SLIDE 0
Mulungushi University
School of Science, Engineering and Technology
Department of Engineering
Bachelor of Engineering in Mechanical Engineering
MEE 242
Engineering Materials II
Lecturer: Dr. Hamweendo A.
LECTURE 11: IRON AND STEEL PRODUCTION
Slide 1
ENGINEERING MATERIALS MEE 242
LESSON 11: IRON PRODUCTION
At the end of this lesson you will know:
1. Raw materials required for iron production,
2. Iron production process in blast furnace,
3. Composition of pig iron product.
Slide 2
RAW MATERIALS REQUIRED IN IRON PRODUCTION
1. IRON ORES :
• Hematite (𝑭𝒆𝟐 𝑶𝟑 ): The principal ore used in the
production of iron, (contain up around 70% iron).
•
Other ores (Contains 50%-70% iron):
 Magnetite (Fe3 O4 )
 Siderite (FeCO3 )
 Limonite(Fe2 O3 .x𝐻2 0. where x = 1.5 approx.)
•
Scrap iron and steel are also widely used today as
raw materials in iron- and steel making
Slide 3
2. OTHER RAW MATERIALS REQUIRED IN
IRON-MAKING
•Coke : Supplies heat for chemical reactions and
produces carbon monoxide (CO) to reduce iron ore,
•Limestone: used as a flux to react with and remove
impurities in molten iron as slag’
•Hot gases (CO, 𝐶𝑂2 , 𝐻2 , 𝐻2 𝑂, 𝑁2 , 𝑂2 , and fuels): used to
burn coke.
Slide 4
PROPORTIONS OF RAW MATERIALS IN IRON-MAKING
To produce one ton of iron, about seven tons of raw
materials are required :
• 2.0 tons of iron ore
• 1.0 ton of coke
• 0.5 ton of limestone
• 3.5 tons of gases
A significant proportion of the by products from iron
production are recycled.
Slide 5
IRON-MAKING IN A BLAST FURNACE
• Blast furnace is a refractory-lined
chamber with a diameter of about
9 to 11 m and a height of 40 m.
• To produce iron, a charge of ore,
coke, and limestone are dropped
into the top of a blast furnace
• Hot gases are forced into the lower
part of the chamber at high rates to
accomplish
combustion
and
reduction of the iron ore to iron by
various REDOX reactions .
Figure1: Blast furnace for iron production.
Slide 6
REDUCTION-OXIDATION (REDOX) REACTION IN IRON MAKING
Hematite reaction with coke: Reduction of 𝑭𝒆𝟐 𝑶𝟑 , Oxidation of CO.
𝑭𝒆𝟐 𝑶𝟑 + CO = 2FeO + 𝑪𝑶𝟐 ……..(1)
𝑪𝑶𝟐 reacts with coke to produce more CO: Oxidation of Coke
𝑪𝑶𝟐 + C (coke) = 2CO
……..(2)
CO reduces Fe0 to Fe and is oxidized to 𝑪𝑶𝟐
FeO + CO = Fe + 𝑪𝑶𝟐
……..(3)
Slide 7
COMPOSITION OF PIG IRON FROM THE BLAST FURNACE
• Iron tapped from the blast furnace is called pig iron.
• Pig iron contains over Carbon (4%) + Silicon (0.3-1.3%),
Manganese (0.5-2.0%), Phosphorous(0.1-1.0%), and
Sulphur ( 0.02-0.08%)
• Further refinement of pig iron is required to produce cast
iron and steel (see lesson 13):
 To convert pig iron into gray cast iron, we use a furnace
called a cupola.
 To produce steel from pig iron, the amount of
impurities in pig iron must be lowered to desired
levels.
Slide 8
END OF TOPIC 11: IRON PRODUCTION
By now you :
1. Raw materials required for iron production,
2. Iron production process in blast furnace,
3. Composition of pig iron product.