In light-sensitive reproductive papers; as ceramic color; as mordant and oxidizing agent in textile dyeing and printing; as reagent for burnishing iron, for giving a black "antique" finish to copper, for coloring zinc brown; in nickel-plating baths; in aluminum brighteners; in wood-preservatives, fungicides, herbicides; in pyrotechnic compositionsl as catalyst component for solid rocket fuel; as nitrating agent for aromatic organosilicon comp[oun]ds; as catalyst for organic reactions." 1