78. What methods can be used to reduce the production of zinc ash?

The factors that accelerate the formation of zinc ash have been identified, and thus methods to reduce zinc ash can be developed accordingly.
(1) Add a specific amount of aluminum to the molten zinc in the galvanizing pot to form a protective Al₂O₃ film on its surface. Experimental results show that a 10-5 mm thick protective film is sufficient to prevent oxygen penetration; (2) Reduce the contact area between molten zinc and air. Typically designed galvanizing pots feature a small opening area and greater depth; (3) Minimize air exchange frequency on the molten zinc surface. Reduce dust extraction fan airflow and improve environmental conditions through alternative methods; (4) Operate the molten zinc level in a protective atmosphere. For example, in the "protective gas reduction method," part of the molten zinc remains within the hood; (5) On the molten zinc surface where galvanized steel pipes do not pass, minimize ash scraping frequency; (6) Apply boron acid-treated activated carbon or a mixture of diatomaceous earth and aluminum oxide to the molten zinc surface; (7) Lower the galvanizing pot temperature to reduce the molten zinc's temperature, thereby decreasing oxidation reactions between the zinc surface and atmospheric oxygen; (8) Prevent chemical elements that accelerate zinc ash formation from entering the molten zinc.