Quantification of hematite and goethite concentrations in kaolin using diffuse reflectance spectroscopy : A new approach to Kubelka-Munk theory
Gonçalves, Ítalo Gomes (Universidade Federal do Rio Grande do Sul. Laboratório de Processamento Mineral. Departamento de Engenharia de Minas)
Petter, Carlos Octávio (Universidade Federal do Rio Grande do Sul. Laboratório de Processamento Mineral. Departamento de Engenharia de Minas)
Lepkoski Machado, Jaqueline (Universidade Federal do Rio Grande do Sul. Laboratório de Processamento Mineral. Departamento de Engenharia de Minas)

Fecha:	2012
Resumen:	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 (R ≈ 0. 99) and experiments with contaminants from the mine are already underway.
Derechos:	Aquest material està protegit per drets d'autor i/o drets afins. Podeu utilitzar aquest material en funció del que permet la legislació de drets d'autor i drets afins d'aplicació al vostre cas. Per a d'altres usos heu d'obtenir permís del(s) titular(s) de drets.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Brightness ; Diffuse Reflectance ; Goethite ; Hematite ; Kaolin ; Kubelka-Munk Theory
Publicado en:	Clays and Clay Minerals, Vol. 60, Núm. 5 (2012) , p. 473-483, ISSN 1552-8367

DOI: 10.1346/CCMN.2012.0600504

11 p, 1.3 MB  Acceso restringido a la UAB

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