General Princioles Of Metallurgy

Question 1

What is the formula of Aluminium ore?

Answer 1

Bauxite (Al₂O₃·2H₂O)

Bauxite is the primary ore of aluminium.

Question 2

What is the formula of Zinc ore?

Answer 2

Zincblende (ZnS), Calamine (ZnCO₃)

These are common ores from which zinc is extracted.

Question 3

What is the formula of Iron ore?

Answer 3

Haematite (Fe₂O₃), Siderite (FeCO₃)

These are key sources of iron.

Question 4

What is the formula of Copper ore?

Answer 4

Copper pyrites (CuFeS₂)

Copper pyrites is a major ore for copper extraction.

Question 5

What is the role of cryolite in the metallurgy of aluminium?

Answer 5

1) Increases the conductivity of alumina
2) Decreases the melting point of molten metal

Cryolite is used to improve the efficiency of the electrolysis process.

Question 6

Explain ‘poling’ in metallurgy.

Answer 6

Poling is the process of purifying an ore containing its own oxide as impurity by stirring molten metal with logs of green wood, releasing hydrogen gases to reduce oxide impurities.

This is commonly used in the refining of blister copper.

Question 7

What is the role of silica in the metallurgy of copper?

Answer 7

Silica acts as an acidic flux to remove iron oxide (FeO) as slag (FeSiO₃).

This helps in the purification of copper during extraction.

Question 8

Give the composition of Brass.

Answer 8

60-80% Cu; 20-40% Zn

Brass is an alloy primarily made of copper and zinc.

Question 9

Give the composition of German silver.

Answer 9

50-60% Cu; 10-30% Ni; 20-30% Zn

German silver is a nickel silver alloy that contains copper, nickel, and zinc.

Question 10

Give the composition of Bronze.

Answer 10

75-90% Cu; 10-25% Sn

Bronze is an alloy of copper and tin.

Question 11

What is matte?

Answer 11

Matte is the molten mixture of cuprous sulphide (Cu₂S) and small amounts of ferrous sulphide (FeS) obtained after smelting during copper extraction.

It is an intermediate product in the production of copper.

Question 12

What is blister copper?

Answer 12

Blister copper is copper obtained after bessemerisation of matte, with a purity of 97-98%.

It gets its name from the blisters formed on the metal surface due to dissolved SO₂.

Question 13

What is the difference between a mineral and an ore?

Answer 13

1) Minerals are natural metal substances present in the earth’s crust.
2) All minerals are not ores; ores are profitable minerals that can be used to extract metals.

Example of minerals: Bauxite and Cryolite.

Question 14

What is the ore of Aluminium?

Answer 14

Bauxite

Bauxite is the primary source of aluminium.

Question 15

True or False: All ores are minerals.

Answer 15

True

However, not all minerals are ores.