![]() At this point, usually bath temperature and bath sample is taken. In this stage, there are gas – solid and solid –liquid phases in the bath.įinishing stage: The scrap is completely covered by the melt and only the solid –liquid phase exists until all the scrap is completely melted. Melting stage: The melting starts at the top surface of the scrap pile, and molten liquid penetrate towards the bottom of the furnace and its height increases whereas the height of the scrap pile decreases. In this stage the gas – solid phases exist. The temperature at the top increases to reach the melting temperature of the scrap. The heating is done by radiation, convection (due to the hot gas going through the scrap porosities) and conduction (due to contact points between scraps). Heating stage: The scrap is heated by the arc and oxy-fuel burners at the top of the furnace. The entire duration of the process can be divided into three main stages: Chemical energy is supplied through many sources which include oxy-fuel burners and oxygen lances. Electrical energy is supplied through the graphite electrodes and normally has a very large contribution in the melting phase. This energy can be electrical or chemical. Melting is carried out by supplying energy to the furnace interior. The EAF processing route could be summarized as follows: In the EAF, scrap and sometimes other raw materials such as DRI, HBI and pig iron are melted and converted into high quality steel by using high-power electric arcs formed between a cathode and one (for direct current DC) or three (for alternating current AC) graphite electrodes (anodes). PRIMARY METALLURGYĮlectric Arc Furnace (EAF) is a central part of the production route of the Electric Steelmaking process that is an alternative to the dominant Basic Oxygen Steelmaking (BOS) route.ĮAF is generally used to produce carbon steels and alloy steels primarily by recycling ferrous scrap. ![]() By using HBI both the availability of the smelting furnace and the safety of employees while charging can be increased. It also frequently breaks the electrodes. ![]() In contrast, scrap is most unwieldy and sometimes needs cutting down, an expensive process. HBI is compact and the briquettes are easy to feed into the furnace. Yuichi, Energy Policy 30, 849 (2002).Hot Briquetted Iron (HBI) is a premium form of DRI that has been compacted at a temperature greater than 650° C at time of compaction and has a density greater than 5,000 kilograms per cubic metre (5,000 kg/m3). Eissenwasser, Iron Steelmaker 3, 24 (1986). Cheng, Metallurgical & Materials Transactions B 47, 3066 (2016).į. Association, Steel Statistical Yearbook 2016 (Brussels: World Steel Association, 2017).Ĭ.L. Zinurov, Innovation in Electric Arc Furnaces (Berlin: Springer, 2010), p. Based on these innovations, a prospective process for the cyclic utilization of CO 2 in the EAF-LF steelmaking process is introduced that is effective in mitigating greenhouse gas emissions from the steelmaking shop. Additionally, bottom-blowing CO 2 in an EAF can strengthen molten bath stirring and improve nitrogen removal, while bottom-blowing CO 2 in a LF can increase the rate of desulfurization and improve the removal of inclusions. For example, coherent jets with CO 2 and O 2 mixed injection can reduce the amount of iron loss and dust generation, and submerged O 2 and powder injection with CO 2 in an EAF can increase the production efficiency and improve the dephosphorization and denitrification characteristics. The utilization of CO 2 in the EAF-LF steelmaking process resulted in improved efficiency, purity and environmental impact. In this study, the recent innovations and improvements in carbon dioxide (CO 2) injection technologies for electric arc furnace (EAF)-ladle furnace (LF) steelmaking processes have been reviewed.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |