Caustic soda is a white, odorless, and solid inorganic compound chemical. Its water solution has numerous applications in different industries because of its highly caustic base and alkalescence. Sodium hydroxide, with the formula NaOH, also known as lye and caustic soda, is a popular strong caustic base. Caustic soda is used in many industries in order to increase the alkalinity of different environments or to dissolve grease, oils, fats and protein-based deposits; So much so that, it’s generally regarded as industrial degreaser and oil remover. The solubility of Caustic Soda in 100 milliliters of 20 centigrade water is 111 grams. Although, its solubility increases as the water gets warmer. It is also soluble in equal proportion in organic solvents such as ethanol, methanol and glycerin.
Caustic Soda is available in four forms.
1. Liquid Caustic Soda or Lye
Caustic Soda Flakes production from liquid caustic soda
Sodium hydroxide, also known as liquid caustic soda, is a corrosive alkali. For storing it in balk or in the production line, special pipes and connectors are needed. Nickle plates, because of their anti-corrosion capability, are generally used in the factories that deal with this chemical. Liquid Soda is turned into solid form for easy handling, storing or transportation.
Using premium quality liquid soda and also up-to-date equipment in producing caustic soda flakes, leads to the production of a very pure and high quality product. Liquid caustic soda flakes is obtained from hydrolysis of brine solution at petrochemical industries and liquid castic soda production plants. Then it is shipped to caustic soda flakes producing plants by means of specific tanks and offloaded in special containers. Chloric Acid, Clorox, Perchlorate, chlorine Gas, and some other chemicals are the by-products of the Liquid caustic soda production process. At the plant, liquid caustic soda is transported from the main container to a small overhead container from which it then cascaded to nickel trays. By heating up to 1400 ºc it is concentrated and transformed from 50% liquid soda to 98% caustic soda flakes. After receiving enough heat, it is carried to cooling drive apparatus and by means of cooling process it converts to thin sheets of caustic soda flakes in the circular walls of grauf. During this process the water content of caustic soda flakes is evaporated and the result product is 98% purified caustic soda flakes which is highly alkaline and corrosive. Right after production, caustic soda flakes are packed in the form of 25kg, 2ply packages which are properly sewed. This matter prevents caustic soda flakes from absorbing humidity and being conglomerated.
Sodium hydroxide, as a powerful alkali, is one of the major industrial chemicals. For example, its production in USA in 1980 was around 12 million tons. Sodium hydroxide is used in many industries in manufacture of pulp and paper, paint factories, Aluminum industry, textiles, drinking water, soaps and detergents and as a drain cleaner. Titrations by standard Sodium hydroxide solution are a very common technique used in labs to quantitatively analyze unknown acids. Olives can be rapidly cured by placing them in a lye (sodium hydroxide) solution. Unfortunately, in this process, if all traces of lye are not removed with a series of cold water rinses, the lye residue may have undesirable effects on consumers’ health.
There are 2 forms of solid and liquid caustic soda in the market. High quality liquid caustic soda usually comes in 2 forms of 50% and 33% purities and is the chief format for exportation; and consequently is more in demand because of its lower price.
Here are some of the industries which use the caustic soda on a regular basis:
-Paints and resins and adhesives industry
-Paper and cardboard Industries
-Leather and Textile Industries
-Oil, Gas and Petrochemical industries
- Automotive industry and neutralizing the acid and battery-manufacturing
- Degreasers industry and other related industries
- Food and Agriculture Industry, milk and dairy industry, canning,
-Beverage factories, edible oil industry and sugar mills.
- Pharmacy and alcohol industry and cosmetics industry
-Metal and plating Industries and, galvanizing, zinc, aluminum
Incompatible materials to Caustic soda
Caustic soda Flakes or solid absorbs air moisture very quickly and deforms and converts into liquid. In addition, due to the extremely high corrosion of this product, it should be maintained in plastic containers with lids and aluminum containers should not be used.
It reacts with many organic and inorganic materials. For example, it combines with strong acids, aromatic nitro, nitro- paraffin compounds and organo-halogen, glycols and organic Peroxides. It burns through P.E.T. plastics such as plastic drink bottles and perforates them. Some metals, also, may react vigorously with sodium hydroxide. The reaction thus produces hydrogen gas.