Sodium hydroxide is a white, translucent solid in the form of flakes, blocks, granules or sticks, odorless, with strong hygroscopicity and deliquescence. It absorbs carbon dioxide (CO₂) from air to form sodium carbonate when exposed. Its aqueous solution is strongly alkaline, slippery to the touch, and highly corrosive.

1. Chemical industry: production of sodium salts, soap, synthetic detergents, pulping cooking agents, viscose fiber

2. Textile: printing and dyeing, mercerizing treatment, fiber refining

3. Metallurgy: aluminum smelting, ore processing, metal cleaning

4. Water treatment: pH adjustment, neutralization of acidic wastewater, water softening

5. Others: food processing (food grade, GB 1886.20), pharmaceuticals, petroleum refining, leather degreasing