Used in the leather tanning industry to remove hair and impurities from animal hides during the liming process. Commonly applied in wastewater treatment to precipitate heavy metals as insoluble sulfides, aiding in pollution control. Employed in the production of sulfur dyes for textiles, particularly in manufacturing dark-colored fabrics. Utilized in the pulp and paper industry to break down lignin in wood during kraft pulping. Also serves in the synthesis of various organic and inorganic chemicals, including sulfide-based reagents and pharmaceuticals.