Used as a catalyst in organic synthesis, particularly in chlorination reactions and the production of dyes and pigments. Employed in the manufacturing of antimony compounds for flame retardants and in the electronics industry for semiconductor doping. Also utilized in analytical chemistry for detecting vitamin A and related compounds through the Carr-Price test, as well as for identifying unsaturation in fats and oils. Serves as a reagent in the preparation of other antimony-based chemicals and in some metallurgical processes for refining metals.