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 Page 1


Mislaneous Buildings Materials                                               
  
CHAPTER 8 
MISLANEOUS BUILDINGS MATERIALS 
8.1 Metals: Metals are employed for various engineering purposes 
such as structural members, roofing materials, damp proof 
courses, pipes, tanks, doors, windows etc out of all the metals, 
iron is the most popular metal and it has been used in 
construction activity since pre-historic times. For the purpose of 
study metals are grouped in the following two categories 
(i) Ferrous metals: Ferrous metals contain iron as their main 
constituent  
Ex: Cast iron, wrought iron, steel 
(ii) Non-ferrous metal: Non ferrous metal does not contain 
iron as their main constituent 
Ex: Aluminium, copper etc 
Important varieties of iron ores: 
 The following are the important commercial varieties of iron 
ores, which are commonly used, in the manufacturing process 
(1) Haematite – Red oxide of iron (Fe
2
O
3
) 65 to 70% of iron 
(2) Limonite – 2Fe
2
O
3
, 3H
2
O ( 60% of iron) 
(3) Magnetite – Fe
3
O
4 
(70 to 73% of iron) 
(4) Pyrite – FeS
2
 (45 to 47% of iron) 
(5) Siderite – FeCO
3
 (40% of iron) 
Page 2


Mislaneous Buildings Materials                                               
  
CHAPTER 8 
MISLANEOUS BUILDINGS MATERIALS 
8.1 Metals: Metals are employed for various engineering purposes 
such as structural members, roofing materials, damp proof 
courses, pipes, tanks, doors, windows etc out of all the metals, 
iron is the most popular metal and it has been used in 
construction activity since pre-historic times. For the purpose of 
study metals are grouped in the following two categories 
(i) Ferrous metals: Ferrous metals contain iron as their main 
constituent  
Ex: Cast iron, wrought iron, steel 
(ii) Non-ferrous metal: Non ferrous metal does not contain 
iron as their main constituent 
Ex: Aluminium, copper etc 
Important varieties of iron ores: 
 The following are the important commercial varieties of iron 
ores, which are commonly used, in the manufacturing process 
(1) Haematite – Red oxide of iron (Fe
2
O
3
) 65 to 70% of iron 
(2) Limonite – 2Fe
2
O
3
, 3H
2
O ( 60% of iron) 
(3) Magnetite – Fe
3
O
4 
(70 to 73% of iron) 
(4) Pyrite – FeS
2
 (45 to 47% of iron) 
(5) Siderite – FeCO
3
 (40% of iron) 
8.1.1 Pig Iron: The crude impure iron, which is extracted from iron 
ores, is known as pig-iron and it forms the basic material for the 
manufacture of cast-iron, wrought iron and steel. 
The pig iron is manufactured by the following operations 
(i) Dressing: Crushed into pieces 25mm, impurities of clay, 
loam and other earthy matter removed by washing, 
magnetic separators are used for magnetic impurities 
(ii) Calcination and roasting: Water and carbon dioxide are 
removing from ores by calcinations. By roasting, making 
the ares hot and very dry after removal of sulphur 
(iii)Smelting: smelting is carried out in a special type furnace 
known as blast furnace. The raw material consists of iron 
ores, the fluxing materials like limestone and fuel like 
coal, charcoal is allowed to through throat portion of the 
furnace. By the reduction, the pig iron collects in the 
hearth of furnace. The slag formed is removed and hot 
gases dust escapes through outlet, which is provided in 
the throat portion of furnace as shown in fig 8.1. 
Page 3


Mislaneous Buildings Materials                                               
  
CHAPTER 8 
MISLANEOUS BUILDINGS MATERIALS 
8.1 Metals: Metals are employed for various engineering purposes 
such as structural members, roofing materials, damp proof 
courses, pipes, tanks, doors, windows etc out of all the metals, 
iron is the most popular metal and it has been used in 
construction activity since pre-historic times. For the purpose of 
study metals are grouped in the following two categories 
(i) Ferrous metals: Ferrous metals contain iron as their main 
constituent  
Ex: Cast iron, wrought iron, steel 
(ii) Non-ferrous metal: Non ferrous metal does not contain 
iron as their main constituent 
Ex: Aluminium, copper etc 
Important varieties of iron ores: 
 The following are the important commercial varieties of iron 
ores, which are commonly used, in the manufacturing process 
(1) Haematite – Red oxide of iron (Fe
2
O
3
) 65 to 70% of iron 
(2) Limonite – 2Fe
2
O
3
, 3H
2
O ( 60% of iron) 
(3) Magnetite – Fe
3
O
4 
(70 to 73% of iron) 
(4) Pyrite – FeS
2
 (45 to 47% of iron) 
(5) Siderite – FeCO
3
 (40% of iron) 
8.1.1 Pig Iron: The crude impure iron, which is extracted from iron 
ores, is known as pig-iron and it forms the basic material for the 
manufacture of cast-iron, wrought iron and steel. 
The pig iron is manufactured by the following operations 
(i) Dressing: Crushed into pieces 25mm, impurities of clay, 
loam and other earthy matter removed by washing, 
magnetic separators are used for magnetic impurities 
(ii) Calcination and roasting: Water and carbon dioxide are 
removing from ores by calcinations. By roasting, making 
the ares hot and very dry after removal of sulphur 
(iii)Smelting: smelting is carried out in a special type furnace 
known as blast furnace. The raw material consists of iron 
ores, the fluxing materials like limestone and fuel like 
coal, charcoal is allowed to through throat portion of the 
furnace. By the reduction, the pig iron collects in the 
hearth of furnace. The slag formed is removed and hot 
gases dust escapes through outlet, which is provided in 
the throat portion of furnace as shown in fig 8.1. 
Mislaneous Buildings Materials                                          
  
 
Fig 8.1  Blast Furnace 
8.1.2 Cast iron: 
Cast iron is manufactured by remelting pig iron with coke and 
limestone. This remelting is done in a furnace known as cupola 
furnace, which is more or less same as blast furnace. Its shape is 
cylindrical with diameter about 1m and height of about 5m as 
Page 4


Mislaneous Buildings Materials                                               
  
CHAPTER 8 
MISLANEOUS BUILDINGS MATERIALS 
8.1 Metals: Metals are employed for various engineering purposes 
such as structural members, roofing materials, damp proof 
courses, pipes, tanks, doors, windows etc out of all the metals, 
iron is the most popular metal and it has been used in 
construction activity since pre-historic times. For the purpose of 
study metals are grouped in the following two categories 
(i) Ferrous metals: Ferrous metals contain iron as their main 
constituent  
Ex: Cast iron, wrought iron, steel 
(ii) Non-ferrous metal: Non ferrous metal does not contain 
iron as their main constituent 
Ex: Aluminium, copper etc 
Important varieties of iron ores: 
 The following are the important commercial varieties of iron 
ores, which are commonly used, in the manufacturing process 
(1) Haematite – Red oxide of iron (Fe
2
O
3
) 65 to 70% of iron 
(2) Limonite – 2Fe
2
O
3
, 3H
2
O ( 60% of iron) 
(3) Magnetite – Fe
3
O
4 
(70 to 73% of iron) 
(4) Pyrite – FeS
2
 (45 to 47% of iron) 
(5) Siderite – FeCO
3
 (40% of iron) 
8.1.1 Pig Iron: The crude impure iron, which is extracted from iron 
ores, is known as pig-iron and it forms the basic material for the 
manufacture of cast-iron, wrought iron and steel. 
The pig iron is manufactured by the following operations 
(i) Dressing: Crushed into pieces 25mm, impurities of clay, 
loam and other earthy matter removed by washing, 
magnetic separators are used for magnetic impurities 
(ii) Calcination and roasting: Water and carbon dioxide are 
removing from ores by calcinations. By roasting, making 
the ares hot and very dry after removal of sulphur 
(iii)Smelting: smelting is carried out in a special type furnace 
known as blast furnace. The raw material consists of iron 
ores, the fluxing materials like limestone and fuel like 
coal, charcoal is allowed to through throat portion of the 
furnace. By the reduction, the pig iron collects in the 
hearth of furnace. The slag formed is removed and hot 
gases dust escapes through outlet, which is provided in 
the throat portion of furnace as shown in fig 8.1. 
Mislaneous Buildings Materials                                          
  
 
Fig 8.1  Blast Furnace 
8.1.2 Cast iron: 
Cast iron is manufactured by remelting pig iron with coke and 
limestone. This remelting is done in a furnace known as cupola 
furnace, which is more or less same as blast furnace. Its shape is 
cylindrical with diameter about 1m and height of about 5m as 
shown in fig 8.2. The raw materials are led from the top and the 
furnace is fired. The impurities of pig iron are removed to some 
extent by oxidation. The molten cast iron is led into moulds of 
required shapes to form what are known as cast iron castings and 
slag is removed from the top of cast iron at regular intervals. 
 
Fig 8.2 Cupola Furnace 
 
Page 5


Mislaneous Buildings Materials                                               
  
CHAPTER 8 
MISLANEOUS BUILDINGS MATERIALS 
8.1 Metals: Metals are employed for various engineering purposes 
such as structural members, roofing materials, damp proof 
courses, pipes, tanks, doors, windows etc out of all the metals, 
iron is the most popular metal and it has been used in 
construction activity since pre-historic times. For the purpose of 
study metals are grouped in the following two categories 
(i) Ferrous metals: Ferrous metals contain iron as their main 
constituent  
Ex: Cast iron, wrought iron, steel 
(ii) Non-ferrous metal: Non ferrous metal does not contain 
iron as their main constituent 
Ex: Aluminium, copper etc 
Important varieties of iron ores: 
 The following are the important commercial varieties of iron 
ores, which are commonly used, in the manufacturing process 
(1) Haematite – Red oxide of iron (Fe
2
O
3
) 65 to 70% of iron 
(2) Limonite – 2Fe
2
O
3
, 3H
2
O ( 60% of iron) 
(3) Magnetite – Fe
3
O
4 
(70 to 73% of iron) 
(4) Pyrite – FeS
2
 (45 to 47% of iron) 
(5) Siderite – FeCO
3
 (40% of iron) 
8.1.1 Pig Iron: The crude impure iron, which is extracted from iron 
ores, is known as pig-iron and it forms the basic material for the 
manufacture of cast-iron, wrought iron and steel. 
The pig iron is manufactured by the following operations 
(i) Dressing: Crushed into pieces 25mm, impurities of clay, 
loam and other earthy matter removed by washing, 
magnetic separators are used for magnetic impurities 
(ii) Calcination and roasting: Water and carbon dioxide are 
removing from ores by calcinations. By roasting, making 
the ares hot and very dry after removal of sulphur 
(iii)Smelting: smelting is carried out in a special type furnace 
known as blast furnace. The raw material consists of iron 
ores, the fluxing materials like limestone and fuel like 
coal, charcoal is allowed to through throat portion of the 
furnace. By the reduction, the pig iron collects in the 
hearth of furnace. The slag formed is removed and hot 
gases dust escapes through outlet, which is provided in 
the throat portion of furnace as shown in fig 8.1. 
Mislaneous Buildings Materials                                          
  
 
Fig 8.1  Blast Furnace 
8.1.2 Cast iron: 
Cast iron is manufactured by remelting pig iron with coke and 
limestone. This remelting is done in a furnace known as cupola 
furnace, which is more or less same as blast furnace. Its shape is 
cylindrical with diameter about 1m and height of about 5m as 
shown in fig 8.2. The raw materials are led from the top and the 
furnace is fired. The impurities of pig iron are removed to some 
extent by oxidation. The molten cast iron is led into moulds of 
required shapes to form what are known as cast iron castings and 
slag is removed from the top of cast iron at regular intervals. 
 
Fig 8.2 Cupola Furnace 
 
Mislaneous Buildings Materials                                         
  
Composition of cast iron: 
(1) Cast iron contains about 2 to 4 percent of carbon. 
(2) Manganese makes cast iron-brittle and hard, so it may be kept 
below  0.75 percent. 
(3) Phosphorous makes brittle and percentage may be 1 to 1.5 
percent. 
(4) Silicon decreases shrinkage and ensures softer and better 
castings and it may be less than 2.5 percent. 
(5) Sulphur makes cast iron brittle and hard and should be kept 
below 0.10 percent. 
 
Properties of casi-iron: 
(1) If placed in salt water, it becomes soft. 
(2) It can be hardened by heating and sudden cooling. 
(3) It cannot be magnetized. 
(4) It does not be rust easily. 
(5) It is fusible. 
(6) It is hard, but brittle also. 
(7) It is not ductile and cannot be adopted to absorb shocks and 
impacts. 
(8) Melting temperature is about 1250
0
 C. 
(9) It shrinks on cooking.