Mössbauer Effect Studies of Iron in Kaolin. II. Surface Iron

S. A. Fysh1, J. D. Cashion and P. E. Clark2
Department of Physics, Monash University, Clayton, Victoria 3168, Australia
1 Now at BHP Co. Ltd., Central Research Laboratories, P.O. Box 188, Wallsend 2287, New South Wales, Australia.
2 Now at Department of Applied Physics, Capricornia I.A.E., Rockhampton, Queensland 4700, Australia.

Abstract: 57Fe Mössbauer spectra have been used to interpret the effects of different cleaning processes on the iron mineralogy of a Weipa, Australia, kaolin. A magnetically separated fraction contained 28% of its iron as hematite likely of secondary origin. An initial centrifugal size separation was shown to give an improved final product, and oxalic acid was found to be more efficient at removing Fe from the kaolinite surface than dithionite bleach. The Mössbauer spectra clearly show that beneficiation steps which give a substantial increase in kaolin brightness result in only minor changes in the clay iron mineralogy. Similar results were also obtained for two commercially available kaolins.

Key Words: Beneficiation • Iron • Kaolin • Mössbauer effect • Surface

Clays and Clay Minerals; August 1983 v. 31; no. 4; p. 293-298; DOI: 10.1346/CCMN.1983.0310407
© 1983, The Clay Minerals Society
Clay Minerals Society (www.clays.org)