The major chemicals manufactured by using sodium metal and other applications are summarized blow:

• Tetra ethyl lead and tetra methyl lead-antiknocking agent for gasoline.
• Organo-metallic compounds.
• Manufacture of refractor metal such as titanium, zirconium and hafnium by sodium reaction to their halides.
• Also for manufacture of tantalum, silicon, magnesium and other metals.
• Metallic potassium and potassium-sodium alloys.
• Calcium metal and calcium hydride.
• Sodium hydride, sodium peroxide.
• Descaling of metals such as stainless steel and titanium.
• As reducing agents in many preparation, manufacture of dyes, herbicides, pharmaceuticals, high molecular weight alcohol’s, perfume materials, Isobasic acid.

The total demand of sodium metal in the country at present is about 1000 TPA out of which the drugs and pharmaceutical industry itself consumes about 950 TPA. There is only one manufacturing unit of sodium metal having its production capacity approximately 200 tonnes per annum. The balance of the demand in the country is met by imports.

PROCESS

Sodium metal is produced by the electrolysis of a molten mixture of Sodium Chloride, Calcium Chloride and Barium Chloride at appropriate temperature employing graphite anode and annular steel cathode. Sodium metal, formed at the cathode, comes up due to lower density compared to the electrolyte and collects in a steel collector ring kept over the cathode where from the molten metal flows into a receiver through raiser pipe. The metal is tapped out periodically from the receiver and cast in ingot moulds.

Chlorine is the main by- product/ effluent which is treated by Calcium Hydroxide. Provision can also be made for bottling of chlorine gas in which case, however a treatment plant for killing chlorine in tail end gases would need to be provided. Killing of chlorine by Calcium hydroxide produces bleaching powder, which can be sold commercially. However, the economy of the same has to be worked out separately and has not been considered in this profile.