Evaluation of steelmaking processes

Objective of the AISI Direct Steelmaking Program is to develop a process for producing steel directly from ore and coal; the process should be less capital intensive, consume less energy, and have higher productivity. A task force was formed to examine available processes: trough, posthearth, IRSID, Electric Arc Furnace, energy optimizing furnace. It is concluded that there is insufficient incentive to replace a working BOF with any of these processes to refine hot metal; however, if new steelmaking capacity is required, IRSID and EOF should be considered. A fully continuous process should not be considered until direct ironmaking and continuous refining are perfected

Decontamination of Steel by Melt Refining: A Literature Review

It has been reported that a large amount of metal waste is produced annually by nuclear fuel processing and nuclear power plants. These metal wastes are contaminated with radioactive elements, such as uranium and plutonium. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain level. Because of high cost, it is important to develop an effective decontamination and volume reduction method for low level contaminated metals. It has been shown by some investigators that a melt refining technique can be used for the processing of the contaminated metal wastes. In this process, contaminated metal is melted wit a suitable flux. The radioactive elements are oxidized and transferred to a slag phase. In order to develop a commercial process it is important to have information on the thermodynamics and kinetics of the removal. Therefore, a literature search was carried out to evaluate the available information on the decontamination uranium and transuranic-contaminated plain steel, copper and stainless steel by melt a refining technique. Emphasis was given to the thermodynamics and kinetics of the removal. Data published in the literature indicate that it is possible to reduce the concentration of radioactive elements to a very low level by the melt refining method. 20 refs

Theoretical Minimum Energies to Produce Steel for Selected Conditions

The energy used to produce liquid steel in today's integrated and electric arc furnace (EAF) facilities is significantly higher than the theoretical minimum energy requirements. This study presents the absolute minimum energy required to produce steel from ore and mixtures of scrap and scrap alternatives. Additional cases in which the assumptions are changed to more closely approximate actual operating conditions are also analyzed. The results, summarized in Table E-1, should give insight into the theoretical and practical potentials for reducing steelmaking energy requirements. The energy values have also been converted to carbon dioxide (CO{sub 2}) emissions in order to indicate the potential for reduction in emissions of this greenhouse gas (Table E-2). The study showed that increasing scrap melting has the largest impact on energy consumption. However, scrap should be viewed as having ''invested'' energy since at one time it was produced by reducing ore. Increasing scrap melting in the BOF mayor may not decrease energy if the ''invested'' energy in scrap is considered

The Future Steelmaking Industry and Its Technologies

The objective of this report is to develop a vision of the future steelmaking industry including its general characteristics and technologies. In addition, the technical obstacles and research and development opportunities for commercialization of these technologies are identified. The report is being prepared by the Sloan Steel Industry Competitiveness Study with extensive input from the industry. Industry input has been through AISI (American Iron and Steel Institute), SMA (Steel Manufacturers Association) and contacts with individual company executives and technical leaders. The report identifies the major industry drivers which will influence technological developments in the industry for the next 5--25 years. Initially, the role of past drivers in shaping the current industry was examined to help understand the future developments. Whereas this report concentrates on future technologies other major factors such as national and international competition, human resource management and capital concerns are examined to determine their influence on the future industry. The future industry vision does not specify specific technologies but rather their general characteristics. Finally, the technical obstacles and the corresponding research and development required for commercialization are detailed

Future Steelmaking Processes: Final Report

There is an increasing demand for an ironmaking process with lower capital cost, energy consumption and emissions than a blast furnace. It is the hypothesis of the present work that an optimized combination of two reasonable proven technologies will greatly enhance the overall process. An example is a rotary hearth furnace (RHF) linked to a smelter (e.g., AISI, HIsmelt). The objective of this research is to select promising process combinations, develop energy, materials balance and productivity models for the individual processes, conduct a limited amount of basic research on the processes and evaluate the process combinations. Three process combinations were selected with input from the industrial partners. The energy-materials and productivity models for the RHF, smelter, submerged arc furnace and CIRCOFER were developed. Since utilization of volatiles in coal is critical for energy and CO{sub 2} emission reduction, basic research on this topic was also conducted. The process models developed are a major product developed in this research. These models can be used for process evaluation by the industry. The process combinations of an RHF-Smelter and a simplified CIRCOFER-Smelter appear to be promising. Energy consumption is reduced and productivity increased. Work on this project is continuing using funds from other sources

Recycling of Waste Oxides in Steelmaking - Final Report

This research primarily examined the use of waste oxide briquettes (WOB), prepared from blast furnace and basic oxygen furnace (BOF) dusts and mill scale, in BOFs and in particular, the reasons for the methods to reduce slopping in BOF when WOBs are used. Also, the recycling of EAF and stainless steelmaking dusts were examined. It is found that at a critical FeO content in the slag, metal drops emulsify increasing the reaction area and rate drastically, promoting slopping. Recommendations were made to delay the build-up of FeO in the slag to this critical value, thus reducing slopping. Although recycling of EAF dusts in the EAF increased energy use and decreased productivity, it provides Fe units, reduces dust disposal by 25-40%, and increases the Zn content of the dust to acceptable levels for the use by Zn-producers. Stainless steelmaking dusts can also be recycled as WOBs adding Cr to the melt and generating CO gas resulting in good slag foaming