The following are its main uses and brief descriptions:
1. Chemical synthesis
-Sulfide production: used as an intermediate to prepare other sulfides (such as sodium sulfide, sodium polysulfide), or used in sulfidation reactions in organic synthesis.
- Reducing agent: Participates in the reduction reaction of certain organic substances, for example in the synthesis of dyes, pesticides or medicines.
2. Mining and Metallurgy
- Metal precipitants: Used in hydrometallurgy to precipitate metals (such as copper, lead, zinc) from solutions and assist in metal extraction.
- Flotation agent: adjust the surface properties of minerals and improve the efficiency of ore flotation separation.
3. Wastewater treatment
- Heavy Metal Removal: Remove heavy metal ions (such as mercury, cadmium, arsenic) from wastewater by generating metal sulfide precipitation.
- Reduction of hexavalent chromium: Reduction of toxic hexavalent chromium (Cr⁶⁺) to less toxic trivalent chromium (Cr³⁺) for easy subsequent treatment.
- Acidic wastewater neutralization: adjust pH and precipitate heavy metals.
4. Leather Industry
- Depilatory: Similar to sodium sulfide, it is used in the depilatory process before leather tanning to break down the keratin in the hair.
5. Textile Industry
- Dye reduction: Used as a reducing agent in the dyeing process of dyes such as indigo to help dye molecules penetrate the fiber.
6. Laboratory Use
- Analytical reagents: used to detect metal ions (such as bismuth, antimony), or as reagents for specific chemical reactions.
Safety Precautions
- Corrosive: Strongly irritating to skin, eyes and mucous membranes, protective equipment must be worn.
- Hydrogen sulfide risk: It is easy to release toxic H₂S gas when in contact with acid or high temperature. It must be operated in a well-ventilated place.
-Storage Conditions: Store in sealed container in a dry environment, away from acids and oxidants.
The application of sodium hydrosulfide needs to be combined with specific process requirements and safety regulations to ensure efficient and environmentally friendly use.