Extractive process for preparing high purity magnesium chloride hexahydrate

This paper refers a method for the preparation of magnesium chloride hexahydrate (bischofite) from Sebkha el Melah of Zarzis Tunisian natural brine. It is a five-stage process essentially based on crystallization by isothermal evaporation and chemical precipitation. The two first steps were dedi...

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Bibliographic Details
Main Authors: Fezei Radouanne, Hammi Halim, M’nif Adel
Format: Article
Language:English
Published: Association of the Chemical Engineers of Serbia 2012-01-01
Series:Chemical Industry and Chemical Engineering Quarterly
Subjects:
Online Access:http://www.doiserbia.nb.rs/img/doi/1451-9372/2012/1451-93721100049F.pdf
Description
Summary:This paper refers a method for the preparation of magnesium chloride hexahydrate (bischofite) from Sebkha el Melah of Zarzis Tunisian natural brine. It is a five-stage process essentially based on crystallization by isothermal evaporation and chemical precipitation. The two first steps were dedicated to the crystallization of sodium chloride and potassiummagnesium double salts, respectively. Then, the resulting liquor was desulfated using calcium chloride solution. After that another isothermal evaporation stage was implemented in order to eliminate potassium ions in the form of carnallite, KCl.MgCl2.6H2O. At the end of this step, the recovered solution primarily composed of magnesium and chloride ions was treated by dioxan in order to precipitate magnesium chloride as MgCl2.6H2O.C4H8O2. This compound dried at constant temperature of 100°C gave good quality magnesium chloride hexahydrate. Besides this salt, the various by-products obtained from the different treatment stages are also useful.
ISSN:1451-9372
2217-7434