Extraction Of Iron From Ore_putligarh(g)_amritsar

IRON

It is about 21% of total metal of earth’s crust and 6.2% of total elements. It belongs to transition group of the periodic table. Its electronic configuration is 2,8,8,6,2.

1)Important 1)Important ores of iron (i) Haematite Fe2O3 (ii) Magnetite Fe3O4 (iii) Limonite Fe2O3,3H2O (iv) Iron pyrites FeS2 (v) Sidrite FeCO3

2) Extraction of iron:- Cast iron is extracted from haematite. It involves following steps:

(i) Concentration of ore:- First of all ore is crushed into minute particles and the crushed ore is concentrated by gravity separation method.

(ii) Calcination:-

Concentrated ore is

calcinated in a furnace. During calcinations moisture is removed. Impurities like Sulphur changes into sulphur dioxide and Arsenic into arsenic oxide (AS2O3) phosphorus to phosphorus oxide (P4O10), all escape out in the form of gases.

(iii) Smelting:-

Iron oxide is reduced with

carbon. Process of smelting is done in blast furnace. Calcinated iron oxide is added in blast furnace along with coke. Coke serves as fuel as well as reducing agent. Lime is also added in the blast furnace which serves as flux. The following reaction takes place in the furnace. (a)

At the base of the furnace coke reacts with oxygen to produce carbon dioxide which moves up and a lot of heat is produced. C + O2 CO2

Coke

Oxygen

Carbon dioxide As the carbon dioxide moves upward it is brought in contact with coke and get converted into carbon monoxide. CO2

+

C

2CO Carbon dioxide

Coke

Carbon Mono-oxide At this zone temperature is 1475-1575 K. In the middle of the furnace temperature is 1075 to 1275 K. In this region calcium carbonate decomposes to produce calcium oxide & carbon dioxide. Calcium oxide so produced combines with silica to form slag. CaCO3 CaO (b)

+

CO2

Calcium carbonate

Calcium oxide

Carbon dioxide CaO

+

SiO2

CaSiO3 Calcium oxide

Silica

Calcium silicate (slag) (c)

At the top portion of furnace the Iron oxide react with carbon monoxide to give liquid iron which moves towards the button of furnace & settled there. This iron is called Cast iron. Fe2O3 +

+

3CO

CO2

Ferric oxide

Carbon Iron

Carbon Monoxide dioxide

Fe

PREPARED BY:Megha Arora Ravina Chawla

GUIDED BY:-

Smt. Asha Rani Govt. Girls Sec. School, Putlighar, ASR.