Process for recovery of mineral values from subterranean formations
AssigneeMobil Oil Corporation
InventorsJoseph G. Savins, Warren F. Johnson
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Abstract
The present invention relates to the in situ recovery of mineral values, particularly uranium, from subterranean formations that contain sulfur in organic or inorganic forms where the sulfur causes premature deletion of an oxidant and reduction in permeability of the formation. The adverse effects due to the presence of the sulfur in the formation are substantially reduced in accordance with the present invention by treating the formations with an aqueous solution of iron-complexing agent and then oxident to preferentially oxidize and solubilize at least a portion of the sulfur in the formation. The present process may be applied either as a pre-treatment process to be followed by a leaching process or simultaneously with the leaching process.
Claims15
A process for the recovery of uranium values from a subterranean formation containing pyritic sulfur compounds and penetrated by injection and production systems, comprising the steps of:
- (a) introducing into the formation via the injection system an aqueous solution of iron-complexing agent and an oxidant to preferentially oxidize and solubilize at least a portion of the sulfur compounds in the formation and inhibit plugging of the formation by insoluble sulfur compounds;
- (b) then introducing a lixiviant comprising a uranium-leaching agent and an oxidant into the formation through the injection system;
- (c) allowing the lixiviant to leach out uranium values in the formation;
- and
- (d) producing the lixiviant and uranium values from the formation via the production system.
Dependencies are inferred from the claim text.