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New Updates on Steelmaking Projects
September 5, 2002
Hydrogen and Nitrogen Control in Ladle and Casting Operations
Project Partners: Carnegie Mellon University, AISI, A. Finkl & Sons, Bethlehem Steel, Dofasco, Gallatin Steel, Heraeus Electro-nite
Status: This project objective is to identify and quantify the sources of hydrogen and nitrogen in EAF and BOF ladle and casting operations. The goal is to develop models to predict hydrogen and nitrogen pickup in steel melts. The model will include decarburization, scrap melting and the use of DRI (direct reduced iron).
During this quarter experiments were conducted to determine the hydrogen and nitrogen pickup from the alloys and carburizers. One experiment using HYDRIS, showed that a carburizer in the form of metallurgical coke having a significant hydrogen impurity does not contribute to the hydrogen pickup. Some experiments were conducted using the CVPI technique to determine the transport of nitrogen through the ladle slag. Experimental work will continue in the next quarter.
In addition to the experimental work, CFD software (CFX) is being developed to formulate the model for absorption of nitrogen during the tapping of steel. Formulation is now in progress and results should be available soon.
Nitrogen Control in Electric Arc Furnace Steelmaking by Direct Reduced Iron Fines Injection
Project Partners: McMaster University, AISI, Dofasco Inc., Gallatin Steel, Ispat Inland, Midrex Technologies, Steel Dynamics
Status: The objective of this project is to develop a technique for nitrogen removal from liquid steel 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. If so, plant trials will be proposed for follow-up study.
Direct reduced iron fines supplied by Ispat have been characterized using multiple types of laboratory analysis. This material is very fine and high in carbon compared to the materials tested previously. These fines should be suitable for the injection studies, though the high carbon to oxygen content may limit nitrogen removal.
A novel rapid heating thermal analysis technique has been established to more closely mimic the high heating rates associated with injection conditions compared to conventional DTA/TGA and has tested with both types of fines. Injection trials will begin the next quarter.
Novel Direct Steelmaking by Combining Microwave, Electric Arc, and Exothermal Heating Technologies
Project Partners: Michigan Technological University, ACME Steel, Cleveland-Cliffs Iron Co., Cober Electronics, INMETCO, Rouge Steel, U.S. Steel, Techint Technology
Status: This project is focused on evaluating novel direct steelmaking by combining several technologies. This project 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.
Iron ore reduction and steelmaking tests continued using three technologies: microwave resistance heating, microwave electric arc heating, and microwave only heating. Samples have been generated under various conditions. Several samples reached very high steel yield, with chemical analysis underway. More experiments are underway to establish the best conditions and methods for iron ore reduction and steelmaking.
Work has also begun on the documentation of the major environmental policies and regulations of federal agencies that affect the steel industry and the proposed technology. A draft of this report is expected to finished in the third quarter.