Verification of Steelmaking Slags Iron Content Final Technical Progress Report

Technical Report · Wed Oct 04 00:00:00 EDT 2006

DOI:https://doi.org/10.2172/892748· OSTI ID:892748

Hwang, J Y

The steel industry in the United States generates about 30 million tons of by-products each year, including 6 million tons of desulfurization and BOF/BOP slag. The recycling of BF (blast furnace) slag has made significant progress in past years with much of the material being utilized as construction aggregate and in cementitious applications. However, the recycling of desulfurization and BOF/BOP slags still faces many technical, economic, and environmental challenges. Previous efforts have focused on in-plant recycling of the by-products, achieving only limited success. As a result, large amounts of by-products of various qualities have been stockpiled at steel mills or disposed into landfills. After more than 50 years of stockpiling and landfilling, available mill site space has diminished and environmental constraints have increased. The prospect of conventionally landfilling of the material is a high cost option, a waste of true national resources, and an eternal material liability issue. The research effort has demonstrated that major inroads have been made in establishing the viability of recycling and reuse of the steelmaking slags. The research identified key components in the slags, developed technologies to separate the iron units and produce marketable products from the separation processes. Three products are generated from the technology developed in this research, including a high grade iron product containing about 90%Fe, a medium grade iron product containing about 60% Fe, and a low grade iron product containing less than 10% Fe. The high grade iron product contains primarily metallic iron and can be marketed as a replacement of pig iron or DRI (Direct Reduced Iron) for steel mills. The medium grade iron product contains both iron oxide and metallic iron and can be utilized as a substitute for the iron ore in the blast furnace. The low grade iron product is rich in calcium, magnesium and iron oxides and silicates. It has a sufficient lime value and can be utilized for acid mine drainage treatment. Economic analysis from this research demonstrates that the results are favorable. The strong demand and the increase of price of the DRI and pig iron in recent years are particularly beneficial to the economics. The favorable economics has brought commercial interests. ICAN Global has obtained license agreement on the technology from Michigan Tech. This right was later transferred to the Westwood Land, Inc. A demonstration pilot plant is under construction to evaluate the technology. Steel industry will benefit from the new supply of the iron units once the commercial plants are constructed. Environmental benefits to the public and the steel industry will be tremendous. Not only the old piles of the slag will be removed, but also the federal responsible abandoned mines from the old mining activities can be remediated with the favorable product generated from the process. Cost can be reduced and there will be no lime required, which can avoid the release of carbon dioxide from lime production process.

• Research Organization: Michigan Technological University, Houghton, MI
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: FC36-01ID14046
• OSTI ID: 892748
• Report Number(s): ID14046; MTU #000910, E21726; TRN: US200719%%833
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ACID MINE DRAINAGE
BLAST FURNACES
CARBON DIOXIDE
ECONOMIC ANALYSIS
IRON
IRON ORES
IRON OXIDES
METAL INDUSTRY
PILOT PLANTS
PROGRESS REPORT
SANITARY LANDFILLS
SEPARATION PROCESSES
SLAGS
VERIFICATION
steelmaking slags
iron units
separation
pig iron
DRI (Direct Reduced Iron)
steel mills
metallic iron
iron ore
blast furnace
acid mine drainage treatment.