MINERAL CONTAMINANTS OF THE SEDIMENTARY KAOLIN ORE FROM IPIXUNA MINE, BRAZIL

The sedimentary kaolin ore of the Ipixuna Mine, in the Brazilian Amazon, contains mineral contaminants such as anatase, hematite and goethite, among others, which change the original white color of kaolin blocks to red, yellow, gray and purple. The main objective of the present study was to identify the mineral contaminants in the ROM kaolin, the textures and their relationships with the deposition environment. Binocular stereomicroscopy and X-ray diffraction were used to define the paragenesis of contaminants from different places of the ore, as well as to characterize the deposition conditions. The contaminants change the white color of kaolin ore to red, yellow, gray and purple. Red is associated with disseminated goethite and hematite in the kaolin ore. Yellow is associated with disseminated quartz, muscovite and anatase in the kaolin ore. Gray results from thin kaolinite multilayers containing low and high concentrations of anatase. Purple results from the disseminated hematite in the kaolin ore.