Method for the preparation of a soldering flux

摘要

A method for the preparation of potassium salts of complex aluminum fluorides which can be used in particular as a flux in particular for soldering lightweight metallic materials. In the method a potassium compound is added to aqueous fluoroaluminic acid, and potassium cryolite or a substance mixture which contains potassium cryolite is added to the resulting suspension. The resulting product is then dried and can be used as a flux for soldering lightweight metallic materials, especially aluminum.