Preparation of monodispersed micaceous iron oxide pigment from pyrite cinders

In this study, pyrite cinders are used as a second raw material for preparing micaceous iron oxide (MIO) pigment by leaching, precipitation and hydrothermal treatment. The optimal conditions for MIO synthesis, such as NaOH concentration, total iron concentration, reaction temperature and reaction time are investigated and discussed carefully, using pigment color and morphology as the major evaluation parameters. In addition, the synthesized products have been characterized by means of XRD and SEM/EDS. Under optimum conditions, the obtained MIO is uniform flake, metallic gray, and its mean particle size and aspect ratio are ~ 7.0 μm and ~ 7.0. A scale-up experiment demonstrates its reproducibility. Besides, all the resulting products fulfill ISO 10601-2007, the standards of micaceous iron oxide pigments for paints.