Where does the heat for the blast furnace come from?
Encyclopædia Britannica, Inc. Blast furnaces produce pig iron from iron ore by the reducing action of carbon (supplied as coke) at a high temperature in the presence of a fluxing agent such as limestone.
What is belly in blast furnace?
Belly – It is the cylindrical portion of the blast furnace below the stack. It connects the upper bosh diameter with the largest diameter of the lower stack. Bosh diameter – It is the diameter of the inside of the lining at the bosh line. It is also the diameter of the straight section or belly above the bosh.
What is added at the bottom of a blast furnace?
The “casthouse” at the bottom half of the furnace contains the bustle pipe, water cooled copper tuyeres and the equipment for casting the liquid iron and slag. Once a “taphole” is drilled through the refractory clay plug, liquid iron and slag flow down a trough through a “skimmer” opening, separating the iron and slag.
Why is hot air blown into the bottom of the blast furnace?
The blast furnace is used to extract iron from its ore. The iron ore, coke and limestone are fed into the top and the hot air is blown into the bottom. This carbon dioxide will then react with more coke to form carbon monoxide. The carbon monoxide then reacts with the iron ore to extract the iron as molten iron.
What heats a blast furnace?
At the bottom of the blast furnace, the hot air of 1200℃ heats the materials and fuels. The hot air with a force of 4.0bar triggers such a force that the materials fly up in the air. Because of the heat, coke chemically dissolves the raw materials.
What happens to slag from blast furnace?
Blast furnace slag (BFS) is a by-product from iron production in blast furnaces, which are fed by a mixture of iron-ore, coke and limestone. In the process, the iron ore is reduced to iron while all remaining materials form the slag, which is tapped off as a molten liquid and cooled.
Which fuel is best suitable for blast furnace process?
Which fuel is best suitable for blast furnace process? Explanation: Coke is best suitable for blast furnace process as it also acts as a reducing agent in smelting iron ore.
Which oxygen is used for blast furnace operation?
More than half the world’s steel is produced in the basic oxygen process (BOP), which uses pure oxygen to convert a charge of liquid blast-furnace iron and scrap into steel.
Which oxide is reduced in blast furnace?
iron(III) oxide
When haematite is reduction in blast furnace?
First calcination and roasting, the ferrous oxide is oxidised to ferric oxide. Then in blast furnace, smelting is done, where it is reduced to get iron. Carbon monoxide is the actual reducing agent of hematite in blast furnace.
When hematite is reduced in blast furnace which gas is released?
One of the important reactions in metallurgy is the reaction of hematite (Fe 2 O 3 ) with carbon monoxide to yield metallic iron [30] .
At which temperature carbon monoxide is used as reducing agent to reduce iron oxide in blast furnace?
As an alternative to iron production in a blast furnace, direct-reduced iron (DRI) is produced by reducing iron ore using a mixture of hydrogen and carbon monoxide (Reaction (5.7) and (5.9)) at temperatures of 800–1000°C.
Why the zinc produced inside the furnace is a gas?
Under the conditions in the furnace zinc is a vapour (gas), whereas lead is produced as a liquid by a similar series of reactions. The zinc vapour is carried into the condenser in a stream of carbon monoxide and carbon dioxide gases (at about 1300 K) and condensed by adsorption in a spray of liquid lead.
Is burning coke in a blast furnace exothermic or endothermic?
Because the coke solution loss reaction is an endothermic reaction, the reaction equilibrium in the blast furnace moves with different coal blending.
Which reduce iron from iron oxide in the blast furnace?
In the blast furnace, iron ore, carbon in the form of coke, and a flux such as limestone are fed into the top of the furnace, while blast of heated air is forced into the furnace at the bottom. Reduction of iron oxides occurs either by carbon or by carbon monoxide, formed by the gasification of carbon.
What is added to a blast furnace to remove impurities?
Limestone is also used to remove impurities from the blast furnace when making iron. The impurities are mostly silicon dioxide (also known as sand). The calcium carbonate in the limestone reacts with the silicon dioxide to form calcium silicate (also known as slag).
It is a type of heat exchanger, in which the heat produced by combustion of the BF gas usually mixed with natural gas (NG) or coke oven gas (COG) is stored in the checkerwork chamber, after which cold air is blown through the hot checkerwork to produce the preheated hot air blast to the furnace.
What is the difference between blast furnace and reverberatory furnace?
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. In contrast, air furnaces (such as reverberatory furnaces) are naturally aspirated, usually by the convection of hot gases in a chimney flue.
Why is Coke used in a blast furnace?
Coke is used as a fuel and as a reducing agent in smelting iron ore in a blast furnace. The carbon monoxide produced by its combustion reduces iron oxide (hematite) in the production of the iron product.
Why Coke is not used as a fuel?
Answer: because fuel has different properties than coke as fuel can help a car move and coke can’t do do that as it does not have the chemicals to complete that task …
What is difference between coke and coal?
What is the difference between coal and coke fuel? Coal is a shiny, black fossil fuel that contains impurities, emits smoke when burned, and produces less heat than coke. Coke is a dull, black byproduct of coal that burns hotter and cleaner. By the 1880s, most plants used coal’s byproduct, coke, to produce steel.
Which is a better fuel coke or coal?
Coke is a better fuel than coal because; -Coke produces more heat on burning than coal. When equal masses of coke and coal are burnt, coke produces more heat. -When coke is burnt smoke is not obtained.
Is Coke a form of coal?
By distilling bituminous coal in retorts to obtain gas for illumination, or by burning it in kilns or pits, the residue left behind is called coke, which is simply coal charcoal, and is nearly pure carbon.