FT-IR Partial Least-Squares Analysis of Tubular Halloysite in Kaolin Samples from the Mount Hope Kaolin Deposit

Abstract

AbstractA method of infrared (IR) analysis for quantitative determination of tubular halloysite in mixtures with kaolinite was investigated for drill hole samples collected during an assessment of paper-coating kaolin resources at the Mount Hope Kaolin Deposit, Eyre Peninsula, South Australia. Tubular, dehydrated halloysite from the deposit does not readily intercalate formamide, and the proportion of tubes in <2 μm size-fractions was determined initially from scanning electron micrographs. For samples showing a range of tube contents, a strong correlation between IR spectral response and counts of halloysite tubes was established using partial leastsquares analysis. This provided a rapid technique suitable for routine determination of tubular halloysite in samples from the Mount Hope deposit. Although the universality of the method remains to be tested, it offers an alternative approach to other analytical techniques for assessment of kaolin deposits where the presence of halloysite is suspected.