Sodium sulfide

Sodium sulfide (CAS 1313-82-2), also known as disodium sulfide, is an inorganic sulfur compound supplied primarily in hydrated flake form.

Where is Sodium sulfide used?

• Leather tanning: primary unhairing agent that breaks down keratin bonds in hides during the beamhouse stage
• Textile dyeing: reducing agent that solubilizes sulfur dyes for coloration on cotton and cellulosic fibers
• Mining and hydrometallurgy: precipitates heavy metal ions from process streams and leachates
• Paper pulp and water treatment: sulfide precipitation and pH adjustment
• It functions as a reducing and precipitating agent in heavy industrial processes.
• Water treatment: acts as an oxygen scavenger to prevent corrosion in pipelines.
• Photographic industry: used as a color developer.
• Ceramics: used as a depressant for quartz.
• Low-iron sodium sulfide is preferred in applications where high purity is crucial and iron could negatively affect the process or final product quality.

Good to know: Technical grade is the standard market form; anhydrous and higher-purity grades exist for specialty applications but are less common in bulk industrial trade.

Formulation notes

• Keep away from acids and oxidizing agents.
• Reacts violently with oxidants.

Typical specification

• Supplied at a minimum assay of 90% (iodimetry), with the balance being water.
• The strongest grade has an iron content below 10 ppm.
• Sodium sulfide Fe 30PP is a specific grade containing a higher iron concentration, generally around 30 ppm.

Regulatory status

• Classified under UN transport Class 4.2 with Packing Group II.
• Has the EU CLP index number 016-009-00-8.
• Classified as corrosive to metals Category 1 (H290).

Storage, packaging and handling

• Commonly available in lined Jumbo Big Bags.
• Keep in tightly closed containers.

Frequently asked questions about Sodium sulfide

In which mineral processing operations is sodium sulfide used as a sulfidizing reagent?

It is used as a sulfidizing reagent in the flotation preparation of oxidized, metallic copper, zinc, and lead minerals.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.