Alkali Scandium Selenites

Alkali Scandium Selenites Anhydrous Alkali Scandium Selenites 

After 10 d contact of ASc(Se03)2-nH20 with H2O (static conditions), the Sc content in the solution is about an order of magnitude higher than for Sc2(Se03)3  

NaGd(Se03)2-2.5H20 NaGd(Se03)2 1.5H20 65 to 95°C 

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Scandium selenite hydrates have been prepared, usually by reaction of scandium compounds like Sc(OH)3 or SCCI3 with H2Se03 or with alkali selenites in aqueous systems. The anhydrous selenites have been obtained by dehydration of the corresponding hydrates. 

The presence of an additional cation also makes the thermogram more complex, as seen for the alkali rare earth selenites (Erametsa et al., 1973) and the corresponding scandium compounds, which also contain variable amounts of hydrogen (Znamenskaya et al., 1978). Below 1000°C the end products contain the alkali ion. The extra cation is volatilized at relatively low temperatures or below 600°C only in the case of ammonium compounds (Erametsa et al., 1973). 

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