METHOD OF PREPARING RAW MATERIAL FROM SODIUM OR CAESIUM IODIDES FOR GROWING CRYSTALS Russian patent published in 2009 - IPC C30B29/12 C01B9/06 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of preparing free running salts of metal halides and can be used in chemical industry, particularly for preparing initial salts of sodium or caesium iodides for growing monocrystals - Nal(Tl), Csl, CsI(Tl), CsI(Na). The method involves loading initial salt into an ampoule, evacuation of the ampoule, heating the salt to 420-450°C with constant evacuation, letting in dry air with subsequent holding, repeated air inlet, holding and pumping in the given modes and repeated evacuation, after which carbon dioxide gas is let in until attaining pressure of 200-400 mm Hg and keeping the salt in a carbon dioxide gas atmosphere for 15-20 minutes.

EFFECT: invention allows for obtaining raw material, more specifically iodides of alkali metals, without impurities of hydroxyl groups, which provides for good scintillation properties of crystals, as well as photochemical stability of crystals; also, the initial salt has a homogeneous powdered structure, ie retains free-running properties.

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