The Production of Iron in the Blast Furnace & Steel-Making

Question 1

What is the main ore of iron?

Answer 1

Hematite, Fe₂O₃

Question 2

_____ makes iron harder and stronger in steel.

Answer 2

Carbon

Question 3

Steels are _____ in which the main metal is iron.

Answer 3

Alloys

Question 4

_______ is used to extract iron.

Answer 4

Blast furnace

Question 5

Blast furnace step 1:

Answer 5

Input Iron Ore, Coke (Carbon), and Limestone (raw materials)

Fe₂O₃, C & CaCO₃

Question 6

Blast furnace step 2:

Answer 6

Coke burns in excess of hot air at the bottom of the furnace to produce Carbon Dioxide
C + O₂ → CO₂

Question 7

Blast furnace step 3:

Answer 7

Carbon Dioxide gets reduced by Carbon

CO₂ + C → 2CO

Question 8

Blast furnace step 4:

Answer 8

Carbon Monoxide reduces Iron Ore

Fe₂O₃ + 3CO → 2Fe + 3CO₂

Question 9

Blast furnace step 5:

Answer 9

Limestone thermally decomposes, helps remove impurity of sand (silica, SiO₂)
CaCO₃ → CaO + CO₂

Question 10

Blast furnace step 6:

Answer 10

Calcium Oxide reacts with Silicon Dioxide (impurities) to form slag, which is then tapped off
CaO + SiO₂ → CaSiO₃

Question 11

What is sinter?

Answer 11

Mixture of coke, limestone and ore created to place in the blast furnace

Question 12

What is air for in blast furnace?

Answer 12

Oxygen is needed to burn the coke and form carbon monoxide (2C+O₂ → 2CO)

Question 13

Why is coke needed in a blast furnace?

Answer 13

The Coke burns to produce carbon monoxide:
2C + O₂ → 2CO
The carbon monoxide then reacts with iron ore to release pure iron:
Fe₂O₃ + 3CO → 2Fe + 3CO₂

Question 14

What is silica?

Answer 14

•The main impurity (sand or rock) which is silicon dioxide •Silicon dioxide reacts with calcium oxide
to form calcium silicate (called slag) which is liquid in the furnace
•Slag flows to the bottom of the furnace
where it floats on the liquid iron and is easily removed

Question 15

How is silica removed from the iron ore?

Answer 15

• Silicon (Si) reacts with air to form Silica, SiO₂

* Silica, SiO₂ reacts with decomposed limestone (CaO or quicklime) to form CaSiO₃, which is slag

Question 16

Slag can be used for ____

Answer 16

Cement

Question 17

Is the iron coming out of the blast furnace pure?

Answer 17

No, it has carbon impurities and is more brittle, referred to as pig iron or cast iron

Question 18

What ingredients are needed to create steel from pig iron?

Answer 18

• Oxygen & lime

* Oxygen (air) is needed to form the oxides of impurities, which then react with lime to form slag

Question 19

Why use steel instead of iron?

Answer 19

It is stronger, more durable, can be alloyed with chromium to form stainless steel

Question 20

What ingredients are put into the blast furnace?

Answer 20

• Iron ore
• Coke
• Limestone
• Hot air

Question 21

Why is iron alloyed with carbon?

Answer 21

So that its strength can be varied and it can be used for many different purposes

Question 22

What is one reason why blast furnaces are dangerous?

Answer 22

They produce carbon monoxide (CO), which is very poisonous

Question 23

The amount of carbon in steels vary between __% and __%

Answer 23

0.2 and 1.5

Question 24

Uses of cast iron.

Answer 24

Gear boxes

Question 25

Uses of mild steel.

Answer 25

Chains

Question 26

Uses of medium steel.

Answer 26

Axles

Question 27

Uses of high-carbon steel.

Answer 27

Razor blades

Question 28

Uses of stainless steel.

Answer 28

Surgical instruments

Question 29

Uses of tungsten steel.

Answer 29

Edges of high-speed cutting tools

Question 30

Uses of manganese steel.

Answer 30

Springs

Question 31

Oxidation is the ____ of electrons.

Answer 31

Loss

Question 32

Reduction is the ____ of electrons.

Answer 32

Gain

Question 33

What does brittle mean?

Answer 33

Easily broken

Question 34

Only ______ alloy makes it weaker.

Answer 34

Soldering

Question 35

Blast furnace temperature:

Answer 35

1500 °C