Formation and Composition of Zinc Ash

Zinc ash, also known as zinc oxide, forms rapidly during hot-dip galvanizing, essentially regenerating immediately after each scraping due to the instant reaction between molten metallic zinc and oxygen in the air, which produces zinc oxide. Additionally, when the solvent on the steel pipes to be galvanized is immersed in the zinc bath, it activates the adsorption of zinc onto the iron surface, with a side effect of forming a portion of zinc ash and solvent residue. Zinc ash is primarily composed of a mixture of zinc oxide, metallic zinc particles, chlorides, and other acid-insoluble impurities. The zinc oxide in zinc ash consists partly of pure zinc oxide and partly of zinc oxide combined with other oxides. Small metallic zinc particles generally account for 15-35% of the total zinc ash content. Depending on the tool used for scooping the ash, this proportion can reach 30-60%, and in some cases, even 70-75%.