Modeling the Profitability and Environmental Impact of Alloy Scrap Sorting & Specialized Scrap Melting

Open Access
- Author:
- Annear, Chris
- Area of Honors:
- Industrial Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Paul Carl Lynch, Thesis Supervisor
Paul Carl Lynch, Thesis Honors Advisor
Omar Ashour, Faculty Reader - Keywords:
- Steel
Supply Chain
Sustainability
linear programming
Engineering Economics
recycling
scrap steel remelting
alloy steel
alloy steel recycling - Abstract:
- The ferroalloys used in the melting of steel to give it its desired elemental alloy composition make up a significant portion of the steel’s cost and greenhouse gas emissions. These ferroalloy additions require intensive mining and refinement. Just like the melting of scrap steel, the costs and emissions of ferroalloy can fluctuate widely depending on the location of the mine and refinery, as well as the element and purity of the ore mined. When melting steel scrap with an intensive melting process a significant portion of these crucial alloying elements already contained within the scrap are lost to the melt slag and need to be replaced with ferroalloy additions. Typically, with low-quality mixed scrap, this intensive melting process helps remove impurities and dirt which could negatively impact the microstructure and properties of the steel. However, this is a considerable problem with high alloy scrap, as the elements lost to the slag can make up a significant portion of the steel’s melting cost. To effectively utilize this value, scrap should be sorted based on its elemental composition and melted with a method that preserves the alloying elements within the steel melting. Using data on furnace elemental loss coefficients and CO2 emissions factors for transportation/refining, a blend of scrap steel can be optimized to minimize ferroalloy additions, reducing material costs and greenhouse gas emissions.