Oxidation
- UO2 + ½O2 = UO3
Oxidation of Uraninite
- UO2 + 2Fe+3 = UO2+2 + 2Fe+2
Iron Couple Oxidation
- 4Fe+2 + O2 + 4H+ = 4Fe+3 + 2H2O
Oxidation of ferrous to ferric
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Leaching
- UO3 + H2SO4 = UO2SO4 + H2O
UO2SO4 + SO4-2 = UO2(SO4)2-2
UO2(SO4)2-2 + SO4-2 = UO2(SO4)2-4
pH < 2.5
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Loading
- R-4X + UO2(SO4)2-4 = R-UO2(SO4)3 + 4X-
Ion exchange of uranylsulfate ion to resin (R), pH < 2.5
(X) denotes mobile ion.
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Elution
- R-UO2(SO4)3 + NH4NO3 + HNO3 = 4NH4UO2(SO4)3 + R-4NO3
pH < 2.5
or
- R-UO2(SO4)3 + NaCl = Na4UO2(SO4)3 + R-4Cl
pH < 2.5
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Two Step Precipitation
- Fe2(SO4)3 + 6 NaOH = 2Fe(OH)3 + 3Na2SO4
Precipitation of Iron Hydroxide at pH of 2.5 and above.
- 2(NH4)4UO2(SO4)3 + 12NaOH = (NH4)2U2O7 + 6Na2SO4 + 6NH4OH + 3H2O
or
- UO2SO4 + H2O2 + 2H2O = UO4•2H2O + 2H2O
Precipitation of Uranyl Sulfate to Uranium Oxide
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