Slag application favors the increase of pH and the availability of nutrients such as Ca, Mg, and Si in the soil, which leads to the increase in the absorption of these elements by the plant, favoring the growth and yield of the crops. Due to the fact that the limes present low solubility in water and little movement in the soil profile [24], the study of the use of slags (silicates) in no-tillage system has increased due to the greater solubility of this residue [2]. In areas where iron and steel are manufactured, an agricultural blast-furnace slag product may be available as an economical alternative to agricultural limestone or dolomite and as a better source of minor nutrients. So, this chapter aims to emphasize the main aspects of the application of slags to soil chemical attributes as elevation of pH and neutralization of Al3+ toxic in acid soils and increase nutrient content as phosphorus, calcium, magnesium, some micronutrients, and silicon. The use of steel slag as fertilisers and soil nutrients is gaining importance across the globe as it represents an eco-friendly application wherein advantages of chemical properties of … We are a community of more than 103,000 authors and editors from 3,291 institutions spanning 160 countries, including Nobel Prize winners and some of the world’s most-cited researchers. Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. India imported 5.5 million tonne urea, 4.4 million tonne DAP and 3.7 million tonnes of potash in 2016-17. The pile of steel slag occupies a huge area of arable land, and causes environmental pollution; moreover, 7%-15% steel can be recycled from steel slag. Heavy metal contents in the slags shown in Table 1 agree with the values which are considered tolerable for application to the soil [10]. Uses in agriculture – Steelmaking slag has fertilizer components CaO, SiO2, and MgO. On the other hand, the content of calciumsilicates, carbonates, and oxides makes it suitable for agriculture purposes, in the case o proved negligible f content of Slag - Usage • Slag aggregates are approved for a number of uses although there are restrictions. The partners are investigating the possibility of using these carbonates, specifically calcium carbonate and magnesium carbonate, as additives in cement production at Taiheiyo Cement’s plants. Contact our London head office or media team here. The slag can then be processed into various gradations for construction use. Click here to join our channel and stay updated with the latest Biz news and updates. In line with the current trend, it is expected that approximately 10,000 ha of valuable land wasted for disposal of ash. Disposal of different wastes produced from different Industries is a great problem for any country. Chemical and physical characterization of different slags. At Tarmac we have over 40 years experience of processing slag into premium and more sustainable construction materials. Examples of slags are steel slag, stainless steel slag, ladle furnace slag, and blast furnace slag; all of these residues have already been tested for agricultural use at some moment, as will be shown in the chapter. The use of steelmaking slag as fertilisers and as liming agents A small amount of slag is used as fertiliser in agriculture and this use depends on the market situations. The metallurgical industries can produce various residues, and some of these residues can be utilized with success in the agricultural activity, as in the case of the steel slag, which has brought important contributions in agricultural production. There are several types of steel slag, which present variation in chemical composition, physical composition, and solubility, and these variations occur mainly, due to the different processes and different raw materials used in the metallurgical industries. Although the above studies did not observe an increase in the heavy metals’ levels in soil and plants, monitoring of the availability of these toxic elements in the soil and in the plant, as well as the characterization of the residue to be used, is fundamental for the success in the residues used in agriculture. Steel slag in the application of glass-ceramics, environmental engineering, agriculture, burn-free bricks, foundry sand, etc. The homogeneous application of the residue in the area and the adequate incorporation in the soil are also important aspects to be considered. It appears in concrete, aggregate road materials, as ballast, and is sometimes used as a component of phosphate fertilizer. How? By making research easy to access, and puts the academic needs of the researchers before the business interests of publishers. Available from: Post-Consumer Waste Recycling and Optimal Production, Steel slag modifying soil chemical attributes, Department of Soil and Environmental Resources, College of Agronomic Sciences, São Paulo State University, Brazil, Paulista Agency Agribusiness Technology Regional Midwest Pole, Brazil, Paulista Agency Agribusiness Technology, Regional Pole Midwest, Brazil, Federal Institute of Techonology North of Minas Gerais, Januária, Brazil. Use of slags can affect human health and environment, because of heavy metal content, which can leache to groundwater or be transferred to surface water. As PhD students, we found it difficult to access the research we needed, so we decided to create a new Open Access publisher that levels the playing field for scientists across the world. In China, the first steel slag fertilizer program invested by Taiyuan Iron and Steel Group and Harsco Corporation of the USA started building in 2011 [4]. This stuff is boiler slag, which is a recycled product from coal burning plants. Table 1 shows the chemical composition of different steel slags compared to wollastonite which is a rock and is considered as the standard of silicates [7]. Its alkaline property neutralizes soil acidity. Studies conducted by [19, 22, 25, 26, 27, 28] showed positive effects in soil acidity correction of surface application of steel slag compared to lime in no-tillage system, in tropical soil. Slags are calcium and magnesium silicates, which show neutralizing action due to SiO32− base [2]. The steel slag is used as a road foundation, and not only can the steel slag be used in a large amount, but also a large amount of ground steel slag can be saved. Si may also influence the uptake and translocation of various macro- and micronutrients and increase plant tolerance to excess of Mn and Fe [37] and Zn, Al, and Cd [38]. The no-tillage system is growing in these areas; however, one of the requirements for the success of this system is that there is no soil revolving, so the acidity corrective material should be applied to the surface without incorporation. The pH and CEC and the presence of cations affect the adsorption and ionic speciation of heavy metals in soils [34]. The supply of P and Si available in the soil for the potato crop, through the application of slag, increased the absorption of these nutrients by the plant, decreasing the lodging and increasing the height of plants and the production of tubers [17]. With the results obtained for the steel slag, it can be concluded that this material was the most resistant to polishing when compared with the natural aggregates. 3. The presence of heavy metals in steel slag is one of the problems with its use that at high levels, it can become toxic and limit its use in agricultural activities. The slag can be mixed with livestock wastes to make compost, so that both slag and livestock waste can be effectively utilized in agriculture. For proper application, the initial chemical characterization of the soil to calculate the dose either for use as corrective of soil acidity or fertilizers is important. have shown that the slag application (1% an d 2% (w/w)) in tea garden soil and (0.5, 1 and. [11] 2. After proper environmental assessment, steel slag can be used as amendment for metal-contaminated soils (Chand et al., 2016). Inside the furnaces, oxygen pressure is injected to remove impurities such as gaseous carbon monoxide, silicon, manganese, phosphorus, and some iron as liquid oxides; these impurities combine with lime and dolomitic lime to form the steel slag. Blast furnace slag can be used also in agriculture because of its high sorption capacity of phosphorus, which remains into the available form for the plants. As a result of growing environmental awareness, iron and steel slag is highly regarded as a recycled material that can reduce impacts on the environment due … These variations may lead to possible increase in the content of these elements in the soil and increase in the availability to the plants. Now the third-largest steelmaker in the world, India produces over 12 million tonnes of slag each year, but less than 20% of that is used in the cement industry while the remaining keeps piling up at the steel mills, while countries like USA and Japan use slags extensively (more than 70% of the produce) in areas such as housing and road construction, land and mine filling. Table 2 indicates the micronutrients and heavy metal contents in different slags [7]. The increase of heavy metals, such as cadmium (Cd), chromium (Cr), nickel (Ni), mercury (Hg), lead (Pb), and arsenic (As), was insignificant compared to the application of 8 t/ha [32]. When coal is “fired” at over 2500 degrees it melts and produces a by-product called slag. In industrial countries, the use of steel slag in agriculture is mature (Wang and Qing, 2006). The steel slag is used as a secondary cementitious binder, or aggregates for road … Our team is growing all the time, so we’re always on the lookout for smart people who want to help us reshape the world of scientific publishing. Today, iron and steel slag is used in many fields where its unique characteristics can be put to effective use. [11] 2. Slag processing GGBS; How Is Slag Used? By that, you can increase the so-called degree of purity of the steel. The application of steel slag in soil can contribute to the chemical attributes of the soil, reflecting the benefits to the agricultural sector; however, this contribution is variable depending on the composition of the used residue making it always important to know the chemical and physical characterization of the residue before its application to the soil. We share our knowledge and peer-reveiwed research papers with libraries, scientific and engineering societies, and also work with corporate R&D departments and government entities. The use of metallurgical solid wastes such as steel slag, in agricultural activity, has become very important to contribute to reducing the accumulation of such wastes in the environment and to increase crop production. By-products of the steel and iron industries, slag aggregates have many valuable properties that can be used in construction, infrastructure and agriculture. The pile of steel slag occupies a huge area of arable land, and causes environmental pollution; moreover, 7%-15% steel can be recycled from steel slag. On one hand, studies based on the use of slag in agriculture will be considered, which treat the use of steel slags for amending acid soils and as source of important factors and growing agents (not only calcium and magnesium compounds, but also other elements such as silicon, providing important beneficial effects for some crops and increasing the plant yields) and its use as Fe source for reducing Fe chlorosis in … Owing to its high Si content, the use of slag as silicate fertilizer is gaining demand. *Address all correspondence to: angeldeys@hotmail.com, Recovery and Utilization of Metallurgical Solid Waste. It is also mixed with materials for making roadways, used as ballast on trains and large trucks, and is also applied as phosphate fertilizer. In addition, steel slag has P in its composition, which may contribute to such results, as can be seen in Table 1. The steel slag boulders were collected from a local steel manufacturing company. At steelworks, steel is made by refining pig iron that is produced by reducing iron ore. For producing one ton of steel in this process, slag is required by approximately 0.4 ton. Its pH-raising effect is similar to that of ground limestone. These materials pose environmental pollution in the nearby locality because many of them are nonbiodegradable. Molt The findings from this study can be used to rank aggregates with respect to their shape properties. HeadquartersIntechOpen Limited5 Princes Gate Court,London, SW7 2QJ,UNITED KINGDOM. EXPERIMENTAL The steel mill at the Tube Rolling Mill Sisak generates approximately 15% of slag per tonne of steel produced in the electric arc furnace. Steel Slag is a product of the iron and steel recycling process, produced by removing the molten impurities from the surface of electric arc furnace smelting pots. “The use of steel slag may be one of the most green solution which may avoid accumulation of large wastes in steel plants as well as help in treatment of soil for improving crop productivity at low cost,” the steel ministry said. Nitrogen fertilization associated with steel slag also increases the dry mass production and the absorption of Si by the marandu grass [42]. Calcium silicate is 6.78 times more soluble than lime [2], so the use of steel slag in the no-tillage system can be an important alternative source for the process of soil acidity correction, because it may promote greater mobility of SiO32− anions in soil profile, ensuring faster soil acidity correction in deeper layers in relation to the lime. Slag is the tool of steel production. Built by scientists, for scientists. Tropical soils are characterized by being acid with excess of Al3+ that is a toxic element to plants because it limits the root development. Several IRC materials have traditionally been used in agriculture as a substitute for limestone. Ferrous slag is currently underutilized. For production of every tone of steel, nearly 150 kg of slag is generated [6]. The steel ministry has requested the agriculture ministry to look into the scope of using these slags particularly in areas, mostly in the eastern part of the country, having acidic soils, where productivity is lower. To date our community has made over 100 million downloads. Slag-based fertilizers applied in Si-deficient paddy soil improved rice growth, productivity, and brown spot resistance [39]. After 18 months of steel slag incubation in an Argisol, it is observed [31] that the solubility of Zn, Mn, Pb, Ni, Cd, and Cu decreased due to the passage of the exchangeable form retained in oxides and residues, explained by the phenomenon of chemosorption influenced by the soil pH. After 27 months of application of steel slag at doses 2, 4, and 8 t/ha, without incorporation, under no-tillage system, there was an increase in base saturation and reduction of Al3+ up to 0.40 m with application of steel slag; in the same period, the effects of limestone on the soil were observed up to 0.20 m (Figure 1) [22]. Owing to its high Si content, the use of slag as silicate fertilizer is gaining demand. 3. The application of steel slag was also studied in acidic tropical soils cultivated under no-tillage system. The steel industry generates large volumes of slag, which are considered as an environmental problem; it is necessary to increase the use of this waste in new processes to avoid disposal in landfills. Like us on Facebook and follow us on Twitter. On the other hand, the study conducted by [7] with surface application of steel slag, blast furnace slag, ladle furnace slag, and stainless steel slag at the installation of the no-tillage system presented that the ladle furnace slag, stainless steel slag, and steel slag had similar efficiency to the lime in the neutralization of soil acidity at 24 months after application. It is a recovered industrial by-product of an iron blast furnace. Though India’s fertilsier production has improved in recent times, it still depends on imports to bridge the demand-supply gap. Although the construction industry does use some slag as an aggregate, most is simply discarded. • Steel slag cannot be used in confined applications such as in concrete, pipe or structure backfill due to the potential for expansion. 2021The Indian Express [P] Ltd. All Rights Reserved. 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The option to use them is more in the eastern part of the country where acidic soil is predominant with lower productivity. Micronutrients and heavy metal contents in different slags. • Steel slag cannot be used in confined applications such as in concrete, pipe or structure backfill due to the potential for expansion. SSS, stainless steel slag; SS, steel slag; LS, ladle slag; BFS, blast furnace slag; W, wollastonite. (EAF) slag can be used as inexpensive absorbing agent in the treatment process for waste waters burdened with metallic ions. We are IntechOpen, the world's leading publisher of Open Access books. Steel slag offers considerable cost advantages over commercial limestone and has been successfully utilized as a substitute for limestone to neutralize soil acidity in agricultural soils in several countries. Steel LD slag can also be used in fertilizers for agricultural applications (Das et al., 2007). SSS, stainless steel slag; SS, steel slag; LS, ladle slag; W, wollastonite; NP, neutralization power; RR, reactivity rate, expresses the percentage of corrective material that reacts in 3 months; ECC, effective calcium carbonate. LD steel slag as fertilizer in agriculture. Developed countries like Japan, USA have taken lead in making fertilisers as slag silicate fertiliser, by-produced lime fertiliser, slag phosphate fertiliser or iron matter of special fertiliser using steel-making slag. However, ladle steel slag, resulting from further refining, is quite different from steel slag [5]. We can also observe different concentrations of Si and P2O5 in the different slags. For instance, BOF slag can be used asreactant for the CO. 2chemical absorption for carbon sequestration from the steel industry (Birat et al. Financial Express is now on Telegram. Steel slag is currently utilized both to treat wastewater, and as a concrete aggregate. on the characterization of slags. Thus, steel slags can be considered as a sustainable alternative to agricultural practice. How- ever, fertilizers and soil amendments represent an ecofriendly appli- cation wherein the advantageous chemical properties of steelmaking slag can be utilized to promote the growth of plants and increase the yield of agricultural products. The slag can be mixed with livestock wastes to make compost, so that both slag and livestock waste can be effectively utilized in agriculture. The different slags have different contents about the components that characterize a material as soil acidity corrective that can provide different effects in the neutralization of the soil acidity. Steel slags can be used in several activities, such as construction and paving, and also in the agricultural sector due to its ability to correct soil acidity, as it contains some nutrients for the plants and also as silicate fertilizer that is capable of providing silicon to the plants. Depending on the iron and steel production process different slag types can be manufactured. In addition to the corrective effect of the slag, several studies point to the efficiency of slag to increase phosphorus nutrient in the soil [7, 17, 19]. Additionally, steel furnace slag has been used as a raw ingredient in Portland cement manufacture, fill, and soil amendment to name but a few applications. Agricultural Slag Comes From Limestone and Dolomite Agricultural slag, or Ag-Slag, is a fine-screened material from the processing of iron blast-furnace slag, a by-product of the iron and steel industry. Slag is the glass-like by-product left over after a desired metal has been separated (i.e., smelted) from its raw ore.Slag is usually a mixture of metal oxides and silicon dioxide.However, slags can contain metal sulfides and elemental metals. Full details of the specific properties and applications for each of the types of slag can be found on the pages as follows: Air-cooled Blast Furnace Slag (ABS) Air-cooled Basic Oxygen Steel Slag (BOS) The molten slag is slowly cooled by a water mist until solidified. There are no conflicts of interest to declare. The slag is disposed to a landfill next to the facility. LS showed the highest content of Si, while SS has a great amount of P2O5 (Table 1). Aspects related to monitoring the presence of heavy metals will be addressed. The iron and steel slag used as aggregates for asphalt roads are iron and steel by-products. Brief introduction to this section that descibes Open Access especially from an IntechOpen perspective, Want to get in touch? Australia: Boral Australia has launched Innovo, an asphalt system product that uses steel slag as a raw material amongst other recyclables. Steel making slag (also: steel slag) is produced during the conversion of hot metal to crude steel in a basic oxygen furnace or during the melting of scrap in an electric arc furnace. What is coal slag? Basic slag (CaSiO3) is produced through the open-hearth method of steelmaking and is used to amend highly acidic soil. In line with the current trend, it is expected that approximately 10,000 ha of valuable land wasted for disposal of ash. It is a recovered industrial by-product of an iron blast furnace. © 2018 The Author(s). Compared with the use of natural sand, the use of iron and steel slag for ground improvement can reduce the cost of ground preparation for construction and other uses. Angélica Cristina Fernandes Deus, Rosemary Marques de Almeida Bertani, Guilherme Constantino Meirelles, Anelisa de Aquino Vidal Lacerda Soares, Lais Lorena Queiroz Moreira, Leonardo Theodoro Büll and Dirceu Maximino Fernandes (December 31st 2018). Slag cement is a hydraulic cement formed when granulated blast furnace slag (GGBFS) is ground to suitable fineness and is used to replace a portion of portland cement. In weathered soils, such as those of the cited studies, the presence of colloids with pH-dependent charges represents more than 70% of the total cation binding sites. Steel LD slag can also be used in fertilizers for agricultural applications (Das et al., 2007). Login to your personal dashboard for more detailed statistics on your publications. The presence of elements in the composition of residues in nontoxic amounts and the soil pH increase contributed to avoid toxicity by heavy metals [32]. Steel slag may contain free lime (CaO or MgO) that may cause the slag to be expansive or cause differential movement when used as a base. Steel can also undergo a greater process of refinement, into a ladle and, at the end of the process, to generate ladle steel slag [5]. The divergence of the results reported above with the application of slag in no-tillage system can be explained by the chemical composition of these residues, because the industrial process promotes the production of several types of slag, with different recrystallization depending on the amount of Ca and Mg and of the cooling time, aspects that may reduce its solubility [29]. Get live Stock Prices from BSE, NSE, US Market and latest NAV, portfolio of Mutual Funds, Check out latest IPO News, Best Performing IPOs, calculate your tax by Income Tax Calculator, know market’s Top Gainers, Top Losers & Best Equity Funds. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The hydroxyl (OH−) produced neutralizes the H+ of the soil solution and the phytotoxic Al3+, and, consequently, there is an increase in pH and a decrease in the concentration of the potential acidity (H + Al) [16]. Steel slag has been used as a soil additive for more than 100 years because of its high lime content, but it also contains more than a dozen other important minerals and …