Page 179 - Materials Chemistry, Second Edition
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150 Waste Management Practices: Municipal, Hazardous, and Industrial
FIGURE 6.9 Electromagnet for moving ferrous wastes onto rail cars.
FIGURE 6.10 Shredder housing at a metal recovery facility.
into the furnace via a crane. The electrodes swing into place over the furnace. The roof is low-
ered and then the electrodes are lowered to strike an arc on the scrap. The arc consists of a plasma
of hot, ionic gases reaching temperatures in excess of 3515°C (6000°F). Contact with the arc ini-
tiates the melting of the scrap. Once the charge is melted, the furnace sidewalls are exposed to
intense radiation from the arc, melting the entire mass. Once the desired steel composition and
temperature are achieved in the furnace, the tap hole is opened, the furnace is tilted, and the steel
pours into a ladle for transfer to the next batch operation (usually a ladle furnace or ladle station).
During the tapping process, alloy additions are made based on the bath analysis and the desired
steel grade (Jones, 2002).
