Electric Arc Furnace (EAF) operation generates a large volume of hazardous waste (K0610) at the baghouse which is the emission control device for the furnace. EAF handling, transportation and processing costs are high. Flux and Carbon use was insufficient. Flux and metallics were being lost with Drop-Out Chamber material disposal.
Flux Reduction: Training was held for Melt Shop crews to maximize flux addition and slag making efficiency. Total high caland dolomite lime use rate has been reduced from 90 lbs/ton of liquid steel in January 2008 to 65 lbs/ton in August 2008.
Injection Carbon reduction: Process training was held for Melt Shop crews to maximize carbon addition effgiciencey. Total carbon use rate has been reduced from 41 lbs/ton of liquid steel in January 2008 to 29 lbs/ton in August 2008.
Drop-Out Chamber material reuse: The Drop-Out Chamber (DOC) is a water cooled vault (29'x29'x25') located beneath the Electric Arc Furnace (EAF) and part of the Direct Evacuation Control (DEC) System, leading to the baghouse. Melt shop crews began reclaiming fluxes and metallic found in DOC material in 2006 by charging it into the EAF rather than loading it out with the baghouse dust as a hazardous waste (K061). A German manufactured extended reach broom truck was purchased to safely load out the stacked and hot DOC material. It was later fitted with an air conditioned cab to protect operator from hot material and heat exposure.
Details of Reductions
Additional Information :
Nucor Steel Texas manufacture approximately 1 million tons per year of rebar, angle, flat, round and square bar products from scrap steel using electric arc furnace, continuous casting and rolling technologies. We were able to reduce our hazardous waste generation while driving costs down to add value to our division though this project.