Abstract There is disclosed a method for the in-situ extraction of metal/mineral values from metalliferous and/or nonmetallic ores occurring in substantially impermeable ore deposits of the laminar gneiss or schist or conglomerate types, or the like. The invention is particularly adaptable for example to the mining of copper and nickle and manganese carbonate or sulphide type ores. In accordance with this invention, the geologic formation containing the ore is first penetrated by two or more, suitably spaced-apart openings, such for example bore holes extending from the earth''s surface to the bottom level of the deposit. There is then established a liquid-permeable ''''base'''' fractured zone interconnecting the lower ends of the bore holes within the ore body by means of a hydraulic-fracturing technique such as described in my U.S. Pat. No. 3,064,957; the base fracture being propped open by means of any suitable agent such as described for example in U.S. Pat. No. 2,645,291. An explosive material of liquid or slurry form is then flowed into the cavitated U-tube system comprising the bore holes and the ''''base'''' fractured zone, thereby replacing the hydraulic fracturing fluid by an explosive material of fluidized powder or liquid or slurry form. This operation is conducted under only substantially the earth''ssurface-ambient atmospheric pressure conditions, thereby eliminating serious prior art hazards. The explosive is then detonated so as to fracture the overlying ore body according to the petro-fabrics of the ore deposit and/or the stress patterns of the mineral constituents thereof. The ore body is thereby rendered permeable, and a suitable solvent/reactive material (such as sulphuric acid in the case of the metal carbonates) for recovery of the desired value-containing salt solution is then caused to percolate through the permeabilized ore deposit. The invention also contemplates a specific geometry for the solvent/reactive flow pattern through the ore body, featuring a vertical migration and ''''floating'''' of the solvent/reactant on top of the more metal concentrated fraction of the product flow stream; thereby maintaining an optimum reactant-to-ore status progressively upwardly within the lateral confines of the ore body. If sulphide type ores are involved oxygen or air and water may be employed as an in-situ solvent/reactant.
The method for extracting metalliferous values from a laminar type impermeable metalliferous ore body comprising: A. penetrating the ore body to provide two or more spaced apart clear openings extending from the earth''s surface and terminating in portions of the ore body at different elevations; B. fluid-pressure fracturing the ore body from the bottom end of the opening terminating at the lowermost elevation upwardly to the bottom end of another of said openings in the laiminar direction of the ore body to provide a permeable zone underlying a higher portion of the ore body of substantial vertical thickness, thereby establishing a substantially closed fluid circulation system including said openings and said permeable zone; C. flowing a fluid type explosive under pressure less than the fracturing pressure into said circulation system so as to fill said permeable zone; D. detonating said explosive so as to permeablize the ore body thereabove; and E. then flowing a sought-for metalliferous solvent/reactant fluid through another of said openings downwardly and through said circulation system so as to percolate through the permeabilized portions of the ore body to produce a product fluid containing the sought-for metalliferous values from the opening terminating at the lowermost elevation.
Claim 2
Independent Claim
199 words
The method for extracting metalliferous values from a laminar type impermeable metalliferous ore body comprising: A. penetrating the ore body to provide two or more spaced apart clear openings extending from the earth''s surface and terminating in portions of the ore body at different elevations; B. fluid-pressure fracturing the ore body from the bottom end of the opening terminating at the lowermost elevation upwardly to the bottom end of another of said openings in the laiminar direction of the ore body to provide a permeable zone underlying a higher portion of the ore body of substantial vertical thickness, thereby establishing a substantially closed fluid circulation system including said openings and said permeable zone; C. flowing a fluid type explosive under pressure less than the fracturing pressure into said circulation system so as to fill said permeable zone; D. detonating said explosive so as to permeablize the ore body thereabove; and E. then flowing a sought-for metalliferous solvent/reactant fluid through another of said openings downwardly and through said circulation system so as to percolate through the permeabilized portions of the ore body to produce a product fluid containing the sought-for metalliferous values from the opening terminating at the lowermost elevation.
Claim 3
Dependent Claim
34 words
A method as set forth in claim 1 wherein said openings into said ore body are provided by two or more horizontally spaced apart bore holes terminating at their bottom ends at different elevations.
Claim 4
Dependent Claim
33 words
A method as set forth in claim 2 wherein said base fracturing process is repeated as many times as may be necessary to coalesce the lower ends of at least two bore holes.
Claim 5
Dependent Claim
22 words
A method as set forth in claim 1 wherein said base fracturing process is performed by means of a hydraulic fracturing technique.
Claim 6
Dependent Claim
31 words
A method as set forth in claim 4 wherein said base fracturing process is conducted initially by means of a hydraulic fracturing technique, and is supplemented by an explosive fracturing technique.
Claim 7
Dependent Claim
39 words
A method as set forth in claim 1 wherein said fluid type explosive is flowed into said circulation system by means of a low pressure pump operating to deliver explosive through the opening hole terminating at the lowest level.
Claim 8
Dependent Claim
30 words
A method as set forth in claim 6 wherein a suction pump is operably connected to another one of the openings to supplement flowage of fluid explosive into said system.
Claim 9
Independent Claim
200 words
The method for extracting metalliferous values from a laminar type impermeable metalliferous ore body comprising: A. penetrating the ore body to provide two or more spaced apart clear openings extending from the earth''s surface and terminating in lower portions of the ore body at different elevations; B. fluid-pressure fracturing the ore body from the bottom end of the opening terminating at the lowermost elevation upwardly to the bottom end of another of said openings in the laminar direction of the ore body to provide a permeable zone underlying a higher portion of the ore body of substantial vertical thickness, thereby establishing a substantially closed fluid circulation system including said openings and said permeable zone; C. flowing a fluid type explosive under pressure less than the fracturing pressure into said circulation system so as to fill said permeable zone; D. detonating said explosive so as to permeabilize the ore body thereabove; and E. then flowing a sought-for metalliferous solvent/reactant fluid through one of said openings, upwardly and through said circulation system so as to percolate through the permeabilized portions of the ore body to produce a product fluid containing the sought-for metalliferous values from an opening terminating at a higher elevation.
Claim 10
Independent Claim
200 words
The method for extracting metalliferous values from a laminar type impermeable metalliferous ore body comprising: A. penetrating the ore body to provide two or more spaced apart clear openings extending from the earth''s surface and terminating in lower portions of the ore body at different elevations; B. fluid-pressure fracturing the ore body from the bottom end of the opening terminating at the lowermost elevation upwardly to the bottom end of another of said openings in the laminar direction of the ore body to provide a permeable zone underlying a higher portion of the ore body of substantial vertical thickness, thereby establishing a substantially closed fluid circulation system including said openings and said permeable zone; C. flowing a fluid type explosive under pressure less than the fracturing pressure into said circulation system so as to fill said permeable zone; D. detonating said explosive so as to permeabilize the ore body thereabove; and E. then flowing a sought-for metalliferous solvent/reactant fluid through one of said openings, upwardly and through said circulation system so as to percolate through the permeabilized portions of the ore body to produce a product fluid containing the sought-for metalliferous values from an opening terminating at a higher elevation.