concentrations in the scrap on steel properties is also presented. Finally, this paper presents a discussion on policy issues that could enhance the use of scrap in steel-making is also presented.

Environmental and Economic Assessment of Recycled Aluminum Alloy Production - A Case Study of China

A life cycle assessment was carried out to estimate the environmental and economic impacts of recycled aluminum alloy production. The impact seen from non-carcinogens, respiratory inorganics, terrestrial ecotoxicity, global warming and non-renewable energy categories played an important role to overall environmental impacts. The impact seen from carcinogens and aquatic ecotoxicity played relatively small role, while the impact seen from the rest categories affect the environment was ignorable. Specifically, the emissions from the aluminum and silicon production stages involved played an important role due to high energy consumption, while potential impact generated from other elements was quite small. Similarly, the cost of old aluminum scrap represented the dominant contribution to overall economic impacts. Accordingly, choosing natural gas based electricity production technology and improving old aluminum scrap consumption efficiency are the efficient way to minimize the overall environmental and economic impact, respectively.

Aluminum Recycling - Challenges and Opportunities

Aluminum has experienced significant growth in several sectors over the last decade as a result of its properties and performance attributes. Aluminum is being recognized by different sectors such as automotive, construction, aerospace, etc. as a one of the best candidate material for various applications. Increasing demand for aluminum-based products and further globalization of the aluminum industry have contributed significantly to the higher consumption of aluminum scrap for re-production of aluminum alloys. In automotive applications, for example, the opportunities for continued growth in powertrain and suspension applications plus lightweighting of body structures offer the potential for considerable further growth. Today, a large amount of the aluminum going into new products is coming from recycled products. This represents a growing "energy bank" of aluminum that will become available for recycling at the end of vehicles' lives, and thus recycling is becoming a major issue, and it is essential to tackle this problem before it is too late. The future growth offers opportunity for new recycling technologies and practices to maximize scrap quality, improve efficiency and reduce cost. The present paper highlights some of the current development work in recycling, the challenges facing the implementation of recycling technologies and the future prospective of the idea.

스크랩(Scrap) 화물의 운송경로별 경제성 평가에 관한 연구

철강산업은 우리나라의 대표적인 국가 전략산업으로 정부의 적극적 정책지원과 민간의 경영노력이 조화를 이루어 1970년대 이후 한 국경제성장의 견인차 역할을 해왔다. 그러나 우리나라의 경우 철강산업 원자재의 대부분을 수입에 의존하고 있는 실정이며, 이때 수입되는 원자재의 중량이 무겁기 때문에 철강산업은 수송업이라 할 만큼 수송비 부담이 큰 산업이다. 수송의 합리화는 철강산업의 주요한 과제라 할 수 있다. 따라서 본 연구에서는 철스크랩의 안정적인 공급확보 차원에서 철스크랩 수출입 관련 해상운송의 운송경로별(컨테이너선 vs 벌크선) 경제성을 분석하였다. 이를 위해서 먼저 국내외 철강산업의 현황에 대해서 살펴보았으며, 연간 세계 조강생산규모와 철스크랩 소비규모, 세계 철스크랩 교역구조를 분석하였다. 또한, 철스크랩 수출입 관련 컨테이너선과 벌크선의 두 운송수단 간의 수송물류비를 비교하기 위해서 "D 사(社)"의 철스크랩 수출입 운송시간과 운송비용 항목을 이용하여 톤당 물리비용을 산정하여 비교하였다. The steel industry, as the national representative strategic industry of our country, has played the motive power for the economic growth of Korea in 1970s as the positive support of the government and the management endeavor of the private were harmonized. However, in case of our country, we have mostly relied on import of the raw materials for the steel industry, and as the weight of the imported raw materials is heavy, the steel industry is the industry whose transport burden is big as it is called 'transport industry'. So, the transport rationalization will be the important task of the steel industry. This study has analyzed the economic efficiency per the transport route (container ship vs bulk ship) of the sea transport related to import/export of the steel scrap on the level acquiring the stable supply of the steel scrap. For this, this study firstly researched the status of domestic/foreign steel industry. And analyzed the world crude steel production volume, steel scrap consumption volume and world steel scrap trading structure. Also, in order to compare the transport logistics expenses between two transport devices, namely, container ship and bulk ship, this study calculated the logistics expenses per ton by using the traffic hours and traffic expenses items as the imported/exported scrap freights of 'D' company.

Smelting steel with increased scrap consumption in oxygen converters

Smelting steel with increased scrap consumption in oxygen converters