Iron and Steel Slags: Global Perspective on the Circular Economy Craig Heidrich1, Karen Kiggins2, Dr. Thomas Reiche3, Dr. Thomas Merkel3 1
Australasian (iron & steel) Slag Association, PO BOX 1194, Wollongong NSW 2500 AUSTRALIA, E: cheidrich@asa-inc.org.au 2 National Slag Association, PO Box 1197, Pleasant Grove UT 84062 USA E: kkiggins@nationalslag.org 3 Euroslag, Bliersheimer Str. 62 47229 Duisburg Germany E: info@euroslag.org KEYWORDS: iron and steel slags (ISS), blast furnace slag, steel furnace slag, metallurgical slag, global production and utilization, regulation, circular economy ABSTRACT During the manufacture of iron and steel, metallurgical slags are produced. Commonly referred to as co-products, these minerals can best be described as amorphous inorganic oxides. Globally, the manufacture of 1.65 billion tonnes of iron and steel, gives rise to the co-production of more than 567 million tonnes of metallurgical slag. Over the past 40 years ‘hard won’ important end use markets have been established for slag within what has become termed the Circular Economy. Existing and proposed end use markets for metallurgical slags or more specifically iron and steel slags (ISS) are not only of critical importance to the economics of iron and steel manufacture, but also to the supply chain participants which have invested, researched, developed and promoted ISS into various end use markets, e.g. construction materials. Globally, the continued growth of ISS utilization is however dependent on many factors beyond steel production processes, but related to quality and characteristics of the resulting slag. Appropriate legislation and regulation coupled with consistent international standards and codes of practice are only a few of the important enablers for easing the way towards full utilization and securing the ‘legal certainly’ for continued investment into ISS. This paper provides a global perspective on ISS use within the Circular Economy and documents the important and essential paradigm shifts from ‘waste’ to ‘product’.. The paper defines types of slags and how they are classified. Additionally, global production will be discussed with an emphasis on the role of waste legislation in creating legal certainty for the ongoing investment into ISS. The paper has been jointly published by members of the World of Iron and Steel Slag Network (WoISS) and is the result of ongoing, international collaboration between respective country industry associations As a non-governmental organization (NGO’s), we inform the public, industry and governmental entities about the beneficial environmental, technical and commercial uses of ISS.
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CHANGING OPERATING ENVIRONMENT The global economy has been experiencing a difficult phase in recent years as global markets adjust to slower levels of growth from emerging economies such as China and India. That is, back in early in 2010, the World Trade Association reported…, global overcapacity remains one of the main issues in the [steel] sector. … iron and steel producers are increasingly required to meet [stricter] environmental requirements, as well as how raw materials are collected and used in the production of steel, are also likely to remain a challenge for the sector.[1] In 2015, concerns over excess capacity again emerged during an OECD high level symposium on the topic. The key conclusion of the symposium was “overcapacity is a global problem requiring a global solution; structural adjustments are required.” In today’s economic climate it could be argued it’s even more crucial that industry policies promote a level playing field for the iron and steel industry. It’s argued that given anticipated population growth, emerging new applications for steel and new markets, the steel industry is likely to return to growth in the next 5 years. Whilst steel is an essential commodity to a modern society, the resulting iron and steel slags have become strategic inputs to downstream industries. World crude steel production reached 1,621 million tonnes (Mt) for the year 2015, down by 2.9% compared to 2014. In 2015, China accounted for 44.8% of the global market for steel (by volume), compared to 45.9% in 2014[2]. One longstanding challenge for the industry has been how to produce steel with lower carbon emissions, whilst reducing its footprint across the whole supply chain. A secondary challenge for the steel industry is not just improving the value of steel in applications, but maximizing the value of associated by-products and co-products within the circular economy. To these ends, addressing the circular economy requires commitment and partnership with downstream supply chain value adders. Steel must embrace and play a key role in the circular business model in which all outputs; steel; by-products and co-products of the process must be designed and manufactured to be repaired, remanufactured, reused and or recycled within the circular economy. This paper establishes a global perspective on iron and steel slags (ISS) use; past, present and future, within the circular economy and documents the important and ongoing paradigm shifts from ‘waste’ to ‘product’. CIRCULAR ECONOMY During the manufacture of iron and steel, metallurgical slags are produced which have been referred to as either; wastes, residuals, by-products, co-products and or products. ISS can be broadly described as amorphous inorganic oxides, having similar chemistry to naturally occurring materials, such as quarried stone. Globally, iron and steel manufacture gives rise to millions of tonnes of metallurgical slag and
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over the past 40 years important ‘hard won’ end use markets[3] for ISS have been developed within what has become termed the circular economy. The circular economy is a modern term used to describe an alternative to a traditional linear economy (manufacture, use, dispose). In a circular economy we keep resources in use for as long as possible, thus extracting the maximum value from them whilst in use, then recover and regenerate products and materials until the end of each service life. In simple terms the circular economy adds value to the steel manufacturing by closing the loop on non-core resources and extracting maximum value by using them as input materials in other products or applications. In the case for ISS using the term ‘wastes’ to describe slags are inconsistent with ‘resource conversation’ and ‘sustainability principles’. Industrial waste is generally referred to as the type of waste produced by industrial activity, such as that generated by factories, mills and mines. Waste can be more generally defined as any substance which is unwanted or unusable material. However, within some regionial legislative frameworks ‘a’ substance is precluded from being waste for the purposes of [legislation] merely because it can be reprocessed, re-used or recycled. This is relatively consistent with ‘resource conversation’ and ‘sustainability principles’ established back in the 1990’s [4]? GLOBAL: PRODUCTION, UTILISATION AND TRADE World crude steel production reached 1,621 million tonnes (Mt) for the year 2015, down by 2.9% compared to 2014. In 2015, China accounted for 44.8% of the global market for steel (by volume), compared to 45.9% in 2014. Globally, iron and steel manufacture gives rise to more than 567 million tonnes of metallurgical slag and over the past 40 years important ‘hard won’ end use markets have been developed within what has become termed the circular economy. The World of Iron & Steel Slag 'network' (WoISS) aims to advance the international management and use of metallurgical slags in ways that are technically sound, economically beneficial and in an environmentally responsible manner. Participating members include National Associations who have a mutual interest in the exchange of information concerning the management of metallurgical slags. During the course of 2015 the Network agreed to gather, collate and publish production and utilization data provided directly by members or from publically available and sources [5,6]. This paper is the culmination of the Network collaboration. Table 1 reports on the estimated annual production of iron and steel slag during 2015. The table summaries slag production by type and major economic region.
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Region European Union (28) Other Europe CIS NAFTA Central and South America Africa Middle East Asia Oceania Total of above countries Co-Products Iron & Steel
BF Slag
A/C Slag
GBF Slag
SFS Slag
BOF Slag
EAF Slag
OHF Slag
Other Slag
Total Slag
28.0 3.6 23.3 10.8 9.4 1.6 0.8 268.1 1.3 346.7
9.4 0.9 11.6 6.8 4.7 0.9 0.4 101.6 0.8 137.1 39.5%
18.6 2.7 11.6 3.9 4.7 0.7 0.4 166.4 0.5 209.6 60.5%
23.6 5.5 14.0 16.6 6.2 2.1 4.8 146.3 0.8 219.9
12.6 1.6 8.5 5.2 3.8 0.6 0.3 117.1 0.5 150.3 68.3% 219.9 39%
11.0 3.9 4.4 11.4 2.4 1.4 4.5 29.1 0.2 68.3 31.1%
0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.5%
0.0 0.0 0.1 0.0 0.1 0.0 0.0 0.1 0.0 0.3 0.1%
51.6 9.1 37.3 27.4 15.7 3.7 5.6 414.3 2.1 566.6
346.7 61%
Table 1 - Estimated annual production of iron and steel slag during 2015 As observed from the collated data, world-wide iron and steel slags production reached 567 million tonnes in 2015. Blast Furnace Iron Slag (BFS) equated to 347 million tonnes or 61% with Steel Furnace Slag1 (SFS) 220 million tonnes or 39%. The largest ISS producing region was Asia with 414.3 million tonnes or 73% of total global production followed by the European Union with 28 million tonnes or 5% of total global production. Focusing on BFS, more than 210 million tonnes or 60% is converted into granulated blast furnace slag (GBFS)2 with the balance of 137 million tonnes or 20% being processed into air-cooled blast furnace slag (ABFS). With regards to ISS utilization rates, these vary widely across all regions, however in this paper we focus only on regions that have provided data, both verifiable and or published. WoISS network members; Australia, Germany, Japan and United States have submitted actual published utilization data for 2015 and are reported. The following Figure 1 compares selected regions and respective utilisation rates by Country.
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SFS includes; Basic Oxygen System Slag, Basic Oxygen Furnace Slag, Electric Arc Furnace Slag, Open Hearth Slag and Other Metallurgical Slags. 2 See table below for process description 4
100%
97%
Australia
92%
100%
83%
Germany
Japan
United States
Figure 1 - Respective utilisation rates by Country. As reported, all regions have high levels of utilization above 80%. These high levels of utilization are a function of a number of factors such as; long term investment and development of ISS within the respective regions well established iron and steel manufacturing operations, and well-defined regulation and standards to facilitate end market use. Moreover, each region has active and established industry associations to assist with stimulating, coordinating, promoting and facilitating awareness and understanding of the environmental, economic, engineering, manufacturing and societal benefits derived from the use of ISS. Being the first globally coordinated and published paper to accurately establish and report on ISS production and utilization, the WoISS network trusts that future updated papers will attract more interest and shared data to create a more complete global perspective on iron and steel slags (ISS) use; past, present and future, within the circular economy. Such efforts are important for documenting the ongoing paradigm shifts from ‘waste’ to ‘product’. OVERVIEW OF COUNTRY CLASSIFICATION OF ISS The development of sound legislation, regulations and other necessary measures designed to provide industry with the level of ‘legal certainty’ are a minimum requirement for capital investment in modern economies. These investments provide for the efficient and effective recovery or value-adding and ‘best use’ of ISS for beneficial ends. The identification of actual, potential and ultimate removal of unnecessary ‘contingent liabilities’ attributable to the generation, processing or sale of ISS must be a key goal for all stakeholders.
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This concept of ‘legal certainty’ and its importance should not be underestimated. Essentially, it underpins all corporate commercial decision-making processes where investments lead to secure associated ‘property rights’ arising from investment to develop resources. Where a substance accrues property rights, they become tradable goods or commodities based on changed perceptions of value. Ambiguity associated with the material’s classification will only result in hesitancy for further investment into future utilization technologies. The following figure 2 shows regional classification spectrum for ISS. The figure illustrates the dislocation throughout regions, which are in-part dominated by interjurisdictional inconsistencies based on varied methods of assessment [7]. It should be noted that both BFS and SFS are combined within this classification spectrum, which further add to the complexity. Countries such Japan, Australia and Canada have adopted more progressive and consistent legislative approaches towards ISS defining them as resources akin to products. Countries such as India and China have moved quickly towards a more positive stance on ISS as resources, driven by natural resource constraints. Europe and the USA represent more complex challenges given the many jurisdictional regions and dislocated policy approaches. Emerging economies such as South and America and South Africa lack industry experience and practical use of ISS, so more conservative ‘risk adverse’ approaches have been adopted. In summary the figure illustrates the complexity and inter-jurisdictional inconsistencies based on varied methods of assessment and treatment of ISS, which gives rise to potential contingent liabilities when ISS are classified as wastes.
Figure 2 – Material Classification Spectrum by Country 6
The concept of ‘contingent liabilities’ can be broadly applied in relation to the generation, processing and or use of materials defined as wastes, and relates to the potential for use of these materials under the relevant regulation. Ultimately, any substance defined as a ‘waste’, regardless of its economic, social or environmental value, continues to be subject to strict controls and reporting requirements exposing participants to legal uncertainty. In the absence of legal certainty, generators, investors, business owners and customers operating in highly-competitive commercial markets typically avoid regulatory uncertainty or risks associated with an activity, resulting in the widespread loss of current and future beneficial utilization opportunities for ISS. On the other hand, the securing of legal certainty for ISS supports sustainable industry development, whilst protecting the environment and human health - both of which are implicit in the community license to operate in society today. Predictably, different jurisdictions’ across the globe have adopted various classification systems for ISS. These classifications broadly are; non hazardous wastes, solid waste, inert waste and resources or products. Obviously the assigned classification has a direct bearing on how and where ISS are used from a legal certainty perspective. CONCLUSIONS The circular economy an important strategic element of steel industry future. Steel producers must embrace and play a key role in the circular business model in which all outputs; steel; by-products and co-products of the process must be designed and manufactured to be repaired, remanufactured, reused and or recycled which are essential in the circular economy. Defining ISS as ‘products’ is more in keeping with slag industry aspirations. In the absence of legal certainty, generators, investors, business owners and customers operating in highly-competitive commercial markets typically avoid regulatory uncertainty or risks associated with an activity. The result being widespread loss of current and future beneficial utilization opportunities for ISS. Securing of legal certainty for ISS supports sustainable industry development, whilst protecting the environment and human health - both of which are implicit in the community license to operate.. Global production of ISS reached 567 million tonnes in 2015 with BFS contributing 347 million tonnes and SFS 220 million tonnes. High Value Added applications such as GBFS dominate the main utilisation pathways. Classification systems of ISS continue to be dislocated throughout many regions, dominated by inter-jurisdictional inconsistencies based on varied methods of assessment and classification. The stakeholders of the ISS industry must remain vigilant to maintain its community license to operate in today’s highly connected society. They must ensure ISS are not used in applications where the characteristics and benefits are inconsistent with the intended application, leading to
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negative or reactive regulatory burden which creates future legal uncertainty and economic value loss. WORLD OF IRON & STEEL SLAG NETWORK The World of Iron & Steel Slag 'network' (WoISS) aims to advance the international management and use of metallurgical slags in ways that are technically sound, economically beneficial and in an environmentally responsible manner. Participating members include National Associations who have a mutual interest in the exchange of information concerning the management of metallurgical slags. Mission – The mission of the network is to foster the increased utilisation of iron and steel slag’s through the collaboration of each respective industry group where appropriate. Goals – Network members collaborate to: •
• • •
•
stimulate the international transfer of technical information related to ISS management and use that can be utilised by planners, designers, specifiers, regulators, purchasers, manufacturers and constructors or other stakeholders; coordinate the international development of appropriate codes, specifications and guides for the use of ISS on par with competing materials and products; promote the international development of appropriate regulations for the increased utilisation of ISS, facilitate awareness and understanding of the environmental, economic, engineering, manufacturing and societal benefits derived from the use of ISS; and share experiences of effective strategies which have lead to increased ISS utilisation within member regions, including changes in legislation, regulation, codes, guides and specifications
Membership is open to any organisation having an interest, but moreover capability and authority to represent aspects of the iron and steel slag supply chain, e.g. iron and steel generators, processors and users of iron and steel slags located within the geographical boundaries of a country or economic region. Current members include; • • • • • •
Australasian (iron & steel) Slag Association (Australia) Brazil Steel Institute (Brazil) Canadian Slag Association (Canada) Euroslag (Europe) National Slag Association (USA) Nippon Slag Association (Japan)
The following figure 1 show the current network (orange) and prospective (yellow) membership including countries or regions developing industry groups.
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Figure 1 – Network Current and Prospective Members The network operates on a voluntary (no fees) and cooperative industry response basis, with the network facilitating the collection and dissemination of agreed industry information for the purpose of aggregation and dissemination for public education and awareness. Image
Description Iron Blast Furnace Slag (BFS) is formed in a blast furnace with molten iron from iron ore in the reducing presence of heated air, coke and limestone. The resulting molten slag and iron, once removed from the furnace, are subject to further processing to form a crystalline, aggregate or ground blast furnace slag. Granulated Blast Furnace Slag (GBFS) is formed when molten blast furnace slag is rapidly quenched from the furnace, rather than left to slowly solidify by air-cooling. Ground Granulated Blast Furnace Slag (GGBFS) is formed when granulated blast furnace slag (GBFS) is further processed or ground using conventional cement clinker grinding technology.
Steel Furnace Slag (SFS) is the co-product of the steel-making process or basic oxygen system/furnace (BOS/F). The slag is removed from the vessel after the exothermic refinement of molten iron and recycled steel in the presence of fluxes and oxygen.
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Electric Arc Furnace Slag (EAFS) is a co-product formed in the electric arc furnace steel making process. In the final stages, EAFS is tapped from the vessel and solidifies prior to further processing. EAFS structure is best described as a solid solution of basic oxides. Melter Slag (MS) is a co-product of the steel making process that converts iron sand to iron by adding coal and limestone to iron sand. Melter slag differs from other slags in that the major oxides (calcium oxide and magnesium oxide) do not occur in their free form in the slag. Klรถckner Oxygen Blowing Maximillanshuette Slag (KOBMS) is a coproduct of the steel making. The vessel is charged with the molten iron from the melter and a small proportion of scrap before refining begins using a top lance and bottom blown tuyeres to produce.
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REFERENCES 1
WTO (2010), Report From The Director-General On Trade-Related Developments; pgs 78
2
WSA (2016). World steel in figures 2016. Brussels, World Steel Association: pgs 31.
3
Heidrich, C. (2004). Slag - the ultimate construction resource. Strategic Products for Government Infrastructure: Cementitious Materials for Concrete, Sydney, NSW, Australia, NSW Department of Commerce. 4
Brundtland Commission (1987). UN World Commission on Environment and Development, United Nations: pgs. 318. 5
World of Iron and Steel Slag Network Production and Utilsation Country Reports (personal communication) 2016 6
WSA (2016). World steel in figures 2016. Brussels, World Steel Association: pgs 31
7
CCA Brazil, (2014) International Survey on the legal classification of iron and steel industry slags. Pgs 29
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