Original Date: 08/26/1996
Revision Date: 01/18/2007

Weirton Steel Corporation (WSC) continually operates two of its four blast furnaces to reduce iron ore into molten metal, which is then further processed into steel. The blast furnace is an irregularly-shaped cylinder that solids are fed into the top (iron ore, sinters, scrap, limestone and coke), and hot air is blown into the bottom. Liquid slag and metal are tapped from the bottom of the furnace, while flue gases and dust escape from the top of the furnace. The blast furnace typically operates continuously for five to seven years before rebuilding is necessary.

Because blast furnaces are major consumers of fuel, WSC has incorporated improvements to reduce fuel consumption and automate the process. Some improvements included increasing the air pressure of the hot air blown into the furnace to 40 psi at the bottom and 12 psi at the top; raising the temperature of the hot blast of air from the stoves of the furnace from 1650°F to 2000°F; incorporating computer control of the stoves; installing high density cooling coils around the refractory brick; installing a closed-loop cooling system; increasing the troughs of the furnace and incorporating a tilt system to better facilitate the filling of the hot metal cars with pig iron; automating the stock house; installing a computer control room to automate the running of the blast furnace and to perform computer modeling; and installing a new scrubber system to improve boiler operations.

Once capital investment to the blast furnace was completed, fuel consumption rates are estimated to have dropped from 970 pounds to 930 pounds of fuel per ton of iron produced. This $78 to $79 million project had a payback period of less than two years, and increased the output to 4,200 tons per day.

For more information see the Point of Contact for this survey.