Synthesis of an Anticorrosive Pigment by Thermal Treatment of Iron Oxides from Steel Industry Wastes

• Main Authors: María Angélica Colpas-Ruiz, Camilo Gnecco-Molina, Gabriel Antonio Jiménez-Rodríguez, M.Sc., José Andrés Pérez-Mendoza, M.Sc., Óscar Fabián Higuera-Cobos, Ph. D.
• Format: Article
• Language: English
• Published: Universidad Pedagógica y Tecnológica de Colombia 2019-07-01
• Series: Revista Facultad de Ingeniería
• Subjects: anticorrosive pigment; hematite; iron oxides; steel industry waste; thermal treatment; x ray diffraction
• Online Access: https://revistas.uptc.edu.co/index.php/ingenieria/article/view/9653

This work reports the obtaining of an anticorrosive pigment composed mainly of hematite (ɑ-Fe2O3) from a powder steel industry waste from rust scale of rebar steel. This residue is mainly composed of Fe2O3 (87.97 %), SiO2 (6.13 %), CaO (1.88 %), Al2O3 (1.30%) and MnO (0.77 %). The total iron oxide of the residue is constituted by the following crystalline phases: magnetite, maghemita, lepidocrocita, wüstite, goethite and hematite. The production of a pigment with a high content of hematite was possible thanks to the high content of precursor iron oxides, which were calcined at different temperatures (750-850 °C) and holding times (0.5-1.50 h). For characterizing the iron content chemically and to identify their iron oxides phases, it was used X-ray fluorescence (XRF) and X-ray diffraction (XRD). The results showed that the pigment with the highest amount of hematite (ɑ-Fe2O3) was obtained at a calcination temperature of 850 °C and a holding time of 1.00 h.