furnace is designed for production of pig iron.First appeared in the XV century.in Europe.In Russia, the first blast furnace was built in 1620 near Tula.Then the fuel for such stoves served charcoal.Only a century later (1709), English inventor Abraham Derby managed to hold blast furnace smelting, replacing charcoal coke Carboniferous.
Centuries of experience has changed the unit of blast furnace, its appearance and the scheme of production of pig iron.But the basics are the same.Today, blast furnace - the construction of about 30 meters (height varies ± 5 m).The height of the entire structure may exceed 80 meters.
How does a blast furnace?
through the upper portion (throat) loading charge (sinter, pellets, iron ore, manganese ore, fuel and fluxes).Here is mine, the largest part of the blast furnace, which is a downward widening cone.Due to this expansion easier omitted solids bulking under heating.By the bottom of the shaft adjacent bosh (wide, cylindrical).It melted mixture.For the steamed, below, are arranged shoulders made in the shape of a truncated cone with a reduced base bottom.Such a section is most suitable for decreasing the amount of material due to melting.
In a cylindrical horn, the lower part of the profile, is the burning of coke and liquid product is going to melt.
Horn is divided into two parts: the upper zone (the blast) and lower (metalopriemschik, which assemble products smelting).Hearth called the lower part of the oven.
in tuyere zone arranged tuyere assemblies, which are fed into the blast furnace blast (heated air).It is this area is responsible for the burning of coke, the temperature here grow to their maximum values - 2000 degrees.Above the furnace top temperature is lower (up to 350 degrees).
In the lower part of the mountain is built iron notch, passed melting products - slag and iron itself.
previously used slag tap hole, but the practice of the last decades has shown that it is more practical to pass through the slag and cast iron notch, with further division mainly trough adjacent to the furnace.
adjacent to the furnace so-called casting yard, where are the tools that reveal iron notch and closing it after the release of slag and pig iron.Here are the gutter with ditches, guides the product melting in buckets.
Released from the oven the product is sent to the main runner where iron is separated from the slag (density difference).From the chute depart two ditches.On the one sent to the slag, on the other - iron.Cast iron is poured into a continuously moving forms (type conveyor), after cooling forms capsize and then be sent in the iron wagons.Slag is poured into the swimming pool, water cooled and pelletized.
each height of the furnace has its own specific temperature, thanks to this process of transition metals from ore and flows.
In the lower part of the furnace enters the combustion of coke sufficient amount of oxygen.Coke burns, transforming into carbon dioxide, which reacts with the coke, converting in the carbon monoxide.Next is a reaction between carbon monoxide and iron oxide.There is a reduction to metal.Iron saturated with carbon and iron is obtained.In addition to three-four percent of the carbon in the alloy is present in minor proportions of manganese and silicon, sulfur and phosphorus.
Actually, the blast furnace, the principle of which has been described here, may well be considered as non-waste production.By-products, appearing during production are used quite outside plants producing iron.The slag is added to the cement, suitable for buildings (as is now widely distributed cinder block) and blast furnace gas is a good fuel, heated air is fed into the blast furnace.
