Zinc ammonium chloride is the inorganic compound with the formula (NH4)2ZnCl4. It is the ammonium salt of tetrachlorozincate. It used as a flux in the process of hot-dip galvanizing.Zinc chloride is the name of chemical compound ZnCl2 or its hydrates. All zinc chlorides are colorless or white and highly soluble in water. ZnCl2 itself is hygroscopic and can be considered deliquescent. Samples should therefore be protected from sources of moisture, such as the atmosphere.
Uses
Steel to be galvanized passes through an acidic cleaning process to remove iron oxide "mill scale". After this process, the surface of the steel is very active and oxide layers begin forming immediately upon exposure to the atmosphere. Zinc ammonium chloride flux in aqueous solution is applied to the steel to reduce any oxides that are formed and/or inhibit them from forming altogether. This allows the molten zinc in the proceeding galvanizing step to maximally adhere to and alloy with the surface of the steel.