Blast Furnace Research Paper

The purpose of a blast furnace is to chemically reduce and physically convert iron oxides into liquid iron .The blast furnace is a huge, steel stack lined with refractory brick, where iron ore, coke and limestone are dumped into the top, and preheated air is blown into the bottom. The raw materials require 6 to 8 hours to descend to the bottom of the furnace where they become the final product of liquid slag and liquid iron. These products are drained from the furnace at regular intervals. Once a blast furnace is started it wilt continuously run for four to ten years with only short stops to perform planned maintenance.

Blast furnaces operate on the principle of chemical reduction whereby carbon monoxide, having a stronger affinity for the oxygen in iron ore than iron does, reduces the iron to its elemental form.

Associated chemical reactions in blast furnace

2 C(s) + O2(g) → 2 CO(g)

C(s)+H2O→CO(g)+H2(g)

Fe2O3 + 3CO → 2Fe + 3CO2

CaCO3(s) → CaO(s) + CO2(g)

SiO2 + CaO → CaSiO3

2.2 Hearth and dead man

The hearth is the lowest, but the most important part of a blast furnace. The life of a furnace considerably depends on its hearth durability, Other parts of blast furnaces can be relined or replaced in a relatively

At the end of the tap, the gas-slag interface tilts down towards the taphole and a considerable amount of slag remains above the taphole level. The iron phase can be drained from levels below the taphole because of the large pressure gradient that develops near the taphole in the viscous slag phase. The average slag-iron interface is therefore lower than the taphole level (Tanzil et al., 1984). Depending on a number of factors, such as liquid production rates, hearth (effective) volume and tapping strategies, the initial stage of a tap cycle varies and can be categorized as iron first, Together iron and slag, Slag-first