Title:
METHOD FOR PRODUCING HIGH-PURITY CRYSTALLINE COMPOUNDS AND DEVICE FOR REALISING THE SAME
Document Type and Number:
WIPO Patent Application WO/1998/000587
Kind Code:
A1
Abstract:
The present invention relates to a method for producing high-purity substances during a single crystallisation process while removing all contaminants. Starting substances are fed into a vacuum reactor, wherein said substances are selected according to a stoichiometric ratio in order to synthesize the target compound. The first starting substance is converted into a gaseous phase and deposited onto the wall of a ring-shaped chamber formed by the inner and outer cylindrical portions of the working region of the reactor body. The first substance is obtained in the form of a thin layer, while the second substance is also converted into a gaseous phase and further sent onto said first substance. The reaction (synthesis) zone is then displaced along the first substance layer using a mobile temperature gradient, and the crystalline compound thus obtained is transferred into an auxiliary region in the reactor. The heating zone is displaced in the direction of the auxiliary region and ensures the single-step recrystallisation of the crystalline compound using a predetermined range of heating temperatures. In order to provide a homogeneous final product having a higher purity, the compound is maintained for a period of time at the heated state, the compact mass being further collected and removed from the reactor. The reactor of the present invention comprises a cylindrical tube with a working region containing an inner tube. The inner tube together with an outer tube define the ring-shaped working chamber where the synthesis and recrystallisation process is carried out. The conversion of the starting substances into a gaseous phase, the reverse operation as well as the recrystallisation of the synthesized compound and the homogenisation and transfer of the final product into the reactor auxiliary region may all be performed by fitting this device with external, internal and local heating units. These units are each provided with means for displacement along the reactor. In order to provide vacuum conditions within the reactor chamber, the device is also provided with an end duct that extends through the reactor lid.
Inventors:
KLEVKOV JURY VIKTOROVICH (RU)
MEDVEDEV SERGEI ALEXANDROVICH (RU)
MEDVEDEV SERGEI ALEXANDROVICH (RU)
Application Number:
PCT/RU1996/000177
Publication Date:
January 08, 1998
Filing Date:
July 02, 1996
Export Citation:
Assignee:
KLEVKOV JURY VIKTOROVICH (RU)
MEDVEDEV SERGEI ALEXANDROVICH (RU)
MEDVEDEV SERGEI ALEXANDROVICH (RU)
International Classes:
C30B11/00; C30B25/08; (IPC1-7): C30B25/00; C30B23/00
Foreign References:
| SU810085A3 | 1981-02-28 | |||
| DE3304060A1 | 1984-08-09 | |||
| SU1807102A | ||||
| DE2738585A1 | 1978-03-02 | |||
| US4314873A | 1982-02-09 | |||
| US4584054A | 1986-04-22 |
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