Abstract
This study specifically investigated reduction of the white smoke originating from flux during the hot-dip zinc galvanizing process. White smoke is generated by ammonium chloride in the flux treatment solution. To replace the ammonium chloride solution, we developed a new flux treatment solution, prepared using some halogen compounds, with sodium chloride, potassium chloride, and/or sodium fluoride added to zinc chloride. The new flux solutions decreased white smoke. It was contained hydrogen chloride and hydrogen fluoride in the exhaust port, but it was not clear that the exhaust gas concentration influenced worker health conditions. The plating thickness and surface obtained when using these new solutions exhibited the same level as hot-dip zinc galvanizing with the ammonium chloride solution. In addition, these retained the same corrosion resistance from the salt spray test. Results show that characteristics of drying and moisture adsorption, and the addition of sodium chloride, potassium chloride, and sodium fluoride inhibited the moisture adsorption of zinc chloride.
