Uses Of Copper and Its Alloy

COPPER :

Copper is easily distinguished from all other metals on account of its red color. It is not found in pure state under the earth. Copper is extracted for copper ores., the chief being copper pyrites. Copper ore is first ground and then smelted in a reverberatory or small blast furnace producing an impure alloy called matte. In the second step air is blown through the molten metal to remove Sulphur and Iron contamination to obtain blister copper in the converter. In the last stage further refinement is carried out to produce pure copper (99.9 per cent) using electrolysis. For pyrites (CuFeS2) and copper glance (Cu2S) , the roasting / smelting process liberates fumes of Sulphur and arsenic which are mandatory for the smelting unit. In India, copper ore is found at Ghatsila in Bihar.

Copper is relatively soft and is very malleable, ductile and flexible, yet very tough and strong. A very efficient conductor of heat and electricity , being second only to silver, it is largely used in wire and sheet form for electrical purposes. Copper may be cast, forged , rolled and drawn into wires. It is non - corrosive under ordinary conditions and it resists weather very effectively . Copper in the form of tubes in used widely in mechanical engineering and also used in the making of munitions. The mechanical properties of copper depend upon its condition. Casting may have a tensile strength of 15 to 17 kg-f per mm2 ( 150 - 170 Newton per mm2) which may be increased to 21.5 to 23.0 by working. The strength of hard - drawn copper wire may be as high as 38 to 46 kg-f per mm2. The melting point of copper is 1083*C.

ALLOYS OF COPPER :

Copper may be alloyed with a wide range of other elements to produce many different alloy groups of Industrial Importance. The Most Important are :

1. Copper Aluminum ( The Aluminum Bronzes).

2. Copper - tin - Antimony ( Babbitt metal).

3. Copper - tin ( The tin Bronzes ).

4. Copper - tin - Phosphorus ( The phosphor Bronzes ).

5. Copper - zinc ( The Brasses ).

6. Copper - Nickel ( The Cupro-Nickels).

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