Selenium impurity in sodium sulphate decahydrate formed by Eutectic Freeze Crystallization of industrial waste brine
Journal Article
2013
Permanent link to this Item
Authors
Journal Title
The Journal of the Southern African Institute of Mining and Metallurgy
Link to Journal
Journal ISSN
Volume Title
Publisher
The Southern African Institute of Mining and Metallurgy
Publisher
University of Cape Town
License
Series
Abstract
Eutectic freeze crystallization (EFC) is a novel technique for the recovery of pure salt and pure water from hypersaline waste brines. It is therefore a promising technology for the treatment of industrial waste waters. The impurities caused by crystallizing salt out of multi-component brines by EFC have not yet been investigated, however. To these ends, the selenium impurity found in sodium sulphate, produced from the waste brine of a platinum operation, was investigated. It was believed that the similarity between sulphate and selenate ions allowed isomorphous substitution of
selenate ions into the sodium sulphate crystals, which was the likely cause of impurity uptake. It was found that the presence of sodium chloride in the industrial brine promotes the uptake of
selenium, while ionic strength of the brine and mass deposition rate of sodium sulphate did not have a significant effect on the selenium uptake. Isomorphous substitution is predicted to be the most
significant mechanism by which all impurities will be taken up when applying EFC to other industrial waste brines.
Description
Reference:
Apsey, G. and Lewis, A.E. (2013). Selenium impurity in sodium sulphate decahydrate formed by Eutectic Freeze Crystallization of industrial waste brine. Journal of the South African Institute of Mining and Metallurgy, Special Edition, 113: 415-421