Uranium from Phosphate Ores and Wet Phosphoric Acid

2 Uranium from Phosphate Ores and Wet Phosphoric Acid 

Ionic radius of U + comparable with Ca- hence in apatites. 

Wet process phosphoric acid from apatites contains 50 to 200 ppm UrOg 

Separation of UgOg from raw wet process phosphoric acid  

In the reduction stripping process uranium(IV) in the raw wet process acid is oxidized to uranium(Vl) by treatment with sodium chlorate, hydrogen peroxide or air at 60 to 70°C, the uranium(VI) formed being extracted with trioctylphosphine oxide/di-(2-ethylhexyl)phosphate in kerosene and the resulting solution finally reductively stripped repeatedly with aqueous iron(II) solutions. This results in an enrichment by a factor of 40. After oxidation of the stripped solution with sodium chlorate or ambient oxygen and renewed extraction of the uranium(VI) formed with trioctylphosphine oxide/di-(2-ethylhexyl)phosphate, the phosphoric acid is removed from the organic phase by washing. The uranium(Vl) is then stripped with ammonium carbonate and precipitated as the ammonium diuranyl-tricarbonato-complex. This is filtered off, washed and calcined. 

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