... -exchange membrane (or diaphragm) caustic soda, potassium hydroxide, chromic anhydride, sodium hydrosulfide, calcium chloride dihydrate , sulfur, phosphorus pentasulfide and other inorganic chemical ... for sulfur dye, disodium hydrogen phosphate, sodium phosphate, magnesium chloride, sodium sulfate, sulfonate, alkali metal carbonate, sodium and other minerals benzoin solution, and ...