Çelik fabrikalarındaki rejenere dekapaj çözeltisinden bakırın gerikazanımı.

Pickling is a metal surface treatment technique, made by strong inorganic acids to prepare metals for subsequent processes. The process generates a substantial amount of waste acid because large amount of acid is spent during the process. The impact of the waste acid to the environment is noticeable. The waste solution contains the contaminants of the metal surface and it is also a source of valuable products, metal salts and copper. When the concentration of copper in the pickling solution exceeds the level of about 100 ppm, randomly plating of copper onto the steel strips which causes visual incompatibility occur. Furthermore, efficiency of pickling decreases with the increase of copper content. Due to their toxic nature, the treatment is mandatory. The aim of this study is to develop an environmentally-friendly and cost-efficient way for recovery of pickling solution using electrodeposition method. The work consisted of reducing the copper content and to extend the lifetime of the pickling solution by this way. By this process, it was also aimed to reduce the amount of landfilled waste and utilize the needed chemicals. The work was performed by gathering information from literature but also from industry in Turkey. The work has been a collaboration between the Middle East Technical University (METU), Borcelik and Borusan Technology Department and R&D Co. Within the scope of copper removal, effects of applied current density, treatable copper concentration and electrolysis duration on copper deposition were studied. Current density was determined as the most effective parameter.Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Metallurgical and Materials Engineering