Separation of uranium from carbonate containing solutions thereof by direct precipitation
AssigneeMobil Oil Corporation
InventorJohn B. Otto, Jr.
Life of this patent
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Abstract
A direct precipitation method based on the insolubility of uranyl phosphate in carbonate containing solutions at pH 6-6.5 and its insolubility at pH 8 is described. The method eliminates the use of ion exchange columns for removing uranium values from uranium leachates and can be readily applied to an integrated field operation.
Claims56
A process for removing uranium values from a liquid solution at pH above about 7 containing carbonate and uranyl ions which comprises dissolving phosphate ions in said solution and lowering the pH of said solution sufficient to precipitate said uranium.
A process for recovering uranium values from a subterranean deposit which comprises (a) penetrating said deposit with at least one injection well and at least one production well in spaced relation with said injection well;
- (b) treating the subterranean deposit to obtain a first pH of at least about 8 and a carbonate ion concentration of at least about 1000 ppm;
- (c) introducing into the deposit a source of phosphate ion and an oxidant capable of oxidizing said uranium to the hexavalent state;
- (d) producing leachate containing dissolved uranium values to the surface;
- and (e) lowering the pH of said leachate to a second pH at which the said uranium precipitates out of solution.
A process for selectively removing uranium values from a liquid solution containing carbonate, uranium, and at least one other mineral value dissolved therein which comprises (a) adjusting the pH of said solution to a first pH higher than 7;
- (b) adding a source of phosphate ion which is soluble in said solution;
- and (c) lowering the pH of said solution to a second pH at which said uranium precipitates out of solution, the amount of said other mineral value present in said precipitate being less than 1% of its original content in said liquid solution.
Dependencies are inferred from the claim text.