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Quantification of Hematite and Goethite Concentrations in Kaolin Using Diffuse Reflectance Spectroscopy: A New Approach To Kubelka-Munk Theory

Published online by Cambridge University Press:  01 January 2024

Ítalo Gomes Gonçalves ,
Carlos Otávio Petter  and
Jaqueline Lepkoski Machado
Ítalo Gomes Gonçalves*
Affiliation:
Laboratório de Processamento Mineral, Departamento de Engenharia de Minas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
Carlos Otávio Petter
Affiliation:
Laboratório de Processamento Mineral, Departamento de Engenharia de Minas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
Jaqueline Lepkoski Machado
Affiliation:
Laboratório de Processamento Mineral, Departamento de Engenharia de Minas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
*
*E-mail address of corresponding author: italogoncalves@ibest.com.br
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Abstract

Kaolin ores are usually contaminated by some Fe-bearing minerals, the strong colors of which degrade the quality of the final product. A spectroscopic technique is sought to quantify the content of hematite and goethite, the main contaminant minerals in the kaolin from Capim River in Brazil, was the focus of this study. The total Fe content obtained through X-ray fluorescence showed a poor correlation with the brightness of kaolin, due to the inability to differentiate between the Fe contained in the (oxyhydr)oxides and the Fe present in the crystalline structure of kaolinite, especially when the Fe-bearing minerals occur in small quantities. Here, a new generic technique to quantify Fe (oxyhydr)oxides in kaolin, based on the Kubelka-Munk theory, is presented. A new interpretation of the theory was made that enables its use without the need to measure thin layers of material. The results with synthetic goethite and hematite were very positive (R2pred ≈ 0.99) and experiments with contaminants from the mine are already underway.

Keywords

BrightnessDiffuse ReflectanceGoethiteHematiteKaolinKubelka-Munk Theory
Type
Article
Information
Clays and Clay Minerals , Volume 60 , Issue 5 , October 2012 , pp. 473 - 483
Copyright
Copyright © Clay Minerals Society 2012

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References

Bishop, J.L. and Murad, E., 1996 Schwertmannite in Mars? Spectroscopic analyses of schwertmannite, its relationship to other ferric minerals, and its possible presence in the surface material on Mars Mineral Spectroscopy: A Tribute to Roger G. Burns 5 337–358.Google Scholar
Gonçalves, I.G., 2009 Determinação da concentração de contaminantes no caolim através da teoria de Kubelka-Munk MSc Dissertation Porto Alegre, Brazil Universidade Federal do Rio Grande do Sul 68 pp..Google Scholar
Gonçalves, I.G. and Petter, C.O., 2007 Kubelka-Munk theory applied to industrial minerals: prediction of impurity content in kaolin Revista Escola de Minas 60 491–496.CrossRefGoogle Scholar
HunterLab, 2008 CIE L*a*b* color scale Insight on Color 8 4 pp.Google Scholar
Ji, J. Balsam, W. Chen, J. and Liu, L., 2002 Rapid and quantitative measurement of hematite and goethite in the Chinese loess-paleosol sequence by diffuse reflectance spectroscopy Clays and Clay Minerals 50 208–216.CrossRefGoogle Scholar
Ji, J. Zhao, L. Balsam, W. Chen, J. Wu, T. and Liu, L., 2006 Detecting chlorite in the Chinese loess sequence by diffuse reflectance spectroscopy Clays and Clay Minerals 54 266–276.CrossRefGoogle Scholar
Kortüm, G., 1969 Reflectance Spectroscopy Berlin Springer-Verlag.CrossRefGoogle Scholar
Liu, Q.S. Torrent, J. Barrón, V. Duan, Q.Z. and Bloemendal, J., 2011 Quantification of hematite from the visible diffuse reflectance spectrum: effects of aluminium substitution and grain morphology Clay Minerals 46 137–147.CrossRefGoogle Scholar
Morris, R.V. and Lauer, H.V., 1990 Matrix effects for reflectivity spectra of dispersed nanophase (superparamagnetic) hematite with application to Martian spectral data Journal of Geophysical Research 95 5101–5109.CrossRefGoogle Scholar
Morris, R.V. Lauer, H.V. Lawson, C.A. Gibson, E.K. Nace, G.A. and Stewart, C., 1985 Spectral and other physicochemical properties of submicron powders of hematite (α-Fe2O3), maghemite (γ-Fe2O3), magnetite (Fe3O4), goethite (α-FeOOH) and lepidocrocite (γ-FeOOH) Journal of Geophysical Research 90 3126–3144.CrossRefGoogle ScholarPubMed
Otsuka, M., 2004 Comparative particle size determination of phenacetin bulk powder by using Kubelka-Munk theory and principal component regression analysis based on nearinfrared spectroscopy Powder Technology 141 244–250.CrossRefGoogle Scholar
Petter, C.O., 1994 Contribution à l’etude de la valorisation de kaolins pour l’industrie papetiere: mise au point d’une methodologie colorimetrique, application à la selectivité miniere PhD thesis France École des Mines de Paris.Google Scholar
Schabbach, L.M. Bondioli, F. Ferrari, A.M. Petter, C.O. and Fredel, M.C., 2009 Efficiency of Kubelka-Munk model in glazes with a black pigment and opacifier Journal of the European Ceramic Society 29 2685–2690.CrossRefGoogle Scholar
Schabbach, L.M. Bondioli, F. and Fredel, M.C., 2011 Colouring of opaque ceramic glaze with zircon pigments: Formulation with simplified Kubelka-Munk model Journal of the European Ceramic Society 31 659–664.CrossRefGoogle Scholar
Scheinost, A.C. Chavernas, A. Barrón, V. and Torrent, J., 1998 Use and limitations of second-derivative diffuse reflectance spectroscopy in the visible to near-infrared range to identify and quantify Fe oxide minerals in soils Clays and Clay Minerals 46 528–536.CrossRefGoogle Scholar
Sherman, D.M. and Waite, T.D., 1985 Electronic spectra of Fe3+ oxides and oxide hydroxides in the near IR to near UV American Mineralogist 70 1262–1269.Google Scholar
Sherman, D.M. Burns, R.G. and Burns, V.M., 1982 Spectral characteristics of the iron oxides with application to the Martian bright region mineralogy Journal of Geophysical Research 87 10169–10180.CrossRefGoogle Scholar
TAPPI, 1977 Brightness of pulp, paper and paperboard (directional reflectance at 457 nm). Technical standard .Google Scholar
TAPPI, 1986 Brightness of clay and other mineral pigments (d/0 diffuse). Technical standard .Google Scholar
Torrent, J. and Barrón, V., 2003 The visible diffuse reflectance in relation to the color and crystal properties of hematite Clays and Clay Minerals 51 309–317.CrossRefGoogle Scholar