Hydrogen and Nitrogen Control in Ladle and Casting Operations
Plan Partners: Carnegie Mellon University, AISI, U.S. Steel, Alaska Steel, Bethlehem Steel, China Steel Corporation, Columbus Joint Venture, Corus, Ispat Inland Steel Co., IRSID, Iscor, Ltd., J&L Specialty Products, Timken Company, SIDERAR, S.A.I.C., North Start Steel, Praxair Inc., Pohang Iron and Steel Co.
Status: This projectï'³ objective is to identify and quantify the sources of hydrogen and nitrogen in ladle and steel transfer operations. The goal is to develop a comprehensive model to predict hydrogen and nitrogen pickup in steel melts.
The latest experiments have studied the interfacial kinetics of HtwoO reaction with liquid iron, though experimental difficulties prevented accurate measurements. Also, analysis of experiments involving the transfer of nitrogen from the atmosphere to the ladle slag showed unreliable high values for nitrogen in the slag, and it is now planned to repeat the experiment and analyze the slag samples using Kjeldahlï'³ analysis. Other experiments are planned using HYDRIS to determine the hydrogen pickup when water is added on the melt, and a continuation of the HtwoO experiments using higher flow rates for reaction gases.
Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection
Plan Partners: McMaster University, AISI, Dofasco Inc., Gallatin Steel, Ispat Inland, Midrex Technologies, Steel Dynamics, Incorporated
Status: The objective of this Plan is to develop a technique to reduce nitrogen in EAFs using injection of direct reduced iron fines. Specifically, experiments will be carried out to establish the relationships between solid injection rates, particle size, direct reduced iron composition, lance depth, sulfur content, temperature, starting nitrogen levels, and the removal of nitrogen from molten steel. A mathematical model will be developed to determine if such practices are economically attractive.
The 1st stage of research concluded the most suitable material leading to DRI fine performance, and subsequently the kinetic pre-modeling has demonstrated that Colorado bubbles up to 1mm in diameter reach the equilibrium nitrogen content almost instantaneously. The pilot plant trials were reviewed due to operational issues, and the feasibility of full-scale trials with one of the partners is currently being assessed.
Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies
Plan Partners: Michigan Technological University, ACME Steel, Cleveland-Cliffs Iron Co., Cober Electronics, INMETCO, Rouge Steel, U.S. Steel, Techint Technology
Status: This Plan is focused on evaluating novel direct steelmaking by combining several technologies. This Plan will generate a solid base of technical, marketing, economic, and policy data; develop energy, environmental, and economic targets; more definitively assess opportunities and barriers; and accumulate knowledge and experience for defining direction for the next phase of development.
The most recent tests have involved microwave steelmaking using hematite ore mixed with different amounts of coal, lime, and binder; and microwave/EAF steelmaking processes under different conditions than previously. Preliminary analyses of the microwave experiment results are similar to those achieved using magnetic iron ore, and the microwave/EAF experiments showed no organic gas emission and only a very small amount of SOtwo. In the coming months, these results will be related to experimental conditions, conclusions drawn, and complimentary experiments focusing on slag basicity, lowering sulphur content, semi-continuous raw material feeding, and microwave plasma reduction will be conducted.
