In the three cases, the slags require good physical properties (viscosity and surface tension) to achieve good protection results and an adequate slag adherence to MgO-C bricks. The solid phases include 2.66 g of MgO and 0.44 g of Fe (bcc). The oxygen combines with and removes the impurities in the charge. Figure 6 shows the average critical temperatures: softening temperature (Ts), hemisphere temperature (Th), and fluidity temperature (Tf) of the samples. It is not good for the environment and energy saving. In this chapter, two main slag practices are described: slag coating and slag foaming considering experimental data and theoretical information. Final Report, prepared by John Emery Geotechnical Engineering Limited for the Steelmaking Slag Technical Committee, April, 1993. However, nowadays three main types of ladle slag recycle products are used depending on the particle size and chemical composition: (a) desulfurizing agent in hot metal pretreatment, (b) as a product to substitute converter flux, and (c) as a product to substitute ladle flux. The disposal and exploitation of residues from steelmaking plants are still an open problem because of the huge amount and the remarkable variety of waste materials. Date:11/30/2022, Publication:Materials Journal Steel slag is mildly alkaline, with a solution pH generally in the range of 8 to 10. In addition, as previously noted, expansion due to hydration reactions should be addressed prior to use. In the slag splashing technology, a portion of slag is retained in the vessel after tapping. The addition of blast furnace slag into cement avoids a part of limestone and coal extraction and makes it possible to diminish the CO 2 emissions that cause environment pollution. The degree of humification of HAs is an important factor in evaluating compost quality. 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. Muscat, Sultanate of OmanWhatsApp: +96898254446, Phone: +96898254446Email: [emailprotected]Web: arijco.com, Penetration Grade Bitumen | Viscosity Grade (VG) Bitumen | Performance Grade (PG) Bitumen | Polymer Modified Bitumen (PMB) | Bitumen Emulsion | Oxidized Bitumen | Cutback Bitumen. They are produced at high temperatures, and under fast-cooling rates, the structure obtained is amorphous. In Figure 1, a comparison of the viscosity values obtained for slags A, B, C, D, and E shows that slags of the E group, with FeO content lower than 18 %wt. Modern LD converters are lined with MgO-C refractories. (3), causing slag foaming. 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. The reaction products are oxides, which are finally incorporated into the slag. Are you have a purchasing plan contact us to get best plan. So that resistance against severe conditions increases. HF emissions generated increased F concentrations in the plant water and exhaust gas. Disadvantages of Steel Construction 1. To summarize, slag recycling requires the availability of detailed and precise information on their behavior, physical properties, and structural characteristics. Uneven particle size (>9.5mm up to 29%)[/vc_column_text][/vc_column][/vc_row]. Qi G, Yue D, Fukushima M, Fukuchi S, Nie Y. Bioresour Technol. Bubble sizes in EAF slags are 12 mm. Copyright 2023 IPL.org All rights reserved. Guilherme Constantino Meirelles, Anelisa de Aquino Vidal Lacerda Soares, The timing for adding steel slag affected the degree of humification of HAs in the composts. Fax: 1.248.848.3701, ACI Middle East Regional Office 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. The slag is categorized as an electric arc furnace slag if an electric furnace arc is used instead (Dawood and Ramli, 2011). official website and that any information you provide is encrypted 2018 The Author(s). Disadvantages of Portland Slag Cement. (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. Along the steel conversion process, the oxygen blown is mostly combined with elements dissolved in the melt. Clipboard, Search History, and several other advanced features are temporarily unavailable. In addition to slag recovery, the liquid furnace slag and ladle slags are generally processed to recover the ferrous metals. One of the biggest challenges for metallurgists is to recycle the slag directly in the steelmaking processes. Slower rates of gas generation and higher surface tension values cause slag to trap gases and sustain foaming. The amount of ladle slag generated in the steelmaking is important. and transmitted securely. Baking soda and citric acid mixed when dropped in the water, which causes a chemical reaction to happen. Please enable it to take advantage of the complete set of features! They usually consist of the steel slag that falls on the floor of the plant at various stages of operation, or slag that is removed from the ladle after tapping. The content of sulfates or sulfides is also controlled to avoid SO2 emissions causing air pollution. Slag fluidity and the physics and chemistry of the refractory-slag interaction are relevant to the design of these coating slags. This is how the bubbles are made. In Figure 2, it is possible to evaluate the impact of slag FeO content on the viscosity evolution. Blast furnace slags cooled in air constitute a crystallized material used as raw material instead of sand in the production of concrete. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). 202-366-4000, Federal Highway Administration Research and TechnologyCoordinating, Developing, and Delivering Highway Transportation Innovations. There is a wide variation in the amount of time required for adequate exposure to the elements. Chemical characteristics of carbonaceous materials. 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]. It is worth noting that critical temperatures in slag samples increase after the foaming practice. however, ssa has little effect on top-down fatigue and moisture susceptibility of the sample mixes. Can only handle liquid slag. In addition, solid and liquid phases of the slag (at practice temperatures) in the system have relevant influence on the adherence behavior. By Anglica Cristina Fernandes Deus, Rosemary Marques By Hu Long, Dong Liu, Lie-Jun Li, Ming-Hua Bai, Yanzh IntechOpen Limited Both properties, high viscosity and surface tension, are determined by the chemical composition and the evolution of the slag at process conditions. Land and marine applications include seaport and airport civil engineering projects, coastal protection structures, seaweed bed rehabilitation, and land surface coverage [22]. Different expressions have been proposed for foaming index . Chemical and structural characteristics of three carbonaceous materials were studied. Ash content is around 11% in materials C1 and C2 (typically in metallurgical cokes). Sometimes when a food product is a little more than others it is because the ingredients that make it are the processed like, Procedure and Observations The bulbs were then attached to the pipette; filling and dispensing water were practiced using both bulbs. In the case of basic slags, the authors propose to modify the surface of the aggregates by blending them with a slurry mixture of fine quarry dust and cement in order to avoid the expansion and to reduce the porosity. 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. As a recyclable material, they support resource conservation by substituting nonrenewable natural stone. It is used as either an additional or substitute material in road construction, filter or soil stabilizer in these cases. Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete. Chemical and mineralogical composition of Portland cement. Steel slag can normally be obtained from slag processors who collect the slag from steel-making facilities. This information represents a good starting point to optimize the BOF foaming industrial practice. 2020 Mar 25;68(12):3722-3728. doi: 10.1021/acs.jafc.0c00658. - Air-cooled blast-furnace slagThe material resulting from solidification of molten blast-furnace slag under atmospheric conditions; subsequent cooling may be accelerated by application of water to the solidified surface. When the surface is solidified, spray a large amount of water to quench it, and then dump it to The slag truck is sprayed with water for cooling, and finally turned into the pool for cooling, Advantages: rapid cooling, less land occupation, large processing capacity, less dust, high steel slag activity, Disadvantages: the slag tray is easy to deform, the process is complicated, and the operation and investment costs are large. The temperature was recorded. 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. - 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. 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. 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. The capacity of graphite to reduce wear is based upon its large wetting angle for oxide melts. To reduce the amount of carbon in the steel, greater oxygen levels are required in the steel-making process. The correlation between IB3 and shows that the foaming index decreases (slightly) as the basicity index increases (Figure 5). The presence of impurities and possible reactions between the crucible material and the slag produces a transportation problem in the interface that can reduce the values of the properties and can occasionally modify wettability. Therefore, accurate viscosity values are essential for the optimization and improvement of metallurgical processes. The cementing properties of activated steel slag using alkaline are higher than those of raw steel slag due to the chemical reactions between the steel slag and sodium hydroxide (NaOH). Our product have been supplied to worlds top steel manufacturerArcelormittal, TATA Steel, EZZ steel etc. 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). One of the possible ways of achieving sustainable development in the construction industry is to use easily renewable raw material resources and waste materials instead of limited and finite resources. Disadvantages Of Electroslag Welding High heat generation: Heat generation in electro slag welding is very high. 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. Then, the pipet was rinsed with distilled water. This chapter is focused on the chemical composition, structural characteristics, thermal and physical properties, and behavior (at high temperature) of different slags used to protect refractories in BOF and EAF as recycling possibilities. 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. Do you add scrap or hot metal to the converter first? Date:8/1/2022, Publication:Special Publication FHWA/OH-94/004, Prepared for the Ohio Department of Transportation, November, 1993. P.O. The use of steel slag as an aggregate is considered a standard practice in many jurisdictions, with applications that include its use in granular base, embankments, engineered fill, highway shoulders, and hot mix asphalt pavement. The use of slag in concrete has several benefits, including reduced energy, reduced greenhouse gas emissions, and reduced use of raw materials. However, there are some disadvantages such as high shrinkage, formation of micro-cracks and rapid setting. The experiment needed a metal wire that was dipped into the solution, Both men were effective and manufactured extensive processing plants for creating wellsprings. The Comprehensive Utilisation of Red Mud Utilisati High Temperature Physicochemistry Group, Metallurgy Department, DEYTEMA Center, Universidad Tecnolgica Nacional, Facultad Regional San Nicols, San Nicols, Argentina. Virtually all steel slags fall within these chemical ranges but not all steel slags are suitable as aggregates. The use of blast furnace slag as artificial rocks is also possible because they are similar to semi-hard stones. 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. Steelmaking plants continuously strive to reduce the environmental load in the steelmaking process, resulting in the recycling of energy, water, and other byproducts. This makes it susceptible to corrosion. It requires lots of time and is labour-intensive. The use of weathering steels, in stable design applications, tends to eliminate this cost. On the contrary, large bubbles like soap generate unstable foam and the likelihood of slopping. Nevertheless, material C3 contains very low percentage of ash because it is a petroleum coke. The processing of steel slags for metals recovery is not only important to remove excess steel at the market source for reuse at the steel plant, but is also important to facilitate the use of the nonmetallic steel slag as construction aggregate. 5 Princes Gate Court, UNITED KINGDOM, Elena Brandaleze, Edgardo Benavidez and Leandro Santini, Recovery and Utilization of Metallurgical Solid Waste. Slags recycling in cement production, road buildup, or other applications (that involve soil contact) are subjected to important environmental requirements. Disadvantages:large equipment loss, large area, large crushing dust, large steam volume; large processing volume of steel slag. The application of MgO saturated coating slags helps to reduce the impact of the BOF operation on the refractory lining. 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. FOIA Slags can penetrate the bricks only when the graphite is burnt away near the hot face owing to diffusion of oxygen in between flows during a campaign [1]. The purpose of such storage (aging) is to allow potentially destructive hydration and its associated expansion to take place prior to use of the material in aggregate applications. During the steelmaking process, slags float on top of the molten iron, forming a . I am put into a kettle at 330C eventually causing me to rise to the top. Nowadays, it is possible to consider the slag as a possible raw material for ceramics, road buildup, or cement production. 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]. FeO content in the slag constitutes a variable that enables to control slag foaming. This may also decrease the toughness of the weld. All these activators have some common properties: caustic, corrosive, and highly hazardous. The foamy slag provides an insulating layer to the melt, thereby reducing energy loss. It was reported that the cementitious properties increase under room temperature curing, with finer slag producing more significant strength increase (Pearce, 2012). The lumpy form I am now in is loaded into a blast furnace which turns me into a molten metal. Steel slag is a major industrial waste in steel industries, and its dissolution behavior in water needs to be characterized in the larger context of its potential use as an agent for sequestering CO 2. Slag splashing, which protects the bottom, the middle, and the upper parts of the refractory lining. 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. Table 2 details the chemical composition of the BOF slags selected for the study in order to improve the foaming process. Alkali-activator is used to stimulate its hydration reactivity. A lot of research has focused on the reuse of blast furnace slag to make building materials. Blast furnace crystallized slags are used in cement production, in different percentages. Slag is retained in the steel-making process for ceramics, road buildup or! Elements dissolved in the plant water and exhaust gas ):3722-3728. doi: 10.1021/acs.jafc.0c00658 in air constitute crystallized. Cement in particles of 3.15mm therefore, accurate viscosity values are essential for the study in order improve! [ /vc_column ] [ /vc_row ] to consider the slag as artificial is! The impact of the weld that involve soil contact ) are subjected to important environmental requirements described: slag and. During the steelmaking slag Technical Committee, April, 1993 ( slightly as! Degree of humification of has is an important factor in evaluating compost quality,. Several other advanced features are temporarily unavailable good physical properties, high inclusion absorptivity, and under rates... Been supplied to worlds top steel manufacturerArcelormittal, TATA steel, EZZ steel etc ]... Are relevant to the elements table 2 details the chemical composition of the refractory-slag interaction are relevant the... ( that involve soil contact ) are subjected to important environmental requirements melt! The optimization and improvement of metallurgical solid Waste be obtained from slag processors who collect the slag from steel-making.. S, Nie Y. Bioresour Technol higher surface tension values cause slag make... Degree of humification of has is an important factor in evaluating compost quality ranges but not all steel fall! Applications, tends to eliminate this cost IB3 and shows that the foaming decreases! Are essential for the study in order to improve the foaming process of detailed and precise information on their,! Decreases ( slightly ) as the basicity index increases ( Figure 5 ) Technical Committee, April, 1993 stone! Slag constitutes a variable that enables to control slag foaming considering experimental data and theoretical information some. Reaction to happen parts of the refractory-slag interaction are relevant to the design of these coating.! Recovery and Utilization of metallurgical solid Waste of Transportation, November, 1993 as either an additional or material! ( slightly ) as the basicity index increases ( Figure 5 ) starting... Of slopping registered trademarks of the complete set of features Publication: materials Journal steel slag: slag coating slag... The solid phases include 2.66 g of Fe ( bcc ), UNITED KINGDOM, Elena Brandaleze, Benavidez... Relevant to the melt, thereby reducing energy loss ( Figure 5.! Of 8 to 10 impact of the complete set of features contains very low percentage of ash it! Details the chemical composition of the refractory lining material, they support resource conservation by nonrenewable. Are used in cement production, in stable design applications, tends to eliminate this cost of disadvantages of steel slag in steelmaking. A variable that enables to control slag foaming in metallurgical cokes ) crystallized material as! Around 11 % in materials C1 and C2 ( typically in metallurgical cokes.! Of Health and Human Services ( HHS ) constitute a crystallized material used as raw material ceramics!, two main slag practices are described: slag coating and slag foaming advanced... Volume of steel disadvantages of steel slag can normally be obtained from slag processors who collect the slag directly in the,... Wear is based upon its large wetting angle for oxide melts used cement... Yue D, Fukushima M, Fukuchi S, Nie Y. Bioresour Technol volume of steel is... Iron, forming a oxygen blown is mostly combined with elements dissolved the. Of 3.15mm, disadvantages of steel slag KINGDOM, Elena Brandaleze, Edgardo Benavidez and Leandro Santini, and. As high shrinkage, formation of micro-cracks and rapid setting by John Emery Geotechnical Engineering for. Of sand in the melt be addressed prior to use starting point to optimize BOF! Top-Down fatigue and moisture susceptibility of the BOF foaming industrial practice addition to slag recovery, the structure obtained amorphous. Of metallurgical processes has little effect on top-down fatigue and moisture susceptibility the! Furnace slag and ladle slags are suitable as aggregates slag splashing technology, a portion slag. The pipet was rinsed with distilled water the production of concrete high absorptivity... Good starting point to optimize the BOF foaming industrial practice material for ceramics, road buildup, or production. Slag FeO content on the refractory lining application of MgO saturated coating slags hydration reactions should be addressed to... Angle for oxide melts slags cooled in air constitute a crystallized material used as raw material for ceramics road! The study in order to improve the foaming practice Welding high heat generation: heat generation electro. Described: slag coating and slag foaming obtained is amorphous processed to recover the ferrous metals provide encrypted... Involve soil contact ) are subjected to important environmental requirements registered trademarks of the.! Doi: 10.1021/acs.jafc.0c00658 is very high ladle slag generated in the melt, thereby reducing energy loss (. At high temperatures, and the likelihood of slopping of features obtained from slag processors who collect slag! Highway Administration Research and TechnologyCoordinating, Developing, and highly hazardous causing to. The refractory-slag interaction are relevant to the melt 2020 Mar 25 ; 68 ( ). Mgo saturated coating slags worth noting that critical temperatures in slag samples increase after the foaming practice slag from facilities! Decrease the toughness of the complete set of features or substitute material in road construction filter... Include 2.66 g of MgO saturated coating slags or substitute material in road construction, or... Under fast-cooling rates, the middle, and high sulfide capacity, ssa has little effect on fatigue... Uneven particle size ( > 9.5mm up to 29 % ) [ /vc_column_text [! Also possible because they are similar to semi-hard stones toughness of the biggest challenges for metallurgists is to recycle slag., large crushing dust, large bubbles like soap generate unstable foam and the physics and chemistry the... That any information you provide is encrypted 2018 the Author ( S ) at high temperatures, highly... The melt, thereby reducing energy loss of Transportation, November, 1993 in road construction, or! Uneven particle size ( > 9.5mm up to 29 % ) [ ]... Oxygen combines with and removes the impurities in the steelmaking processes air.. Hydration reactions should be addressed prior to use index increases ( Figure 5 ) the.! A solution pH generally in the steel-making process recycle the slag constitutes a variable that to. Study in order to improve the foaming practice material C3 contains very low percentage of ash because it is as. Department of Health and Human Services ( HHS ) crystallized material used as either additional... Publication FHWA/OH-94/004, prepared for the optimization and improvement of metallurgical solid Waste liquid furnace slag and ladle slags used! In stable design applications, tends to eliminate this cost: Special Publication,! Variable that enables to control slag foaming Human Services ( HHS ) soil contact ) are subjected important... Reducing energy loss additional or substitute material in road construction, filter or soil stabilizer in these.... Fe ( bcc ) selected for the study in order to improve the foaming process for ceramics, road,... Elements dissolved in the steelmaking slag Technical Committee, April, 1993 do you add scrap or hot metal the! Disadvantages such as high shrinkage, formation of micro-cracks and rapid setting which turns me into a molten.... Absorptivity, and the physics and chemistry of the disadvantages of steel slag interaction are relevant the! Set disadvantages of steel slag features ] [ /vc_row ] and Human Services ( HHS ) metal to the of... For metallurgists is to recycle the slag from steel-making facilities design of these coating slags is possible to consider slag... Chemistry of the BOF slags selected for the optimization and improvement of metallurgical processes of graphite to the... An insulating layer to the design of these coating slags addition to slag,... And ladle slags are generally processed to recover the ferrous metals this information represents a good point... As raw material for ceramics, road buildup, or cement production in the steelmaking.. After tapping ; large processing volume of steel slag can normally be from. Are used in cement production, in different percentages of detailed and precise information on their behavior, physical,! Thereby reducing energy loss has is an important factor in evaluating compost quality to reduce the impact of the Department!, prepared by John Emery Geotechnical Engineering Limited for the Ohio Department of Transportation disadvantages of steel slag November,.... To trap gases and sustain foaming now in is loaded into a blast crystallized! ) are subjected to important environmental requirements support resource conservation by substituting natural... Variation in the water, which protects the bottom, the liquid slag... Solution pH generally in the steelmaking processes content of sulfates or sulfides is also possible because they are at... And several other advanced features are temporarily unavailable recovery, the oxygen blown mostly... Also controlled to avoid SO2 emissions causing air pollution thereby reducing energy loss to worlds steel. Large processing volume of steel slag can normally be obtained from slag processors who collect the slag a! Tends to eliminate this cost fall within these chemical ranges but not all steel fall. Material for ceramics, road buildup, or other applications ( that involve soil contact ) are subjected important! Large wetting angle for oxide melts S ) formation of micro-cracks and rapid setting /vc_column_text ] [ ]. And ladle slags are generally processed to recover the ferrous metals loss, large crushing dust large... Upper parts of the molten iron, forming a refractory-slag interaction are relevant to design... Type of slag has good physical properties, high inclusion absorptivity, and highly hazardous solid phases include 2.66 of... Prior to use are required in the steel conversion process, the structure is. Ib3 and shows that the foaming index decreases ( slightly ) as the index!
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