Steel slag is a by-product of steel making and is produced during the separation of the molten steel from impurities in steel-making furnaces. In many smelting processes, oxides are introduced to control the slag chemistry, assisting in the removal of impurities and protecting the furnace refractory lining from excessive wear. Blast furnace Iron and steel slag refers to the type of metal manufacturing slag that is generated during the process of manufacturing iron and steel products. Iron is extracted from iron ore in a blast furnace by a process known as reduction. Slag is a byproduct from steel production that would otherwise wind up in landfills. Copyright © 2021 Elsevier B.V. or its licensors or contributors. • Steel slag cannot be used in confined applications such as in concrete, pipe or structure backfill due to the potential for expansion. We use cookies to help provide and enhance our service and tailor content and ads. Synthetic slag practice is normally used to obtain clean steels and also for the desulphurization of the liquid steel. Typically, rock wool insulation is composed of a minimum of 70 to 75 percent natural rock. What are Iron and Steel Slags: Iron and steel slags are co-products of iron and steel production respectively that are used in a variety of applications including but not limited to construction, agricultural, and environmental remediation. Molten slag diverted from the iron blast furnace is rapidly chilled, producing glassy granules that yield desired reactive cementitious characteristics when ground into cement fineness. However, the most important application is construction. Carbon monoxide burns off and the other impurities form slag. Steel slag is an unavoidable by-product in Iron & Steel making, it is essentially a mixture of metal oxides and silicon dioxide i.e silicate. Steel, alloy of iron and carbon in which the carbon content ranges up to 2 percent (with a higher carbon content, the material is defined as cast iron). Dust from the slag, a byproduct from steel manufacturing, contains metals at levels that are harmful to infants and toddlers but also for kids up to 18 years old, a state toxicologist report says. BLAST FURNACE SLAG. The raw materials - iron ore, coke and fluxes - are fed into the top of the furnace. Selected physical properties of steel slag are shown in Table 10.1. 2SiO2, and some other oxides exist in steel slag (Sersale, Amicarelli, Frigione et al., 1986; Shi, 2004). Andrzej Cwirzen, in Self-Compacting Concrete: Materials, Properties and Applications, 2020. Slag is used in the manufacture of high-performance concretes, especially those used in the construction of bridges and coastal features, where its low permeability and greater resistance to chlorides and sulfates can help to reduce corrosive action and deterioration of the structure. [2], Historically, the re-smelting of iron ore slag was common practice, as improved smelting techniques permitted greater iron yields—in some cases exceeding that which was originally achieved. The steel slag is used as a secondary cementitious binder, or aggregates for road construction (Sheen et al., 2013; Manso et al., 2004). Steel slag Aggregate (SSA) is a byproduct of the production of steel in an electric arc furnace. [3], Ground granulated slag is often used in concrete in combination with Portland cement as part of a blended cement. Ferrous slag is currently underutilized. Ground granulated slag reacts with a calcium byproduct created during the reaction of Portland cement to produce cementitious properties. Slag is primarily used in the cement and construction industries, and largely in road construction. Description: A ground powder made with an appropriate mill from a glassy granular material formed when molten iron blast furnace slag is rapidly chilled as by immersion in water.” “Slag is a nonmetallic byproduct of the production from the production of iron. Steel slag (SS) is a by-product obtained during the separation process of molten steel from impurities. Very limited research was done so far on its application in production of a normal concrete and even less for the self-compacting concrete. The electric arc furnace slag aggregates showed tendency to expand, which is related to the presence of certain volumetrically unstable periclase and free line (Evangelista and de Brito, 2010). Although the construction industry does use some slag as an aggregate, most is simply discarded. [6], Glass-like by-product left over after a desired metal has been separated from its raw ore, Learn how and when to remove this template message, "The chemical composition of glass in Ancient Egypt by Mikey Brass (1999)", "High Performance Cement for High Strength and Extreme Durability by Konstantin Sobolev", https://en.wikipedia.org/w/index.php?title=Slag&oldid=994305414, Articles needing additional references from April 2020, All articles needing additional references, Articles with unsourced statements from April 2009, Creative Commons Attribution-ShareAlike License, This page was last edited on 15 December 2020, at 01:23. Concrete made with recycled steel slag is 17 percent stronger than traditional concrete. Slag is a byproduct of steel production and is similar in character to volcanic rocks such as basalt and granite. … However, slags can contain metal sulfides and elemental metals. In this case, the slag is termed synthetic. Binders may be used, depending on the product. Slag is the collection of compounds that are removed. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. 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Traditionally it has been used mainly as an aggregate but for some types there are other applications, such as a … Slag produced by steel mills is relatively abundant in industrial areas of the world and is often exported from steel production sites for use as fill material. By far the most widely used material for building the world’s infrastructure and industries, it is used to fabricate everything from sewing needles to oil tankers. It was reported that the X-ray diffraction pattern of steel slag is close to that of Portland cement clinker. In nature, iron, copper, lead, nickel and other metals are found in impure states called ores, often oxidized and mixed in with silicates of other metals. The advantage is speed, as the process is roughly 10 times faster than the open-hearth furnace. It is produced in large quantities during steel-making operations that use electric arc furnaces. Steel slag is a byproduct from steelmaking industry and has been recycled in many countries around the world for decades. Steelmaking slag is an integral part of the steelmaking process. Slags are principally divided into blast furnace slag and metallurgical slag. Steel slag is residue from the steelmaking process, made of minerals like silica, alumina and titanium from iron sand, and combinations of calcium and magnesium oxides. During the Bronze Age of the Mediterranean there were a vast number of differential metallurgical processes in use. Steel slag is an industrial byproduct obtained from the steel manufacturing industry. [citation needed]. At voestalpine the slags resulting from the steelmaking process are separated into blast furnace and metallurgical slags and then recycled. By continuing you agree to the use of cookies. Steel slag aggregates can be acidic or basic and can leach hazardous elements (Pellegrino and Faleschini, 2016). In many smelting processes, oxides are introduced to control the slag chemistry, assisting in the removal of impurities and protecting the furnace refractorylining from excess… A slag by-product of such workings was a colorful, glassy, vitreous material found on the surfaces of slag from ancient copper foundries. Steel slag can furthur be used in granular base, embankments, engineered fill, highway shoulders, and hot mix asphalt pavement. Slags are one of the most natural products of all. While slags are generally used to remove waste in metal smelting, they can also serve other purposes, such as assisting in the temperature control of the smelting, and minimizing any re-oxidation of the final liquid metal product before the molten metal is removed from the furnace and used to make solid metal. Ferrous and non-ferrous smelting processes produce different slags. In the production of iron, the blast furnace is charged with iron ore, fluxing agents, usually limestone and dolomite, and coke as fuel and the reducing agent. Depending on the used production technology, the steel slag can be divided into a basic oxygen steel slag, an electric arc furnace slag and a ladle furnace slag (De Brito and Saika, 2013). Slag is the collection of compounds that are removed. This rapid cooling, often from a temperature of around 2,600 °F (1,430 °C), is the start of the granulating process. But steel slag has a negative impact on the environment when disposed. Iron and steel slag, also known as ferrous slag, is produced by adding limestone (or dolomite), lime and silica sand to blast furnaces and steel furnaces to strip impurities from iron ore, scrap and other ferrous feed materials and to lower the heat requirements of the iron- and steelmaking processes. It was primarily blue or green and was formerly chipped away and melted down to make glassware products and jewelry. Because of the slowly released phosphate content in phosphorus-containing slag, and because of its liming effect, it is valued as fertilizer in gardens and farms in steel making areas. The major components of these slags therefore include the oxides of calcium, magnesium, silicon, iron, and aluminum, with lesser amounts of manganese, phosphorus, and others depending on the specifics of the raw materials used. Trace amounts of chemicals may be detected during chemical analysis. We looked specifically at ferrous slag, the leftover material from the smelting of iron and steel, in the Chicago-Gary area of Illinois and Indiana. The smelting of copper, lead and bauxite in non-ferrous smelting, for instance, is designed to remove the iron and silica that often occurs with those ores, and separates them as iron-silicate-based slags. Like other industrial byproducts, slag actually has many uses, and rarely goes to waste. [5] To flux the silica produced during steelmaking, limestone and/or dolomite are added, as well as other types of slag conditioners such as calcium aluminate or fluorspar. The water carries the slag in its slurry format to a large agitation tank, from where it is pumped along a piping system into a number of gravel based filter beds. In some smelting processes, such as ilmenite smelting to produce titanium dioxide, the slag is the valuable product instead of the metal.[1]. Properties and Uses of Steelmaking Slag. In that case wide variety of use of steel slag becomes relevant. Steel Slag Price - Select 2020 high quality Steel Slag Price products in best price from certified Chinese Steel Slag Pot manufacturers, Cast Steel Slag Ladle suppliers, wholesalers and factory on … It is produced during the separation of the liquid steel from impurities in steelmaking furnace and is a non-metallic by-product of steelmaking process. For example, slags from stainless steel production are susceptible to high leaching rate of chrome. Slag in welding is the result of and the by product of arc welding (welding with an electric arc). Slag is a coating. There are a number of different types of Slag that are available and the information within these web pages refers solely to Ferrous Slags which are a by-product of the iron and steel … Steel slag is commonly used to cover driveways, to fill potholes, repair farm lanes, residential entrances, or yards.Steel slag is not just good for driveways, it is also used by homeowners as a landscaping stone in back yards around a pool area or patio. Steel slag can also be produced by smelting iron ore in a basic oxygen furnace. Since the unit volume of Portland cement is reduced, this concrete is less vulnerable to alkali-silica and sulfate attack. The few performed studies showed that steel slag aggregates tend to have a higher density and an increased water absorption in comparison with natural aggregates. There are two distinct types of slag produced at the BlueScope Steel Port Kembla Site; Blast Furnace Slag and Steel Furnace (or BOS) Slag. Slag : What Is Slag? Along with the diversified uses, steel slag efficiently replaces natural aggregates both coarse and fine, in a conventional concrete mixture. Some of the earliest such uses for the by-products of slag have been found in ancient Egypt. Steel slag, an unavoidable by-product in iron and steel production, may soon finds its way into agricultural land as soil nutrient, potentially cutting down India’s dependence on fertiliser imports. The iron ore is a mixture of iron oxides, silica, and alumina. This process causes several chemical reactions to take place within the slag, and gives the material its cementitious properties. Any sandy component or quartz component of the original ore automatically carries through the smelting process as silicon dioxide. During the steelmaking process, slags float on top of the molten iron, forming a barrier against oxygen and maintaining the internal temperature. The separated slags are processed into valuable products. What is Slag? Common components of and steel slag are limestone (CaO) and silica (SiO2). However, Iron & Steel Slag is non metallic in nature and does not contain hazardous materials. Slag from steel mills in ferrous smelting, on the other hand, is designed to minimize iron loss and so mainly contains oxides of calcium, silicon, magnesium, and aluminium. The layer on top of your weld left after you have welded. Slag needs to be removed so that you can; 1. Slag is a byproduct of metal smelting, and hundreds of tons of it are produced every year all over the world in the process of refining metals and making alloys. They are comparable to … As the slag is channeled out of the furnace, water is poured over it. Table 10.1. Synthetic slag consists of prepared mixture of several individual oxides which is used during secondary steelmaking to assist the steel treatment in the ladle from the viewpoint of effective refinement. The remaining volume of raw material is blast furnace slag. Basic slag is a co-product of steelmaking, and is typically produced either through the blast furnace - oxygen converter route or the electric arc furnace - ladle furnace route. Steel mill slag produced from electric furnaces or open hearths typically contains one-third to one … At the same time the abrasion resistance tends to be enhanced (Anastasiou and Papayianni, 2006). During smelting, when the ore is exposed to high temperatures, these impurities are separated from the molten metal and can be removed. Welding Slag is formed by metal oxides and other chemical compounds. Slags are one of the most natural products of all. The slag has a lower density than steel and therefore floats on top of the molten steel. During the early 20th century, iron ore slag was also ground to a powder and used to make agate glass, also known as slag glass. What is Steel Slag. Slag - Usage • Slag aggregates are approved for a number of uses although there are restrictions. Physical properties of steel slag (De Brito and Saika, 2013). When the filtering process is complete, the remaining slag granules, which now give the appearance of coarse beach sand, can be scooped out of the filter bed and transferred to the grinding facility where they are ground into particles that are finer than Portland cement. … A good example is steelmaking slag: quicklime and magnesite are introduced for refractory protection, neutralising the alumina and silica separated from the metal, and assist in the removal of sulfur and phosphorus from the steel. During smelting, when the ore is exposed to high temperatures, these impurities are separated from the molten metal and can be removed. With world steel production now well over a billion tonnes per year, the slag that arises from some of the processes involved is a major resource. Slag, by-product formed in smelting, welding, and other metallurgical and combustion processes from impurities in the metals or ores being treated. The high iron oxide content of the aggregate results in an aggregate that is very hard and very dense (SSA is 20-30% heavier than naturally occurring aggregates such as basalt and granite It was also ground into powder to add to glazes for use in ceramics. The filter beds then retain the slag granules, while the water drains away and is returned to the system. It is a recovered industrial by-product of an iron blast furnace. • Blast furnace slag may be used in concrete. However, most modern steel plants use what's called a basic oxygen furnace to create steel. Iron and steel slags are coproducts of iron and steel manufacturing. [4] The slag can also be used to create fibers used as an insulation material called slag wool. Concrete containing ground granulated slag develops strength over a longer period, leading to reduced permeability and better durability. 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. In nature, iron, copper, lead, nickel and other metals are found in impure states called ores, often oxidized and mixed in with silicates of other metals.