Abstract: A method of enhancing the remediation of contaminated soils and ground water, production of oil and gas, and production of any solid, gas, and/or liquid from subsurface geologic and man-made formations including the steps of estimating the geometric boundaries of the region containing the material to be recovered, drilling a recovery well(s) into subsurface in a strategic location to recover the material of interest, establishing multiple sources of acoustical power in an array about and spaced-apart from the surface or at various depths below the surface in a borehole(s) and/or well(s), directing a volume of acoustical excitation from the sources into the region containing the material to be recovered, the excitation in the form of either controllable sinusoidal, square, pulsed, or various combinations of these three waveforms, and controlling the phasing, frequency, power, duration, and direction of these waveforms from the sources to increase and control the intensity of acoustical excitation in the region

Abstract: Hydrocarbons trapped in solid media, such as bitumen in tar sands may be recovered from deep formations by relieving the stress of the overburden and causing the formation to flow from an injection well to a production well, for example, by fluid injection, recovering a tar sand/water mixture from the production well, separating the bitumen and reinjecting the remaining sand in a water slurry.

Abstract: A process is described for solution mining isolated, mechanically mined-out areas of soluble evaporite ore to recover remaining ore reserves, wherein the mined-out areas are separated from an operational mine area by barrier pillars of the evaporite ore, by drilling at least one vertical well bore from the surface to a predefined distance above the evaporite ore body, converting the drilling of the vertical well bore to a substantially horizontal well bore at a predetermined distance below the ground level, continuing the drilling parallel to and within the evaporite ore body to form a well bore one end of which is connected to the mined-out area, developing a connection from the operating mine area to the other end of the well bore, drilling an injection well from the surface into the mined-out area, injecting an aqueous solvent into the injection well, passing the solvent into the mined-out area, removing solvent enriched in dissolved evaporite ore from the mined-out area, passing such enriched solvent from

Abstract: The invention provides caverns and methods for producing caverns in bedded salt deposits for the storage of materials that are not solvents for salt. The contemplated salt deposits are of the bedded, non-domed variety, more particularly salt found in layered formations that are sufficiently thick to enable the production of commercially usefully sized caverns completely encompassed by walls of salt of the formation. In a preferred method, a first bore hole is drilled into the salt formation and a cavity for receiving insolubles is leached from the salt formation. Thereafter, at a predetermined distance away from the first bore hole, a second bore hole is drilled towards the salt formation. As this drill approaches the salt, the drill assumes a slant approach and enters the salt and drills through it in a horizontal direction until it intersects the cavity for receiving insolubles.

Abstract: Evaporite mineral solution mining process and apparatus comprising the steps of undercutting a bed or massive deposit by in-air jetting with an aqueous solution followed by solution mining of the mineral above the undercut with monitoring and control to cease the solution mining when the roof rock is adequately exposed to maintain a stable roof and stable pillar support. The resulting cavity exhibits steeply angled, nearly vertical sidewalls, flared upwardly and outwardly only 10.degree. to 15.degree. from the vertical plane normal to the edges of the undercut as compared to 45.degree. typical for morning glory cavities. A first plan vertical production well is drilled with a sump provided substantially adjacent to the floor rock. A second horizontal well is developed up dip to intersect and communicate with the production well. The air jet tool mechanism provides horizontal, slightly upwardly inclined jets (0.degree.-15.degree.

Abstract: A hot fluid is injected through an injection well into a coal seam to induce more rapid and complete desorption of methane therefrom and to cause desorbed methane to proceed toward a nearby production well in the coal seam.

Abstract: The invention provides a process for converting subterraneous ore overlain by an adjacent formation of porous rock into an enclosed zone of fragmented ore by first blasting a void space in the porous rock and secondly explosively expanding the ore into the void space. The invention also provides a process for the extraction and recovery of values from a subterraneous ore overlain by an adjacent formation of porous rock. The invention is particularly useful for the extraction and recovery of carbonaceous values from subterraneous oil shale.

Abstract: Elemental sulfur in substantially pure form is recovered from an underground sulfur formation which has been previously been mined by the Frasch process by injection of hot water into the underground formation to melt at least a portion of the sulfur, removing the resulting mixture of sulfur and hot water to the surface, separating the mixture of sulfur and hot water, recovering the sulfur as molten sulfur, and recycling the water to the underground formation. In alternatives, the water may be treated with additives to prevent corrosion, and scale and to reduce hardness and enhance separation of sulfur and water. The process is practiced using a conventional Frasch sulfur well in combination with a bleed water well and/or injection well. Also provided is a method and apparatus for separating molten sulfur from a mixture of molten sulfur and water.

Abstract: An in-situ coal gasification process for practice on a formation having one or more dipping coal seams that involves, directionally drilling a production wellbore into a burn module designated in each coal seam each from a separate surface location and, from one surface location, directionally drilling injection wellbores to a designated burn module in a coal seam.

Abstract: Nahcolite solution mining process comprising drilling at least one well into a Nahcolite bed, circulating hot barren aqueous liquor in a cavity in said Nahcolite bed for a time sufficient to produce a pregnant liquor having an increase in the concentration of NaHCO.sub.3 in the range of from about 3 to about 20% while maintaining Na.sub.2 CO.sub.3 concentration in the range of about 0.25-4%, preferably less than 2.5%, withdrawing said pregnant liquor, cooling said pregnant liquor to preferentially precipitate NaHCO.sub.3 therefrom and to produce a barren liquor, recovering said NaHCO.sub.3, and reheating and re-injecting said barren liquor in said well. The cavity temperature is maintained below about 250.degree. F. and preferably below about 200.degree. F. The barren liquor is injected at a pressure of below about 150 psig. The pregnant liquor is extracted at a temperature in the range of from about 85.degree. F. to about 200.degree. F., and the cystallization occurs at a temperature of about 25.degree.-120.

Abstract: Process for obtaining increased yields of minerals from bedded ore desposits in the absence of natural confining beds, by confining the flow of leach solution to the mineralized zone through operation of wells comprising, (a) injecting ground water into the barren zones above and below the mineralized zone while simultaneously injecting leaching solution into the mineralized zone at a single injection well location, and (b) recovering ground water from barren zones while simultaneously recovering leaching solution from the mineralized zone at a single recovery well location.

Abstract: The present invention relates to a new process of heap leaching and comprises the following steps:(a) preparing the ground to receive the heap;(b) forming the heap;(c) sinking injection wells into the heap;(d) injecting the leaching solution by means of injection wells; and(e) recovering the leaching solution at the base of the heap, or by pumping from wells neighboring those used for injection.

Abstract: A process for reducing scale formation in off-shore production platforms where sea water is used as a water-flooding medium. During production, sea water and connate water interact to make scale forming precipitates. Said precipitates fall out in an oil/water separator. Subsequently, additional sea water is injected as the separated aqueous phase leaves said separator thereby causing additional precipitates to form. Via this method, decreased amounts of scale preventing inhibitors are required.

Abstract: A method of in-situ leaching is disclosed in which the ore body is incapsulated by impermeable barriers. A grid of injection and production wells are drilled into the ore body. Horizontal barriers are formed at the top and bottom of the ore body by creating an overlapping pattern of horizontally-oriented fractures filled with polymer, above and below the ore body, radiating from each of the injection and production wells. A ring of boundary wells may also be drilled surrounding the ore body. The strata around each boundary well is fractured and a polymer is then injected to form a vertical barrier around the periphery of the ore body. The lixiviant is then introduced to extract the desired mineral values. In addition, water may be injected under pressure into guard wells between the ore body and the vertical and/or horizontal barrier wells to further reduce any migration of lixiviant into neighboring formations.

Abstract: The present invention embodies an improved method for the in situ mining of low to impermeable minerals to sweep out sections of deposits beneath the surface of the earth.

Abstract: A solution mining process for recovering mineral values from a subterranean mineral-bearing formation, which includes (1) a first injection-and-production phase during which a leaching solution is injected into the formation and a pregnant liquor is simultaneously recovered from the formation, (2) a production-only phase during which injection is suspended and additional pregnant liquor is recovered from the formation, and (3) a second injection-and-production phase.

Abstract: A method of extraction of metallic sulfides (Matte) from an ore deposit in situ. The contained sulfides are smelted by resistor induced heat creating a matte containing precious metals, including, but not limited to, platinum-group metals and gold and silver (as well as copper, nickel, iron, sulfur, etc). The heavier portion of the bath (matte) settles to the bottom and the slag rises to the top. Further smelting is controlled by positioning of the electrode pairs in the bath, thus regulating heat generation by modulation of the resistance between said electrodes. Placement of the electrodes in cased drill holes strategically placed to intersect and penetrate the ore-bearing horizons results in extraction of the valuable metals as matte. The matte can be recovered either as a liquid, or, after cooling, as a solid.

Abstract: A method for the in situ leaching of a subterranean mineral (e.g. uranium) deposit which permits the use of downflow ion exchange columns without requiring expensive filtration equipment to remove particulate material and/or sediment from the leach solution. The injection and production wells are gravel packed so that all of the heavier particulate material will be filtered from the leach solution as it flows into the production well. The bed of ion exchange resin in the downflow column is then used to filter the finer sediment from the leach solution as the resin adsorbs the uranium from the leach solution. The barren leach solution from the ion exchange column can be used to makeup fresh leach solution without any further filtration. The loaded resin is removed from the ion exchange columns and is screened to remove the fine sediment. The resin is then eluted and screened again to remove any sediment that may accumulate during elution.

Abstract: Mineral values, particularly uranium, are recovered from subsurface earth formations containing the same, as well as cations which form precipitates with sulfuric acid leach solutions, by injecting into at least one injection well a preliminary acidic solution capable of forming soluble materials with at least one of the precipitate-forming cations, such as calcium and iron cations, passing the preliminary acidic solution through the subsurface formation for a time sufficient to form such soluble materials, withdrawing the preliminary acidic solution containing the solubilized materials from at least one producing well, thereafter, injecting a sulfuric acid leach solution into said injection well, contacting the subsurface formation with the leach solution for a time sufficient to extract significant amounts of mineral values from the formation and produce a pregnant leach solution containing the thus solubilized mineral values and withdrawing the pregnant leach solution from the production well.

Abstract: Mineral values, particularly uranium, are recovered "in situ" from a subsurface earth formation by completing at least one well in the mineralized formation adjacent either the top or the bottom of the mineralized formation, completing at least one second well in the mineralized formation adjacent the opposite of the top and the bottom of the mineralized formation, forming a horizontally-oriented fracture in the mineralized formation adjacent at least one of the top and the bottom of the mineralized formation, each of which fractures is in open communication with that well which has been completed at a corresponding vertical level, injecting a leach solution, adapted to solvate the mineral values, into the first or the second well, which thus becomes an injection well, and thence into that fracture which is in communication with the injection well and producing the leach solution, containing solvated mineral values, from the other of the first and second wells, which thus becomes the production well, whereby

Abstract: In accordance with the present invention, mineral values are recovered from subsurface earth formations containing the same as well as calcium-containing materials by injecting into at least one injection well an aqueous sulfuric acid leach solution adapted to extract such mineral values from the subsurface formation and containing a solubility increasing agent, such as sodium chloride, adapted to significantly increase the solubility of calcium sulfates in water, in an amount sufficient to thus increase the solubility of calcium sulfates in water, contacting the subsurface earth formation with the leach solution for a time sufficient to extract significant amounts of mineral values from the formation and produce a pregnant leach solution containing the thus extracted mineral values and to thus solubilized significant amounts of calcium sulfates and withdrawing the pregnant leach solution from at least one producing well.

Abstract: The present invention relates to an improved process for the solution mining of a mineral from a subterranean formation. More specifically, the invention relates to an improved process which enhances significantly the recovery of a mineral from a subterranean formation via solution mining. The improvement comprises periodically ceasing injection of leach solution while continuing production to alter the path of flow of the leach solution between an injection well and a production well and subsequently injecting leach solution.

Abstract: Mineral values, particularly uranium, are recovered in situ from a heterogeneous subsurface earth formation containing the mineral values, which formation comprises zones of both high and low permeability, including injecting a plurality of separate slugs of leach solution adapted to solvate the mineral values into at least one injection well in communication with all zones of the formation, injecting a slug of a gas which is essentially insoluble in the leach solution between each two successive volumes of leach solution and withdrawing the pregnant leach solution, containing mineral values, from at least one production well in communication with all zones of the formation. The method can be further improved by injecting a mobility modifier, adapted to decrease the mobility of the leach solution, at the trailing end and/or leading end of the leach solution which is in contact with a slug of the gas. In a preferred embodiment, the mineral values contain significant amounts of uranium.

Abstract: This invention relates to a process for reducing to environmentally acceptable levels the amount of soluble or mobile contaminants in formations that have been subjected to in situ leaching to recover mineral values therefrom. The present process is also applicable to surface milling operations. In accordance with the present invention, an aqueous solution containing orthophosphates is introduced into the formation to immobilize contaminants by forming a relatively stable precipitate. For example, radionuclides such as uranium, thorium or radium form stable precipitates with orthophosphates.When the formation fluids contain a high concentration of carbonates, the formation fluids are treated to reduce the carbonates concentration to levels which do not substantially interfere with the phosphate precipitation of contaminants.

Abstract: In-situ combustion of tar sand formations is improved by introducing into an unminable tar sand formation prior to initiation of in-situ combustion hydrogen sulfide produced from upgrading tar sands from a minable tar sand formation in an area proximate the area of the unminable formation. The stream of hydrogen sulfide may contain a small proportion of hydrocarbons condensible at temperature and pressure conditions of the unminable formation. The improvement is applicable to both forward and reverse in-situ combustion processes.

Abstract: An oxygenated lixiviant is transported down an injection pipe into the leach zone at the bottom of an injection pipe, the lixiviant leaches the ore and the pregnant lixiviant containing metal compounds is recovered through a recovery pipe. The metal compounds are separated from the lixiviant and the lixiviant is regenerated, reoxygenated and recycled. The pressure of the lixiviant at the downstream end of the injection pipe is substantially equal to the pressure of the lixiviant at the upstream end thereby permitting maximum oxygenation without any degassing.

Abstract: Subterranean generation of heat as a source of energy optionally accompanied by the production of minerals. In subterranean formations of minerals that are capable of undergoing an enthalpic degradation, such degradation is artificially accelerated by several orders of magnitude. To this end a bore hole is drilled down to the desired formation and accelerated enthalpic degradation is made to occur by a suitable ignition. For the extraction of energy the bore hole is flushed with water and the resulting steam is withdrawn. In one embodiment, one and the same bore hole is used for charging water and withdrawing steam. In another embodiment the bore holes are arranged pairwise, one bore hole of each pair serving for ignition and introduction of water and the other serves for the withdrawal of steam.

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.

Abstract: A process is described for the recovery of uranium from ore wherein the ore is leached, the resulting leachate is passed over an anion exchange resin, and the resin is then eluted with an elution solution containing an anion capable of replacing the uranyl anion captured on the resin, followed by treatment with a sulfite-containing solution so that polythionates captured on the ion exchange resin are reacted to form essentially thiosulfate and trithionate. Preferably, the sulfite solution also contains other anions.

Abstract: A method of recovering boric acid from a subterranean deposit of colemanite ore by solution mining, comprises:supplying a leach solution comprising hydrochloric acid to the subterranean deposit via an injection well in communication therewith, whereby colemanite ore is dissolved and an aqueous pregnant solution of boric acid and calcium chloride is formed in the deposit;withdrawing the pregnant solution of boric acid and calcium chloride from said deposit via a production well in communication therewith;separating boric acid from the withdrawn solution;adding sulfuric acid to the resultant concentrated solution from which boric acid has been separated, whereby hydrochloric acid is regenerated therein and CaSO.sub.4.2H.sub.2 O is formed;separating CaSO.sub.4.2H.sub.2 O from the resultant solution containing regenerated hydrochloric acid thereby forming a regenerated leach solution; andrecycling the regenerated leach solution to the subterranean deposit of colemanite via an injection well.

Abstract: The ammonium ions in a subterranean clay-containing formation may be removed by flushing the formation with a calcium ion containing restoration fluid having substantially the highest pH effective to prevent precipitation of calcium hydroxide from said restoration fluid. The calcium ion concentration in the restoration fluid is maintained between about 10,000 and 100,000 ppm until the ammonia concentration in the produced fluid peaks or is less than about 100 ppm. Thereafter the calcium ion concentration is maintained at about 400 to about 600 ppm until the desired level of ammonia is obtained, usually about 1-3 ppm.

Abstract: In the subsurface solution mining of mineral values, especially uranium, in situ, magnesium bicarbonate leaching solution is used instead of sodium, potassium and ammonium carbonate and bicarbonates. The magnesium bicarbonate solution is formed by combining carbon dioxide with magnesium oxide and water. The magnesium bicarbonate lixivant has four major advantages over prior art sodium, potassium and ammonium bicarbonates.

Abstract: The present invention relates to a process for recovery of uranium from a carbonate lixiviant additionally containing other contaminants such as molybdenum and silica, by adjusting the pH of the lixiviant to a value of at least 4 and treating the lixiviant to obtain a carbonate concentration of at least 50 ppm by weight. Subsequently the lixiviant is treated with an aqueous solution containing a sufficient amount of ferric iron to precipitate the contaminants without substantial precipitation with the uranium values. The precipitate is separated from the lixiviant. The treated lixiviant is passed through an ion exchange to retain uranium values.

Abstract: A process is described for improving yields and leaching rates of mineral values in highly reducing uranium-bearing formations, while minimizing deleterious environmental impact, by injecting an oxidant such as gaseous air or O.sub.2 into the formation prior to leaching. The preoxidation may be enhanced by the presence of CO.sub.2 gas in the pre-leaching oxidant. The process is particularly suitable for systems employing a CO.sub.2 /O.sub.2 lixiviant. The presence of sulfate ion further improves the leaching rate of such a system.

Abstract: In an acidic in situ leaching system, a short circuit passage through a subterranean formation between a fracture associated with an injection well and a fracture associated with a production well can be plugged by introducing a non-acidic liquid for displacing acidic leach liquid from the short circuit passage, introducing into the injection well a basic composition including a sealing material that gels under acidic conditions, and introducing sufficient liquid into the injection well to displace at least a portion of the basic composition containing sealing material from the injection well into the short circuit passage. Liquid flow between the injection well and the production well is then discontinued for a sufficient time for residual acid in the subterranean formation surrounding the short circuit passage to contact the sealing material and cause gelation of the sealing material in the short circuit passage. The introduction of acidic leach liquid to the formation can then continue.

Abstract: The present invention relates to a process for the recovery of uranium and other minerals from uranium ore where at least part of the uranium is present as refractory uranium-mineral complexes, comprising subjecting the uranium ore to mild oxidative carbonate leach fluid to dissolve and remove readily soluble uranium minerals, subsequently subjecting the uranium ore to an oxidative chemically severe leaching system to dissolve and remove the refractory uranium-mineral complexes, and separating and recovering the uranium and other mineral species in the leachate fluids. The process may be applied to in-situ uranium leaching operations or to surface leaching operations.

Abstract: The present invention relates to a method for restoring to environmentally acceptable levels the soluble contaminants in a subterranean formation that has been subjected to oxidative leaching. The contaminants are defined as those ionic species that when subjected to calcium ions form precipitates which are insoluble in the formation fluids. In accordance with the present invention, soluble calcium values are introduced into the formation. The level of contaminants is monitored and when such reaches the desired level, the introduction of soluble calcium values is stopped. The introduction of calcium values may be achieved in several ways one of which is to inject into the formation an aqueous solution containing therein solubilized calcium values. Another method of introducing calcium values into a formation, is to inject into the formation an aqueous solution containing carbon dioxide to solubilize calcium values, such as calcium carbonates, found in the formation.

Abstract: A method for mining subsurface deposits by injection of foam or a foaming agent plus air or other gas, or foam-making materials, into a selected porous zone above a sulphur bed or zone, and concomitantly displacing the gas and/or fluids occupying such porous zones concomitantly and/or thereafter, heating the sulphur bed below the foam injected deposit with superheated water or other means with the foam confining the upward movement of the superheated water or other fusion medium to the sulphur-bearing zone.

Abstract: Solution mining method particularly adapted for recovery of potash and the like from relatively thin, inclined strata at substantial depths and involving the dissolution of ore strata, overlain by insoluble strata, while leaving the remainder of the formation in place. Water is injected down a bore hole at a predetermined rate and, being much less dense than present brine, flows in an updip direction along the top of the cavity to a forward mining face remote from the drill hole. Loaded, heavy brine flows downdip along the bottom of the stratum to an outflow pipe communicating with the bottom of the bore hole.

Abstract: This invention is a comminution process for treating coal with a drying gas to form fractures which weaken the structure of the coal and make it easier to disintegrate mechanically, chemically or by fluid force. Another aspect of this invention is a process for treating an underground formation of coal with a dry gas for a time sufficient to form cracks and fractures in a portion of the formation in order to increase the permeability of the coal formation to the flow of fluids therethrough. Processes for in-situ combustion of the coal formation are therefore more efficient since the coal formation is more permeable to the flow of gas therethrough.

Abstract: An in situ leaching or solution mining process is conducted in a subterranean cavity in communication with a well bore. The subterranean cavity is gradually enlarged by inducing spallation of formation particles and/or collapse of the roof into the cavity by repeatedly cycling the hydraulic pressure in the subterranean cavity. The hydraulic pressure is preferably increased during a period of at least about two hours. The hydraulic pressure can be gradually decreased during a period of at least about two hours or can be suddenly decreased. Rapid pressure pulses can be applied to liquid in the subterranean cavity by detonation of shaped charges of explosive with the axis of force of the charge being directed along the axis of the well.

Abstract: A multiple branch well for use with in situ leach mining of deep lying ore bodies. The branch wells may be formed by a method disclosed in a related invention. Each well may have two branches one of which is a producer well and one an injector well. Internally of the main casing from which the two branch casings extend are--from the lower end up--a packer unit, a tubing hanger, and a wireline retrievable hydraulically generated pump. The packer and tubing hanger serve their conventional function of, respectively, blocking the flow of leach fluids and holding the branch tubular casing in place within the main casing. The hydraulic pump joins the tubular casings to maintain a constant ratio of produced fluid to injected fluid. This pump is operated by a pressurized fluid source. Since it is retrievable and hydraulically operated, the pump can be brought to the surface for any repairs or maintenance and it requires less surface plumbing with no down hole electrical power.

Abstract: A method of drilling and completing multiple branch wells extending from a main generally vertical hole. This invention finds its primary applicability in in situ leach mining of deep (500 to several thousand feet) lying ore bodies such as uranium, copper, etc. Initially, the main generally vertical hole is drilled, cased, and cemented. Whipstock drilling guides are placed to extend downwardly and outwardly from the bottom of the casing for this hole and cemented in place. These guides are the same in number as the branch holes to be drilled. In addition, the well bore casing contains an indexing dog just above the whipstock drilling guide. The actual drilling of the branch wells is accomplished with a floating index collar and a drill bit assembly which runs therewith. The indexing dog is fixed in the main hole and engages the indexing collar so that the drill bit is oriented to drill into one of the whipstock drilling guides.

Abstract: A process is described for improving yield and leaching rates of mineral values in uranium-bearing formations associated with high brine aquifers by using high pressure CO.sub.2 /oxidant in the leaching solution. The high pressure CO.sub.2 overcomes the inhibiting effect of NaCl on the rate of leaching. Uranium is recovered at the well head by ion exchange at a pH of about 4.5 to about 5.0 either under pressure to keep the CO.sub.2 in solution or with provision for CO.sub.2 recovery and recycle.

Abstract: A method is disclosed for restoring to environmentally acceptable levels the soluble molybdenum values in a subterranean formation which has been subjected to in situ oxidative leaching by passing through the leached formation an aqueous restoration fluid containing ferrous ion.

Abstract: A two-stage in situ uranium leaching process is described wherein H.sub.2 SO.sub.4 /oxidant is used as the principal leaching solution. Prior to leaching, the formation is treated with a dilute solution of hydrochloric acid, carbonic acid, or other acid (without oxidant) capable of removing the most accessible portions of CaCO.sub.3. The pretreatment improves the permeability of the formation and precludes plugging with CaSO.sub.4. The invention is particularly advantageous when applied to ores which cannot readily be leached with alkaline solutions.

Abstract: A process for obtaining useful products from an oil shale formation that has intermixed nahcolite and dawsonite. An aqueous solution of sodium hydroxide, containing a surfactant, is injected into the formation via wells. The sodium hydroxide reacts with the nahcolite to yield a sodium carbonate solution, which is withdrawn for further processing. Thereafter the shale is retorted in situ, with controlled pyrolysis while supplying air in controlled amounts, and petroleum products are recovered. Then water is sent into the retorted formation to produce steam, which is recovered. At some stage before or after the retorting, the dawsonite is reacted with NaOH and recovered as sodium aluminate in solution, which may be hydrolyzed or carbonated above ground to precipitate hydrated alumina. Carbon dioxide may be added to the recovered sodium carbonate aboveground to precipitate sodium bicarbonate, which may be heated to form solid sodium carbonate.

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.

Abstract: Subterranean mineral deposits, such as oil shale or the like, are prepared for in situ retorting by selectively mining out an area at the base of the deposit leaving an overlying deposit supported in a suitable manner such as by a plurality of pillars. The overlying deposit is expanded in any suitable manner into the underlying area in a fashion to create a predetermined distribution of permeability from an area of low permeability to an area of high permeability. An inlet is provided at the low permeability area and an outlet at the high permeability area. A suitable medium is introduced into the deposit at the low permeability end for extracting and forcing mineral values from the deposit toward the outlet end for recovery. .Iadd.

Abstract: This is a method to connect two or more drill holes, such as drill holes at distances of 2,000 to 5,000 feet or more apart, for the purpose of producing soluble ores, such as sylvanite or carnallite, from thick, deep ore bodies or from thin, shallow ore bodies. The drill holes are connected utilizing a signal-sending device in an initial drill hole and a sigal-receiving device in a subsequent drill hole. A fluid is injected down one of the holes forcing the effluent from the other hole thus forming a mined-out corridor between the two holes. This procedure can then be repeated with subsequent, offset drill holes.