Preparation of Anhydrous Magnesium Chloride from Bischofite (MgCl2·6H2O) I. Reaction Crystallization of Magnesium Chloride Hexammoniate

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Magnesium chloride hexammoniate (MgCl2·6NH3) is an intermediate product for preparation anhydrous magnesium chloride by reaction crystallization method. An experiment study of a semi-batch reaction crystallization is presented. In a single feed operation, magnesium chloride solution is fed to a stirred methanol solution mixed with ammonia to crystallize magnesium chloride hexammoniate. The median crystal size of product increases with increasing stirring rate, reaches a maximum, and then decreases again. Decreasing feed rate or decreasing stirring time increases the crystal size significantly. The reaction temperature and concentration of magnesium ion can also influence the crystal size distribution (CSD). A double feed operation can create larger crystal size than that of single feed operation. The relationship between crystal size and the content of water of the product is discussed.

Info:

Periodical:

Materials Science Forum (Volumes 488-489)

Edited by:

W.Ke, E.H.Han, Y.F.Han, K.Kainer and A.A.Luo

Pages:

57-60

Citation:

X. T. Wang et al., "Preparation of Anhydrous Magnesium Chloride from Bischofite (MgCl2·6H2O) I. Reaction Crystallization of Magnesium Chloride Hexammoniate", Materials Science Forum, Vols. 488-489, pp. 57-60, 2005

Online since:

July 2005

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$38.00

[1] Georges J. Kipouros, Donald R. Sadoway, Journal of Light Metals, 2001(1), p.111.

[2] Peacey John G ; Kennedy Mark W ; Walker Thomas P, US5565080, (1995).

[3] Amundsen Ketil, Eklund Hans Ragnar, SchmidtRalf, U.S. Patent 6, 042, 794, (2000).

[4] Sivilotti Olivo Giuseppe; Sang Jean Victor; Lemay Rejean, WO9422763, (1994).

[5] Baldyga, J.; Podgorska, W.; Pohorecki, R. Chem. Eng. Sci., 50(8)(1995), p.1281.

[6] Mullin J. W, Crystallization: third edition, Butterworth-Heinemann, London, (1992).

[7] Torbacke M, Rasmuson AC, Chem. Eng. Sci., 56 (7) (2001), p.2459.

[8] Aaslund, Bengt L.; Rasmuson, Aake C , AIChE J., 38(3)(1992), p.328 Fig. 12 the CSD of the two types of operations.

[6] 8 10 12 14 16 18 20 22 24 26.

[20] [30] [40] [50] [60] [70] [80] [90] 100 A-Crystal size B-Water Water(%) Median crystal size(¦Ì m) Temperature(¡æ) 0. 2 0. 4 0. 6 0. 8 1. 0 1. 2 BA Fig. 10 Influences of temperature on median crystal size and water content.

[6] 8 10 12 14 16 18 20 22 24 26.

[20] [30] [40] [50] [60] [70] [80] [90] 100 A-Crystal size B-Water Water(%) Median crystal size(¦Ì m) Temperature(¡æ) 0. 2 0. 4 0. 6 0. 8 1. 0 1. 2 BA Fig. 11 Influence of temperature on CV.

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