Advances in Ferrous Metallurgy: Advances in Ironmaking, Steelmaking, and Casting
Sponsored by: AIST Metallurgy—Processing, Products and Applications Technology Committee
Program Organizers: Daniel Baker, LIFT; Emmanuel De Moor, Colorado School of Mines; Kishlay Mishra, Nucor Castrip Arkansas LLC; Lijia Zhao, Northeastern University
Monday 8:00 AM
October 18, 2021
Room: A210
Location: Greater Columbus Convention Center
8:00 AM
Cost Modeling and Life Cycle Analysis of Low-Emissions Iron Production: Muntasir Shahabuddin1; Adam Powell1; Yan Wang1; Nikolaos Kazantzis1; Brajendra Mishra1; 1Worcester Polytechnic Institute
Electrolytic reduction of hematite ore or waste bauxite tailings (red mud) has the potential to become a low-emission alternative to traditional blast furnace and direct reduction processing techniques for production of iron. Use of electrolytic reduction in these contexts will allow for valorization of toxic red mud waste. This study involves a techno-economic analysis of two electrowinning technologies and a CO2 emissions analysis of the two processes under study against incumbent and other novel iron production processes. Monte Carlo simulations were performed to account for uncertainties surrounding variable feedstock composition and process parameters. Under these conditions, the more favorable electrowinning process results in emissions significantly undercutting current carbothermic processes, and comparable to other novel iron production processes such as HYBRIT and molten salt electrolysis.
8:20 AM
Thermodynamics and Kinetics of Coke Breeze Combustion Under Different Oxygen Content in Sintering Process: Dongqing Wang1; 1Shougang Group
In order to investigate the influence of oxygen content in sintering flue gas on the heat generated by coke combustion and sintering flue gas , the thermodynamic calculation was carried out with FactSage software. Combustion kinetics under different oxygen content was studied with thermogravimetric analyzer. Thermodynamic research results showed that under the condition of sintering with iron ore fines, the oxygen content in the combustion-supporting air was abundant. When the oxygen content was more than 7%, the solid fuel in the sintered layer could meet the combustion conditions and release all the heat. Kinetic experiment results showed that the combustion rate of coke breeze in 5 minutes with 13% oxygen content in flue gas was equivalent to combustion rate of coke breeze of in 2.75 minutes21% oxygen content in flue gas. Therefore, if the combustion time was long enough, the heat released by low-oxygen flue gas would be basically equal to that of high-oxygen flue gas.
8:40 AM
The Study and Optimization of Calcium Flux for Self-fluxed Pellets: Xiangjuan Dong1; Wei Wu1; Yu Cao2; Kai Wang2; Gele Qing3; Ming Li2; Wenwang Liu2; 1Central Iron and Steel Research Institute; 2Shougang Jingtang United Iron & Steel Co, Ltd; 3Shougang Research Institute of Technology of Shougang Group Co., Ltd.
In order to reduce pollutants and CO2 emissions, increasing the application ratio of pellets in BF has become the development tendency. With the ratio increasing, it's necessary to increase the basicity to compensate for the lack of slag basicity in BF. In this paper, six calcium flux, limestone powder, lime, hydrated lime, dolomite, lightly burned dolomite and carbide slag, was studied, by analysis the physical and chemical properties, including microstructure, thermal properties, and ballability, providing a scientific basis for optimization the flux. According to the study, hydrated lime has better property and decreases the amount of bentonite consumption to obtain the pellets with low silica. The new producing technologies of self-fluxed pellets with hydrated lime were applied on the indurating machine. The low-silica self-fluxed pellets with basicity 1.10, SiO2 content 2.2%, and reduction swelling index 16.5% were successfully used by 55% rate in the 5500m3 BF in Shougang Jingtang.
9:00 AM
Structure Optimizations of Submerged Entry Nozzle in a Steel Slab Continuous Casting Mold: Yushi Tian1; Lijun Xu2; Shengtao Qiu2; Rong Zhu1; 1University of Science and Technology Beijing; 2Central Iron & Steel Research Institute
Abstract: To improve the quality of steel slabs, the effects of submerged entry nozzle Structures on fluid flow in a slab mold (1500mm×200mm) were investigated by using a 1:2 scale water model and a three-dimensional mathematical model. Through the analysis of mold level fluctuations, flux covering, flow field and so on under different nozzle structures and operating parameters of the existing and optimized nozzles, the optimum operating conditions of the existing and optimized nozzles were obtained, and then the reasonable submerged entry nozzle structure were put forward in this slab mold. The physical and mathematical simulations provide a scientific basis for optimizing flow field and nozzle structures design in a steel slab mold as well as for determining the best operating parameters for the existing process.
9:20 AM
Impact of Alloy Composition on the Hot Ductility of Steel during Continuous Casting: Alyssa Stubbers1; Thomas Balk1; 1University of Kentucky
The connection between alloy content and high-temperature ductility behavior of steels is due to the inhibition of diffusion and precipitate formation caused by additional material present in alloys. This diffusion and precipitation behavior can cause low ductility regions to occur during crucial operations of a continuous casting process which may cause transverse cracking or total breakouts of steel. In this study, a range of alloys containing Nb, V, N, and Ti were examined to identify and characterize the influence of alloying elements on ductility behavior at temperatures above 700°C. Using a Gleeble 3500, samples were hot tensile tested and quenched at failure for subsequent analysis using SEM and TEM techniques to evaluate ferrite to austenite phase transformations and precipitate formation. Ductility profiles and microstructural information were then used to construct a clearer picture of how alloying elements interact within the steel microstructure to modify high-temperature material properties.