The iron blast furnace(cont) The structure is of steel with a refractory brick lining (inert oxides in the upper region of the furnace carbon blocks in the hearth ). About 15m inside diameter(at its widest) and 50m high. Producing about 4,000 tons molten iron per day most of the furnace is filled with a descending and reacting mixture of coke, iron ore and limestone which are fed in at the top Surrounding the furnace at the bottom is a gas main( bustle pipe )carrying preheated air(the blast )to the furnace The air flows into the bottom of the furnace(the")through pipes called""?. This air burns part of the coke, producing the heat needed for endothermic reactions and for bringing the solids up to the high temperature where they react Also carbon monoxide is produced and this too can reduce oxides. Periodically the molten iron is tapped from the furnace and the molten slag is tapped separately. The limestone is present in the charge to the furnace to flux the
The iron blast furnace (cont). The structure is of steel with a refractory brick lining (inert oxides in the upper region of the furnace carbon blocks in the hearth). About 15m inside diameter (at its widest) and 50m high. Producing about 4,000 tons molten iron per day. Most of the furnace is filled with a descending and reacting mixture of coke, iron ore and limestone which are fed in at the top. Surrounding the furnace at the bottom is a gas main (“bustle pipe”) carrying preheated air (the “blast”) to the furnace. The air flows into the bottom of the furnace (the “bosh”) through pipes called “tuyeres”. This air burns part of the coke, producing the heat needed for endothermic reactions and for bringing the solids up to the high temperature where they react. Also carbon monoxide is produced and this too can reduce oxides. Periodically the molten iron is tapped from the furnace and the molten slag is tapped separately. The limestone is present in the “charge” to the furnace to “flux” the …
The iron blast furnace(cont) gangue oxides (largely silica) in the slag (i.e to yield a slag with a low enough melting point and viscosity that it will flow readily out of the furnace). The slag, a molten mixture of oxides, is a waste product. The gasses passing up through the furnace are in counter-current flow with the descending solid (and liquid iron in the bosh); the gases leave from the top of the furnace, at which point they are a mixture of nitrogen, carbon monoxide, carbon dioxide hydrogen and water vapor This is a low grade fuel which is usually burned in"stoves to preheat the blast
The iron blast furnace (cont). …gangue oxides (largely silica) in the slag (i.e to yield a slag with a low enough melting point and viscosity that it will flow readily out of the furnace). The slag, a molten mixture of oxides, is a waste product. The gasses passing up through the furnace are in counter-current flow with the descending solid (and liquid iron in the bosh); the gases leave from the top of the furnace, at which point they are a mixture of nitrogen, carbon monoxide, carbon dioxide, hydrogen and water vapor. This is a low grade fuel which is usually burned in “stoves” to preheat the blast