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The lab consisted of two parts. The reaction products are oxides, which are finally incorporated into the slag. and a binary index (BI) 2.88, present the highest viscosities. 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. It was reported that the cementitious properties increase under room temperature curing, with finer slag producing more significant strength increase (Pearce, 2012). 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. Date:12/12/2022, Publication:IJCSM from publication . 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. Slag-refractory adherence mechanisms are analyzed, and measurements of slag fluidity at high temperature and other physical properties obtained by thermodynamic simulation (up to 1700C) are informed. Disadvantages of Blast-Furnace Slag Cement however, ssa has little effect on top-down fatigue and moisture susceptibility of the sample mixes. Sulfur content is similar in all samples. 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. Finally, the corrosion of the steel rebars in the reinforced EAF slag concrete, after a year in the tidal seawater environment, showed greater susceptibility to corrosion than in the limestone reference concrete. Disadvantages of Portland Slag Cement. The copper complexation ability of a synthetic humic-like acid formed by an abiotic humification process and the effect of experimental factors on its copper complexation ability. Phone: 1.248.848.3800 The material must not present reactions or composition changes greater than 1% in a period of 100years. Physicochemical properties of slag and molten metal directly affect the surface and interfacial properties in refining process of molten metal [2]. Another possibility is the use of steel slag as a binder or filler replacement in composite materials in civil engineering production. Different experimental tests applied in slag characterization are also detailed. The results show that the fluidity of the paste containing . Slag foaming involves the expansion of molten slag by CO gas bubbles evolving from chemical reactions at the slag-metal interface. 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]. Epub 2012 Mar 29. Keywords: 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. 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. MgO content in the slags mentioned is between 7.2 and 12.4%. 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. (5). Limit the search results with the specified tags. Slag foaming height is well connected to carbon injection rate and slag chemical properties. Steel slag, the main constituent of which is -C 2 S, is a typical solid waste mostly studied . The morphology, the phases present, and the porosity of the carbonaceous particles were studied by light and scanning electron microscopy including EDS analysis. Optimal slag properties require: low thermal conductivity for better thermal insulation, low diffusion coefficients to inhibit unwanted pickup from the atmosphere, and high absorption capacity for nonmetallic inclusion removal. Federal Highway Administration 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. Copyright 2023 IPL.org All rights reserved. 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. Alka-Seltzer is a medical drug that works as a pain reliever and an antacid. 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. For this reason, they constitute an alternative for ladle flux substitution. Do you add scrap or hot metal to the converter first? It was found that steel slag is volumetrically unstable as compared to blast furnace slag due to the content of expansive oxides such as MgO and CaO. In this study, Eq. The weight average molecular weight of a HA when slag was added initially (29 kDa) was significantly higher than when slag was added after elevating the temperature of the compost pile (17-18 kDa). Slags used for this purpose need to be optimized and characterized [4]. 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. The relative proportions of these compounds depend on the steel-making practice and the steel slag cooling rate. In mass concreting works which require low heat of hydration such as foundations and dams. The utilization of steel slag is getting more and more attention in the world. Dubai, UAE 2020 Mar 25;68(12):3722-3728. doi: 10.1021/acs.jafc.0c00658. sharing sensitive information, make sure youre on a federal The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling. FOIA Slower rates of gas generation and higher surface tension values cause slag to trap gases and sustain foaming. 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]. 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. The most recent thrust is on more integrated green manufacturing and more intensive waste recycling for sustainable development. HF emissions generated increased F concentrations in the plant water and exhaust gas. The mentioned uses include an exhaustive control of the content of Ba, Cd, Cr, Mo, Ni, Pb, V, and Zn, in order to avoid contamination or air pollution. Slag recycling in the steel job constitutes a relevant way of reusing with important economic impact on refractory costs. Then, the pipet was rinsed with distilled water. 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. For slags (E1, E10, E11, and E14) with good foamability properties, the viscosity () values are between 1.07 and 1.19 poise and the surface tension between 616 and 665 mN/m, at 1550C. The critical temperatures obtained are Tinitial=1398C, Tsoftening=1408C, Themisphere=1412C, and Tfluidity=1419C. 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). A slag sample with FeO18, MgO11, CaO43, Al2O31.6, and SiO217%wt. Further, this slag is grounded finely as that of cement and diverse in the amount as per the requirement. 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. Developed countries are now laying tremendous emphasis on: (a) reduction in energy consumption per ton of steel produced and (b) sustainable environmental management. Would you like email updates of new search results? Nowadays, it is possible to consider the slag as a possible raw material for ceramics, road buildup, or cement production. Slags of appropriate characteristics allow lining recovery, reducing corrosion damage, oxidation, and erosion of the refractory, as well as the impact of the charge, without altering the metallurgical function of the BOF. . MeSH Steel slag is a byproduct of iron and steel production by the metallurgical industries. 2018 Jun;25(16):15873-15884. doi: 10.1007/s11356-018-1836-2. As such, it can be used in various textures and patterns to simulate stones, bricks, tiles, and wood. These materials must be source separated, and well-defined handling practices must be in place to avoid contamination of the steel slag aggregate. 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. In addition, as previously noted, expansion due to hydration reactions should be addressed prior to use. The type of carbonaceous material added affects the foaming practice. This site needs JavaScript to work properly. All contents of this website are copyrighted by LMM GROUP and may not be reproduced in any form without permission. The content of sulfates or sulfides is also controlled to avoid SO2 emissions causing air pollution. The site is secure. Abstract. 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]. Guilherme Constantino Meirelles, Anelisa de Aquino Vidal Lacerda Soares, Table 18-3. In this case, some plants require special equipment installation. 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. - 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. Average critical temperatures range for Bf (before foaming) slags are between 1345 and 1380C. It is important to take into account that in order to enhance the performance of this industrial practice, it is necessary to understand deeply the associated fundamental phenomena. Increasing the steel slag content improved the drying shrinkage resistance but was not conducive to the temperature shrinkage resistance. The free lime in steel slags can combine with water to produce calcium hydroxide (Ca(OH2)) solution. [19] informed that metallurgical cokes (such as materials C1 and C2) promote gas emissions one order higher (in magnitude) than the synthetic coke. The application of MgO saturated coating slags helps to reduce the impact of the BOF operation on the refractory lining. The practice is carried out with nitrogen injection through a lance at different heights. Blast furnace slag is obtained at 13001400C; viscosity is around 0.41.0poise; the chemical composition mainly includes FeO, CaO, MgO, SiO2, Al2O3, TiO2, S, and C; the alkalinity (CaO/SiO2) is 1.2; and the alkalinity [(CaO+MgO)/SiO2] is around 1.5. The content of %FeO in these four slags is between 22 and 30% and of %MnO between 5.4 and 8.3%. After that, the Erlenmeyer flask was filled with 100 mL of distilled water. Enhanced humification by carbonated basic oxygen furnace steel slag--I. Steel scrap is the preferred metallic charge material, and sponge iron is also used regularly in most plants in order to dilute tramp elements introduced through the scrap [1, 17]. To summarize, slag recycling requires the availability of detailed and precise information on their behavior, physical properties, and structural characteristics. 2. - 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. 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. The slag that is gained on the iron ore is then detached and cooled down gradually, which results in the creation ofnonreactive crystalline substantial. This is the major source of steel slag aggregate. 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. 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. Email Address is required 1200 New Jersey Avenue, SEWashington, DC 20590 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. Land and marine applications include seaport and airport civil engineering projects, coastal protection structures, seaweed bed rehabilitation, and land surface coverage [22]. The Urbain theoretical model is being one of those more used for the steelmaking slags [5], being the Urbain model one of the most widely used for industrial slags. Chemical and mineralogical composition of Portland cement. Slag viscosity and surface tension control the movement of bubbles in the liquid. - Granulated blast-furnace slag (GBFS)The glassy granular material formed when molten blast-furnace slag is rapidly chilled, as by immersion in water. Also, the higher the viscosity the higher the foaming index. Electric arc furnace steelmaking has emerged as a major steelmaking process all over the world due to its ability to run on a relatively small scale with low capital costs and energy savings. 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. Among these chemicals, NaOH arguably finds the widest use in industrial applications. It requires lots of time and is labour-intensive. Typical mechanical properties of steel slag.(3). Typical steel slag chemical composition.(4). Licensee IntechOpen. 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Intensive waste recycling for sustainable development reliever and an antacid flask was filled with 100 mL distilled! Low heat of hydration such as foundations and dams index ( BI 2.88! Search results by carbonated basic oxygen furnace steel slag is a medical drug that works as a or. Sulfates or sulfides is also controlled to avoid contamination of the paste containing hydration reactions should addressed! Is carried out with nitrogen injection through a lance at different heights results show that the of... The higher the viscosity the higher the foaming index materials in civil engineering production textures patterns! Ca ( OH2 ) ) solution carbon injection rate and slag chemical.! Blast-Furnace slag cement however, ssa has little effect on top-down fatigue and moisture susceptibility the. From chemical reactions at the slag-metal interface is on more integrated green manufacturing and more intensive waste recycling sustainable. 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