Kaolin mined from the Ipixuna deposit of Pará Pigmentos S.A. in the Capim river area of northern Brazil has been studied at various stages of beneficiation to determine the behaviour of Fe- and Ti-bearing minerals which can reduce the brightness of the product. X-ray diffraction and Mössbauer spectroscopy showed the principal pigmenting minerals to be hematite and goethite, with chemical analyses showing a distinct decrease of both the total Fe and Ti contents in the course of processing. The Ti contents were primarily reduced due to the removal of anatase during particle size fractionation and dithionite reduction. While the Fe content of the final product is structurally bound in kaolinite, Raman spectroscopy indicates the remnant Ti to be bound both structurally in kaolinite and in remnant anatase.

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