Environmental Perspectives on Zinc Plating Technologies for Steel

The article discusses the main technologies for applying zinc coatings, which makes it possible to protect steel products from corrosion and thereby reduce the harmful impact on the environment. A description of the technological features of hot-dip galvanizing, electro galvanizing, thermal diffusion galvanizing, cold galvanizing, and thermal spraying galvanizing is given. A comparative analysis of the considered galvanizing technologies was carried out from the point of view of their harmful effects on the environment and human health. The article shows that surface preparation before hot-dip galvanizing, including pickling in acids, fluxing, degreasing in alkaline solutions and rinsing in water, has a negative impact on the environment and requires significant costs for disposal and neutralization of waste solutions. Electroplating production is one of the most dangerous sources of environmental pollution, due to the fact that both in the surface preparation process and during the coating itself, reagents and electrolytes are used that are harmful to both the environment and human health. The most environmentally friendly technologies for applying zinc coatings are thermal diffusion and thermal spraying galvanizing. When preparing the surface, these zinc plating methods allow mechanical cleaning of the surface using abrasive materials, which significantly reduces the burden on the environment. The use of zinc wire instead of powder during thermal spraying will improve the economic efficiency of the process compared to powder technologies, which will make this galvanizing method the most promising and environmentally friendly for protecting steel structures from corrosion.