Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001
· These furnaces are large heated vessels, and they are lined with bricks of refractory materials.
· Iron pellets, limestone, and coke are mixed together and dumped into the top of the furnace.
· Air is preheated to 2000°F and this is used to `blast' the mixture into the furnace. The coke ignites, and elevates the temperature of the mixture to 3000°F. This results in a reduction of the iron oxides, and separation of the slags.
· After some period of time (a few hours) the furnace is tapped, and the iron is drawn off to large ladles. This `pig' iron typically has a impurity contents of 4% C, 1.5% Si, 1% Mn, 0.04% S, 0.4% P.