Is a carbonate leach for ThO2 possible?

[eigenmax]

Carbonate leaches are often used in uranium chemistry a way to leach uranium into solution. Thorium dioxide is highly insoluble in everything except hot, concentrated sulphuric acid. Would a carbonate leach work for thorium?

 

[DrDu]

As far as I know, the carbonate complexes involve uranyl VI, while both U IV and Th IV are insoluble. For Th, 4 is already the maximal possible oxidation state, so the answer is no.

 

[eigenmax]

Ah, ok. Thanks.