Chemical and physical activation of natural pyrite as potential inorganic pigment material

Pyrite is one of the minerals on Borneo Island. It has a disadvantage for soil quality due to its acidic properties. One of the main components of pyrite is iron, which promises to be utilized as an inorganic pigment. This research aims to transform pyrite into red-brown pigment material-based iron oxide. Based on the XRF result, the highest component is Fe, with a percentage up to 42%. This data is also suitable for an iron oxide phase from the diffractogram of pigment, followed by the presence of silica and alumina structures. The physical activation process successfully transformed the color of the of the materials from gold to red-brown. Then, the molecular vibration of Fe–O also appears on FTIR spectra at a wavenumber of 483 cm-1 and T–O–T bending at 994 cm-1. Moreover, morphological observation exhibits the aggregation of particles and the distribution of iron elements on the entire area of pigment surface. Based on the above findings, it can be concluded that pyrite minerals can be transformed into hematite-based red pigment, which is promising to be utilized in the painting sector.