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Understanding solid caustic soda

July 10, 2023

What is Solid Caustic Soda (Sodium Hydroxide)?

Sodium hydroxide, also called “Caustic Soda” is a white, crystalline, odorless solid with the chemical formula NaOH which actively absorbs the moisture from the air. It is a highly caustic base, alkali and very soluble in water. It is a synthetically produced substance and can cause severe chemical burns to exposed skin.


Caustic Soda Applications

Sodium hydroxide (caustic soda) is one of the basic raw materials used in almost every industry. Some of the most important uses of Solid Caustic Soda are as follows:

  1.  Alumina Recycling Industries
  2.  Plastic coatings production
  3. Soap and cleaner’s production
  4. Production of various detergents
  5. Processing the textile products
  6. Oil refining
  7. Water and wastewater treatment – producing sediment and corrosion inhibitors
  8. Metal processing
  9.  Various adhesives
  10. Chemical products
  11. Chemicals used in animal husbandry, protection of plants and chemical fertilizers
  12. Food industry
  13.  Metallurgy industry for cleaning metals
  14. Extraction and drilling – metal extraction, oil and gas extraction
  15. Paint and coating industries
  16. Paper industry for producing paper pulp
  17. Industrial raw materials or intermediate compounds in chemical reactions
  18. Bleaching and degreasers
  19. pH regulator in industries
  20. Baking soda and sodium methoxide with caustic soda production
  21. Plunger solution production
  22. Leather and tanning industry
  23. As bleaches


Industrial applications of caustic soda:

  • Sodium hydroxide is used in manufacturing sodium salts and detergents, pH adjustment, and the synthesis of organic compounds.
  • Sodium hydroxide is utilized to increase the alkalinity of the mixture or to neutralize the acids.
  • In the oil industry, sodium hydroxide is used as an additive in drilling mud to increase the alkalinity of drilling mud systems, bentonite, increase the viscosity, and neutralize any acidic gases (such as hydrogen sulfide and carbon dioxide).
  • Caustic soda is used in refining crude oil to remove sulfur impurities.
  • Sodium hydroxide is used to produce soap and detergents.
  • Solid caustic soda is used to make synthetic textile fibers (e.g., Rayon).
  • About 56% of the sodium hydroxide produced is used for industrial purposes, of which 25% is used in the paper industry.
  • Caustic soda is used in the refining of bauxite ore from which aluminum metal is extracted. The mentioned process is known as the “Bayer process”.
  • Solid soda is used in degreasing metals, refining oils, and making paints and bleaches.

Food applications of caustic soda:

  • Caustic soda is used in food processing and preparation in food industry. The following includes the use and importance of solid caustic soda:
  • Washing fruits and vegetables in the industry
  • Chocolate and cocoa processing
  • Producing caramel color
  • Cooking chicken
  • Beverage processing
  • Thickening the ice-cream texture
  • Processing and removing the bitterness of olives by increasing the caustic soda
  • Making some desserts and cake powder or dessert powder
  • Making some canned food


Solid Caustic Soda Production

Producing liquid caustic soda is the first step in the process of manufacturing solid caustic soda. In the next stage, going through the evaporation and concentration processes turns the solution into solid caustic soda with a purity of 98 to 99%.


Solid Caustic Soda Packaging and Transportation

Sodium Hydroxide easily absorbs moisture when exposed to air, and the surface gets wet and gradually dissolved. This is why this product is packed in two-ply coverage. Flakes are first bagged in a gunny-plastic layer and then, they are put in a resistant and strong cover of nylon-plastic.

It is advised that Caustic Soda Flakes are placed in a closed and roofed dry storage while transporting to avoid exposure to direct wind and sun rays.


Advantages of Solid Caustic Soda over Liquid Caustic Soda

Liquid soda has a purity of 48 to 50% and has similar properties and applications to solid soda in various industries. The main advantages of solid form over liquid one, are as follows:

  1. Eliminating the possibility of freezing in cold seasons and regions
  2. Easier Transportation with common equipment and reducing the possibility of damages and dangers imposed by liquid caustic soda
  3. The possibility of loading in high tonnage with less volume
  4. Much easier storage conditions to prepare and less storage space required
  5. Reducing the absorption of pollution, weathering and further safety