Commonly known as Caustic soda, lye or sodium hydrate, it is a white crystalline substance used in a variety of industrial applications, including pulp, paper, detergent and chemical processing industry. And it is also used in the alumina, petrochemical and textile industries. Chemical compound NaOH, it is commercially available in solid forms (e.g., pellets, sticks or chips) and in water solutions of various concentrations. Both forms vary in purity. It readily absorbs carbon dioxide and moisture from the air. It is soluble in water, alcohol and glycerin, and it also is caustic.
Caustic Soda is most commonly manufactured by the electrolysis of salt brine using diaphragm, membrane or mercury cell technology. Chlorine and hydrogen are co-produced using all three technologies.
Caustic Soda Applications
Caustic soda is used in a variety of industrial applications as a reactant in manufacturing other sodium compounds which may be intermediate or end-use products. Items such as sodium hypochlorite used as household bleach and disinfectant, and sodium phenolate used in antiseptics and for manufacturing aspirin.
Caustic soda is used in the manufacturing of soaps and surfactants in soap powders. Soap, a mixture of chemical compounds, is formed by the hydrolysis of animal and vegetable oils and fats. Soap powders consist of a mixture of soap and other ingredients which themselves may be sodium chemicals.
The use of caustic soda is confined primarily to finishing operations in the textile industry. This includes scouring (removing contaminants such as pectins and waxes), bleaching (treating scoured cloth with an oxidizing agent) and mercerizing (improving luster and dye absorption).
Caustic soda is supplied in the form of beads, prills and powder.