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Date of Award
2014
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Chemical Engineering (PhD)
College, School or Department Name
Department of Chemical Engineering
First Advisor
S. Komar Kawatra
Abstract
One of the most critical steps of iron making is reduction of iron oxide into metallic iron. A carbon-rich material is required as a reducing agent in order to reduce iron oxide. Currently, all the reducing agents are non-sustainable, non-renewable and are derived from fossil fuel. Utilization of fossil fuel derived reducing agent causes emission of large amounts of CO2 from iron and steel industry. Approximately, 69 million metric tons of CO2 was released in year 2006 by iron and steel making industry alone in US (EPA, 2010). Iron and steel industry is also among the most energy intensive industries. Other problems faced by iron making industry are; depletion of high grade iron ores and unavailability of such a binder for iron ore pelletization which does not contaminates the iron oxide pellets.
Carbon is also stored in form of carbohydrates in different types of biomass e.g. woods, plants, and starch. Self-reducing iron oxide pellets were made using biomass as a reducing agent. These pellets were fired at different temperatures and residence times, and high quality pig iron nuggets were successfully produced. Results show that biomass has potential to reduce iron oxide into metallic iron and capable of producing pig iron over a wide range of operating conditions.
In other two different studies presented in this thesis proved that low grade iron ores can be used to directly produce metallic iron. Higher amount of iron was recovered when low grade ore was used to produce iron compared to upgraded ore. Another important area, iron ore pelletization was also studied. A binder that can provide high compressive strength to the iron oxide pellets and does not contaminates the pellets with other impurities is very desirable. Different types of organic and inorganic binder were used to produce iron oxide pellets. Results show that there are organic binders that are capable of providing high degree of strength to iron oxide pellets without diluting the total iron content.
Recommended Citation
Srivastava, Urvashi, "Sustainable Iron Making Processes", Dissertation, Michigan Technological University, 2014.