Mineral contaminants from sedimentary kaolin deposit of Ipixuna Mine, Brazil

Abstract

The sedimentary kaolin deposit of the Ipixuna Mine in the Brazilian Amazon contains mineral contaminants such as anatase, hematite and goethite among others whose occurrences change the color white of kaolin blocks to red, yellow, gray and purple. The main objective of this study was to identify the mineral contaminants in ROM kaolin, textures and their relationships with the deposition environment. Binocular stereomicroscopy and X-ray diffraction were used to define the paragenesis of contaminants from several areas of the ore and to characterize the conditions of the deposition. The mineral contaminants lend the ore red, yellow, gray and purple colors. Red is associated with the mixture of goethite and hematite with the kaolinite. The yellow color is due to the addition of quartz, muscovite and anatase. Gray results from kaolinite layered with low and high concentrations of anatase. The purple color is due to the mixture of kaolinite and hematite.