CHEMISTRY OF AMERICIUM - 4. THE STABILITY OF Am(V) AND Am(VI) IN NITRIC ACID SOLUTIONS AND IN THE SOLUTIONS CONTAINING OZONE GAS, FLUORIDE, OR PHOSPHATE IONS.

Abstract

The coprecipitation technique with BiPO//4 and ThF//4 was applied to studying the stability of Am(V) and Am(VI) at concentrations lower than 10** minus **6. It was found that **2**4**1Am(V) and **2**4**1Am(VI) were rapidly reduced to **2**4**1Am(III) in nitric acid solutions at low acidities and at high temperatures, but the reduction was effectively inhibited by the presence of ozone gas or fluoride ions. On the other hand, **2**4**3Am(V) and **2**4**3Am(VI) are found to be rather stable in nitric acid solutions, while they were readily reduced to **2**4**3Am(III) in phosphate solutions in the same manner as **2**4**1Am(V) and **2**4**1Am(VI).