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Backscattered electron micrograph of a carbon-based ramming material with (a) carbon as aggregate and a matrix consisting of (b) Al 2 SiO 5 , (c) Fe 3 Si, and (d) FeS
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Although carbon is typically considered a reductant in pyrometallurgical smelting processes, it can also be applied as refractory material in the furnace containment system. The paper introduces researchers, new to the field, to refractory materials and the role they play in the design of the furnace containment system. It also provides an overview...
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Citations
... Other important carbon-containing refractories in steelmaking are alumina-carbon (Al 2 O 3 -C), alumina-silicon carbide-carbon, (Al 2 O 3 -SiC-C), zirconia-carbon, and magnesia-calcia-carbon [40]. ...
The chemical and thermophysical properties of carbon make it essentially irreplaceable for non-reductant uses in many high-temperature metallurgical processes. At present, biocarbon substitutes are not technically feasible for large-scale application in electrode and refractory materials that are such vital consumables in the steel, aluminum, and non-ferrous metal industries. Carbon electrodes of all types, including Söderberg, prebaked, and anodes/cathodes for Al, graphite electrodes, as well as carbon lining pastes are all similar in that they are comprised of a granular carbon aggregate bonded in a carbon-based binder matrix. Similarly, refractories such as MgO–C utilize both natural (mined) graphite and carbon-based binders. Replacement of fossil carbon materials with biocarbon substitutes has the potential to dramatically reduce the carbon footprints of these products. However, there are considerable materials engineering challenges that must be surmounted. The technological demands for these applications and potential for substitution with biogenic carbon are explored.
Graphical Abstract
... The acidic lining materials have the major constituents from the quartz, which is obtained from quartz rock, that is, igneous rocks known as ganister or quartzite which contains 93 to 98% silica (SiO2) (Osoba and Afolabi, 2012) The development of new compositions of composite materials with the goal of increasing the refractoriness and slag resistance of fireclay refractories with special attention paid to the selection of certain binders and special additives is now imperative (Mkrtchyan and Aripova 2022). Currently, compositions of new generation refractory materials are obtained on the basis of fine and highly purified oxides (Roy et al., 2020) nano-and other advanced materials (Mendonca et al., 2020).The main factor that controls the production of refractories and their characteristics is the application they are used for, operating conditions in terms of operating temperature, ambient air (gases, vapors, and liquids), the mechanical load, and the extent of the change in temperature (Boch and Niepce, 2007) The refractory lining often consists of layers of different materials based on their thermal conductivity, gas permeability, temperatures the material can withstand, resistance to chemical wear by process material (in insulating designs), and cost (Thethwayo and Steenkamp, 2020). It is necessary to produce range of refractory materials with different properties to meet range of processing conditions. ...
... Temperature of the outer metal, ( ) was calculated from Fourier's law as 14.24℃ using equation (11) Where: ...
The search for improved refractory materials to enhance the performance of the furnace is still a basic factor in the heart of researchers. Production of high temperature furnace with good performance for pilot scale has been limited due to the grade of refractory available to the manufacturers. The research is aimed at developing an electric furnace using bentonite and kaolin with sodium silicate as refractory material. The developed furnace was designed using solid works software. The materials used in the fabrication of the designed furnace were mild steel of 2 mm thickness, angle bar of 6 mm thick, hinges, bolts and nuts, fibre glass and composite material (Bentonite, Sodium silicate and Kaolin). The materials considered for electrical unit were heating element, control switch, temperature controller and thermocouple capable of measuring to maximum temperature of 1300℃. The furnace was fabricated with inner and outer dimensions of 276 × 276 × 276 mm and 346 × 346 × 346 mm, respectively. The ratio of the composite material of Bentonite, Sodium silicate and Kaolin used was calculated using thermal conductivity analysis. The performance of the developed furnace was evaluated using 5 kg of brass and five samples of aluminum of 1, 2, 3, 4, and 5 kg to determine the throughput and its efficiency. The throughput of the developed furnace gave 21.02 3 with Bentonite, Sodium silicate and Kaolin ratio of 1:1:40. The efficiency of the developed furnace in terms of maximum temperature and heating rate are 96.2% and 73.1% respectively. The developed furnace is therefore suitable for use at higher temperatures than the existing furnace which is suitable for graphitization of carbonaceous materials. Hence, this furnace is recommended for use in research laboratories and small-scale foundry industries where the heat needed is within the attained temperature.
... The acidic lining materials have the major constituents from the quartz, which is obtained from quartz rock, that is, igneous rocks known as ganister or quartzite which contains 93 to 98% silica (SiO2) (Osoba and Afolabi, 2012) The development of new compositions of composite materials with the goal of increasing the refractoriness and slag resistance of fireclay refractories with special attention paid to the selection of certain binders and special additives is now imperative (Mkrtchyan and Aripova 2022). Currently, compositions of new generation refractory materials are obtained on the basis of fine and highly purified oxides (Roy et al., 2020) nano-and other advanced materials (Mendonca et al., 2020).The main factor that controls the production of refractories and their characteristics is the application they are used for, operating conditions in terms of operating temperature, ambient air (gases, vapors, and liquids), the mechanical load, and the extent of the change in temperature (Boch and Niepce, 2007) The refractory lining often consists of layers of different materials based on their thermal conductivity, gas permeability, temperatures the material can withstand, resistance to chemical wear by process material (in insulating designs), and cost (Thethwayo and Steenkamp, 2020). It is necessary to produce range of refractory materials with different properties to meet range of processing conditions. ...
... Temperature of the outer metal, ( ) was calculated from Fourier's law as 14.24℃ using equation (11) Where: ...
... The carbon oxidation by external agents (usually atmospheric oxygen) is called "direct oxidation" (1)(2), as opposed to carbothermal reduction, or "indirect oxidation" (3), which occurs in MgO -C materials via a solid-state reaction with other refractory components [6,7,11,12,[22][23][24]. ...
... Refractory raw materials (RRMs) industrial applications have rapidly grown over time, which is related to the growing demands for durable materials for high-temperature applications [1][2][3]. In the light of this development, numerous academics with a deep interest in the deployment of RRMs that are both high-performing and affordable have invested into developing a creative framework that would make RRMs available to users [1]. ...
... Graphite is a critical and strategic nonmetal mineral with significant physical and chemical properties, such as thermal stability, electrical conductivity, high thermal conductivity, chemical stability, and neutron radiation resistance (Feng et al. 2022;Fuks et al. 2020;Li, Dunzik-Gouga, and Wang 2017;Luo et al. 2022;Thethwayo and Steenkamp 2020;. As a nonrenewable strategic material, graphite is widely used for developing energy storage in various modern equipment Lopez, Dumas, and Del Barrio 2008;Shi, Sun, and Yang 2015;. ...
... Хоча вуглець зазвичай вважається відновником у процесах пірометалургічної плавки, він також може застосовуватися як вогнетривкий матеріал у системі захисної оболонки печі. Робота [11] присвячена вогнетривким матеріалам і їхній ролі в конструкції системи захисної оболонки печі. Також розглянуто вуглецевмісні вогнетривкі матеріали та їхнє відповідне застосування, включаючи вогнетривку футеровку системи захисної оболонки печі. ...
For the sintering of ceramic products, high-temperature electric furnaces are used, which work both in a protective environment and in air. In some technological processes, for example, for the production of ceramic carriers for afterburning car exhaust gases based on SiC and Al2O3, only air furnaces are used. Silicon carbide (SiC – silicate) heaters and molybdenum disilicide (MoSi2) are used as resistive heaters in such furnaces. Due to the relatively small resource of their work, it is energetically beneficial to use the residual heat when cooling the furnace. At the same time, there is a significant saving of electricity for heating. The residual heat is largely determined by the thermal insulation of the lining and the correct distribution of the heat balance of the furnace. The speed of temperature rise affects the thermal balance of the furnace in general, and even the speed of cooling of the furnace, which creates additional energy saving opportunities, which reduces the cost of ceramic products. The article examines the technological processes of sintering ceramic products in high-temperature electric furnaces. A calculation algorithm was selected for performing comparative assessments of energy intensity and possible implementation, which can be used in the analysis of specific situations regarding different types of ceramic parts, the sintering temperature of which exceeds 1400 °C. A factography of the dependences of the power distributed over the floor area on the floor area and the specific power on the internal volume for a range of models of Mobilotherm furnaces designed for firing ceramics with the maximum operating temperature was obtained. It was found that the additional reduction in energy consumption during sintering in electric furnaces for the production of one product and the increase in production productivity are associated with the balancing of the thermal balance of the furnace, the reduction of heat losses and the use of furnace designs in which residual heat can be used. The conducted studies make it possible to assume that the developed methods of calculating the heat balance allow choosing the most optimal furnace heating modes, recommending the most heat-resistant and heat-insulating lining materials.
... The attack of gaseous oxygen on oxide-C bricks, known as direct oxidation, has been extensively studied for MgO-C refractories by different authors [1,[8][9][10][11][12][13][14][15][16][17][18][19][20]. The oxidation of carbon (reactions (1) and (2), [8,14,16,19,21]), which is mainly found in these materials as graphite and residual carbon, has been established as the main process (among others reactions such as those involving antioxidants or impurities) responsible for the material degradation, since no protective layer is formed (active oxidation [22]). ...
... The generation of carbon products instead of CO x , results in no CO 2 emissions. More importantly, as high-value products, carbon products have critical applications in many industries, such as metallurgy (Zhang et al., 2016), batteries (Zhang et al., 2021), catalysis (Yoon et al., 2005), adsorbents (Wong et al., 2018), refractories (Thethwayo and Steenkamp, 2020), and so on. ...
... However, further improving the quality of refractories faces many difficulties and high costs. Theories and experiments have disclosed that the performance of refractory materials depends closely on their working temperatures [12]. ...
A long campaign life of the trough of the blast furnace (BF) is important for improving the BF operation efficiency, reducing the cost of blast furnace ironmaking, and bettering the working conditions of the casting yard. In this paper, a water cooling device was designed for the trough of a BF with a volume of 630 m3. The effect of water cooling on lengthening the unit campaign life of the trough was investigated using industrial tests, numerical simulations, and theoretical analysis. Results showed that by using water cooling, the throughput of the trough in a unit campaign was increased by 40,000 tons, and its unit campaign life was increased by 34 days. During a unit campaign cycle, the influence of the water cooling device on the temperature distribution in refractory materials gradually developed from the low-temperature zone to the high-temperature zone, and the expansion of the high-temperature zone was suppressed. Therefore, the water cooling device inhibited the dissolution of refractory materials and retarded the chemical erosion from the molten slag and the atmosphere.
