Preliminary Studies Of Fluoride Analysis On Uranium Containing Samples (ADU) Obtained From Production Of UO2 Powder

The study on quantitative determination of fluoride in uranium containing solid samples by using pyrohydrolysis technique has been carried out for the first time in Vietnam (at the Center for Analytical Chemistry-CAC, ITRRE, VAEI). The apparatus of pyrohydrolysis has thus been investigated for self-making firstly in CAC according to a structural scheme published in a literature. The preliminary studies on this self-made pyrohydrolytic apparatus showed that fluoride was separated from the sample matrix containing uranium (ADU) in water steam flow at 950oC within 30 minutes and condensed HF vapour through a water-cooling condenser was then collected at a flow rate of about 0.5 ml/min. in a PE flask. The fluoride concentration in solution was quantitatively determined with both electrochemical technique using fluoride ion selective electrode (ISE) and ion chromatography (IC). The recovery of fluoride analysis was achieved about 95 %. (author)