The material must not present reactions or composition changes greater than 1% in a period of 100years. The Urbain model [5] classified the oxides into three groups: Modifiers: XM=XCaO+XMgO+XNa2O+XK2O+3XCaF2+XFeO+XMnO+2XTiO2+2XZrO2. The reaction between FeO present in the slag and carbon is strongly endothermic. 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. UNITED KINGDOM, Elena Brandaleze, Edgardo Benavidez and Leandro Santini, Recovery and Utilization of Metallurgical Solid Waste. Along the steel conversion process, the oxygen blown is mostly combined with elements dissolved in the melt. The slag is categorized as an electric arc furnace slag if an electric furnace arc is used instead (Dawood and Ramli, 2011). To avoid volumetric instability of the cement material, MgO content is determined. Next, The flame test required the solution made during the solubility test. Various types of slag are produced: To summarize, slag recycling requires the availability of detailed and precise information on their behavior, physical properties, and structural characteristics. The tufa precipitates associated with steel slags are attributed to the leachate combining with atmospheric carbon dioxide. Efforts are on for economic use of all types of steel plant wastes, such as slag, dust, and flue gases [1]. government site. 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. Because the slag used in the present study contained several-tens ng g-1 to several g g-1 of toxic elements (B, Cu, Cr, and Zn), leaching tests for these elements from the prepared composts were carried out. The steel slags produced at this stage of steel making are generally referred to as raker and ladle slags. In this chapter, two main slag practices are described: slag coating and slag foaming considering experimental data and theoretical information. Consequently, an alternative is the application of theoretical models to estimate the viscosity and surface tension, as a function of temperature, on the basis of slag chemical compositions [13, 14]. A lance is lowered into the converter and high-pressure oxygen is injected. The slag processor must also be aware of the general aggregate requirements of the end user. Collins, R. J. and S. K. Ciesielski. Basicity index, viscosity, surface tension and foaming index values. Average critical temperature values (melting behavior) of the slags before and after foaming practice. Maintenance cost of a steel structure is very high. Oxidation and reduction reactions continuously change slag composition, and chemical reactions produce CO gas that also changes significantly with time [19]. Invalid Email Address. To reduce the amount of carbon in the steel, greater oxygen levels are required in the steel-making process. Careers. The results show that the fluidity of the paste containing . In addition, the decrease of refractory consumption is a crucial topic of consideration for all steel plants. Tufalike precipitates, resulting from the exposure of steel slag aggregates to both water and the atmosphere, have been reported in the literature. Also, a good adherence behavior on MgO-C samples was obtained by means of dipping tests. official website and that any information you provide is encrypted Disadvantages Of Electroslag Welding High heat generation: Heat generation in electro slag welding is very high. After that, the Erlenmeyer flask was filled with 100 mL of distilled water. The type of carbonaceous material added affects the foaming practice. Chemical and mineralogical composition of Portland cement. The results are in agreement with Pretorious [18], who suggests low or medium values of surface tension in the slag for good foaming behavior. Tufa is a white, powdery precipitate that consists primarily of calcium carbonate (CaCO3). 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 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. 8600 Rockville Pike - 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. Nowadays, it is possible to consider the slag as a possible raw material for ceramics, road buildup, or cement production. On this base, material C3 is the most favorable for the slag foaming practice due to the size and distribution of the pores. 2009 Apr 30;163(2-3):1289-97. doi: 10.1016/j.jhazmat.2008.07.136. Environ Int. It is worth noting that critical temperatures in slag samples increase after the foaming practice. 2 . Slag with low FeO and high MgO is desirable. With a decade of international business experience and maintaining universal trade relation with three continents, our group gathered under the name of Arij Global Trading to supply our esteemed customers Grade-A quality of different mineral products. London, SW7 2QJ, Of more importance is the mineralogical form of the slag, which is highly dependent on the rate of slag cooling in the steel-making process. In this study, Eq. Table 18-1. Brief introduction to this section that descibes Open Access especially from an IntechOpen perspective, Want to get in touch? HHS Vulnerability Disclosure, Help The most commonly used alkaline activators are sodium hydroxide, potassium hydroxide, sodium water glass, and potassium water glass. Foam with small bubbles is dense avoiding the risk of slopping and promoting good slag adherence to the refractory surface. Increasing the steel slag content improved the drying shrinkage resistance but was not conducive to the temperature shrinkage resistance. Metallurgical cokes affect foaming because of the ash content. Typical steel slag chemical composition.(4). BSSF Advantages. 48331-3439 USA This may also decrease the toughness of the weld. Free calcium and magnesium oxides are not completely consumed in the steel slag, and there is general agreement in the technical literature that the hydration of unslaked lime and magnesia in contact with moisture is largely responsible for the expansive nature of most steel slags. There is a wide variation in the amount of time required for adequate exposure to the elements. How? These steel refining processes give rise to another type of slag, called "Ladle Furnace Slag" (or "LFS"), in a range of approximately 30-80 kg per tonne of refined steel. The Urbain model [5] and Zaharia, Sahajwalla and Khanna model [17] were used to determine viscosity and surface tension, respectively. It contains a mixture of sand, cement, crushed rock, pebbles, and water. Experimental measurements have difficulties associated with the high temperature needed (or the high melting point of some slags). Books > Licensee IntechOpen. Steel slag is a byproduct of iron and steel production by the metallurgical industries. Disadvantages of Steel Construction 1. Noureldin, A. S., and R. S. McDaniel. Federal Highway Administration Do you add scrap or hot metal to the converter first? All the slags were classified into three ternary basicity index (IB3) ranges: 1.9>IB3>2.29, 2.29>IB3>2.74, and 2.74>IB3>3 and then placed in ISD (%MgO-%FeO). Dirceu Maximino Fernandes. 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. To avoid volumetric instability of the cement material, MgO content is determined. High-grade steels have high carbon content. wood which could have been used but it is longer lasting and is one of the strongest construction materials. They have high bulk specific gravity and moderate water absorption (less than 3 percent). Typical physical properties of steel slag. In addition, the high-temperature molten slag is subjected to stress concentration and rupture due to the rapid cooling and shrinking of the water. These different slags must be segregated from furnace slag to avoid contamination of the slag aggregate produced. To date our community has made over 100 million downloads. 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. Furthermore, the 250-mL beaker was weighed, and its mass was recorded. Application of blast furnace slag in civil engineering. Different types of porous carbonaceous particles identified. All these activators have some common properties: caustic, corrosive, and highly hazardous. This requires extra cost and special care. Elemental and spectroscopic characterization of humic-acid-like compounds during composting of olive mill by-products. All contents of this website are copyrighted by LMM GROUP and may not be reproduced in any form without permission. When sodium bicarbonate dissolves in water it splits apart into sodium and bicarbonate ions. Up to 18 months may be needed to hydrate the expansive oxides. If the FeO increases in the slag, the viscosity decreases and causes foam bubbles to drain more rapidly, resulting in foam decay. For this reason, it is relevant to characterize and increase the knowledge on the effects of the carbonaceous materials applied in the foaming practice. Phone: +971.4.516.3208 & 3209, ACI Resource Center It is important to highlight that the foaming index decreases as the size of carbonaceous particle increases. 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. An increase in silica concentration promotes lower surface tension of slag and leads to smaller CO gas bubbles and their easier escape from the slag. However, there are some disadvantages such as high shrinkage, formation of micro-cracks and rapid setting. Page Owner: Office of Research, Development, and Technology, Office of Safety, RDT, TRT Terms: Waste products as road materials--Handbooks, manuals, etc, Pavements, Asphalt concrete--Design and construction--Handbooks, manuals, etc, Pavements, Concrete--Design and construction--Handbooks, manuals, etc, Pavements--Additives--Handbooks, manuals, etc, Fills (Earthwork)--Design and construction--Handbooks, manuals, etc, Roads--Base courses--Design and construction--Handbooks, manuals, etc, Wastes, Environmental impacts, Recycling, Coordinating, Developing, and Delivering Highway Transportation Innovations, Sodium Sulfate Soundness Loss (ASTM C88), %, Hardness (measured by Moh's scale of mineral hardness)*, California Bearing Ratio (CBR), % top size 19 mm (3/4 inch)**. It requires lots of time and is labour-intensive. Roll rings for high speed rolling of ribbed steel bars, Three dimensional carbide rolls for cold rolling. This is another alternative to avoid the risk of slopping. The growth of the arc furnace-based steel industry has been encouraged by modern arc furnaces of large capacity and ultra-high power, electrical efficiency improvement, and metallurgical efficiency through oxygen lancing or the co-jet technology. Also, EAF slags are commonly used to avoid refractory wear and decrease energy consumption. FOIA Figure 6 shows the average critical temperatures: softening temperature (Ts), hemisphere temperature (Th), and fluidity temperature (Tf) of the samples. 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). Slag is of great relevance in metallurgy processes for steel quality; however, during long years, it was considered an important waste together with the accumulation of refractories after use. 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 growing trend in the construction industry is to develop sustainable buildings. Process characteristics and process: high-temperature liquid steel slag is quenched and solidified and broken in a high-speed rotating drum with water as the cooling medium. If a converter is used in the steel-making process, with water being sprayed on the slag for cooling purpose, the slag generated is termed a converter slag. At the end of the refining operation, the liquid steel is tapped (poured) into a ladle while the steel slag is retained in the vessel and subsequently tapped into a separate slag pot. The use of blast furnace slag as artificial rocks is also possible because they are similar to semi-hard stones. The content of sulfates or sulfides is also controlled to avoid SO2 emissions causing air pollution. 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. Due to this property, this type of cement can be used where the problem of thermal cracking is foreseen.