Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-06T04:54:16.677Z Has data issue: false hasContentIssue false

Silver Sorption by Manganese Oxide

Published online by Cambridge University Press:  10 February 2011

R. Ravikumar
Affiliation:
Department of Materials Science and Mineral EngineeringUniversity of California, Berkeley, CA 94720
D. W. Fuerstenau
Affiliation:
Department of Materials Science and Mineral EngineeringUniversity of California, Berkeley, CA 94720
Get access

Abstract

Silver-manganese oxide ores are present in western United States, Mexico, South America, and Sumatra. The amount of silver varies between a few parts per million (ppm) to thousands of ppm. However, these ores are not compatible with conventional metallurgical treatment for the extraction of silver. This research is the study of the nature of silver binding with one model manganese oxide phase, cryptomelane. Cryptomelane is widely present in the United States and in parts of Colorado, with silver-bearing cryptomelane ore bodies containing up to a maximum of 1 wt% of silver. In order to better understand the nature of silver binding in cryptomelane, synthetic samples of cryptomelane were prepared and characterized, and then used for silver sorption experiments. The silver uptake appears to be a function of the solution chemistry conditions, pH and potassium nitrate concentration. The sorption of silver was found to increase with decreasing pH and at a fixed pH value, the sorption density was higher at a lower potassium nitrate concentration. Kinetics and equilibrium sorption data from lithium and sodium nitrate background electrolyte demonstrates three main results: firstly, most of the uptake of silver is compensated by release of potassium; secondly, the exchange for silver with protons and potassium ions is almost stoichiometric; and lastly, the importance of tunnel sites for the sorption reaction in cryptomelane. An ion-exchange model for the uptake of silver onto cryptomelane will also be discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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

1. Boyle, R. W., Geol. Survey of Canada, Dept. of Energy, Mines and Resources Bull. 160, pp. 264 (1968).Google Scholar
2. Hewett, D. F. and Fleischer, M., Econ. Geol. 55, No. 1, pp. 151 (1960).Google Scholar
3. Radtke, A., Taylor, C. M. and Hewett, D. F., Econ. Geol. 62, pp. 186206 (1967).Google Scholar
4. “Investigation of natural resources”, Geol. Survey Prof. Paper 575, p. A6 (1967).Google Scholar
5. Hilderbrand, F. A. and Mosier, E. L., USGS - Bulletin 1382– C (1974).Google Scholar
6. Pesic, B. and Wey, J. E., Trans. AIME 280, pp. 18461849 (1986).Google Scholar
7. Scheiner, B. J., Pool, D. L., Sjoberg, J. J., and Lindstrom, R. E., U. S. Bureau of Mines Report 7736 (1973).Google Scholar
8. Clevenger, G. H. and Caron, M. H., U. S. Bureau Mines Bull. 226, pp. 110 (1925).Google Scholar
9. Burns, R. G. and Bums, V. M. in The Oceanic Lithosphere, edited by Emiliani, C. (John Wiley & Sons Inc., New York, 1981), p. 875914.Google Scholar
10. McKenzie, R. M., Miner. Mag. 38, pp. 493502 (1971).Google Scholar
11. von W., Buser, Graf, P. and Feitknecht, W., Helv. Chimica Acta 37, No. 7, pp. 23222333 (1954).Google Scholar
12. Healy, T. W., Herring, A. P. and Fuerstenau, D. W., J. Coll. Inter. Sci. 21, pp. 435444 (1966).Google Scholar