Pig Iron

Question 1

General

Answer 1

Most impure form
C- 5 to 6%
Blast furnace

Question 2

Manufacturing process

Answer 2

Dressing
Calcination and roasting
Smelting

Question 3

Dressing

Answer 3

Process of removal of impurities from iron ore
Iron ore- 25mm sized pieces- washing or electromagnetic separation

Question 4

Calcination and roasting

Answer 4

Calcination : to remove co2
Roasting : to remove volatile material like sulphur

Question 5

Smelting

Answer 5

Melting of iron ore
To remove metal
Done in blast furnace

Question 6

Blast furnace parts

Answer 6

Throat_feeding zone(ore, fuel, flux-limestone)_bell and cone /double cup and cone.

Stack/inwall_18m_85-87°

Cylinder/barrel_total length:dia of cylinder =>4 to 4.5

Bosh_ burning zone_hottest part_ht=10-20% of total ht_76-80°

Hearth/crucible

Tuyers_ air circulation

Question 7

Properties of pig iron

Answer 7

Fusible temp-1200°C
Do not rust
Strong in compression
Weak in tension and shear
Cannot be magnetized, welded, riveted, tempered

Question 8

Types of pig iron

Answer 8

Bessemer pig_steel_haematite ore
Grey/foundry_cast iron
White/forged_wrought
Mottled pig_between grey and white pig_strong_heavy foundry casting