Differences Between Pearl Caustic Soda and Flake Caustic Soda

Appearance

Flake Caustic Soda: Usually appears as flakes, with a typical thickness of about 1–2 mm. The size can be adjusted according to production processes and needs, commonly in rectangular or square shapes.

Pearl Caustic Soda: Granular form of sodium hydroxide with relatively uniform particle sizes, typically spherical, ranging from 0.5 to 2 mm in diameter.

Production Process

Flake Caustic Soda: The production process is relatively simple. Caustic soda solution is evaporated and concentrated, then cooled and solidified into flakes. Generally, the solution is heated in an evaporator to remove moisture, and once a certain concentration is reached, it flows into a cooling drum. As the drum rotates and cools, the caustic soda solidifies on its surface and is scraped off by a blade to form flakes.

Pearl Caustic Soda: The production process is more complex, typically involving spray drying or granulation. In spray drying, highly concentrated caustic soda solution is sprayed into hot air, causing rapid evaporation and formation of granules. In granulation, flake caustic soda is melted and passed through special granulating equipment to form spherical granules.

Applications

Flake Caustic Soda: Widely used in chemical, dyeing, wastewater treatment, disinfection, pesticide, and electroplating industries. In chemical production, it is used in manufacturing soap, paper, textiles, and dyes. In wastewater treatment, it helps regulate pH levels. In food processing, it can be used as an acidity regulator, among other applications.

Pearl Caustic Soda: Mainly used in pharmaceuticals, cosmetics, and other chemical industries. In laboratories, pearl caustic soda is more convenient to use than flake. In chemical manufacturing, it is used for producing formic acid, oxalic acid, borax, phenol, sodium cyanide, soap, synthetic fatty acids, and synthetic detergents. In the textile and dyeing industry, it serves as a desizing agent, scouring agent, mercerizing agent, and solvent for vat dyes and indigo dyes. In the metallurgical industry, it is used to produce aluminum hydroxide, alumina, and surface treatment agents for metals.