Download extraction of iron ore

EXTRACTION OF IRON ORE
INTRODUCTION
One of the most important resource is minerals. It has a decisive influence
on the economic development of a country. Iron ore is the basic resource of a nation’s
development. Iron is described as the backbone of a civilization. Let us see how iron is
extracted.
AIMS AND OBJECTIVES.
To know how iron is extracted from its ore.
METHOD OF STUDY
Referring books, internet.
DATA COLLECTION.
In the earth crust iron is found as an oxide, a carbonate & a sulphide as it is quite reactive.
The chief ore from which iron is extracted is called haemetite. It is mostly iron oxide [Fe2O3] mixed
with some sand [silica, SiO2] the ore is concentrated by hydraulic washing & magnetic separation.
Iron is obtained by the reduction of its ore, haematite [Fe2O3] in a big furnace called
blast furnace (in fig :). The furnace is narrow at the bottom, widens out in the middle & again narrows
down at the top .It is made from steel &the inner regions are lined with fire proof bricks
The iron ore mixed with coke &limestone to form a mixture. This mixture is known as
‘charge ‘.The charge is then introduced into the blast furnace from the top. A blast of hot air is blown in
through the base of the furnace. The following reactions take place in the blast furnace.
1) The coke combines with oxygen to form carbon dioxide. This reaction is highly
exothermic & large amount of heat is evolved.
C(s) +O2 (g) CO2 (g) +heat
2) Due to the intense heat in the furnace lime stone [CaCO3] decomposes to form calcium
oxide & carbon dioxide
CaCO3(s) CaO(s) +CO2 (g)
3) The carbon dioxide reacts with more coke to form carbon monoxide
CO2 (g) +C(s) 2CO (g)
4) Iron (III) oxide present in the ore is then reduced by carbon monoxide to form liquid iron. The
molten iron trickles down & collects at the bottom of the furnace.
Fe2O3(s) +3CO (g) 2Fe (i) +3CO2 (g)
5) Calcium oxide formed in reaction (ii) reacts with silicon dioxide (sand) present in the ore
as impurity to form molten calcium silicate known as slag.
CaO(s) +SiO2(s) CaSiO3 (i)
The molten slag also flows down the furnace. It is lighter than molten iron. It does not
mix with iron &forms a molten layer of iron. It thus protects the freshly prepared iron from
oxygen. Otherwise, iron would be converted into its oxide.
The molten iron &slag are drawn off through separate openings at the bottom of
the furnace. The molten iron is allowed to solidity in moulds of casts. It is called pig iron or cast
iron. The presence of carbon in pig iron makes it very hard &brittle. It is not very useful
because it contains many impurities. The main impurity present in it is carbon (about 4%). Most
of the molten iron is, therefore, converted to steel. The molten slag, after solidification is
mainly used for road building.
The extraction of iron from hematite in the blast furnace is a continuous process.
Once started, the blast furnace can continue up to ten years .In India iron is extracted at Bihar
Durgapur, Rourkela, & Jamshedpur etc.
CONCLUSION
From this project we have done , all can understand how iron is extracted from its ore
PREPARED BY,
JEREENA.J.A, SREEKUTTY .K.B., NEETHU.M.V. [CLASS X.R] [SCHOOL G.G.H.S.S.
COTTON HILL] [GUIDES GOPIKA, DEEPA, USHA]