1 Sridhar Seetharaman POSCO Professor Carnegie Mellon University Department of Materials Science and Engineering Pittsburgh, PA 15213, USA SIPC, Pittsburgh September 10 th, 2009 Carnegie Mellon Physical Chemistry of Steel Processing and its Relevance to Sustainability

Outline What is left to do? Research areas Introduction of the speakers

Critical for PA Sustainable Iron making – 31.7 million net tons (US-Steel) of steel, 49,000 employees. – 14 GJ/tone of Energy (10.4 Practical minimum) – 960 kg CO 2 per tone Steel (aprx. 9% of total industrial)

Motivation Fruehan & Paxton: Source: U.S. Department of Energy, Office of industrial Technology Process1.5Energy (GJ/tonne product) Actual Req.Absolute Min.%DifferencePractical Min.%Difference Liquid Hot Fe (5%C) Liquid Steel (BOF) Liquid Steel (EAF) Hot Rolling Flat Cold Rolling Flat Comparison of Energy Requirements

Motivation Fruehan & Paxton: Source: U.S. Department of Energy, Office of industrial Technology Process1.5Energy (GJ/tonne product) Actual Em.Absolute Min.%DifferencePractical Min.%Difference Liquid Hot Fe (5%C) 1,447-1,5591, , Liquid Steel (BOF) Liquid Steel (EAF) Hot Rolling Flat Cold Rolling Flat Comparison of CO 2 emissions

Opportunities Iron-making: by far the greatest factor for energy consumption and CO 2 output ! Steelmaking, casting, TMPC: far less important but together do add up.

Two Types of Solutions 1. Incremental changes (1-2%) Low risk, and likely return Moderate efforts

Iron and Steelmaking Research (CISR) Extraction Casting Thermo-mechanical processing Casting Extraction Melt Processing Refining Chemical Metallurgy Thermo-mechanical processing Physical Metallurgy Hypothesis driven questions are needed !!

Examples of incremental changes Product quality improvements: issues such as non-metallic inclusions and surface cracks Product yield: Fe loss to slag (e.g. de- sulfurization), Fe loss during annealing) Process disruptions: clogging, breakouts in caster Process changes to reduce energy / increase efficiency: CSP casting, Strip casting

Two Types of Solutions 2. Radical changes (10% or more) Risky High cost (must be multiple companies with federal support) Highly collaborative and interdisciplinary

The Fundamental Issue Fe 2 O 3 ore reduction to Fe Issues: – CO 2 generation – Cooking and and availability of cooking coals

Challenges Raw-materials: Reduction material, less reliability on coking coals CO 2 output, capture and sequestration

Processes/Ideas Natural gas based processes: – MIDREX (Feed reformed natural gas into a shaft furnace, DRI) – FINMET (Feed reducing gas to a Fluidized bed, DRI) Coal Flexible processes: – FINEX (use of Fe-fines, flexibility in reductant) – COREX (coal gasification and reduction to DRI) No radical effect on CO 2 !

Ongoing project: Reduction with high volatile coal

Challenges Raw-materials: Reduction material, less reliability on coking coals CO 2 regulations, output, capture and sequestration

Challenges Raw-materials: Reduction material, less reliability on coking coals CO 2 regulations, output, capture and sequestration

Regulations Ms. Catherine Izard (PHD candidate) – Evolving regulatory changes and limits

Challenges Raw-materials: Reduction material, less reliability on coking coals CO 2 regulations, output, capture and sequestration

Ongoing project: Increase recycling Wüstite Steel 1)Oxidation of Iron 2)Copper enrichment and diffusion back into steel Weight Percent Copper Temperature (°C)   + L  + (Cu)  + (Cu)  Initial Cu Content ~ 0.5 wt% Solubility limit ~ 8 wt% 1150°C 3)Separation of copper-rich liquid 4)Liquid penetrates austenite grain boundaries Fe-Cu Phase Diagram Grain Boundary 10 μm Wüstite Iron Copper-rich Layer GB Penetration

Ongoing project: Increase recycling Embrittled grain boundaries lead to surface cracking during hot rolling Scrap contains copper and its expected to increase Savings of $1.00 / ton possible with 0.01 wt% increase in copper tolerance* *Yalamanchili, B., P. Power, and J. Nelson, Effect of residual elements on low carbon rod quality and implications to the end user. Wire Journal International, (5): p. 100.

Ongoing project: Reduction with wood char

CO 2 output reduction: Processes/Ideas Industrial perspective from Dr. Fred Mannion, US-Steel research

Challenges Raw-materials: Reduction material, less reliability on coking coals CO 2 regulations, output, capture and sequestration

CO 2 separation: Oxygen Blast Furnace Reduce need for nitrogen separation in off gas Thermal control issues Oxygen separation in the first place

CO 2 capture and sequestration: Processes/Ideas Overview of efforts in the power industry by Professor John Kitchin

Our speakers in this session Evolving Regulatory Scene for Carbon Management, Catherine Izard, PhD Candidate, Department of Engineering and Public Policy, Carnegie Mellon Research on CO 2 Capture in the Institute for Advanced Energy Solutions, John Kitchin, Assistant Professor, Department of Chemical Engineering, Carnegie Mellon Corporate Representative: Fred Mannion, US Steel