Symbol:Cd
Melting point:321.1'C
Electron configuration:[Kr]4d105s2
Atomic number:48
Atomic mass:112.4110.008u
OreCommon NameFormula
SulphideGreenochiteCds

Cadmium

Cadmium is a bluish white metal having a brilliant luster and closely resembling zinc. It is very malleable and ductile. It has melting point at 320'C. It is found as sulphide. It is also found in zinc ore. During the extraction of zinc, cadmium is extracted as a byproduct. The main ore of cadmium is Greenochite(CdS). The producers of cadmium metal are USA, Russia, Germany, Japan, Australia, Canada, Belgium, and Mexico. Cadmium and its compounds are used in different chemicals and pigments. Cadmium is also used in electroplating and metal spraying. It is used for making aluminium and cadmium alloys to produce electrical transmission wire. Cadmium coating is applied to copper alloys, aluminium alloys and magnesium based alloys. The coating of cadmium is white and the luster is bright. It has high resistance to the alkalis. It is also resistant to sea water and other tropical corrosion effects.

Plating of Cadmium

It can be done by vapor deposition and electroplating method. Cadmium vapor is spread into a chamber where the equipments to be electroplated are kept. Then these equipment's are rotated. Due to continuous spray and rotation the cadmium vapor is deposited. Electrolysis is carried out by making electrolyte with cadmium oxide, sodium cyanide and sodium hydroxide. The temperature is kept between 20'C to 40'C. The anode is of cadmium plated copper rods. The cathode is the equipment to be plated with cadmium metal. Stainless steel equipments are also used as cathode for plating of cadmium. The refrigeration parts, auto-mobile parts, underwater equipments and aircraft components are electroplated with cadmium. The cadmium plating is very thin and meets moderate conditions of corrosion.