What are the uses and application methods of caustic soda?

Sodium hydroxide Uses and Usage Methods

I. Core Application

Industrial Manufacturing

Pulpwood: Used for removing lignin from wood, separating cellulose to make pulp, and enhancing paper strength.

Textile Printing and Dyeing: As a desizing agent, it removes wax and grease from cotton fabrics to enhance fiber strength; adds luster to the fabric during the silk finishing process.

Refining Oil: Neutralizes acidic substances in oil products to enhance purity of finished goods.

Chemical Production: Formic acid, oxalic acid, and other chemicals, as well as daily consumer raw materials such as soap and detergents.

Cleaning and Disinfection

Kitchen Cleaning: Dissolves grease, suitable for cleaning appliances such as range hoods and stoves. The dilution ratio is typically 1:20 to 1:50 (sodium hydroxide:water).

Toilet Cleaning: Let the stains in the bathroom and toilet sit for 5-10 minutes before rinsing.

Disinfection: Used for sterilizing equipment or environments, it breaks down the viral protein structure with strong alkali.

Other fields

Agriculture: Neutralize acidic soil and adjust pH levels to promote crop growth.

The food industry: Use must be strictly controlled as an acid neutralizer or fruit peeling agent.

Wastewater Treatment: Adjusting industrial wastewater pH levels and reducing heavy metal ion content.

How to Use and Precautions

Proportions and Operations

General Cleaning: Mix 1 part of caustic soda with 20-50 parts of water, adjusting the ratio based on the stubbornness of the stain.

Industrial Use: Requires calculation of concentration, such as dissolving non-cellulosic components in dilute alkali solutions in papermaking.

Safety Standards

Protective gear: A toxic gas mask, chemical-resistant gloves, and safety goggles must be worn during operation.

Storage Conditions: Store in a cool, shaded area (≤30℃), away from fire and acidic substances.

Emergency Measures

Skin Contact: Rinse with clean water for 15 minutes, and seek medical attention if necessary.

Eye Contact: Lift the eyelid and rinse thoroughly with plenty of clean water; seek immediate medical attention.

Sodium hydroxide, also known as caustic soda, is widely used in industrial and domestic applications due to its strong alkalinity. However, strict adherence to safety regulations is essential to avoid corrosion or poisoning risks.