Spectrophotometric characterization of iron and titanium minerals in sedimentary kaolin deposit

• The ore mineral contaminants are quartz, muscovite, hematite, goethite and anatase.
• Contaminants defining the spectral classification of the ore into seven groups
• The amount of hematite, goethite and anatase defines the exploitation of the deposit.
• ROM ore with high goethite and low hematite amounts can be mined and processed.
• Spectral Group VI should be processed without blending with other spectral groups.

The northern region of Brazil produces kaolin for paper industry. Ipixuna Mine, located in the Pará State, exploits important sedimentary kaolin deposits, which are extracted ROM material blocks that vary in color depending on both the paragenesis and concentration of mineral contaminants. Samples were collected from different mining fronts, which represented the different varieties of ore. Samples were processed in a pilot plant. Both products and tailings were analyzed to define the mineral paragenesis and color data. Specific studies on the iron and titanium minerals and spectrophotometry were performed on the samples. The results indicated that the proportion of goethite, hematite and anatase and the particle size of the last two minerals in the blocks of ore affect their color and mineral processing efficiency. This study defined seven spectral groups of kaolin ore, the relationship of the groups with the paragenesis of mineral contaminants, varieties of ore that can be economically processed and the best blending options between ore varieties to improve the processing operations.