Solution mining process
AssigneeUnion Oil Company of California
InventorWilliam E. Showalter
Life of this patent
Estimating the term…
Abstract
Process for the solution mining of minerals from a subterranean formation using a dilute aqueous carbonic acid leaching solution and intermittent injection of an oxidizing agent.
Claims17
In a method for the solution mining of a substance which in an oxidized state is soluble in an aqueous leaching solution, said method comprising the steps of (1) introducing an oxidant and an aqueous leaching solution into a subterranean formation containing said substance, thereby to solubilize said substance in situ to form a pregnant liquor, (2) recovering said pregnant liquor from said formation, and (3) separating said substance from said pregnant liquor, the improvement comprising:
- utilizing as said aqueous leaching solution a solution comprising a dilute aqueous carbonic acid solution;
- and
- intermittently introducing said oxidant into said formation.
A method for the solution mining of metal values selected from the group consisting of uranium, thorium, vanadium, copper, nickel, molybdenum, rhenium and selenium, from a subterranean formation containing said metal values, comprising the steps of:
- (a) penetrating said formation with at least one injection well and at least one production well in spaced relation with said injection well;
- (b) introducing into said formation through said injection well discrete slugs of (1) an oxidant-containing leaching solution comprised of a dilute aqueous carbonic acid solution containing an oxidant selected from the group consisting of hydrogen peroxide, oxygen and oxygen-containing gases, and (2) an oxidant-free leaching solution comprised of a dilute aqueous carbonic acid solution to leach in situ said metal values from said formation thereby forming a pregnant liquor, each of said oxidant-containing and oxidant-free solutions having a pH less than about 7 and a bicarbonate ion concentration between about 380 ppm and about 1000 ppm, and the concentration of said oxidant in said oxidant-containing solution being between about 100 ppm and about 300 ppm on a free oxygen basis;
- (c) recovering said pregnant liquor at said production well;
- (d) forming a barren liquor by separating said metal values from said pregnant liquor;
- (e) introducing gaseous carbon dioxide into at least a portion of said barren liquor thereby to form a dilute carbonic acid solution;
- and
- (f) recycling at least a portion of the solution formed in step (e) for reintroduction into said formation to displace said slugs of said oxidant-containing and oxidant-free solutions through said formation.
Dependencies are inferred from the claim text.