Skip to main content Accessibility help
×
Home

Analysis of kaolinite/chrysotile mixtures by ashing and x-ray diffraction

  • Jennifer R. Verkouteren (a1), Eric S. Windsor (a1), Joseph M. Conny (a1), Robert L. Perkins (a2) and J. Todd Ennis (a2)...

Abstract

A simple ashing procedure for a mixture containing kaolinite and chrysotile is described that converts kaolinite to amorphous metakaolinite while retaining the diffraction intensity of chrysotile. This ashing procedure removes the X-ray diffraction (XRD) pattern overlap between kaolinite and chrysotile that can interfere with the analysis of even high concentrations of chrysotile. Samples are ashed at 460 °C in a muffle furnace for 40 h to completely convert kaolinite to metakaolinite. The complete conversion of 1 g of kaolinite under these conditions was determined for two standard kaolinite samples from Georgia, KGa-1 and KGa-2. Two of the most common types of commercial chrysotile, long-fiber Canadian and short-fiber Californian chrysotile, are demonstrated to retain diffraction intensity after ashing at 460 °C. Both chrysotile samples have the same integrated intensity for the (002) reflection prior to ashing, although the peak breadths for the two samples are quite different. Ashing at 480 and 500 °C reduces the diffraction intensities of both chrysotile samples by 15%, and broadens the peaks by approximately 3%. Using the prescribed ashing procedure and x-ray diffraction with an internal corundum standard, two kaolinite-bearing building materials containing chrysotile near 0.01 mass fraction were analyzed. The ashing procedure has additional advantages in reducing some samples to powders and removing volatile components, thereby eliminating some sample preparation procedures and concentrating any chrysotile present in the sample. The removal of volatile components improves the sensitivity of XRD analysis to concentrations below 0.01 mass fraction chrysotile.

Copyright

Corresponding author

References

Hide All
Campbell, W. J., Huggins, C. W., and Wylie, A. G. (1980). Chemical and Physical Characterization of Amosite, Chrysotile, Crocidolite, and Nonfibrous Tremolite for Oral Ingestion Studies by the National Institute of Environmental Sciences, U.S. Bureau of Mines Report of Investigation 8452 (USGPO, Washington, DC), 1980-603-102/41.
De Stefano, L., De Luca, F., Buccolieri, G., and Plescia, P. (2000). “Milling effects upon quantitative determinations of chrysotile asbestos by the reference intensity ratio method,” Powder Diffr. PODIE2 15, 2629. pdj, PODIE2
Djemai, A., Balan, E., Morin, G., Labbe, J. C., and Muller, J. P. (2001). “Behavior of paramagnetic iron during the thermal transformations of kaolinite,” J. Am. Ceram. Soc. JACTAW 84, 10171024. jac, JACTAW
Giese, Jr., R. F. (1988). Kaolin Minerals: Structures and Stabilities, in Reviews in Mineralogy Vol. 19, edited by S. W. Bailey (Mineralogical Society of America, Washington D.C.), pp. 29–62.
Gualtieri, A.and Artioli, G. (1995). “Quantitative determination of chrysotile asbestos in bulk materials by combined Rietveld and RIR methods,” Powder Diffr. PODIE2 10, 269277. pdj, PODIE2
Gualtieri, A. F., Moen, A., and Nicholson, D. G. (2000). “XANES study of the local environment of iron in natural kaolinites,” Eur. J. Mineral. EJMIER 12, 1723. eum, EJMIER
Hodgson, A. A. (1979). Chemistry and Physics of Asbestos, in Asbestos, Properties, Applications, and Hazards Vol. 1, edited by L. Michaels and S. S. Chissik (Wiley, New York), pp. 67114.
Hu, R., Block, J., Hriljac, J. A., Eylem, C., and Petrakis, L. (1996). “Use of x-ray powder diffraction for determining low levels of chrysotile asbestos in gypsum-based bulk materials: Sample preparation,” Anal. Chem. ANCHAM 68, 31123120. anc, ANCHAM
Jeyaratnam, M.and West, N. G. (1994). “A study of heat-degraded chrysotile, amosite and crocidolite by x-ray diffraction,” Ann. Occup. Hyg. AOHYA3 38, 137148. aog, AOHYA3
Khorami, J., Choquette, D., Kimmerl, F. M., and Gallagher, P. K. (1984). “Interpretation of EGA and DTG analyses of chrysotile asbestos,” Thermochim. Acta THACAS 76, 8796. tha, THACAS
Klein, C. (1993). Rocks, Minerals, and a Dusty World, in Reviews in Mineralogy Vol. 28, edited by G. D. Guthrie, Jr. and B. T. Mossman (Mineralogical Society of America, Washington D.C.), pp. 759.
Lee, S., Kim, Y. J., and Moon, H. (1999). “Phase transformation sequence from kaolinite to mullite investigated by an energy-filtering transmission electron microscope,” J. Am. Ceram. Soc. JACTAW 82, 28412848. jac, JACTAW
Mangia, A. (1980). “A new approach to the problem of kaolinite interference in the determination of chrysotile asbestos by means of x-ray diffraction,” Anal. Chim. Acta ACACAM 117, 337342. acy, ACACAM
Massart, D. L., Vandeginste, B. G. M., Deming, S. N., Michotte Y., and Kaufman, L. (1988). Chemometrics: A Textbook (Elsevier, Amsterdam), p. 86.
Mumpton, F. A.and Thompson, C. S. (1975). “Mineralogy and origin of the Coalinga asbestos deposit,” Clays Clay Miner. CLCMAB 23, 131143. cld, CLCMAB
Perkins, R. L. and Harvey, B. W. (1993). “Method for the determination of asbestos in bulk building materials,” U.S. Environmental Protection Agency EPA/600/R-93/116, Office of Research and Development, Washington, DC 20460.
Rickards, A. L.and Badami, D. V. (1971). “Chrysotile asbestos in urban air,” Nature (London) NATUAS 234, 9394. nat, NATUAS
Sánchez-Soto, P. J., del Carmen Jiménez de Haro, M., Pérez-Maqueda, L. A., Varona, I., and Pérez-Rodriquez, J. L. (2000). “Effects of dry grinding on the structural changes of kaolinite powders,” J. Am. Ceram. Soc. JACTAW 83, 16491657. jac, JACTAW
U.S. EPA (1982). “Interim method for the determination of asbestos in bulk insulation samples,” U.S. Environmental Protection Agency, 600/M4-82-020.
Veblen, D. R. and Wylie, A. G. (1993). Mineralogy of Amphiboles and 1: 1 Layer Silicates, in Reviews in Mineralogy Vol. 28, edited by G. D. Guthrie, Jr. and B. T. Mossman (Mineralogical Society of America, Washington D.C.), pp. 61137.
Wicks, F. J. (2000). “Status of the reference x-ray powder-diffraction patterns for the serpentine minerals in the PDF database—1997,” Powder Diffr. PODIE2 15, 4250. pdj, PODIE2
Wicks, F. J. and O’Hanley, D. S. (1988). Serpentine Minerals: Structures and Petrology, in Reviews in Mineralogy Vol. 19, edited by S. W. Bailey (Mineralogical Society of America, Washington D.C.), pp. 91–159.
Wylie, A. G. (1993). “Modeling asbestos populations: A fractal approach,” Can. Mineral. CAMIA6 30, 437446. can, CAMIA6

Analysis of kaolinite/chrysotile mixtures by ashing and x-ray diffraction

  • Jennifer R. Verkouteren (a1), Eric S. Windsor (a1), Joseph M. Conny (a1), Robert L. Perkins (a2) and J. Todd Ennis (a2)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed