Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-02T22:20:26.998Z Has data issue: false hasContentIssue false
  • English
  • Français

The Determination of Low Levels of Quartz in Commercial Kaolins by X-ray Diffraction

Published online by Cambridge University Press:  10 January 2013

N.J. Elton ,
P.D. Salt  and
J.M. Adams
N.J. Elton
Affiliation:
ECC International, John Keay House, St. Austell, Cornwall, PL25 4DJ, England
P.D. Salt
Affiliation:
ECC International, John Keay House, St. Austell, Cornwall, PL25 4DJ, England
J.M. Adams
Affiliation:
ECC International, John Keay House, St. Austell, Cornwall, PL25 4DJ, England
Get access Rights & Permissions [Opens in a new window]

Abstract

Legislation in the United States and Canada requires labelling of products containing ≥ 0.1 wt.% crystalline silica. Kaolin clays are used in a variety of industries and usually contain low levels of total (i.e., respirable plus non-respirable) quartz, even after beneficiation. X-ray diffraction procedures have been developed here which are suitable for the quantification of total quartz in commercial kaolins with accuracy sufficient to satisfy the legislation. Separation and analysis of the respirable fraction is not addressed in this paper; however, the procedures described would be applicable to such samples if sufficient were available. Use of the 50.1° 2θrather than the 26.6° 26 (CuKα) quartz peak avoids most of the potential problems of overlap with reflections from other accessory minerals. It is shown that profile fitting techniques and optimised experimental procedures allow the determination of quartz in bulk samples to ± 0.03 wt.% (95% confidence) at the 0.1 wt.% level, and ± 0.1 wt.% at the 1.0 wt.% level, with tolerable data collection times.

Type
Research Article
Information
Powder Diffraction , Volume 7 , Issue 2 , June 1992 , pp. 71 - 76
Copyright
Copyright © Cambridge University Press 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bish, D.L.& Howard, S.A.(1988). J. Appl. Crystallogr. 21, 86.CrossRefGoogle Scholar
Bish, D.L.& Reynolds, R.C. Jr.(1989). Sample Preparation for X-Ray Diffraction, in: Bish, D.L.& Post, J.E., Eds., 1989 Modern Powder Diffraction. Reviews in Mineralogy Vol. 20 Mineralogical Society of America.Google Scholar
Borg, I.Y.& Smith, D.K.(1969). Calculated X-ray Powder Patterns for Silicate Minerals, Geological Society of America, Memoir 122.CrossRefGoogle Scholar
Brindley, G.W.(1980). Quantitative X-ray Mineral Analysis of Clays, in: Brindley, G.W.& Brown, G., Eds., Crystal Structures of Clay Minerals and their X-ray Identification, Mineralogical Society, London.CrossRefGoogle Scholar
Brown, G.& Brindley, G.W.(1980). X-ray Diffraction Procedures for Clay Mineral Identification, in: Brindley, G.W.& Brown, G., Eds., Crystal Structures of Clay Minerals and their X-ray Identification, Mineralogical Society, London.Google Scholar
Carter, J.R., Hatcher, M.T.& Di Carlo, L.(1987). Anal. Chem. 59, 513.CrossRefGoogle Scholar
Emig, J.A.& Smith, D.K.(1989). Pow. Diff. 4, 209.CrossRefGoogle Scholar
Groves, J.A.& Ellwood, P.A.(1985). Ann. Occup. Hyg. 29, 429.Google Scholar
Hamilton, R.D., Peletis, N.G.& Miles, W.J.(1990). Detection and Measurement of Crystalline Silica in Minerals and Chemicals, presented at AIME Crystalline Silica meeting, 9 April 1990, Washington, DC.Google Scholar
Howard, S.A.& Preston, K.D.(1989). Profile Fitting of Powder Diffraction Patterns, in: Bish, D.L.& Post, J.E., Eds., 1989. Modern Powder Diffraction. Reviews in Mineralogy Vol. 20, Mineralogical Society of America.Google Scholar
Howard, S.A.& Snyder, R.L.(1983). Adv. X-ray Anal. 26, 73.Google Scholar
HSE (1987). Quartz in Respirable Airborne Dusts Laboratory Method Using Infra-Red Spectroscopy (Direct method), Methods for the Determination of Hazardous Substances: MDHS 37, UK Health and Safety Executive. (See also: MDHS 38 (As Above, but KBr disc method)).Google Scholar
Klug, H.P.& Alexander, L.E.(1974). X-ray Diffraction Procedures, John Wiley & Sons, New York.Google Scholar
Pickard, K.J., Walker, R.F.& West, N.G.(1985) Ann. Occup. Hyg. 29, 149Google Scholar
Press, W.H., Flannery, B.P., Teukolsky, S.A.and Vetterling, W.T.(1986). Numerical Recipes, Cambridge University Press.Google Scholar
Rowse, J.B.& Jepson, W.B.(1972). J. Thermal Anal., 4, 169.CrossRefGoogle Scholar
Salt, P.D.(1981). International Laboratory 11, 76.Google Scholar
Snyder, R.L.& Bish, D.L.(1989). Quantitative Analysis, in: Bish, D.L.& Post, J.E., Eds., Modern Powder Diffraction. Reviews in Mineralogy Vol. 20, Mineralogical Society of America.Google Scholar
Stanisz, G.J., Holender, J.M.& Soltys, J.(1989). Pow. Diff. 4, 70.CrossRefGoogle Scholar
Vachtl, J.(Ed.) (1969). Report on the XXIII International Geological Congress, Prague, 1968. Proceedings of Symposium I: Kaolin Deposits of the World, Vol. A - Europe, Vol. B - Oversea Countries (Academia, Prague).Google Scholar