Abstract: A process is provided for the separation of substances by melt crystallization. The organic mixtures which are difficult to crystallize are heated to a temperature sufficient to obtain a melt with the melt then being moved through a three-dimensional crystallization matrix having a large specific area. The melt is slowly cooled over a temperature range so as to achieve a selective crystallization from the supersaturated melt in the carrier matrix. A deposited crystal phase is thereafter melted and separated from the carrier matrix and removed by centrifugation. The carrier matrix may have a crystallization-promoting microstructure surface and may consist of an openpored foam.

Abstract: A process is provided for the separation of substances by melt crystallization. The organic mixtures which are difficult to crystallize are heated to a temperature sufficient to obtain a melt with the melt then being moved through a three-dimensional crystallization matrix having a large specific area. The melt is slowly cooled over a temperature range so as to achieve a selective crystallization from the supersaturated melt in the carrier matrix. A deposited crystal phase is thereafter melted and separated from the carrier matrix and removed by centrifugation. The carrier matrix may have a crystallization-promoting microstructure surface and may consist of an openpored foam.

Abstract: In the tube (41) of a tube assembly of a crystallization apparatus, an insert (43) is provided which increases the effective surface in the interior of the tube (41). The insert has subsequent different sections (45, 46, 47). Seen in direction of flow the effective surface per unit of length of a subsequent section (46, 47) is larger than the effective surface of the previous section (45, 46). Because the heat removal by the coolant is a limiting factor for the kinetics of crystallization, the amount of crystals produced per unit of length of the tube is not substantially increased by the insert, but a smaller linear growth velocity is obtained at the surface of the crystals. This provides for better conditions for forming clean crystals. The inserts (343, 443 . . .