Production of composite powders used in the production of electrical contacts comprises continuously mixing a solution of a silver compound and a solution of a reductant to a solution of zinc oxide to precipitate the silver

摘要

Production of composite powders based on silver-tin oxide comprises continuously adding a solution of a silver compound and a solution of a reductant in a reaction cycle to a solution of zinc oxide with intensive mixing to precipitate the silver. Preferred Features: The silver compound is silver nitrate, acetate, carbonate, citrate or oxalate. The reductant is ascorbic acid, citric acid, oxalic acid, formic acid or hydroxylamine. In 2O 3, Bi 2O 3, CuO, WO 3 or MoO 3 is contained in the aqueous dispersion of tin oxide.