Recrystallisation by other methods

This method can also include separation of two substances by a situation similar to the crossover effect. At constant pressure solubility falls at first with 

Tester and his colleagues have studied the deposition of salt (NaCl and Na2S04) from supercritical water at c, 550°C and 250 bar, by mixing a stream of cold salt solution with larger stream of the supercritical water [108]. The motive was to study the salt nucleation and growth which occurs during oxidations in supercritical water. 

A different process, which produces crystals of c. 200 im, called gas antisolvent recrystallisation, has been developed by Krukonis and coworkers [109]. Carbon dioxide is compressed into a solution in acetone, for example, which causes expansion of the solution, a lowering of solubility and by control of conditions, slow recrystallisation. In some experiments cyclotrimethylene-trinitramine has been crystallised and separated from a cyclotetramethylenete-tranitramine impurity. 

and Ely, J.F. (1991) Supercritical Fluid Technology, CRC Press, Boca Raton. 

Fukuzato, R. (1991) in Proc. 2nd Int. Symp. Supercritical Fluids, (ed. M.A. McHugh), Johns Hopkins Univ., Baltimore, pp. 196-200. 

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