Product character Thin flakes, red, soluble in water, slightly soluble in alcohol, in soluble in ether, presents strong alkaline solution, easily oxidized when exposed to air, poison. Usage Maily used in making sulfur dyestuff intermediates, reducer, mordant, flotation agent, depilatory for leather, digestion auxiliary in paper-making, and also widely used in pigmeng and rubber industry. Table Spec150PPM200PPM250PPM300PPMNa2S (%) ≥60.060.060.060.0Na2CO3 (%) ≤2.02.02.02.0Water Insoluble (%) ≤0.20.20.20.2Fe (%) ≤0.0150.020.0250.03