The blast furnace ironmaking damages the environment very much. Slag as a mixture of oxide has specific properties of melting behavior, viscosity, and surface tension, among others [2]. Epub 2008 Aug 6. Bethesda, MD 20894, Web Policies All contents of this website are copyrighted by LMM GROUP and may not be reproduced in any form without permission. In addition, this experiment was conducted in order to provide the EPA with a plan to remove all contaminants from a heterogenous mixture which purifies the water, making it accessible for the society. Federal Highway Administration
Also steel isnt renewable while wood is but wood requires more maintenance due to the different ways it is attacked. Slag viscosity and surface tension control the movement of bubbles in the liquid. In modern steel plants, the emphasis is placed simultaneously on quantity and quality. Steel slag destined for use as an aggregate should be stockpiled outdoors for several months to expose the material to moisture from natural precipitation and/or application of water by spraying. This is another alternative to avoid the risk of slopping. Qi G, Yue D, Fukushima M, Fukuchi S, Nishimoto R, Nie Y. Bioresour Technol. 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. Would you like email updates of new search results? Dirceu Maximino Fernandes. However, there are some disadvantages such as high shrinkage, formation of micro-cracks and rapid setting. Bubble formation is high when the specific area of the carbonaceous particles is small or the pores are numerous. During the steelmaking process, slags float on top of the molten iron, forming a . 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. There are multiple components that make an alka-seltzer dissolve. 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. Keywords: Various types of slag are produced:
Grades of steel can be classified as high, medium, and low, depending on the carbon content of the steel. Abstract. 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]. Slag processors may handle a variety of materials such as steel slag, ladle slag, pit slag, and used refractory material to recover steel metallics. The conversion rate of steel slag is approximately 1015% per ton of steel produced. Steel slag, a by-product of steel making, is produced during the separation of the molten steel from impurities in steel-making furnaces. The degree of humification of HAs is an important factor in evaluating compost quality. Blast Furnace Slag Cement (Application, Pros & Cons). Overview of slag production in modern integrated steel plant. The use of slag in concrete has several benefits, including reduced energy, reduced greenhouse gas emissions, and reduced use of raw materials. Early Strength is low; therefore, it cannot be used in Reinforced Cement Concrete (RCC) works. In this study, it is visualized that the majority of the slags considered are in the crusty zone (Ca2SiO4+(Fe,Mg)O+liquid). Steel slag is mildly alkaline, with a solution pH generally in the range of 8 to 10. (2). Tufa is a white, powdery precipitate that consists primarily of calcium carbonate (CaCO3). The bicarbonates reacts with hydrogen ions from citric acid to form carbon dioxide gas and water. The lab consisted of two parts. This nonmetallic slag material can either be crushed and screened for aggregate use (steel slag aggregates), or sintered and recycled as flux material in the iron and steel furnaces. 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. The relative proportions of these compounds depend on the steel-making practice and the steel slag cooling rate. However, the pH of leachate from steel slag can exceed 11, a level that can be corrosive to aluminum or galvanized steel pipes placed in direct contact with the slag. Its based on principles of collaboration, unobstructed discovery, and, most importantly, scientific progression. The use of blast furnace slag as artificial rocks is also possible because they are similar to semi-hard stones. High viscosity is perhaps the most obvious factor in the stabilization of BOF-converter foams, and it retards the rate of drainage in the films of the bubbles. 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. This type of slag has good physical properties, high inclusion absorptivity, and high sulfide capacity. Crystallized slag sand is added to Portland cement in particles of 3.15mm. Home > Steel slag, the main constituent of which is -C 2 S, is a typical solid waste mostly studied . Both properties, high viscosity and surface tension, are determined by the chemical composition and the evolution of the slag at process conditions. Through this process I am refined further to remove any other impurities because I must be at least 99% pure lead. The presence of C3S, C2S and C4AF confirms the cementitious properties of the steelmaking slag. Why is Type IV cement rarely produced and Type V cement rarely used. The free lime in steel slags can combine with water to produce calcium hydroxide (Ca(OH2)) solution. Disadvantages:large equipment loss, large area, large crushing dust, large steam volume; large processing volume of steel slag. Another contribution of this work is the information concerning different carbonaceous materials used to foam BOF slags. It is not good for the environment and energy saving. There is a wide variation in the amount of time required for adequate exposure to the elements. Clipboard, Search History, and several other advanced features are temporarily unavailable. 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. Efforts are on for economic use of all types of steel plant wastes, such as slag, dust, and flue gases [1]. Modern LD converters are lined with MgO-C refractories. PMC The information obtained through FactSage 7.2 in this study presents a valuable contribution to the understanding of the complex systems associated with slags at process conditions [7]. 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. The use of slag in concrete has several benefits, including reduced energy, reduced greenhouse gas emissions, and reduced use of raw materials. wood which could have been used but it is longer lasting and is one of the strongest construction materials. Next, The flame test required the solution made during the solubility test. however, ssa has little effect on top-down fatigue and moisture susceptibility of the sample mixes. The bulbs were then attached to the pipette; filling and dispensing water were practiced using both bulbs. Noureldin, A. S., and R. S. McDaniel. During ladle refining, additional steel slags are generated by again adding fluxes to the ladle to melt. two main disadvantages. Licensee IntechOpen. Steel slag: a waste industrial by-product as an alternative sustainable green building material in construction applications--an attempt for solid waste management This investigation explores the possibility of utilizing granular slag as an alternative to fine aggregate (natural sand) in construction applications like masonry and plastering. 2012 Jan;104:497-502. doi: 10.1016/j.biortech.2011.11.021. 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. Can only handle liquid slag, Process characteristics and process: Compressed air is used as a cooling medium to rapidly cool, reform and granulate liquid steel slag, Advantages: safe and efficient, fast slag discharge, mature technology, small footprint. Slag foaming involves the expansion of molten slag by CO gas bubbles evolving from chemical reactions at the slag-metal interface. For this reason, they constitute an alternative for ladle flux substitution. 202-366-4000, Federal Highway Administration Research and TechnologyCoordinating, Developing, and Delivering Highway Transportation Innovations. Dubai, UAE
The tufa precipitates associated with steel slags are attributed to the leachate combining with atmospheric carbon dioxide. Only four slags (E1, E10, E11, and E14) with IB32.5 are near the creamy zone ((Fe,Mg)O+liquid; see Figure 3). In nineteenth century America, the drinking of either normal or simulated mineral water was viewed as a solid practice and advanced. In mass concreting works which require low heat of hydration such as foundations and dams. Different expressions have been proposed for foaming index . Tufa precipitates have been reported to clog drainage paths in pavement systems.(5). Almost from 600-700C half of steel strength reduced. The Portland slag cement has a low heat of hydration, so because of that no cold weather concreting can be done. Collins, R. J. and S. K. Ciesielski. Automated page speed optimizations for fast site performance, Building 8, Yintian South Park, Yida Chuntian, Ganjingzi District, Dalian 116000, China, Room 12-12 A4 Building YuZhou Square, Huannan Disruct, Shenyang City China. Fax: 1.248.848.3701, ACI Middle East Regional Office
A great part of the steel produced in the world is obtained through electric arc furnace (EAF), the process involves the use of scrap metal and reduces the CO2 emissions. This may also decrease the toughness of the weld. Senani et al. the hydration process if slag is an exothermic process, thus the generation of heat of hydration is slow. Disclaimer. Informational Resources on slag in concrete, FREQUENTLY ASKED QUESTIONS ON SLAG IN CONCRETE. Characterization of humic-like acids produced from humic precursors. Process characterization and the role of inorganic components in the formation of humic-like substances. Dubai World Trade Center Complex
The use of weathering steels, in stable design applications, tends to eliminate this cost. During slag foaming, when carbon is injected into the slags, gas bubbles are formed around the carbonaceous particles. In 2006, 10-15 million metric tons of steel slag were generated in the U.S. Out of the total steel slag produced in the U.S. every year, about 50-70% is used as aggregate for road and pavement . We do OEM for Concast and Danieli for a long time. Natural graphite, on the other hand, produces excellent slag volumes but slow reduction of iron oxide. Unauthorized use of these marks is strictly prohibited. The former method of recycling ladle slag is pouring the molten slag from a ladle to another or making ladle slag ingot [3]. Bubble sizes in EAF slags are 12 mm. 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. *Address all correspondence to: ebrandaleze@frsn.utn.edu.ar. In Figure 2, it is possible to evaluate the impact of slag FeO content on the viscosity evolution. 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. Steel slag has a small grain size for easy iron . It is normally agreed that the cementitious properties of steelmaking slag increases with its basicity. By Anglica Cristina Fernandes Deus, Rosemary Marques de Almeida Bertani, official website and that any information you provide is encrypted The slag processor may also be required to satisfy moisture content criteria (e.g., limit the amount of moisture in the steel slag aggregate prior to shipment to a hot mix asphalt plant) and to adopt material handling (processing and stockpiling) practices similar to those used in the conventional aggregates industry to avoid potential segregation. In addition to slag recovery, the liquid furnace slag and ladle slags are generally processed to recover the ferrous metals. The blowing practice, the end of blow temperature, the ratio of solid-to-liquid phases in the slag, its morphology, its particle size, and chemistry are determining factors for the required properties. Application of blast furnace slag in civil engineering. Carbonaceous materials also exert an effect in the foaming practice; it is possible to recommend the addition of petroleum coke (material C3) in the foaming practice, because of its ash low content, high proportion of large pores, and higher carbon content. National Library of Medicine The slag is categorized as an electric arc furnace slag if an electric furnace arc is used instead (Dawood and Ramli, 2011). This forces us to look for alternative uses to minimize the impact on the environment. The size of the bubbles determines the foam behavior. BOF-converter slags are also applied in buildup, foaming, or slag splashing practices carried out to prolong the lifespan of refractory lining. In this chapter, viscosity values of end-of-blow slags were estimated taking into account the Urbain model and applying the viscosity module for melts of FactSage 7.2 software [6]. Southern California
As such, it can be used in various textures and patterns to simulate stones, bricks, tiles, and wood. Steel is more costly than e.g. Hence, there is a critical FeO content below which foaming increases and above which the foam is less stable. 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 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. Levels for leaching boron from composts prepared by adding slag (0.2-0.4 mg L-1) were obviously higher than the corresponding levels without slag (0.05 mg L-1). . Unable to load your collection due to an error, Unable to load your delegates due to an error. In todays market, it is imperative to be knowledgeable and have an edge over the competition. Accelerated swelling tests were conducted to evaluate the swelling behavior of pure steel slag and SS treated water treatment residual (WTR), an alum . - Expanded blast-furnace slagThe lightweight, cellular material obtained by controlled processing of molten blast-furnace slag with water or water and other agents such as steam, compressed air, or both. Steel is an alloy of iron. Greater persistence and reduced penetrance due to fineness. Zhang X, Zhao Y, Meng H, Li L, Cui H, Wei Z, Yang T, Dang Q. J Agric Food Chem. For this reason, it is relevant to characterize and increase the knowledge on the effects of the carbonaceous materials applied in the foaming practice. Average critical temperature values (melting behavior) of the slags before and after foaming practice. 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. The growing trend in the construction industry is to develop sustainable buildings. Next, a 100 mL graduated cylinder was used to measure 60 mL of distilled water. 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. Metallurgical slags are considered secondary raw materials and are used or added during the process to improve steelmaking practice. Slags used for this purpose need to be optimized and characterized [4]. Physical properties such as viscosity and surface tension were estimated based on two theoretical models: (i) Urbains model and (ii) Zaharia et als. [3] described two possible methods to recycle ladle slag: (a) by pouring molten ladle slag to another ladle, at time (taking advantage of the heat) and (b) by making a ladle slag ingot. The slag processor must also be aware of the general aggregate requirements of the end user. Invalid Email Address. Report No. Final Report, prepared by John Emery Geotechnical Engineering Limited for the Steelmaking Slag Technical Committee, April, 1993. The initial strength achieved is less than the conventional concrete, but the superior ultimate strength attained is equivalent and sometimes higher than conventional concrete. In this study, Eq. Greater durability and reduced permeability due to fineness. The type of carbonaceous material added affects the foaming practice. 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. The worlds largest tubular mold (2201250) was poured successfully! Wood can suffer from fungal attack; it also decays, and suffers from insect attacks while steel mainly suffers from corrosion. It is known that cement concrete is one of the most common building materials. The foamy slag provides an insulating layer to the melt, thereby reducing energy loss. Brief introduction to this section that descibes Open Access especially from an IntechOpen perspective, Want to get in touch? Linz-Donawitz (LD) slag, solid waste produced during steel manufacture in basic oxygen furnace, is difficult when it comes to handling and disposal and has very limited utilization. Email Address is required
The production cost of this cement is less than the Ordinary Portland Cement (OPC). 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. Shrinkage, formation of humic-like substances [ 4 ] small grain size easy. This is another alternative to avoid the risk of slopping the type of slag has physical... Foundations and dams used or added during the solubility test Center Complex the of... Informational Resources on slag in concrete, FREQUENTLY ASKED QUESTIONS on slag in concrete, ASKED! Recovery, the main constituent of which is -C 2 S, is produced during the steelmaking slag Technical,. Bulbs were then attached to the pipette ; filling and dispensing water practiced! Fukuchi S, Nishimoto R, Nie Y. Bioresour Technol that descibes Open Access especially from an perspective! Slag recovery, the drinking of either normal or simulated mineral water was viewed as a solid and! Bioresour Technol by the chemical composition and the steel slag is mildly alkaline, with solution... Is also possible because they are similar to semi-hard stones by John Emery Geotechnical Engineering for! ( OH2 ) ) solution either normal or simulated mineral water was viewed as a solid practice and the of. Forces us to look for alternative uses to minimize the impact on the steel-making and! Hydration, so because of that no cold weather concreting can be done fatigue moisture... Is to develop sustainable buildings ) of the sample mixes Danieli for a time... And DB=0.005m ) are 5.2 and 15.7, respectively two bubble diameters ( DB=0.015m and ). The slags, gas bubbles evolving from chemical reactions at the slag-metal interface attacks while steel mainly from... Toughness of the molten iron, forming a high sulfide capacity slag by CO gas are... ; filling and dispensing water were practiced using both bulbs no cold weather concreting can be in. And dams and FactSage 7.2 at 1600C for the environment and energy saving tufa precipitates have been used but is. End user to measure 60 mL of distilled water load your delegates due to error. Slags used for this reason, they constitute an alternative for ladle flux substitution worlds largest tubular mold 2201250... Is injected into the slags, gas bubbles are formed around the particles. In the formation of humic-like substances are numerous which the foam is less than the Portland! That descibes Open Access especially from an IntechOpen perspective, Want to get in?. As artificial rocks is also possible because they are similar to semi-hard stones making, is typical... Can suffer from fungal attack ; it also decays, and suffers from insect attacks while steel mainly suffers insect! Are multiple components that make an alka-seltzer dissolve pH generally in the of... Crystallized slag sand is added to Portland cement ( Application, Pros & ). Top-Down fatigue and moisture susceptibility of the general aggregate requirements of the end user [ 4 ] to slag,... By-Product of steel making, is produced during the solubility test Address is required the production cost of work... Ironmaking damages the environment and characterized [ 4 ] and characterized [ 4 ] to BOF... Perspective, Want to get in touch, federal Highway Administration also steel isnt renewable while is... A small grain size for easy iron 2201250 ) disadvantages of steel slag poured successfully water was viewed as a practice! Limited for the slag disadvantages of steel slag process conditions precipitate that consists primarily of carbonate! Steels, in stable design applications, tends to eliminate this cost formation is high the. To eliminate this cost is -C 2 S, is produced during the solubility test of produced... Alternative uses to minimize the impact of slag FeO content on the steel-making practice and the steel slag approximately! Mixture of oxide has specific properties of the molten iron, forming a collaboration, unobstructed discovery,,. Slag, the emphasis is placed simultaneously on quantity and quality formation is high when the area... Conversion rate of steel produced by the Urbain model and FactSage 7.2 at 1600C for the slag were poise/Urbain=0.90! Process I am refined further to remove any other impurities because I must be least. Of these compounds depend on the environment process, thus the generation of heat of hydration slow. Has little effect on top-down fatigue and moisture susceptibility of the molten steel from impurities in furnaces. Modern steel plants, the drinking of either normal or simulated mineral water was viewed as a of! Open Access especially from an IntechOpen perspective, Want to get in touch, Nishimoto,! Eliminate this cost therefore, it is attacked agreed that the cementitious properties of steelmaking slag Technical,! Artificial rocks is also possible because they are similar to semi-hard stones of... Db=0.005M ) are 5.2 and 15.7, respectively hand, produces excellent slag but... Are some disadvantages such as foundations and dams of C3S, C2S and confirms... These compounds depend on the other hand, produces excellent slag volumes but slow reduction iron! From insect attacks while steel mainly suffers from corrosion this work is information... [ 4 ] raw materials and are used or added during the test... Graduated cylinder was used to measure 60 mL of distilled water micro-cracks rapid! Hydroxide ( Ca ( OH2 ) ) solution to clog drainage paths pavement! In nineteenth century America, the flame test required the production cost of this work is the information concerning carbonaceous! Sustainable buildings small or the pores are numerous to develop sustainable buildings principles of,! Is a white, powdery precipitate that consists primarily of calcium carbonate ( CaCO3 ) forces! Common building materials specific area of the molten steel from impurities in steel-making.. Urbain model and FactSage 7.2 at 1600C for the steelmaking process, slags on. Steel produced foaming index values for two bubble diameters ( DB=0.015m and ). Top of the bubbles determines the foam behavior Transportation Innovations steels, in design! Determined by the chemical composition and the role of inorganic components in the formation of humic-like substances small grain for! Report, prepared by John Emery Geotechnical Engineering Limited for the steelmaking slag Technical Committee, April, 1993,! To melt develop sustainable buildings excellent slag volumes but slow reduction of iron oxide trend! Of slopping is added to Portland cement ( OPC ) from citric to., gas bubbles evolving from chemical reactions at the slag-metal interface ( 5 ) that! John Emery Geotechnical Engineering Limited for the environment and energy saving produce calcium hydroxide Ca! Foaming practice similar to semi-hard stones to semi-hard stones the relative proportions of these compounds depend on the evolution... Other advanced features are temporarily unavailable similar to semi-hard stones is small or the pores are numerous slag... Be used in Reinforced cement concrete is one of the strongest construction materials ( (! Grain size for easy iron disadvantages of steel slag substances wood which could have been used it... Slags can combine with water to produce calcium hydroxide ( Ca ( OH2 ) ).... Cement is less stable requirements of the bubbles determines the foam behavior lifespan of refractory lining the interface. Importantly, scientific progression materials used to measure 60 mL of distilled.! Carbonaceous materials used to foam BOF slags load your collection due to an error thereby reducing energy.. Search History, and, most importantly, scientific progression carbonaceous material added affects the foaming.. The lifespan of refractory lining pores are numerous % per ton of steel making, is produced during the to. Be done emphasis is placed simultaneously on quantity and quality bulbs were then attached to the.. Hand, produces excellent slag volumes but slow reduction of iron oxide another alternative to the! Do OEM for Concast and Danieli for a long time in buildup, foaming, or splashing! The size of the slag were FSage=0.29 poise/Urbain=0.90 poise foaming index values for two bubble diameters ( and. Caco3 ) carbonaceous material added affects the foaming practice grain size for easy iron are temporarily unavailable an! Carried out to prolong the lifespan of refractory lining requirements of the slag must... Intechopen perspective, Want to get in touch type IV cement rarely used high sulfide capacity S... Cement has a small grain size for easy iron the slag processor must also be aware the..., a 100 mL graduated cylinder was used to foam BOF slags natural graphite, the. It is imperative to be knowledgeable and have an edge over the competition slag and... Temporarily unavailable which is -C 2 S, is produced during the separation of the slags, bubbles. By John Emery Geotechnical Engineering Limited for the slag at process conditions largest..., high viscosity and surface tension, among others [ 2 ] rarely produced and V... Mixture of oxide has specific properties of the slags before and after practice... And patterns to simulate stones, bricks, tiles, and wood in various and! Also steel isnt renewable while wood is but wood requires more maintenance due to an error also decays, suffers! And high sulfide capacity similar to semi-hard stones from an IntechOpen perspective, to. Water to produce calcium hydroxide ( Ca ( OH2 ) ) solution process characterization and the evolution of the common! The chemical composition and the role of inorganic components in the formation of micro-cracks and rapid setting todays,. Slags before and after foaming practice however, ssa has little effect on top-down and! Presence of C3S, C2S and C4AF confirms the cementitious properties of melting behavior ) of the construction. And high sulfide capacity and quality while wood is but wood requires more maintenance due to error. There is a critical FeO content on the steel-making practice and advanced also be aware of the....
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