Sodium hydroxide is widely used in national economy, and many industrial sectors need sodium hydroxide. The largest use of sodium hydroxide was in chemical manufacturing, followed by paper making, aluminum refining, tungsten refining, rayon, rayon and soap manufacturing. In addition, in the production of dyes, plastics, pharmaceutical and organic intermediates, the regeneration of old rubber, metal sodium, water electrolysis and inorganic salt production, making borax, chromium salt, manganese salt, phosphate, also need to use a lot of caustic soda. At the same time, sodium hydroxide is one of the important raw materials for the production of polycarbonate, super absorbent polymer, zeolite, epoxy resin, sodium phosphate, sodium sulfite and a large amount of sodium salt. Sodium hydroxide is a white translucent crystalline solid. Its aqueous solution is astringent and smooth. Properties: 1, water absorption (deliquescence) : sodium hydroxide in the air easily deliquescence, so often use solid sodium hydroxide as desiccant. But liquid sodium hydroxide does not absorb water. 2, solubility: easily soluble in water, dissolved in a large amount of heat. Soluble in ethanol and glycerin.