Process for the preparation of lanthanum carbonate dihydrate

A process for the preparation of stable lanthanum carbonate of the formula

• La2(CO3)3.xH2O
• wherein x=2.0±0.2
• which comprises:
• (i) reacting aqueous lanthanum chloride hydrate with aqueous ammonium bicarbonate at 20-60° C.
• (ii) isolating the resultant lanthanum carbonate hydrate by filtration
• (iii) washing the wet lanthanum carbonate hydrate with water to get rid of the chlorides
• (iv) partial drying of lanthanum carbonate hydrate at 60-65° C.
• (v) suspending the partially dried lanthanum carbonate hydrate in a hydrocarbon solvent
• (vi) refluxing the medium under azeotropic conditions in the presence/absence of vacuum to get lanthanum carbonate dihydrate
• (vii) filtering and drying of the resultant lanthanum carbonate dihydrate at 60-65° C.