Chemistry

Salt for the chemical industry 

Salt is an essential raw material for many industrial processes. It is mainly used in three major sectors of the chemical industry:
• the electrolysis of sodium chloride
• the manufacture of sodium carbonate
• the production of sodium sulphate

The electrolysis of sodium chloride

The electrolysis of sodium chloride yields:
• chlorine
• caustic soda (sodium hydroxide)
• and, under certain conditions, sodium chlorate or metallic sodium  

Chlorine is mainly used in the manufacture of plastics, particularly PVC (polyvinyl chloride), but also to produce chlorinated solvents and bleaching and disinfecting agents, such as bleach.

Soda ash is a key intermediate in chemistry. It is used in many sectors, notably in the manufacture of man-made fibres, paper pulp and alumina.   

Sodium chlorate is used as a bleaching agent or as a weedkiller.

Sodium metal is used in organic chemistry as a synthetic agent, as well as in the nuclear industry, where it can serve as a heat transfer fluid.

Sodium carbonate

Sodium carbonate, commonly known as ‘soda crystals’ in domestic use, is an important reagent (base) in the chemical industry.

It is mainly used in the glass industry. Its production relies on the use of several raw materials:
• sodium chloride
• calcium carbonate (limestone)
• as well as an intermediate: ammonia

Sodium sulphate

Sodium sulphate is used in several industrial sectors:   
• the paper industry, for the treatment of wood pulp
• the glass industry
• the manufacture of detergents
• and as an intermediate in the production of other chemicals

It is produced by a thermal process in which crystallised sodium chloride is mixed with sulphuric acid at a temperature above 550 °C.