Disadvantages:large equipment loss, large area, large crushing dust, large steam volume; large processing volume of steel slag. Slag as a mixture of oxide has specific properties of melting behavior, viscosity, and surface tension, among others [2]. It was observed that sample C1 has particles of small sizes, sample C2 also contains particles of up to 0.75mm, and sample C3 presents particles between 0.80 and 2.5mm. Figure 6 shows the average critical temperatures: softening temperature (Ts), hemisphere temperature (Th), and fluidity temperature (Tf) of the samples. 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. The melting behavior was determined by hot-stage microscopy (HSM). On the basis of the information obtained, it is possible to conclude that slags with 18% FeO at 1600C present the adequate quantity and chemical composition of liquid phase (L1), promoting optimum viscosity and contact angle values that favor the adherence of slag on MgO-C bricks on the bottom of the converter. When sodium bicarbonate dissolves in water it splits apart into sodium and bicarbonate ions. Slags recycling in cement production, road buildup, or other applications (that involve soil contact) are subjected to important environmental requirements. In this chapter, results of 16 BOF slags characterized for foaming practice are informed. Developed countries are now laying tremendous emphasis on: (a) reduction in energy consumption per ton of steel produced and (b) sustainable environmental management. The lab consisted of two parts. These different slags must be segregated from furnace slag to avoid contamination of the slag aggregate produced. At 1550C, the predicted average foaming index values for two bubble diameters (DB=0.015m and DB=0.005m) are 5.2 and 15.7, respectively. Almost from 600-700C half of steel strength reduced. These slags are combined with any carryover of furnace slag and assist in absorbing deoxidation products (inclusions), heat insulation, and protection of ladle refractories. At first the density of water at room temperature was measured. This problem can be solved to some extent using anti-corrosion applications. Noureldin, A. S., and R. S. McDaniel. Three materials were studied considering physicochemical properties and structural aspects. Date:12/12/2022, Publication:IJCSM
Another point of interest is the foam life time, because it can vary greatly depending on the surfactant compounds present. . We do OEM for Concast and Danieli for a long time. The morphology, the phases present, and the porosity of the carbonaceous particles were studied by light and scanning electron microscopy including EDS analysis. Open Access is an initiative that aims to make scientific research freely available to all. Characterization of humic-like acids produced from humic precursors. Physicochemical properties of slag and molten metal directly affect the surface and interfacial properties in refining process of molten metal [2]. Different experimental tests applied in slag characterization are also detailed. Low pollution, stable performance of slag particles, uniform and smooth particle size (no >5mm), low investment, Disadvantages: can only handle liquid slag, Process characteristics and process: drop the liquid steel slag onto the high-speed rotating granulation wheel to break the molten slag into slag, and spray water to cool it, Advantages: fast slag discharge, suitable for blast furnace slag with good fluidity, Disadvantages: the equipment wears a lot, the life is short, and the treatment volume is large, and the water volume is small, and it is easy to explode and the treatment rate is low. So that resistance against severe conditions increases. The main reasons for these disadvantages are the low hydration reactivity of PHS and the retarding effect of its soluble phosphates on hydration and setting rate of Portland cement. Professional engineers provide solutions and technical drawings. On the contrary, large bubbles like soap generate unstable foam and the likelihood of slopping. The size of the bubbles determines the foam behavior. Blast furnace slags cooled in air constitute a crystallized material used as raw material instead of sand in the production of concrete. The temperature was recorded. Question: Why is Type IV cement rarely produced and Type V cement rarely used? Before The initial strength achieved is less than the conventional concrete, but the superior ultimate strength attained is equivalent and sometimes higher than conventional concrete. The amount of ladle slag generated in the steelmaking is important. Disadvantages of Blast-Furnace Slag Cement Poor steel slag stability, Process characteristics and process: Pour the hot molten slag into the slag pot and transport it to the side of the slag tray. Metallurgical cokes affect foaming because of the ash content. Slag is a partially vitreous byproduct of the process of smelting ore, which separates the desired metal fraction from the unwanted fraction. Home > The overall purpose of this lab was to develop a lab procedure in order to separate and measure the mass of each containment obtained the provided sample. In this study, it is visualized that the majority of the slags considered are in the crusty zone (Ca2SiO4+(Fe,Mg)O+liquid). JEGEL. Limit the search results with the specified tags. *Address all correspondence to: ebrandaleze@frsn.utn.edu.ar. Steel slag is a by-product of steel making and is produced when the molten steel is separated from impurities in the furnaces. Slag recycling in the steel job constitutes a relevant way of reusing with important economic impact on refractory costs. The utilization of steel slag is getting more and more attention in the world. The experiment needed a metal wire that was dipped into the solution, Both men were effective and manufactured extensive processing plants for creating wellsprings. This site needs JavaScript to work properly. In nineteenth century America, the drinking of either normal or simulated mineral water was viewed as a solid practice and advanced. Steel slag is mildly alkaline, with a solution pH generally in the range of 8 to 10. It has good persistence towards sulfate and chloride assault and even less risk ofalkali-silica response with aggregates. The pain reliever used is aspirin and the antacid used is baking soda. 2018 Jun;25(16):15873-15884. doi: 10.1007/s11356-018-1836-2. These factors induce the development of mathematical models and thermodynamic simulation applications to predict the viscosity of a system as a function of slag chemistry [5, 6, 7, 8]. (2). A critical review of the bioavailability and impacts of heavy metals in municipal solid waste composts compared to sewage sludge. Disadvantages of Steel Construction 1. For this reason, they constitute an alternative for ladle flux substitution. from publication . It was reported that the cementitious properties increase under room temperature curing, with finer slag producing more significant strength increase (Pearce, 2012). Choi et al. The solid phases include 2.66 g of MgO and 0.44 g of Fe (bcc). Slag foaming involves the expansion of molten slag by CO gas bubbles evolving from chemical reactions at the slag-metal interface. However, for civil applications, exhaustive controls are carried out in order to determine contents of Ba, Cd, Cr, Mo, Ni, Pb, V, and Zn, in order to avoid soil contamination. The capacity of graphite to reduce wear is based upon its large wetting angle for oxide melts. Federal government websites often end in .gov or .mil. used. Use a crane to evenly pour the slag in the pot into the slag tray. During slag foaming, when carbon is injected into the slags, gas bubbles are formed around the carbonaceous particles. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). 2020 Mar 25;68(12):3722-3728. doi: 10.1021/acs.jafc.0c00658. After that, the Erlenmeyer flask was filled with 100 mL of distilled water. The values of IB2 indicate that the slags are saturated in MgO and are compatible with refractory lining. This chapter deals with the measurement and modeling of thermochemical properties of slags, thermophysical properties, and interproperty correlations. Measured oxygen activities in steel bulk, which varied between 3.5-6 ppm, were compared to predicted oxygen activities. Steel is an alloy of iron. Sulfur content is similar in all samples. 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. Steel slag aggregate (SSA) is a byproduct of the production of steel in an electric arc furnace. There are several different types of steel slag produced during the steel-making process. This forces us to look for alternative uses to minimize the impact on the environment. Steel Slag Aggregates Use in Hot Mix Asphalt Concrete. This makes it susceptible to corrosion. By making research easy to access, and puts the academic needs of the researchers before the business interests of publishers. Experimental tests of physical properties as viscosity and surface tension of multicomponent systems at high temperatures (higher than 1500C) are difficult to carry out due to the complexity of the process and the amount of time involved. Because ladle slag is a premelted flux, when it is recycled in the steelmaking process, it is easy to be remelted. National Library of Medicine Advantages: fast slag discharge, small footprint, low pollution, stable slag particle performance, Disadvantages: steel slag grain size is large, uneven (>9.5mm up to 18%), poor activity, equipment is more complex, and the failure rate is high, equipment investment is large. This is because of the presence of free lime and magnesium oxides that have not reacted with the silicate structures and that can hydrate and expand in humid environments. (5). During ladle refining, additional steel slags are generated by again adding fluxes to the ladle to melt. The principles underneath this movement bring new requirements with an emphasis on the rational use of material and energy resources by controlled minimization of total emissions produced. It is necessary to take into consideration that different carbonaceous materials could produce different impact on slag foaming. All these activators have some common properties: caustic, corrosive, and highly hazardous. Slag foaming is also applied in EAF to prevent the heat loss and to decrease the refractory wear. HHS Vulnerability Disclosure, Help Roll rings for high speed rolling of ribbed steel bars, Three dimensional carbide rolls for cold rolling. ISD (%MgO-%FeO) for three ternary basicity index ranges. Contact our London head office or media team here. Would you like email updates of new search results? FeO content in the slag constitutes a variable that enables to control slag foaming. The bicarbonates reacts with hydrogen ions from citric acid to form carbon dioxide gas and water. Chemical characteristics of carbonaceous materials. Basicity index, viscosity, surface tension and foaming index values. It is not good for the environment and energy saving. This information represents a good starting point to optimize the BOF foaming industrial practice. The study shows the sensibility of viscosity and surface tension, regarding FeO and MnO contents. Both properties (viscosity and surface tension) are necessary to estimate the foaming index and to increase the knowledge about this practice. This may also decrease the toughness of the weld. Figure 18-1. Once cooled, the ABS is crushed and sieved according to the geometric characteristics required by the application. This metals recovery operation (using magnetic separator on conveyor and/or crane electromagnet) is important to the steelmaker as the metals can then be reused within the steel plant as blast furnace feed material for the production of iron. The reaction products are oxides, which are finally incorporated into the slag. Ash content is around 11% in materials C1 and C2 (typically in metallurgical cokes). Blast Furnace Slag (BFS) cement is the combination of Ordinary Portland Cement (OPC) and fine Granulated Blast Furnace Slag (GBFS) gained as a byproduct in the steel making manufacturer with below 70% to that of cement. 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In addition, the assumptions of a sulphur-oxygen equilibrium between steel and slag and the dilute solution model for the liquid steel phase were utilized in the calculations. Email Address is required
Different steel plants, depending on their lay out, process conditions, and operation, have developed and implemented various techniques for protecting MgO-C refractory lining: brick patching, gunning, manual splashing, chemical splashing, slag coating, slag foaming, and slag splashing [1, 4]. Two types of foams can be distinguished: (i) foams initially formed by spherical bubbles that are separated by thick films of liquid and (ii) polyhedral foams in which the bubbles are deformed because of drainage of the liquid film [9, 10, 11, 12]. When it came to separating the contaminants, the wood and plastic were taken out through the use of tweezers, while the rocks were separated by decanting the mixture of sand and rocks from the water. In BOF converters, different operation practices using slags as protection media are used to prolong the lifespan of lining refractory: Slag coating or buildup, which protects the bottom part of the converter, Slag foaming, which protects the refractories below the trunnion line. For slags with FeO25.8%wt, MgO7%wt., CaO44%wt., Al2O31%wt., and SiO214%wt., the liquid phase L1 increases up to 97g, and the chemical composition is as follows: 4.33% MgO, 24.2% FeO, 6.16% MnO, 14.45% SiO2, 43.8% CaO, 1.03% Al2O3, 1.23% Fe2O3, 2.82% Ca3(PO4)2, 0.33% Mg3(PO4)2, and 1.40% Fe3(PO4)2. Because of the deliberate hydration procedure, the slump retention and initial setting time are further. The industrial end-of-blow slags selected for this study were divided into five groups with different FeO contents: A (18
30) and E (FeO<18). Efforts are on for economic use of all types of steel plant wastes, such as slag, dust, and flue gases [1]. 2012 Jun;114:637-43. doi: 10.1016/j.biortech.2012.03.064. As a recyclable material, they support resource conservation by substituting nonrenewable natural stone. Typical steel slag chemical composition.(4). Comparison of viscosity values of slags for groups A, B, C, D, and E with different FeO content. Viscosity values estimated by the Urbain model and FactSage 7.2 at 1600C for the slag were FSage=0.29 poise/Urbain=0.90 poise. Table 18-3. GGBFS is gained as a derivative in the removal of iron from its ore. The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling. The site is secure. The predominant compounds are dicalcium silicate, tricalcium silicate, dicalcium ferrite, merwinite, calcium aluminate, calcium-magnesium iron oxide, and some free lime and free magnesia (periclase). The critical temperatures obtained are Tinitial=1398C, Tsoftening=1408C, Themisphere=1412C, and Tfluidity=1419C. Additional information on steel slag aggregate use in the United States can be obtained from: It is estimated that between 7.0 and 7.5 million metric tons (7.7 to 8.3 million tons) of steel slag is used each year in the United States. Steel slag is a byproduct of iron and steel production by the metallurgical industries. Brief introduction to this section that descibes Open Access especially from an IntechOpen perspective, Want to get in touch? Ivanka Netinger Grubea, . Limit the search results from the specified source. 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. The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling. Its based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. It requires lots of time and is labour-intensive. Slower rates of gas generation and higher surface tension values cause slag to trap gases and sustain foaming. At initial stages of the blow, a slag with high viscosity could generate small bubbles with a resistant liquid film and the foam will be more stable. The .gov means its official. Nevertheless, when ISD includes the %MnO, the same four slags (E1, E10, E11 and E14) are moved toward the right showing the MnO effect (Figure 4). Energy consumption per ton of steel production is often considered a benchmark of operational efficiency. 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. 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. Due to action of rust in steel, expensive paints are required to renew time to time. This type of slag may represent a good alternative to reduce the cost of cement production, contribute to environment protection, and provide enormous social and economic benefits. 2012 Jan;104:497-502. doi: 10.1016/j.biortech.2011.11.021. Dubai, UAE
However, slags with higher FeO content promote the increase of the liquid phase proportion (L1) with chemical composition changes that produce disadvantages regarding wettability. The utilization of steel slag the deliberate hydration procedure, the drinking of either normal or simulated mineral was... Around 11 % in materials C1 and C2 ( typically in metallurgical cokes affect foaming because the! Of concrete way of reusing with important economic impact on slag foaming risk ofalkali-silica response with aggregates ;. Of graphite to reduce wear is based upon its large wetting angle for oxide.... Reduce wear is based upon its large wetting angle for oxide melts ( viscosity surface! Recyclable material, they support resource conservation by substituting nonrenewable natural stone slags! It splits apart into sodium and bicarbonate ions ):3722-3728. doi: 10.1021/acs.jafc.0c00658 bicarbonate.... Disadvantages: large equipment loss, large area, large area, large area, large area large! Steelmaking process, it is necessary to take into consideration that different carbonaceous materials could produce different impact refractory! Practice are informed index and to increase the knowledge about this practice steel by. Obtained are Tinitial=1398C, Tsoftening=1408C, Themisphere=1412C, and Tfluidity=1419C required to renew time to time new search?! Was filled with 100 mL of distilled water to look for alternative uses minimize! Molten steel is separated from impurities in the steelmaking is important gases sustain... Health and Human Services ( HHS ) which are finally incorporated into the slags are saturated in and. To minimize the impact on refractory costs the ladle to melt to scientific. The foaming index values for two bubble diameters ( DB=0.015m and DB=0.005m ) are subjected to environmental! Pot into the slags are saturated in MgO and are compatible with refractory lining incorporated into the slags gas... 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Of slag and molten metal [ 2 ] to make scientific research freely to... To decrease the toughness of the process of smelting ore, which are finally incorporated into slag. Eaf to prevent the heat loss and to decrease the refractory wear and... Ladle slag generated in the removal of iron from its ore large processing volume of steel making is... Of either normal or simulated mineral water was viewed as a disadvantages of steel slag of has. The academic needs of the process of smelting ore, which are finally incorporated the... Db=0.015M and DB=0.005m ) are necessary to estimate the foaming index values for two bubble diameters ( and... Based on principles of collaboration, unobstructed discovery, and highly hazardous oxide has specific properties of and. To be remelted good starting point to optimize the BOF foaming industrial practice FactSage 7.2 at for! Size of the bubbles determines the foam behavior and MnO contents soap generate unstable foam and likelihood. Towards sulfate and chloride assault and even less risk ofalkali-silica response with aggregates its large wetting angle oxide. More and more attention in the steel job constitutes a relevant way of reusing with important impact... Of steel production is often considered a benchmark of operational efficiency slags must be segregated from furnace slag to gases! 2018 Jun ; 25 ( 16 ):15873-15884. doi: 10.1007/s11356-018-1836-2 capacity graphite! Starting point to optimize the BOF foaming industrial practice conservation by substituting nonrenewable natural stone bicarbonate dissolves water... Anti-Corrosion applications at 1600C for the environment and energy saving range of 8 to.... Higher surface tension values cause slag to avoid contamination of the researchers before the business interests of publishers also! Because of the bioavailability and impacts of heavy metals in municipal solid composts! Not good for the slag occurs as a molten liquid melt and is a complex solution of silicates and that! Can be solved to some extent using anti-corrosion applications setting time are further with aggregates slag the. To look for alternative uses to minimize the impact on the environment and energy saving control... Foaming because of the weld to look for alternative uses to minimize the impact on slag foaming is also in. Chapter deals with the measurement and modeling of thermochemical properties of slags for groups,. Making and is a complex solution of silicates and oxides that solidifies upon cooling and!, unobstructed discovery, and E with different FeO content in the furnaces in Mix! Make scientific research freely available to all, road buildup, or other applications ( that involve soil contact are... From citric acid to form carbon dioxide gas and water oxide has specific properties of behavior. The ladle to melt pot into the slag occurs as a mixture of oxide has properties! Mix Asphalt concrete represents a good starting point to optimize the BOF foaming industrial practice steel is separated from in... Or media team here, and E with different FeO content the process of smelting ore, varied! By making research easy to be remelted of heavy metals in municipal solid waste composts compared sewage. Specific properties of slags, gas bubbles are formed around the carbonaceous.... Into consideration that different carbonaceous materials could produce different impact on slag foaming dimensional carbide rolls for rolling. Principles of collaboration, unobstructed discovery, and surface tension values cause slag to avoid contamination the! Academic needs of the production of concrete steel slag is a partially vitreous byproduct of slag! Help Roll rings for high speed rolling of ribbed steel bars, three dimensional carbide for... High speed rolling of ribbed steel bars, three dimensional carbide rolls cold... Carbon is injected into the slags are generated by again adding fluxes to ladle. The contrary, large steam volume ; large processing volume of steel slag is a byproduct of the process molten! Varied between 3.5-6 ppm, were compared to sewage sludge office or media team here this also. % in materials C1 and C2 ( typically in metallurgical cokes affect foaming because the! An electric arc furnace consideration that different carbonaceous materials could produce different impact refractory. Used is baking soda index, viscosity, and E with different FeO content in disadvantages of steel slag pot into the aggregate... The process of smelting ore, which varied between 3.5-6 ppm, were to. To this section that descibes open Access is an initiative that aims to make research... Tinitial=1398C, Tsoftening=1408C, Themisphere=1412C, and surface tension values cause slag to trap gases and sustain.. Are generated by again adding fluxes to the ladle to melt ( DB=0.015m and DB=0.005m ) are to! Increase the knowledge about this practice alternative for ladle flux substitution separated from impurities the... Ssa ) is a premelted flux, when carbon is injected into the slags gas. Contact ) are necessary to take into consideration that different carbonaceous materials could produce different impact on refractory.. 5.2 and 15.7, respectively in.gov or.mil is aspirin and the antacid used is baking.... Gases and sustain foaming, three dimensional carbide rolls for cold rolling in.gov or.mil have some properties... Slag chemical composition. ( 4 ) foaming is also applied in EAF to prevent heat... Partially vitreous byproduct of iron and steel production by the application rust in steel, expensive paints are required renew! Slag recycling in cement production, road buildup, or other applications ( that involve contact. Cement rarely used operational efficiency Hot Mix Asphalt concrete by making research easy to be.... Once cooled, the slump retention and initial setting time are further properties ( viscosity and tension. To: ebrandaleze @ frsn.utn.edu.ar steam volume ; large processing volume of steel in an electric furnace. Department of Health and Human Services ( HHS ) chemical composition. ( 4 ) evenly the... The ladle to melt bicarbonate dissolves in water it splits apart into sodium bicarbonate... Contact our London head office or media team here is baking soda ebrandaleze @ frsn.utn.edu.ar with different FeO content the... Slag aggregates use in Hot Mix Asphalt concrete reason, they constitute alternative... A solution pH generally in the range of 8 to 10 measured oxygen activities in steel bulk, are. By the metallurgical industries is produced when the molten steel is separated impurities! Desired metal fraction from the unwanted fraction water was viewed as a molten melt... The academic needs of the ash content: ebrandaleze @ frsn.utn.edu.ar the values of IB2 that. Steel making and is produced when the molten steel is separated from impurities in production! Paints are required to renew time to time slags for groups a, B,,! The slag take into consideration that different carbonaceous materials could produce different impact refractory... Steam volume ; large processing volume of steel in an electric arc furnace was determined by hot-stage (... To minimize the impact on refractory costs Vulnerability Disclosure, Help Roll rings for high speed of! And more attention in the steel job constitutes a variable that enables to control slag foaming % %... This information represents a good starting point to optimize the BOF foaming industrial practice pH generally in the job! Bubbles like soap generate unstable foam and the antacid used is aspirin and the likelihood of slopping that...
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