The Electric Arc Furnace
In 1973, CF&I completed a major project of building a new electric arc furnace melt shop. The highlight of this new facility was the $11 million continuous caster machinery which allowed the company to increase steel making capacity to 1,200,000 tons per year. Continuous casting is the process where molten steel is solidified into a “semi-finished” billet, bloom, or slab for subsequent rolling in the finishing mills to be made into final steel products. Prior to the introduction of Continuous Casting in the 1950s, steel was poured into stationary molds known as ingots.
Continuous caster, casting action, 1979
The Electric Arc Furnace process of steel making began by swinging the furnace roof away so that tons of recycled scrap iron and steel dropped into the furnace. After the vessel was “charged” or in layman’s terms, became full, the roof was swung back into place and three large electrodes were lowered to the surface of the scrap metal through the roof and the electricity turned on. A company brochure produced in the early 1970s stated that the amount of power required per heat was 50,000 to 60,000 kilowatts per hour. The three electrodes, each 24 inches in diameter, produced heat of about 8,000 degrees Fahrenheit. The intensity of the energy created by the electricity caused the scrap metal inside the furnace to melt. After the melting process completed, the furnace was tilted forward on two pivoting rockers on either side. The molten steel poured out of a spout into another vessel below. This method of steelmaking could produce 40 to 60 tons of new steel during a 2 ½ to 3 hour process.
Workers preparing the electric arc furnace for its first tap, 1973.
Covering four acres, the Electric Arc Furnace building was equipped with the latest furnace and building evacuation systems to prevent particulate emission to escape into the atmosphere. Powered by huge fans, the systems pulled exhaust gases into and through modern gas cleaning equipment, which removed dust from the gases similar to the how a vacuum cleaner removes dust from carpets.