Chemical Industries SS1 Chemistry Lesson Note

A Chemical industry is defined as one that uses chemistry to make chemicals from other chemical substances (raw materials).

The important raw materials used in the chemical industry include:

(i) air 

(ii) CaCO3 

(iii) Sea water and rock salt 

(iv) Sulphur 

(v) Metallic mineral ore 

(vi) Coal

(vii) Natural gas and petroleum.

SOURCES OF RAW MATERIALS IN CHEMICAL INDUSTRY

1. AIR: Air is the chief source of O2 and N2. N2 is important because it is used in the manufacture of NH3. NH3 itself is used in the manufacture of trioxonitrate (v) acid which is used in the making of explosives, plastics and other materials. NH3 is also used in the manufacture of NH4+ salts like HN4 and O3, (NH4)2SO4 which are used in manufacturing fertilizers.
2. CALCIUM TRIOXOCARBONATE (iv) (CaC03): CaCO3 in the form of limestone, chalk and marble is the source of lime or calcium oxide which is used for making concrete and cement. It can also be the source of raw materials for the production of baking powder and also for CO2 which can be used to produce sodium trioxocarbonate (iv) by the Solvay process.
3. SEA WATER AND ROCK SALT: Salt or NaCl occurs as rock salt in underground deposits and seaseawaterdium chloride salt is the major starting material for many chemical industries. Sea water is also the source of NaBr from which bromine is manufactured on a large scale. Electrolysis of NaCl produces chlorine. 

The other main product is NaOH which is used in the manufacture of soap and textiles and petroleum refining, as well as other chemicals such as Na2CO3 which is also a source of material for the glass industry and in the manufacture of detergents. It is also used in the softening of water in the public water works department. The chlorine produced can be made to react with hydrocarbon obtained from fossil fuel. 

The chlorohydrocarbon are versatile raw material. They are used in the making of synthetic rubber, paint removers, refrigerants and several types of insecticides and industry cleaning.

4. SULPHUR: is an element which is obtained naturally from the ground by the Frasch process or iron pyrites (FeS2), copper pyrite (CuFeS2), gypsum (CaSO4.2H2O) and anhydride which are the raw materials in chemical industries where SO2, H2SO3, H2SO4 are produced. From the acids, compounds like (NH4)2SO4 (fertilizer), paints, dyes, explosives, synthetic fibres and accumulators are manufactured.
5. NATURAL GAS and PETROLEUM: Petroleum is a major and very important raw material for petrochemicals like CH4, ethane, propane, butane, ethyne, butadiene, isoprene, benzene and phenol. From these petrochemicals, other products and chemicals like fertilizers, agricultural motor fibre and plastics are made. These chemicals have their different industries e.g. agricultural industries. Petroleum products like petrol, diesel, and kerosene were marketed by foreign oil companies like Shell, Mobil, Gulf and Texaco.