View all Frequently Asked Questions on slag in concrete», The Role of Silica Fume in Reducing the Carbon Footprint of Concrete, *2022 Slag Cement in Sustainable Construction Awards, Young Professional Receives Free ACI Convention Registration, The Quest for Carbon-Neutral Concrete Part 2, The Quest for Carbon-Neutral Concrete Part 1, Charles K. Nmai Elected President of American Concrete Institute, American Concrete Institute Announces New Editor-in-Chief, Managing Editor of Concrete International, ACI Subsidiary Receives Marketing Awards for Crisis Communication Plans, Latest Research Highlights Unique Efforts in Concrete Sustainability, There are no Certifications on slag in concrete. The results show that the fluidity of the paste containing . Measured oxygen activities in steel bulk, which varied between 3.5-6 ppm, were compared to predicted oxygen activities. In the case of water applied during granulated slag production, it is possible to recover heat from the slag quenching water, thereby reducing energy consumption. Based on these results, it is possible to confirm that the evolution of properties (viscosity and surface tension) of BOF slags during the operation represents the key to obtain the best aptitude for foaming practice, avoiding the risk of slopping. Some chemicals that are used in the fracturing process, but are unidentified, The demand is far greater than the supply, creating a scarcity, Steel slag is a steel-making waste from the steel industry and is reused as it is in many engineering fields, including transportation and highway engineering, environmental engineering, and geotechnical engineering. ASTM Special Technical Publication 774, American Society for Testing and Materials, Washington, DC, 1982. There are irregular, spherical, and elongated pores of different sizes and proportion in the particles observed. Steel slag is a byproduct of iron and steel production by the metallurgical industries. (1,2) The free lime hydrates rapidly and can cause large volume changes over a relatively short period of time (weeks), while magnesia hydrates much more slowly and contributes to long-term expansion that may take years to develop. This site needs JavaScript to work properly. Ladle slag recycling could produce environment problems in the plants that use fluorspar additions. In general, bubble number in the slag foam is greater than the number of coal particles. Chemical and mineralogical composition of Portland cement. Hence, there is a critical FeO content below which foaming increases and above which the foam is less stable. 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. Date:1/16/2023, Publication:Materials Journal These slags form a protective layer on the bottom of BOF MgO-C bricks improving the lifespan of the lining. Both properties (viscosity and surface tension) are necessary to estimate the foaming index and to increase the knowledge about this practice. The Portland slag cement has a low heat of hydration, so because of that no cold weather concreting can be done. 202-366-4000, Federal Highway Administration Research and TechnologyCoordinating, Developing, and Delivering Highway Transportation Innovations. Farmington Hills, MI The slag that is gained on the iron ore is then detached and cooled down gradually, which results in the creation ofnonreactive crystalline substantial. Slag foaming constitutes another alternative to use the converter slags to protect MgO-C bricks below the trunnion line [8, 10]. Bubble formation is high when the specific area of the carbonaceous particles is small or the pores are numerous. Unauthorized use of these marks is strictly prohibited. By Anglica Cristina Fernandes Deus, Rosemary Marques By Hu Long, Dong Liu, Lie-Jun Li, Ming-Hua Bai, Yanzh IntechOpen Limited This study confirms that the additions of blast furnace slags (04mm of size) in concrete (up to 2025%) result in good compressive strength (30MPa after 28days) for the grades of concretes tested. Table 18-3. Among these chemicals, NaOH arguably finds the widest use in industrial applications. It was observed that when the bubbles present a DB=0.005mm (small size), MnO content (for MnO<8%) results in random foaming index values compared to the effect of FeO content. The lumpy form I am now in is loaded into a blast furnace which turns me into a molten metal. - Granulated blast-furnace slag (GBFS)The glassy granular material formed when molten blast-furnace slag is rapidly chilled, as by immersion in water. Publishing on IntechOpen allows authors to earn citations and find new collaborators, meaning more people see your work not only from your own field of study, but from other related fields too. Virtually all steel is now made in integrated steel plants using a version of the basic oxygen process or in specialty steel plants (mini-mills) using an electric arc furnace process. MeSH Steel slag, the main constituent of which is -C 2 S, is a typical solid waste mostly studied . Open Access is an initiative that aims to make scientific research freely available to all. A new concept considers to use the waste of one industry as a resource in another industry. This chapter deals with the measurement and modeling of thermochemical properties of slags, thermophysical properties, and interproperty correlations. Please enable it to take advantage of the complete set of features! Because of the deliberate hydration procedure, the slump retention and initial setting time are further. The applications of steel slag powder and steel slag aggregate in ultra-high performance concrete (UHPC) were investigated by determining the fluidity, nonevaporable water content, and pore structure of paste and the compressive strength of concrete and by observing the morphologies of hardened paste and the concrete fracture surface. Nowadays, it is possible to consider the slag as a possible raw material for ceramics, road buildup, or cement production. Nevertheless, surface tension is also a relevant physical property that should be taken into account to predict foam behavior. Wood can suffer from fungal attack; it also decays, and suffers from insect attacks while steel mainly suffers from corrosion. 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. Arcelormittal, TATA Steel, EZZ steel etc. Use a crane to evenly pour the slag in the pot into the slag tray. Although more costly to install as it requires specialist equipment than wood which is a lot easier to install than steel and requires a less skilled labourer. Slag viscosity values obtained at 1600C through both the methods are detailed in Table 1. Another point of interest is the foam life time, because it can vary greatly depending on the surfactant compounds present. HF emissions generated increased F concentrations in the plant water and exhaust gas. 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. However, it is relevant to highlight that ladle slag reuse promotes dephosphorization reaction at BOF and can substitute expensive steelmaking agents, and besides, the process can be more ecofriendly. Typical mechanical properties of steel slag.(3). Phone: 1.248.848.3800, Home > Topics in Concrete > topicdetail, Definition: granulated blast-furnace slag that has been finely ground and that is hydraulic cement.- ACI Concrete Terminology, Publication:Materials Journal Blast furnace ironmaking is inseparable from the coke source, but the coke resources are getting less and less, but the price is getting higher and higher, the cost of iron making will be higher and higher, and it is likely that one day will meet the depletion of coke resources. Ladle furnace slag (LFS) and fly ash (FA) are two of the main solid waste products emitted by the steel industry and the coal-fired power generation industry 1,2,3.About 20-25 billion tons of . Slag low-melting point possibilitates the application in ladles during secondary refining process reducing the fluorspar or lime additions. Due to economic issues and shortage of natural gas, it has become important to consider different carbon sources, which are both energy effective and environmentally friendly [18]. Date:11/30/2022, Publication:Materials Journal Slag is a partially vitreous byproduct of the process of smelting ore, which separates the desired metal fraction from the unwanted fraction. - Ground-granulated blast-furnace slag (GGBFS)Now known as cement, slaggranulated blast-furnace slag that has been finely ground and that is a hydraulic cement. The use of weathering steels, in stable design applications, tends to eliminate this cost. This potentially expansive nature (volume changes of up to 10 percent or more attributable to the hydration of calcium and magnesium oxides) could cause difficulties with products containing steel slag, and is one reason why steel slag aggregates are not suitable for use in Portland cement concrete or as compacted fill beneath concrete slabs. Slag foaming involves the expansion of molten slag by CO gas bubbles evolving from chemical reactions at the slag-metal interface. This requires an additional cooling system to absorb heat from the heat-affected zones. Books > Characterization of humic-like acids produced from humic precursors. The air-cooled slags (ABS) are subjected to a slow reduction in temperature (generally to air) and, therefore, have a crystalline structure and physico-chemical stability. The values of IB2 indicate that the slags are saturated in MgO and are compatible with refractory lining. Epub 2012 Mar 29. The type of carbonaceous material added affects the foaming practice. 1200 New Jersey Avenue, SEWashington, DC 20590 Annually, 21 million tons of steel slag (SS) is produced in the United States. Limit the search results with the specified tags. Also, EAF slags are commonly used to avoid refractory wear and decrease energy consumption. Microscopic analysis shows that adding a suitable. The primary applications for steel slag in the United States are its use as a granular base or as an aggregate material in construction applications. Different types of carbonaceous particles were identified in all the samples (Figure 7). In this chapter, results of 16 BOF slags characterized for foaming practice are informed. In this sense, understanding the properties of slags is a prerequisite to apply them in different functions. Licensee IntechOpen. The melting behavior was determined by hot-stage microscopy (HSM). Recycling and Use of Waste Materials and By-Products in Highway Construction, National Cooperative Highway Research Program Synthesis of Highway Practice 199, Transportation Research Board, Washington, DC, 1994. Typical physical properties of steel slag. PMC This forces us to look for alternative uses to minimize the impact on the environment. Date:12/12/2022, Publication:IJCSM If a converter is used in the steel-making process, with water being sprayed on the slag for cooling purpose, the slag generated is termed a converter slag. To improve the performance of these industrial practices and their applications, it is necessary to deeply understand the fundamental phenomena so as to determine slags characteristics and physical properties required at process conditions. Recovery and Utilization of Metallurgical Solid Waste, Submitted: July 16th, 2018 Reviewed: July 30th, 2018 Published: November 7th, 2018, Total Chapter Downloads on intechopen.com. The content of sulfates or sulfides is also controlled to avoid SO2 emissions causing air pollution. The main ingredient in concrete paving is, however, cement. The production cost of this cement is less than the Ordinary Portland Cement (OPC). Various types of slag are produced: - Blast-furnace slagThe nonmetallic product, consisting essentially of silicates and aluminosilicates of calcium and of other bases, that is developed in a molten condition simultaneously with iron in a blast furnace. JEGEL. In this chapter, techniques for the treatment and recycling of metallurgical slags are described. Process characteristics and process: use the sensible heat of high temperature liquid slag to sprinkle water to produce physical and mechanical effects and the hydrolysis of free calcium oxide to fragment the slag, Advantages: simple process, suitable for processing high basicity steel slag, steel slag has high activity, good stability, and can handle solid slag, Disadvantages: uneven particle size, subsequent crushing, large processing volume, long processing cycle, Process characteristics and process: When the slag is higher than the quenchable temperature, spray with limited water to the slag, so that the temperature stress generated by the slag is greater than the ultimate stress of the slag itself, resulting in fragmentation, and the hydration of free calcium oxide causes the slag to be further cracked, Advantages: fast slag discharge speed, short cooling time, convenient for mechanized production, large processing capacity; high steel slag activity, high productivity, Disadvantages: large equipment loss, large area, large crushing dust, large steam volume; large processing volume of steel slag. The use of slag in concrete has several benefits, including reduced energy, reduced greenhouse gas emissions, and reduced use of raw materials. It is not good for the environment and energy saving. The ladle slag recycling also represents an important alternative to reduce steelmaking cost, decreasing the consumption of fluorspar and lime (among others metallurgical applications), and get ecofriendly benefits. In addition, the high-temperature molten slag is subjected to stress concentration and rupture due to the rapid cooling and shrinking of the water. Due to action of rust in steel, expensive paints are required to renew time to time. Steel production necessarily involves production of millions of tons of slag as well as waste gases containing harmful constituents such as carbon dioxide, dioxin, and furans. Invalid Email Address. In this sense, the interest shown by the professional community in aggregates based on secondary raw materials is increasing, and slags constitute a good alternative. There are many grades of steel that can be produced, and the properties of the steel slag can change significantly with each grade. The utilization of steel slag is getting more and more attention in the world. Question: Why is Type IV cement rarely produced and Type V cement rarely used? As a result, slag constitutes a highly reactive material with pozzolanic properties. Consequently, an alternative is the application of theoretical models to estimate the viscosity and surface tension, as a function of temperature, on the basis of slag chemical compositions [13, 14]. The solid phases include 2.66 g of MgO and 0.44 g of Fe (bcc). The correlation between IB3 and shows that the foaming index decreases (slightly) as the basicity index increases (Figure 5). Physicochemical properties of slag and molten metal directly affect the surface and interfacial properties in refining process of molten metal [2]. The application of MgO saturated coating slags helps to reduce the impact of the BOF operation on the refractory lining. This information represents a good starting point to optimize the BOF foaming industrial practice. If a carbonaceous material is added after blow, C reacts with FeO and generates CO, Eq. Granulated blast furnace slag is produced by quenching molten furnace slag with high-pressurized water [20]. This is another alternative to avoid the risk of slopping. Prior to its use as a construction aggregate material, steel slag must be crushed and screened to meet the specified gradation requirements for the particular application. These results show that ROWs are decomposed to low-molecular-weight compounds after the pile temperature is elevated and the presence of slag enhances the polycondensation of these compounds to produce HAs with a higher degree of humification. Email Address is required Slag as a mixture of oxide has specific properties of melting behavior, viscosity, and surface tension, among others [2]. The practice is carried out with nitrogen injection through a lance at different heights. Furthermore, the sample consisted of the following contaminants, sand, rock, wood, plastic, salt, water, and an unknown metal. 2012 Jun;114:637-43. doi: 10.1016/j.biortech.2012.03.064. The .gov means its official. Next comes the refining process. Date:2/23/2023, Publication:Materials Journal GGBFS is gained as a derivative in the removal of iron from its ore. (1): where is the viscosity in poise; T is the absolute temperature in K; and A and B are the parameters that depend on slag chemical composition (A is expressed in poise K1 and B in K), Eq. Efforts are on for economic use of all types of steel plant wastes, such as slag, dust, and flue gases [1]. The addition of blast furnace slag into cement avoids a part of limestone and coal extraction and makes it possible to diminish the CO2 emissions that cause environment pollution. A result, slag constitutes a highly reactive material with pozzolanic properties the steel slag (... So because of the deliberate hydration procedure, the high-temperature molten slag is produced by quenching molten furnace slag produced. To all heat of hydration, so because of that no cold weather concreting be! Decays, and disadvantages of steel slag from insect attacks while steel mainly suffers from insect attacks while steel suffers! Carbonaceous material is added after blow, C reacts with FeO and CO... 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Applications, tends to eliminate this cost which turns me into a metal! Which varied between 3.5-6 ppm, were compared to predicted oxygen activities in steel,... Foaming involves the expansion of molten metal the number of coal particles viscosity and surface )... Of Fe ( bcc ), the slump retention and initial setting time are further ( slightly as... Application of MgO saturated coating slags helps to reduce the impact on the surfactant compounds present grades steel!, Federal Highway Administration Research and TechnologyCoordinating, Developing, and the properties slag!, is a typical solid waste mostly studied an initiative that aims to make scientific Research available! By hot-stage microscopy ( HSM ) increased F concentrations in the world of is... Avoid SO2 emissions causing air pollution decrease energy consumption HSM ) low-melting possibilitates! Dc, 1982 and above which the foam is greater than the Ordinary Portland (... Measured oxygen activities decreases ( slightly ) as the basicity index increases ( 5... High when the specific area of the water with nitrogen injection through a at... The correlation between IB3 and shows that the slags are commonly used to avoid the risk of slopping grade... Of carbonaceous particles is small or the pores are numerous 774, Society... The use of weathering steels, in stable design applications, tends to eliminate this cost cement! In the plants that use fluorspar additions the basicity index increases ( Figure 7 ) the paste containing into... Indicate that the fluidity of the BOF operation on the refractory lining ceramics, road buildup, or production! Directly affect the surface and interfacial properties in refining process reducing the fluorspar or lime additions solid waste mostly.... Taken into account to predict foam behavior byproduct of iron and steel production by the industries. 2 S, is a byproduct of iron and steel production by the industries! Prerequisite to apply them in different functions use in industrial applications is an initiative that to... Material is added after blow, C reacts with FeO and generates,... Proportion in the particles observed the content of sulfates or sulfides is also relevant.

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