Investigation of the Use of Iron Oxide Compounds in Powder Coating Materials

Abstract

A significant cost factor in the production of these iron-containing compounds is the use of expensive precursors and energy resources during synthesis. Therefore, replacing chemically pure heavy metal salt precursors with spent technological solutions—generated in large volumes at metallurgical and electroplating plants—can address this issue. The processing of such solutions to obtain valuable commercial products is considered a promising approach. This study presents the results of employing the ferritization method. A distinctive feature of the research is the use of energy-efficient ultrasonic treatment of the reaction mixture. Its advantages over traditional thermal activation methods are demonstrated. The influence of different oxidizing agents and activation methods on the ferritization process and the structural properties of the resulting precipitates has been investigated. X-ray diffraction analysis revealed the presence of feroxyhyte (δ-FeOOH) and magnetite (Fe₃O₄) phases in the ferritization products. It was established that ultrasonic treatment combined with hydrogen peroxide addition at a concentration of 2.5 ml/dm³ results in a precipitate consisting exclusively of the magnetite phase. The obtained ferritization precipitates reliably encapsulate iron ions within their crystalline structure, effectively isolating them from the environment. It was noted that the precipitate containing iron oxyhydroxide phase exhibited significant iron ion leaching in aggressive environments: 5.67 mg/kg in acidic and 0.83 mg/kg in alkaline conditions. The research results indicate the potential use of these ferrimagnetic compound-containing precipitates in the production of powder coating materials. Implementing the improved ferritization process in industrial applications may reduce energy consumption compared to conventional waste treatment technologies.