Characterization, beneficiation and utilization of a kaolinite clay from Assam, India

Abstract Kaolin available in Deopani, Assam of northeastern region of India was characterized by FTIR, XRD, DTA and by wet chemical analysis methods. The major impurities in the clay are quartz and siderite. Wet sieving of the clay by −53-μm sieve removes almost all the quartz and a major amount of Fe bearing impurities. The iron content of the clay may be reduced further by treating with wet high intensity magnetic separator (WHIMS) or leaching with organic acids. The effectiveness of various leachants follows the order: Oxalic>Oxalic+EDTA>Malonic>Citric acid. Almost all the nonstructural iron may be removed at room temperature by using 0.4 M oxalic acid solution. The leached clay may find use as a ceramic raw material and filler material for paper and other materials.

[1]  O. Borggaard,et al.  SELECTIVE EXTRACTION OF AMORPHOUS IRON OXIDES BY EDTA FROM A DANISH SANDY LOAM , 1979 .

[2]  P. E. Clark,et al.  Mössbauer Effect Studies of Iron in Kaolin. I. Structural Iron , 1983 .

[3]  E. Derouane,et al.  Iron in kaolinite with special reference to kaolinite from tropical soils , 1976, Clay Minerals.

[4]  K. Bahranowski,et al.  On the Possibility of Removal of Non-Structural Iron from Kaolinite-Group Minerals , 1993, Clay Minerals.

[5]  S. Groudev.  Biobeneficiation of mineral raw materials , 1999 .

[6]  F. Vegliò,et al.  Development of a Bleaching Process for a Kaolin of Industrial Interest by Oxalic, Ascorbic, and Sulfuric Acids: Preliminary Study Using Statistical Methods of Experimental Design , 1996 .

[7]  T. Rodrigues,et al.  Bleaching of Brazilian kaolins using organic acids and fermented medium , 1996 .

[8]  M. K. Lloyd,et al.  Improvement of Iron Leaching in Clays. Optimizing Processing Parameters in Sodium Dithionite Reduction , 1970 .

[9]  L. Brakalov,et al.  High-gradient magnetic treatment of kaolin , 1987 .

[10]  L. Toro,et al.  Process development of kaolin pressure bleaching using carbohydrates in acid media , 1994 .

[11]  M. Wilson,et al.  Clay mineralogy : spectroscopic and chemical determinative methods , 1994 .

[12]  R. E. Meads,et al.  Substitution by Iron in Kaolinite , 1967 .

[13]  D. Amarasiriwardena,et al.  Quantitative Determination of Aluminum-Substituted Goethite-Hematite Mixtures By Mössbauer Spectroscopy , 1986 .

[14]  M. Lalithambika,et al.  Effect of organic acids on ferric iron removal from iron-stained kaolinite , 2000 .

[15]  E. Baumgartner,et al.  Heterogeneous electron transfer as a pathway in the dissolution of magnetite in oxalic acid solutions , 1983 .

[16]  D. Jefferson,et al.  Electron-Microscopic and Mössbauer Spectroscopic Studies of Iron-Stained Kaolinite Minerals , 1975 .