Borehole Mining System and Methods Using Sonic-Pulsed Jetting Excavation and Eductor Slurry Recovery Apparatus
A borehole subsurface mining system and methods for generating sonically pulsed hydraulic jets for subsurface excavation and slurry extraction, combining modulated oscillating energy at relatively low frequencies produced from a sonic drill head of working sonic core drilling rigs in combination with energy and water flow from a pressurized pumping system, to perform pulsed jet slurry mining of underground resource deposits through at least one partially cased subterranean borehole using a sonic drill head member and rod string members in relation to which the attached inventive pulsed jetting apparatus and methods operate. The system design and methods includes an adaptably attachable, sectional, tubular combination apparatus assembly with at least one casing member in general axial alignment comprised of sonic rod, jetting educator coupling, transition rod, jetting sub-coupling and jetting shoe rock bit members. Also includes methods for sump heavy concentrate core barrel extraction and for optimizing high density slurry extraction.
This application claims the benefit of U.S. provisional application No. 62/071,420, filed Sep. 23, 2014 and entitled BOREHOLE MINING SYSTEM AND METHODS USING SONIC-PULSED EXCAVATION AND EDUCTOR SLURRY RECOVERY APPARATUS, which provisional application is incorporated by reference herein in its entirety.REFERENCES
Dehkhoda, S., “Experimental Study of Rock Breakage With Pulsed Water Jets”, 8th Asian Rock Mechanics Symposium, Sapporo, Japan, October 2014; Foldyna, J. et al., “Transmission of Acoustic Waves”, Proceedings of the International Congress of Ultrasonics, Vienna, Apr. 9-13, 2007 Paper ID. 1458; Lohn, P. D. et al., “Improved Mineral Excavation Nozzle design Study”, Bureau of Mines Open File Report 33-77, April 1976; Nebecker, E. B., “Percussive Jets—State-of-the-Art”, Proceedings of the Fourth U.S. Water Jet Conference, The University of California, Berkeley, Aug. 26-28, 1987; Nebecker, E. B., “Standoff Distance improvement Using Percussive Jets”, Proceedings of the Second U.S. Water Jet Conference, School of Mines & Metallurgy, University of Missouri-Rolla, May 1983; Savanick, G. A., “Hydraulic Mining: Borehole Slurrying”, SME Mining Engineering Handbook, p. 1930-1938; Savanick, G. A., “Hydraulic Mining Experiments in an Underground Mine in St. Peter Sandstone. Clayton Iowa”, Proceedings of the Second U.S. Water Jet Conference, School of Mines & Metallurgy, University of Missouri-Rolla, May 1983; Savanick G., et al., “Prototype Borehole Miner Selectively Extracts Gold From Permafrost”, Technology News, No. 40, July 1997; Simpson, A., Positive Preliminary Evaluation of Borehole Mining at the Hansen Uranium Deposit, Black Range Minerals ASX Release, 13 Feb. 2012; Stabler, Nate, Terra Sonic International LLC, video research, “Water Pulsation Test”, Reno Business Park, 27825 State Route 7, Marietta, Ohio 45750, Mar. 20, 2015; Summers, D., et al., “Considerations in the Comparison of Cavitating and Plain Water Jets”, Proceedings of the Second U.S. Water Jet Conference, School of Mines & Metallurgy, University of Missouri-Rolla, May 1983; Wu, W. Z. et al., “Dynamic Characteristics of Waterjets Generated from Oscillating Systems”, Proceedings of the Fourth U.S. Water Jet Conference, The University of California, Berkeley, Aug. 26-28, 1987.PATENTS
Archibald, W., et al., “Underground Mining System”, U.S. Pat. No. 3,797,590, March 1974; Bodine, A., “Sonic Apparatus and Method for Slurry Well Bore Mining and Production”, U.S. Pat. No. 4,366,988, January 1983; Claringbull, Peter, “Apparatus for Waterjet and Impact Drilling and Mining”, U.S. Pat. No. 4,319,784, Mar. 16, 1982; Coakley, J., “Borehole Mining Valve Actuation”, U.S. Pat. No. 4,440,450, April 1984; Drivdahl, K. S., et al., “Methods of Preloading a Sonic drill head and Methods of Drilling Using the Same”, U.S. Pat. No. 8,356,677 B2, Jan. 29, 2013; Hall, M., et al., “Apparatus for Boring Through Earth Formations”, U.S. Pat. No. 3,897,836, Oct. 18, 1973; Huffman, L. H, et al., “Hydraulic Mining Method”, U.S. Pat. No. 4,536,035. Aug. 20, 1985; Smith, B., et al., “Sonic Drill Head”, U.S. Patent No. 20120255782 A1. Apr. 8, 2011; Webb, L. A., et al., “Well tubing/casing vibrator apparatus”, U.S. Pat. No. 7,066,250, Jun. 27, 2006; Wenneborg, Z. et al., “Subterranean Slurry Mining Apparatus”, U.S. Pat. No. 3,747,696, July 1973; Vijay, M., et al., “Ultrasonic Waterjet Apparatus”, U.S. Pat. No. 8,006,915 B2, August 2009.FIELD OF THE INVENTION
Illustrative embodiments of the disclosure generally relate to subsurface borehole mining and sonically pulsed jet mining. More specifically, illustrative embodiments of the disclosure relate to a sonically (i.e. acoustically) pulsed jet mining system design and methods, which describes fluidic communicated tubular, multi-sectional pulsed jetting apparatus and methods that can be combined or integrated with existing attachable sonic mining tools and pumping members to engage attach-ably with a sonic drill head of an existing sonic core-drilling machine and also to the attached elastic sonic rod string and emplaced sonic casing for the purpose of deep hydraulic pulsed jet excavation while facilitating extraction of subsurface mineral deposits as slurry to the surface through a single borehole; sonically pulsed jet mining slurry production efficiency and economic benefit can be significantly increased as compared to corresponding continuous-stream jet mining and can be used in association with an innovative sump trap/sonic core barrel recovery method employed to concentrate and extract heavy debris from a pulsed jet mining site to the surface that eductor siphoning or other pumping methods fail to extract.BACKGROUND OF THE INVENTION
in recent years, establishing the knowledge of generating an effective pulsation in a high-pressure open hydraulic system has been actively pursued, in particular by interests related to industrial uses, such as in mining and pressure-washing. This is because by pulsating water streams into more discreet bolts the cutting and eroding efficiencies increase with water impact pressure and impact stress upon a target material; pulsating hydraulic jets also can increase effective range (i.e. stand-off distance from a target) as compared to a corresponding continuous-flow jet system.
Research and development of various methods and systems relating data and results that confirm the benefits and potential of pulsed jetting in mining, have been conducted. Such research has examined a range of frequencies, pressures and other aspects of modifying pulsating jet advantages particularly within non-submerged analysis parameters, notably including research by: Dehkhoda, S., Experimental and Numerical Study of Rock Breakage by Pulsed Water Jets; Foldyna, J. et al., “Transmission of Acoustic Waves”; Nebecker, E. B., “Percussive Jets—State-of-the-Art” and “Standoff Distance improvement Using Percussive Jets”; and Wu, W. Z. et al., “Dynamic Characteristics of Waterjets Generated from Oscillating Systems”. The research results show that pulsed jets can be: more efficient at eroding and breaking target mineral materials by applying intermittent stress pulses as compared to continuous-flow jets; electrically, mechanically and acoustically propagated pulsed waves can be generated and modulated in a high-pressure hydraulic system; effective pulse energy can be propagated at significant stand-off distances from a jetting nozzle; and nozzle design can significantly produce different jet stream and pulsed characteristics. As such, a pulsed jetting mining system can be economically more efficient by consuming less amounts of water and energy as compared to a correspondingly effective continuous-flow jetting system. Unfortunately for the mining industry, as related by Dehkhoda, S., “Experimental and Numerical Study of Rock Breakage by Pulsed Water Jets”, the breakage mechanism by pulsed water jets is “poorly understood” and, as such, has not as yet resulted in wider use of hydraulic pulsed jetting in mining. However, advancements are being made; a mineral cutting mechanism has been described and developed that produces high-energy, ultra-sonically pulsed waterets for limited use in mining and can be applied to effectively cut solid mineral targets, resulting in Vijay, M., U.S. Pat. No. 8,006,915 B2, describing a surface ultra-sonic pulsed jetting hydraulic cutting apparatus with a very short but effective range for cutting stone, but which is not suitable for commercial subsurface submerged mining.
Submerged hydraulic jet mining has been researched for years. Dr. G. A. Savanick, a mining authority in the art of hydraulic jet slurry mining, discusses its general historical progress in the SME Mining Engineers Handbook, Chapter 22.4, Hydraulic Mining: Borehole Slurrying”, also describing various industrial-scale jet mining projects from the early-twentieth century to more current times reviewing different continuous-flow jet mining methods and site parameters, e.g. phosphate mining showing an average of 32 tons/hour removed by submerged continuous-flow jetting in one project. He also personally researched, funded by NIOSH, the problems encountered with constructing a small-scale subsurface borehole jetting system using one and also multiple jets and eductor mechanisms, noting that certain problems inherent primarily to the slurry recovery system required solving (which he could not do) before the system could be economically used. He further elucidates with additional jet mining research conducted on an open-face surface St. Peter Sandstone that meeting certain commercial parameters (jetting 25-50 tons/hour with eductor recovery of 40 tons/hour) is possible in achieving synchronous jetting excavation and eductor slurry recovery of sandstone. He does not, however, give mention of any successful commercial pulsed jetting operation in the industry; but he does relate that in spite of certain economic constraints the process of subsurface continuous-flow jet slurry mining can be commercially viable in very specific situations, as recently indicated by Simpson in his report, “Positive Preliminary Evaluation of Borehole Mining at the Hansen Uranium Deposit”.
Research and patents do indicate a continuing interest in borehole mining for increased mining efficiency using pulsed jetting methods, which is especially evident in submerged borehole-related mining projects. Hall, M., et al., as an example, in, “Apparatus for Boring through Earth Formations”, U.S. Pat. No. 3,897,836, describes an apparatus and method for mechanically generating a peripheral pulsed hydraulic jetting action at the drill bit to facilitate drill-bit boring of a borehole. Also used to achieve pulsed jetting are high-pressure high-frequency pulsed cavitating jets, which may sometimes be referred to in the prior art as self-modulated jets, and can be similar to the patented design as described by Johnson, V. E. et al., “Enhancing Liquid Jet Erosion”, U.S. Pat. No. 4,389,071, which presents apparatus and method for pulsed jet mining (with very short stand-off distance) by generating significant cavitation effects within associated complex nozzle structures producing a pulsed jetting action that erodes closely associated target minerals. However, the search continues for an improved economical pulsed-jetting mining apparatus system and methods that will allow for expanded commercial mining of submerged subsurface mining sites with acceptable economic production rates and an effective stand-off distance. Continuous-flow jet nozzles, such as the commonly employed Leach & Walker 3-D type nozzle, continue to be used predominantly in industry for hydraulic jetting and washing. David Summers in “Considerations in the Comparison of Cavitating and Plain Water Jets” discusses the difficulties associated with generating various jetting effects when submerged and otherwise, which includes a very limited jet range with cavitating pulsed jetting methods. According to David Summers, continuous-flow jet nozzles, such as the Leach & Walker 3-D type, do not tend to cavitate when submerged and thereby provide a greater stand-off distance in mining excavation as compared to using cavitating ultra-sonic pulsed jets. However, as a result of the lack of viable commercial subsurface jetting system and methods, the mining industry must use continuous-flow jetting in some mining situations where jetting can be applied, even with its relatively low mining production efficiency. The mining industry has generally not embraced the existing subsurface jetting methods provided by the prior art for recovery of subsurface mineral deposits. Traditional mining methods of mineral deposits are most commonly used by the mining industry since they are more economically feasible than existing borehole jet mining systems and methods.
Various submersible borehole-related jetting mining apparatus and methods are patented, some even have a sonic mechanism attached, though the prior art does not indicate sonic wave energy being propagated to generate pulsed jetting slugs at significant stand-off distances from a nozzle for commercial mining use. However, the present inventive system and methods application proposes a new and innovative submersible, low-frequency, acoustically-pulsed pressurized hydraulic jet mining system and methods; the system and methods describes a process capable of subsurface mining excavation and simultaneous eductor recovery facilitation (without submersible valves or complicated tooling) that can be attached to a sonic core-drilling machine (i.e. sonic drill head) for subsurface pulsed jetting mining in a commercially efficient manner. Capable of interchangeably using the rods and casing of the sonic drilling system the inventive system has attachable component tools that transform a sonic core drilling rig into a sonic mining rig. It is not described in the art of subsurface borehole mining. Such a system and methods can provide a new and improved economic alternative for efficient subsurface mining using sonically pulsed high-pressure high-volume jetting with simultaneous excavation and slurry recovery. This is in addition to using established and traditional sonic core-sampling methods, with minimal lead-time from discovery of a valuable mineral deposit to its sonically pulsed jetting excavation and recovery in an eco-friendly way, which is characteristic of using a sonic core drilling rig.
Different drilling technologies and systems have been used to discover mineral deposits for years and continue to improve the logistical approach to profitable mining. Sonic drilling using sonic drilling rigs is one such drilling system that has evolved with time. However, sonic drilling principles, in practice and theory, have been available for years, the original idea commonly credited to George Constantinesco in 1910, providing the current general concept for sonic core-drilling. The idea itself was documented by A. G Bodine first filed in 1956 for U.S. patenting. In 1965 “Method and Apparatus for Sonic Jarring with Fluid Drive”, U.S. Pat. No. 3,168,140 was granted to A. G. Bodine describing an acoustic method for retrieving drilling pipe stuck in a borehole, which economically facilitates the proposed inventive mining system and methods where tools can be retrieved in a caving incident while mining and also in retrieving unstable sump concentrates using a core barrel. Sonic drills and drilling machines have been developed over the years and are used to vibrate a drill pipe at frequencies usually between 80 to 150 cycles per second (i.e. Hz) and higher, to fluidize contacted ground and thereby allows a drill pipe to sonically bore into the ground with minimal resistance or to be salvaged. Minimal fluid circulation in the borehole is usually used with sonic drills while drilling to obtain core samples or retrieving rod string tools. The material ahead of the sonic drill bit is pressed into the surrounding formation or is captured in the core barrel and is recovered at the surface through a stable borehole casing as a core sample (for analysis). Sonic drills and drilling machines have the disadvantage of a relatively high purchase cost. Efforts over the past fifty some years have resulted in improved reliability and desirability of this tool for use in demanding commercial surface drilling and core recovery operations. Sonic drills are currently particularly efficient tools for drilling primarily unconsolidated and some consolidated materials to maximum depths of usually less than 1000 feet for small commercial rig models. As compared to the more commercially used mud or pneumatic rotary drill rigs that incorporate mechanical means of drilling—the sonic drill uses approximately 50% less horsepower, advances in depth in aggregate much faster due to liquefaction of contact material, and produces up to 70% less waste in cuttings while using only small amounts of water for flushing and bit cooling and has relatively no seismic registration to destabilize surrounding ground. Many patents have made applications of the “sonic” vibration technology, allowing sonic drilling to be a well-established and commercialized core-drilling system in modern times. It has not however been described in prior art as being used as a sonic (acoustic) source and mining platform of a system using acoustically pulsated hydraulic jets for subsurface excavation and slurry recovery to the surface, as this patent application proposes.
An experiment was conducted in March of 2015, at the request of the inventors of the inventive system design and methods, to investigate the inventive proposed system and methods, performed under the direction of Nate Stabler at Terra Sonic International (a sonic core drilling rig manufacturer in Ohio). The research effort was recorded on video showing the propagation of energy waves through a low-pressure water column as a semi-discrete to discrete pulsating stream of water moving through an elastic metal sonic drill rod, exiting from the sonic rod's bottom end, attached at its top end by adaptor to a sonic rig's activated sonic drill head oscillating at approximately 150 Hz. Though only an oscillating low-pressure open hydraulic tubular rod system, this pulsing result provides strong evidence and support for economic development and commercialization of sonically pursed jetting from a sonic drill rig's sonic drill head and is in accord with the study by Foldyna J. et al., “Transmission of Acoustic Waves”, 2007 that shows propagation of acoustic pulsing waves in a high-pressure hydraulic system. Therefore, based on this study by a manufacturer of sonic drill rigs directly and in correlation with other research indirectly, the proposed inventive system design and methods, with the proposed inventive apparatus attached by sonic drill rods to a sonic core drilling rig's sonic drill head, can become a high-pressure pulsating hydraulic jetting system. This inventive system design can result in a subsurface modulated pulsed jet mining operation that is efficient in production and mobile, generally speaking but not in a limiting sense, using a sonic drill head mounted on a sonic drill rig platform for providing pulsing energy through the spindle to the sonic rods, use of the proposed inventive sonic jet tooling and sonic rod string in conjunction with a high-pressure (e.g. 500-1500 psig), high-flow (e.g. 300-600 gal/min) water pump, water source and supportive equipment, working within and beneath an unattached sonic borehole casing and using appropriate efficient short nozzle designs, such as a quartic-type nozzle design for rock breakage as described by Lohn, P. D. et al, “Improved Mineral Excavation Nozzle Design Study” in April 1976, in conjunction with hydraulic pump continuous-flow pressure jet mining consistent with prior associated research in jet mining.
Sonic drill head construction is variable in design, with many patents pertinent to the proposed invention, including such as, Smith, B. et al., “Sonic Drill Head”, U.S. Patent No. 20120255782 A1, and Drivdahl, K. S., et al., “Methods of Preloading a Sonic Drill Head and Methods of Drilling Using the Same”, U.S. Pat. No. 8,356,577 B2, and Webb, L. A., et al., “Well tubing/casing vibrator apparatus”, U.S. Pat. No. 7,066,250. Such patents are pertinent to this application primarily in that they describe mechanisms producing oscillating waves of energy of vibrational force that are transmitted and propagated into an attached drilling rod string, which can usually be both rotated and vibrated at variable and relatively low frequencies (usually between 0-150 Hz, which is only limited in range by the design of the oscillating head) to effect ground penetration of attached tooling members, such as drill rods, casing, core barrel. Combined energy from at least one pressurizing water pump and the sonic drill head, with conduit fluidic communication, can be propagated as pulsed jets through jetting nozzles of the proposed system and methods apparatus to generate a repetitive pulsing hydraulic jetting effect, according to research. This requires the use of appropriately designed nozzle members for functional specificity within the constraints of each system, which can be a high-pressure, high-volume hydraulic process for subsurface commercial mining functions. With the proposed system and methods an industrial well-proven sonic drill head and sonic drilling rig (Terra Sonic international TSi 150CC) will be used in conjunction with a water reservoir, high-pressure energy pumping member (e.g. Gould's model 3393 pump) that are in fluidic communication using high pressure conduits, check valves and sonic rods to the inventive pulsed jetting apparatus. These are only examples of appropriate standard equipment known to the mining industry in prior art that can be used, not to be considered to limit the scope of this application to similar equipment in the present or future, with the proposed inventive pulsed jetting mining system and methods. This equipment, or generally similar equipment, is required to supply adequate water volume and pressure to pass through the sonic drill head member, through its spindle, attached to a rod or sonic rod string to which is attached the tubular inventive apparatus with nozzles to generate hydraulic pulsed jets. Usually in the sonic drill head there is at least one rotating eccentric mass mounted and mechanically activated in an inner housing to generate acoustic or vibrational energy waves, usually sinusoidal, that are propagated as energy wave pulses to the traversing conduit and attached tubular spindle and into the rod string and inventive system and methods apparatus. Such energy wave propagation is prevented from returning through the contained water column to the high-pressure water pump member by one or more check valves in the interconnecting conduit member between the pump and the sonic drill head. Rotational and wave energy from the sonic drill head is imparted to the spindle that is attached to a sonic drill rod and drill rod string with vibrations of the rotating eccentric mass being usually isolated from an outer housing of the sonic drill head, protecting the drill tower (i.e. mast) and drill rig from inordinate vibration and from dampening the energy transfer to the sonic drill rod string.
Archibald. William, et al., U.S. Pat. No. 3,797,590, has a pertinent patent in that it describes a composite mining capsule inserted into a small borehole for subsurface submerged mining using a single non-pulsing jet and includes a downhole positive displacement pump (not an eductor siphon as used by the proposed inventive system and methods) and inlet pipe for lifting dense slurry to the surface within a designated conduit from depths of 100 feet or deeper. Archibald addresses the problems of using two-foot diameter boreholes and the difficulty of recovering dense slurry with his invention, thus he attempts to provide an economical manner of borehole mining, in part by not using an eductor siphon-type pumping mechanism. Archibald's design orients his pump member in a sump, which can be blocked by large boulders that can gravitate to his sump and may even trap his pump with boulders from a caving incident. The proposed inventive system and methods does not have this potentially disastrous problem because it uses a sump to trap large heavy slurry solids for later recovery using a sonic core barrel; it also produces and uses positive hydraulic pressure inherent to recycling approximately 400 to 500 gallons of water per minute through the mining site, initially entering the site by exiting from the mining tools into the mining site and then upwardly into the annulus space and onto the surface. The proposed systems and method sub-coupling with nozzles is a pulsed jetting member using usually a plurality of pulsed jetting streams to fracture and erode target mineral as well as to agitate dense slurry moving it into the ceiling entrance of the annulus space between the rod and casing strings, with high-density of slurry being maintained as it is transported upwardly to the surface in part by means of eductor couplings with pulsing jets. Slurry recovery through the annulus is facilitated by a multiplicity of inventive eductor couplings using small pulsed jetting streams entraining the slurry and helping to lift slurry and facilitate the inherent hydraulic forces moving fluid up through the annulus. The inventive tooling also uses preferably two diametrically opposed laterally pulsed jets as opposed to one continuous-flow jet that Archibald uses, whereby pulsed jetting can provide increased efficiency for cutting mineral target and agitation and thereby better economics of slurry production, especially logical with using multiple jets. Further, using the sump member to trap heavy and large mineral fragments, sometimes referred to as a rat hole in the mining industry, the inventive system and methods becomes very economical since the lighter jetted debris material tends to agitate quickly upward through the annulus, separating from the heavier elements which gravitate to the sump along with boulders which can be easily fractured by applying pressure from the terminal shoe rock bit having the additional benefit of downwardly pulsing jet with fragments further agitated and flushed up to be fragmented further with the lateral pulsing jets, which are positioned immediately above the terminal shoe rock bit. A terminal shoe rock bit with its central pulsing jet can also constantly agitate the contents of the sump trap, which is located immediately below the shoe rock bit, as well as perform fracturing of any boulders that gravitate to and block the sump. Using an impingement pulsed jetting force as well as shearing rotational and compressive forces applied by mechanical contact of the shoe rock bit to a boulder; boulders at the sump do not present a problem of capturing and sticking the inventive system and methods since it is part of a sonic rod string system, that by design is known by prior art to be retrievable from such occurrences. Periodically the rod string and inventive system and methods apparatus are removed from the mining site. The sonic core barrel can then be reattached to the sonic rod string and can be reinserted into the borehole recovering the sump contents, in an innovative method to recover extra heavy jetting debris, which are extruded at the surface, with core barrel detachment at which time the mining tooling is reattached to the sonic rod string for continuing the pulsed jet mining, but with a newly opened sump. This exchange can be done very quickly. This mining process can be accomplished through a small borehole, e.g. 9.25 inch diameter borehole to easily excavate a 300 to 400 foot deep resource site and much deeper. In comparison, Archibald's combination mining tool and methods can result in boulder blockage at the sump as well as expensive loss of tooling and do not use an eductor pump. Multiple pulsing jets, as with the proposed invention, when applied in a coherent manner can be very efficient regarding time, safety and production in mining, which Archibald does not use. Further, the inventive tooling, including a sub-coupling with multiple lateral pulsing jets having nozzle exit dimensions being flush with sonic rod string external wall dimensions allows for unimpeded sonic retrieval of the inventive sonic apparatus and sonic rod string from the subsurface mining site should a caving incident occur and still allows recovery of the sump contents using a sonic core barrel. The proposed inventive system allows for surface processing of slurry and recycling of water or storage. The proposed inventive system and methods allow for refilling the site with gangue and recovery of sonic casing, as is considered standard practice in the art of borehole mining. Archibald's mining capsule and method of mining are very different from the proposed inventive system and potentially much less economical to operate.
Bodine, Albert, U.S. Pat. No. 4,366,988, has a pertinent patent in that it discloses a sonic drill head type attached to a composite tool with a “sonic pump” that removes slurry from the mining site by vibratory action creating intermittent pressure differentials facilitated by downhole foot valves located within the composite tool. Bodine does not describe entraining of fluid as described by the proposed inventive system and methods which uses an entraining eductor siphon pumping action with multiple eductor couplings using pulsed jetting to facilitate slurry lift in addition to hydraulic forces moving slurry through the annulus up to the surface. Also, Bodine describes a recovery method facilitated by vibration helping to move slurry and oil that rises to the surface as a “floating” extraction method. He does not address the difficulty in maintaining high density slurry throughout his extraction process. Bodine uses vibratory action to move the liquid and mineral material in the side walls of said well bore and uses check valves within the piping assembly, which is a recovery method that is much less efficient than the eductor pulsed jet recovery slurry method (through the annulus) as described in the inventive system and methods. Also, Bodine describes jet action, but the swing jet rotors (source of resonant vibration) effect only the inner tubing member not the jetting conduit members (column 3; line 5) and springs isolate the vibratory energy from the jetting conduits (column 3; line 21), so this system cannot generate a vibratory pulse to the jetting system from resonant vibration and essentially describes a continuous-flow jetting system. So this embodiment represents an oscillating head that is detached from its jetting conduits and cannot generate a pulsed jet, which is proposed by the inventive system and methods. Bodine's invention of an oscillating head is essentially different from modern sonic drill heads (as used with modern sonic core drill rigs) that have an attached tubular rod member traversing through and interfacing with the drill head member, with the tubular member transferring pumped water through the sonic drill head into the borehole through the rod string to the inventive apparatus and jetting nozzles to generate pulsed jets. Therefore, sonic energy is not described by Bodine to generate “pulsing” jets of water in his invention, as it does in the inventive proposal. Also, Bodine's invention does not use the annulus to transport slurry to the surface, but uses a dedicated conduit with check valves, whereas the inventive system has no moving parts within the borehole aside from the sonic rod string itself that moves with the drill head spindle attachment, up and down and in rotation. Bodine's system is described as being within a borehole casing but does not use the annulus between the casing and the complex rod system to transport slurry as does the inventive system and method. Bodine a so describes using a complex “rod” comprised of external and internal rods welded concentrically together to form an annulus in stable “concentricity” and does not represent a single sonic rod or rod string that is independent though partially positioned inside of a sonic casing as does the proposed inventive system with inventive mining tooling attachments. The inventive system and methods describe the sonic drill head function and drill rig as an established platform and source of sonic wave energy. Therefore it is an object of this proposed invention to economically enhance the subsurface borehole exploratory and mining process in multiple ways. Primarily it achieves this by using pulsed jetting to generate more efficient jetting excavation and eductor coupling movement of slurry, simultaneously being performed with the single tubular and attachable multi-sectional mining apparatus system and methods. Further, the proposed system and methods benefit from drilling the borehole quickly using an established sonic drill rig, emplacing a sonic borehole casing string, removing the sonic core barrel tool member from the rod string to determine value of a discovered mineral site and to attach the inventive mining tools that are reinserted into the borehole for efficient pulsed jetting to erode and cut mineral deposit. Simultaneously, pulsed jetting in one or more eductor coupling apparatus help facilitate slurry movement up to the surface through the annulus for processing and recycling water for reuse. By sonically propagating and using sonic wave energy in addition to pump energy, various hydraulic pulsed jets are generated through appropriate nozzle design and application, for either a cutting/agitating function or an eductor function in the proposed invention, which is different than Bodine's invention, which requires downhole moveable hardware and must have intermittent movement of slurry that can settle. Having a sonic head attachment interfaced with a high-pressure high volume water column is critical for pulsing the jet, which is central to the purpose of presenting a more economical means of mining mineral material than is presented by prior art, including Bodine's invention. Otherwise a jetting system without a pulsing influence can only present a continuous-flow high-pressure jetting operation, as Bodine invention describes, which is less efficient and not as economical as the pulsed jet mining system proposed in the inventive system and methods. Even without the pulsing component to the jets, the proposed system used with a sonic drill rig is different in its simpler design and uninterrupted eductor facilitation of recovery of slurry through the annulus. Also, the inventive system and methods provides additional benefit from the recovery potential provided by the sonic rig supported sump/core barrel recovery method.
Coakly, John, U.S. Pat. No. 4,440,450, describes a combined rotating mining apparatus which comprises multiple conduits with internal valves and moving parts that allow changing the function of the apparatus between mining and drilling modes while still in the borehole and having modulation function of alternating pressure levels to facilitate higher system pressures at the jetting nozzle and eductor when in mining mode. This apparatus washes cuttings from the base of the tool not allowing concentration of fragmented debris around the base of the tool and ejects them into the jetting stream and mined space. A drilling bit, an eductor and continuous flow jet are described by Coakly as basically comprising his complex apparatus used for borehole slurry mining. In comparison, the proposed system and methods uses a shoe bit with at least one pulsed jetting nozzle to fracture boulders that gravitate to the sump member and also to agitate lighter mineral fragments into the slurry and into the annulus in the ceiling of the mined cavity. The sump is used to trap heavy material that will periodically be retrieved using a core drill, which is periodically quickly done to also analyze the mineral site and deepen the cavity. Once the cavity becomes too deep for dense slurry to enter the annulus space in the cavity ceiling an independent eductor which is commonly used in the prior art can be inserted through a second borehole into the cavity as an independent eductor mechanism as a facilitating method to improve the rate of recovering large deposits using the efficient pulsed jetting excavation method or the site can be abandoned if deemed uneconomic. The proposed system and methods can pulse its jets with a mean pressure in a range of approximately 500-1500 psig, with a flow rate of approximately 300-600 gal/min and with a sonic frequency of approximately 150 Hz, which can be varied in different ways depending on multiple factors, such as mineral type, nozzle type and oscillating rate. There are no moving parts in the proposed inventive system and methods as compared to Coakly's invention, with less tendency to break down. Though similarities exist for borehole mining, Coakly's invention does not generate more efficient pulsed jetting as the proposed system can do with dual cutting jets and Coakly presents a less efficient drilling process as compared to the proven sonic drilling process, which is only required in the proposed system and methods initially to reach the target depth and periodically to retrieve sump concentrate. Though the Coakly invention uses a single eductor above the mining jet in his complex tool, which can conceivably be lost with a caving event, the proposed system and methods can be retrieved and provide multiple methods for slurry extraction whereby it is capable of using multiple eductors and eductor couplings along more options to modify the mining rate for optimal recovery.
Huffman, Lester, et al. describes multiple boreholes and use of an inserted pumping tool and crusher to pump slurry up from a sump member, as it particularly pertains to mining an inclined seam of coal. Huffman's system though having similarities to the inventive system, such as using recycled water, at least one sump and a possible use of multiple boreholes is different from the proposed inventive system and methods and less efficient primarily because it does not use pulsed jetting and is subject to caving with loss of pumping tooling in the sump. With the proposed inventive system and methods, multiple boreholes can also be used to generate higher slurry recovery rates with a deep deposit, especially since more efficient sonically pulsed jet mining is used to generate slurry. In the situation of a significantly inclined seam a modified sub-coupling using three pulsed jetting nozzles may be used, depending on the logistics of maintaining rod stability at the mining site. At an incline and with denser coal slurry the depth that the proposed inventive system and methods can work should be much greater than in a vertical orientation and may not even require an additional independent eductor in a sump orientation, especially extending the casing string length by adding sections of additional sonic casing thereby positioning the sonic casing string and slurry collecting annulus lower opening into the mining cavity and closer behind the advancing pulsed jetting sub-coupling with additional eductor sub-couplings being added to the rod string, Being able to add casing section to facilitate denser slurry engagement is a preferred embodiment of the inventive system plan and methods to increase recovery, as needed and to recover certain deposits in specific instances. In any case, the proposed inventive system and methods with a sonic drill rig and pulsed jetting system and methods should improve the rate of coal slurry recovery and mining coal seam economics, including reducing the chance for equipment loss as compared to the Huffman invention. This embodiment is not identified by prior art of borehole mining of inclined seams of coal.
Wenneborg, William et al., U.S. Pat. No. 3,747,696, describes an invention that is pertinent to subsurface slurry mining and the proposed system and methods in that this prior art uses a combination slurry drilling and mining system. It is, however, different in that it is a complex borehole apparatus with multiple inner conduits and moving valves, with mechanical hydraulic systems and modes for drilling and mining without requiring that the apparatus (having an eductor nozzle and mining nozzle and drill bit foot valve) be pulled out of the borehole or well cavity. This uses a rotary-type drilling rig and does not use borehole casing. This is not a sonic-related system and is without pulsed jetting, therefore is likely to be less efficient for excavation of a subsurface mineral deposit as compared to the proposed system and methods. Further it requires significantly high positive pressure differentials to shift from drilling to mining mode and is likely to be subject to more problematic maintenance issues from higher pressures impacting the more complicated apparatus as compared to the relatively simplistic proposed systems and methods, which are more efficient and work without moving parts within a borehole stabilized (in part) using a casing. Catastrophic collapse with a caving incident is always a potential for loss of borehole tooling, but is much less likely with sonic core drilling apparatus tooling, as is used with the proposed system and methods.
Claringbull, Peter, U.S. Pat. No. 4,319,784, describes an impact driver system that is pertinent to the proposed system and methods in that it uses a casing with either one or two drill rods freely moving within the casing that have a drilling shoe on the inner pipes. The outer casing is intermittently struck with a piston to provide periodic impulses to advance the casing as a drilling method. As a mining method it describes using continuous-flow pressurized water or air being injected down through the annulus in association with the casing, using a rotatable inner dual-pipe system with a drilling shoe and a plurality of jet passages and jetting nozzles forcing mining debris up to the surface centrally through the inner pipe. This is a percussion-type of casing drilling system that advances the casing with an associated continuous-flow jet mining system using a rotary bit with water and air for mining. This patent does not use a sonic drill head and does not propagate energy pulses to generate a repetitive pulsed jet from a central tubular rod for the purpose of mining. It uses differential water and air pressure to retrieve mining debris to the surface through a central pipe. It does not provide an entraining flow with an eductor structure or anything similar to an eductor coupling mechanism for retrieving slurry. This is a system that is limited to mining at relatively shallow depth especially due to percussion energy dampening and has predictably low production capacity potential due primarily to the problem of retrieving dense drilling cuttings and debris with particle bridging and other issue inherent to moving slurry through conduits. In comparison, such issues have been addressed within the constraints of the proposed inventive system and method with its sonically pulsed jetting apparatus facilitating excavation and slurry recovery through the annulus, as well as its method for sump concentrate recovery, used with an existing sonic core drilling rig that will potentially generate high production rates with subsurface borehole mining.
Unfortunately current knowledge does not provide a viable wide ranging economically feasible subsurface jet mining system and methods, especially with more environmentally problematic or incremental deposit discoveries, primarily because of inefficiencies of current subsurface jet mining systems and methods that the present invention addresses.
What is needed is an innovative and improved cost-effective, comm ercial-scale, efficient and adaptive subsurface borehole mining system design and methods that will allow for the immediate mining site analysis and mining of subsurface mineral resources, providing the mining industry and particularly sonic core drilling rig operators, the opportunity to mine a valuable discovered mineral deposit almost immediately by using a simple pulsed jet mining system design and methods that are adaptable to the sonic drill mining rig and adjustable for improved production rates and recovery of subsurface slurry, while minimizing environmental impact. The inventive design and methods should provide a dynamic interaction between the sonic core drill rig operator, sonic drill head, a high-pressure high-volume hydraulic pump and a discovered and recoverable resource site that can be hundreds of feet deep but not available to traditional mining practices because of economic, safety or regulatory concerns. Other features of the system and methods of the invention will become apparent from time to time throughout the discussion and claims as hereinafter related.Summary and Objects of the Invention
Generally speaking, this invention relates to a new dynamic pulsed jet hydraulic mining system and methods using an existing sonic core drilling machine's sonic drill head attached to a rod string as a pulsing energy source in combination and simultaneously with a high-pressure and high-volume pumping member that comprises a fluid communicated tubular apparatus assembly member at the bottom end of an attached sonic rod string, sectioned into three member parts two of which have jetting nozzles that jet high-energy water pulses for mineral excavation and agitation and another tubular apparatus, a pulsed jetting eductor coupling, which is interconnected between the sonic rods of the rod string positioned in the annulus of the borehole to facilitate slurry lift to the surface. In addition, a sump trap method with sonic core barrel recovery is incorporated into the inventive system and methods as a method for recovering slurry fragments too heavy to be recovered by an eductor siphon. The inventive system design and methods integrate use of the common and proven mobile sonic drill head suspended on an established sonic drill rig's tower, using established sonic casing, sonic drill rods and core barrel tooling used to perform the function of sonic core drilling. By sonically core drilling a site, a sonic rig can discover a valuable subsurface deposit by means of core sampling then by employing the inventive design's apparatus that is attachable to the sonic rod string as a pulsed hydraulic jet mining system, while using additional methods as needed, the site can be mined. Water is supplied to the system and methods depending on the situation having many possibilities for options including mining water recycling, with respect to legal allowances and availability, e.g. water truck. Use of water for mining can include ancillary systems well known by the industry, such as a hydrocyclone system for improving water clarity, bone char containment channeling for water filtration, and by using a collapsible and movable reservoir, since relatively little water may be required for pulsed jetting using the inventive system and methods per site. Slurry is processed on the surface using standard methods, such as by employing wet gravity separation techniques of heavy precious gems, minerals (e.g. monazite with europium) and metals, such as gold, with preference being given to filtering slurry for recycling of water resources and using settling ponds, all components of mining and standard methods well known to the mining industry. Slurry may also be stored for processing at another time or transported to another site for refinement processing, depending on the constraints related to the equipment, crew and material being excavated, also regarding local laws, weather, geography and special processing requirements. Reclamation at completion of a borehole mining project is generally known in the mining industry to be a relatively low-cost and effective method as compared to more traditional mining reclamation methods with reclamation of a borehole site consisting primarily of backfilling the borehole with a gangue of washed sand. Unfortunately, the overall economic benefit of borehole mining is lacking. In the present art, borehole mining is a high-cost operation. With prior art the costs are very high because of expensive and specialized equipment that cannot generate significant production. Ideally, a borehole drilling and mining system should provide not only a specific sampling opportunity but a simple and efficient system design and methods that can be combined with an existing system to immediately begin mining the discovered deposit, facilitating immediate recovery of a commercially valuable subsurface resource identified during the sampling, which provides an economic advantage with the present invention.
Primary evidence of the present invention was demonstrated and recorded by an experiment conducted in Ohio, August of 2015, at the request of the inventors who are both experienced in core drilling and mining, by Terra Sonic International (a sonic core drilling rig manufacturer) with related documented statement of results herein submitted (video also available) as direct evidence to support the claims of a new system design and methods using an activated sonic drill head to generate pulsing energy waves. The sonic, i.e. acoustic, energy that is produced in the sonic drill head is interfaced with and oscillates a flowing water column's energy state, that is in association with a tubular elastic metal sonic drill rod's walls that also oscillate, while the water column is moving through the sonic rod having an exit opening in the open-ended system that can be used with one or more convergent-type nozzles. Such a sonic system using a sonic drill head as an oscillator, when pressurized, can generate a relatively low frequency cyclic pulsed jetting stream emitting from the aperture of a nozzle, which has not been recognized by prior art as of a manner of generating a commercial pulsed jetting apparatus for pulsed jet mining. It is the claim of the inventors that the energy differentials of such waves produced by a sonic drill head and combined with a high energy pressure and high flow pumping system can be concentrated by an established nozzle design, e.g. quartic nozzle, and associated apparatus to generate pulsing jets of either a discrete or semi-discrete nature, or both, and that the resultant modulated sonically pulsed jetting bolts with hammering effect will have significant stand-off distances and commercial application to increase jet cutting efficiencies, especially in subsurface hydraulic borehole jet mining, though surface mining applications are also possible. Other research disclosed in the prior art, including Foldyna, J. et al., “Transmission of Acoustic Waves”, 2007, also supports the claims of the inventors that a high-pressure system can propagate energy waves, but prior art does identify a commercial way for doing so or a design for a relatively low-frequency pulsed jetting system using a sonic drill head with a system design and methods for simultaneous excavation and extraction of slurry, as described by the inventors.
With the present invention a network of core sampling boreholes can be quickly drilled using a sonic core drilling rig, a characteristic speed of operating the sonic drilling machines that is well known in the industry and an advantage to a mining system's economic advantage. An efficient and quick core analysis process is also well known to the industry, e.g. handheld X-ray spectrometer, which can help reveal a target site's dimensions and content, allowing mining feasibility to be established quickly to determine economic logistics of borehole mining the site. With the proposed inventive system and methods having increased mining efficiency, not getting tools stuck in the borehole, having easily replaceable inventive apparatus, taking less time with the addition of relatively few additional components, i.e. a pumping system and sonic rod string attachable pulsed jetting apparatus—many mining sites not currently available to mine because of mining economics and traditional mining restrictions will become economically feasible to mine and will have a short lead time because of the portability of the proposed invention. A single borehole pulsed jet mining method can be used at certain sites following a sonic casing emplacement with its bottom end above the target mineral site. Pulsed jetting excavation and eductor coupling facilitation of slurry extraction can commence almost immediately by applying the invention apparatus to a rod string. As an example, a sonic core drilling rig can discover an approximate ten to fifteen cubic yard gold-containing placer “glory hole” at one hundred and fifty feet depth that will require on average about two hours to sonically core drill, with emplace casing string and perform sample analysis, and less than one hour following that will be required for pulsed jet mining extraction, assuming conservative rates of corresponding continuous-flow jetting systems, but with much greater efficiency than continuous-flow jetting. Pulsed jet mining, removal of casing and refilling the excavated site should require much less time than a continuous-flow jetting system, if it can even do a comparable job. Using the jetting pulsed system and methods with a sonic drill head as a pulsing source and a sonic drill rig platform will predictably prove to be a faster and more efficient process for mining using the invention, with pulsed jetting excavation to be fast, and done simultaneously with efficient slurry recovery through the annulus of the single hole borehole. With pulsed jetting into the annulus space there will be fewer tendencies for particle bridging with higher slurry density transport as facilitated by eductor coupling pulsed jetting. Another advantage of the inventive system is the use of the sonic drill rig's minimal tendency to lose equipment from being stuck and lost in a borehole from a caving incident. Multiple boreholes can also be simultaneously and quickly used employing at least one additional independent eductor syphon, another advantage of the system and methods, to quickly and economically increase slurry extraction rate if required by sonically pulsed jetting high excavation rates and the particular logistic parameters of the site, e.g. small cobbles and sandy shallow alluvial deposit with few boulders allowing faster excavation as compared to a deep paleo-channel having large boulders and a predictable slower borehole mining excavation rate.
Following core sample inspection and favorable mining feasibility logistics, one or more borehole sonic casings can be positioned, as practiced in prior art, relative to the mining target depth to minimize any unnecessary subsurface ground removal using the subsurface pulsed jet mining process' systems and methods. When more than one borehole may be required for efficient mining, it will be cased for the possibility of using the addition of an independent eductor siphoning mechanism, another preferred embodiment of this inventive process, which is an option for increasing efficiency of slurry extraction from the mining site in the event that a higher efficient rate of slurry production from pulsed jet mining exceeds the rate of extraction through the annulus by the inventive coupling eductors. This is an option for further minimizing costs of mining, requiring less time on a mining site. Sonic casing strings can be emplaced into each borehole related to a subsurface mining site (easily done with a sonic core drill rig having a sonic drill head attachment, sonic rods, casing members and other equipment required for standard sonic core drilling operations, all of which are preferred embodiments of this invention) so that the bottom end of each emplaced casing or casing string is positioned at approximately the top of the targeted mineral deposit level. The top of each emplaced casing is positioned at or above the surface ground level. The lead time from subsurface mineral discovery to excavation with this present inventive system and methods can be very short since the sonic drill rig is used to retrieve core samples and can drill boreholes quickly and more effectively as compared to other core drilling methods in addition to the inventive mining system and methods capability.
In further discussing the situation in the prior example of discovering a ten cubic yard “glory hole”, at least one borehole is over-drilled through the deposit to form a sump member, a preferred embodiment of the present invention method, which is significantly deeper than the deposit's lower level and that the sump member will be significant for trapping and removing larger and heavier pulsed jetted debris from the slurry circulation that may not be extracted through the annulus or an independent eductor siphoning method, occurring as the process expands the borehole to a subsurface mining cavity. In this example, the “glory hole” may be considered a relatively small concentrated alluvial deposit, so with jet mining of the deposit generally completed the sonic rod string is tripped out of the borehole with the core barrel being exchanged and substituted for the inventive pulsed jetting apparatus assembly. The core barrel is then inserted into the cased borehole on the rod string, through the mining cavity to the sump member where it re-bores the sump member capturing its contents for returning to the surface. This may require several repeated steps to make certain that all concentrated contents of the sump trap member are recovered to the surface. This describes an innovative method for subsurface recovery of mining debris used in coordination with the inventive sonic pulsed jet mining system and methods, and is a preferred embodiment of the inventive system and methods.
Establishing a high orientation of the bottom of the casing and opening into the annulus in the upper portion, i.e. ceiling, of the expanding jet mined cavity is another preferred method and embodiment of the present invention. This is potentially a more economical method to use as described with the invention's single borehole slurry extraction as compared to prior art, where the slurry intake mechanisms for extracting slurry to the surface may be in a pumping tool or siphon where the intake is on or near the bottom of the borehole mining cavity and can result in gravitational catastrophic blockages by boulders of the intake mechanism, tool damage or tool loss. This is an obvious potential problem in prior art remediated by the present invention orienting its casing bottom and annulus to a high orientation in the cavity. In certain instances, such as with an inclined mineral seam, the sonic casing string may be periodically extended and stabilized with its bottom being intermittently advanced deeper into the mining cavity, above and closely following the pulsed jetting mining apparatus as it excavates the seam to allow for more efficient slurry lift using the eductor coupling pulsed jetting effect within the annulus in closer approximation to the excavation in order to better facilitate upward movement of dense slurry to the surface, which is another preferred method and embodiment of the invention.
The sonic core drill has a small seismic signature also facilitating minimal ground disturbance with less de-stabilizing forces compared to impact rotary drills, with sonic drill rotations of approximately 200 rpm compared to percussion rotary drills having 600 rpm or more. Catastrophic subsiding, or caving in, at a subsurface mining site that has an actively mined borehole cavity has not been reported in prior art as a problem with subsurface jetting, but it is always an improved and desirable protocol with mining operations to minimize any disturbance to untargeted ground stability, which provides for a safer work environment. This is also a benefit of having a water-filled mining cavity and borehole where a relatively maintained hydrostatic pressure level in a water-filled mining site helps stabilize the integrity of the mining cavity while mining, which is also a preferred embodiment of the invention.
With a casing string properly emplaced in a borehole and stabilized, using commonly known methods for casing stabilization, with the casing's bottom just above the targeted deposit site, the borehole having a sump member by over-drilling the target zone, the mining process can begin. Using another preferred embodiment, a sonic rod or rod string will be of appropriate diameter size to fit within the emplaced casing internal dimensional space allowing at least three times the size of the preferred particle size that is expected to be extracted through the annulus from the mining cavity site to the surface. This spatial ratio requirement is known commonly in the pumping industry to inhibit particle bridging with eductor siphon mechanism spaces. For example, with a standard sonic casing having an 8.4 inch internal diameter it would be recommended that an acceptable standard rod diameter be used of 4.25 inches, for extracting 0.5 inch slurry fragments. The appropriately sized sonic rod is threadably attached to the sonic head spindle member and adaptor.
Pulsed water jetting eductor couplings, a preferred embodiment of the system and methods invention, can be added intermittently between sonic rods in the sonic rod string that will predictably function with pulsed jetting within the annulus to facilitate slurry lift to the surface through the annulus space from the mining cavity using the Venturi effect. The Venturi effect is a commonly known siphoning effect of pumping describing kinetic energy of pressurized jetted motive fluid from a pump being used to entrain another less pressurized fluid (i.e. slurry). A pulsed jetting hydraulic stream from an eductor coupling nozzle enters the annulus through a partial vacuum chamber and then mixes with the slurry fluids in a partial diffuser chamber, i.e. a figure-eight concavity in the outer coupling surface which is contiguous with the aperture from the upwardly angled convergent nozzle, against a counter pressure provided in part by the internal sonic casing wall. This generates a suctional pulse upwardly in the annulus drawing dense slurry upwardly and tends to disrupt bridging of slurry particles. Inventive pulsed jetting eductor couplings can have one or more convergent small nozzles circumferentially positioned with associated partial chambers angled upwardly that produce pulsed water eductor jets. Though pulsed eductor jets may inherently be relatively small and inefficient individually, as compared to one with fully formed chambers, the inventive system and methods provide that a multiplicity of small pulsed jets and chamber indentations per coupling be used to facilitate dense slurry lift along with the net movement of the slurry up the annulus by virtue of a net positive suction head and hydraulic gradient, i.e. adding hundreds of gallons per minute by pulsed jet mining to the mining cavity. A regulator on the pump adjusts for volume changes. An eductor will fail by cavitation if it does not receive enough net positive suction head, which is a circumstance generally avoidable by the proposed subsurface mining system and methods that uses a water-filled mining site, another preferred embodiment of the invention. Failure of the invention's eductor system is especially unlikely since there are no moving parts in this basic eductor design, which facilitates slurry lift with a beneficial hydraulic head gradient orientation and proper pump size, but also because this process can have an additional back-up source of fluid and pump, another embodiment of the system and methods. Water can be pumped into the casing annulus if fluid levels fall, as may be monitored by an actuating sensor at the casing's top most edge where a casing collar can be attached to funnel effluent slurry from the annulus into a slurry catch box. An example that might cause a temporary eductor failure would be a subsurface crevice draining the excavation site. If an eductor mechanism fails the slurry recovery system can easily be restarted once the source of cavitation is corrected. There are many corrective methods for such an occurrence that are commonly known to the mining industry, such as applying calcium carbonate to the borehole. The borehole can also be refilled with sand with all tooling removed and the site abandoned, pending site logistic evaluation. Pulsed coupling eductor jetting can add extraction efficiency for moving slurry through the annulus by intermittent agitation of slurry lift flow, inhibiting particle bridging and annulus blockage. Eductor couplings can be manufactured in various lengths and dimensions such as by machining, 3-D printing or molding, fitting and threadably adapting to sonic rod string matching material specifications of the sonic manufacturing industry requirements for safety and longevity of use.
The inventive sonically pulsed water jetting mining system and methods employs a tubular sectional apparatus assembly, in addition to the sonically pulsed jetting eductor couplings, that is another preferred embodiment of the system. The inventive system and methods tubular sectional apparatus assembly is comprised preferably of a transition rod, a jetting sub-coupling and a shoe rock bit, in addition to at least one sonic rod, one or more jetting educator couplings and one or more casing members, in multiple sections, though they may be manufactured as combined sections, that are generally attached to one another in tubular alignment, in at least one preferred embodiment of the inventive system, and attached, except for the casing, to the bottom end of a sonic rod that is in fluidic communication with a water column by way of adaptor and spindle to the sonic head.
The top most, or first, section of the single tubular apparatus is comprised of at least one transition rod that may be weighted to facilitate rotational balance of the rod string and provide additional stability with pulsed jetting and may also be formed to allow additional guide vanes or extending length of guide vanes originating in the conduit interior of the pulsed jetting sub-coupling member section that is immediately below and attached to the transition rod's bottom end to facilitate improved pulsed jet coherency as water flow exits a nozzle as a cutting pulsed hydraulic jet, in either semi-discreet or discreet bolts depending on many factors. The pulsed jetting sub-coupling is the preferred second section, i.e. middle section, of the inventive system and methods apparatus assembly. It incorporates one or more jetting nozzles, preferably two diametrically opposed to reduce reactive thrust, that facilitate formation of coherent jets preferably using guide vanes to optimize rock fracturing capability at significant stand-off distances for commercial slurry production. Considering the relatively small cross-dimension of the sonic rod string and apparatus which have the same outer diameter, generating a coherent pulsed jet requires a short nozzle design known to prior art as a quartic-type nozzle, which one or more are incorporated into the design of the jetting sub-coupling. The quartic-type (4th-degree polynomial) combined with taper is a nozzle design that can be variously modified in shape as required by the dimension of the apparatus using guide vanes to reduce turbulence and to generate significant jet impact fluxes for optimal rock breakage and disaggregation of mineral targets. Significant commercial slurry production at significant stand-off distance can be achieved using such known short nozzle designs, or modifications thereof, in the inventive system and methods that will generate pulsing and increased efficiency in slurry production. Several known nozzle-type designs can be used in the invention and modified to optimize function with an approximate 90 degree flow direction change and acceleration with pulsed static head potential energy being converted to pulsed kinetic energy at the nozzle to generate jet pulsing that can be modulated in frequency at the sonic head, as well as rotated, as well as moved up and down by rod string connection to the movable sonic head on the sonic drilling rig tower. The third and bottom section of the inventive system and methods apparatus consists of a sonic shoe rock bit that has at least one sonic pulsing nozzle placed between crushing plates (e.g. made of carborundum) or wedges to crushingly fragment large rock fragments or boulders by moving the rod string and attached rock shoe bit with at least one downwardly pulsing jet, up and down and in rotation to generate rock-fracturing torque and compression from the sonic drilling rig as well as using the immediate jet pulsing effect. The pulsing jet nozzle, which can incorporate a standard Leach&Walker-type nozzle design, is directed downwardly into the sump beneath the shoe rock bit to cut and to agitate light settled slurry fragments back into the slurry solution for transport to the surface through the annulus space, while concentrating heavy fragments in the sump trap. The sonic shoe rock bit can also include laterally directed nozzles to generate additional pulsing jets that laterally project a pulsed cutting fluidic stream for fracturing mineral matrix similar to the function of the jetting sub-coupling, as a modification which is another embodiment of the invention. The preferred method for integrating one or more pulsed laterally cutting jets is to incorporate nozzles in a sub-coupling, with at least one pulsed jetting nozzle immediately above the sonic shoe rock bit, which is at the bottom end of the sonic rod string. The laterally pulsed jetting nozzles with guide vanes can be most effectively manufactured using 3-D printing and angled generally laterally to project a horizontal pulsed jet stream to one angled slightly (e.g. 10 degrees) upwardly to facilitate floor inclination to facilitate gravity's force to continually move fragments into the cutting stream and towards the sump trap. The transition tool that interconnects the bottom end of the rod string to the sub-coupling member may also be manufactured with guide vanes to compliment the guide vanes in the sub-coupling. Also, the sonically pulsed sub-coupling jetting nozzle can be constructed to be angled slightly downward to facilitate pressure washing of the excavated cavity floor into the sump or an independent eductor. A sonic shoe rock bit nozzle may be thread-ably attached or machined or manufactured into the sonic shoe rock bit member. The jetting nozzles integrated into the inventive systems and methods components are designed for liquid pulsed laminar stream jetting and to minimize turbulence with cutting pulsing jet streams, which are the primary excavating nozzles, but also for producing effective downwardly pulsed jetting stream for agitating sump slurry for lift facilitation of lighter material. A jetting nozzle must operate within specific constraints of design, ejecting fluid into a coherent stream balancing laminar flow with turbulence to achieve the different tasks required of subsurface mining using the inventive system and methods.
The inventive sonically pulsed system and methods may efficiently pulse hydraulic jets with a mean pressure in a range of approximately 500-1500 psig, with a flow rate of approximately 300-600 gal/min and with a sonic head frequency of about 150 Hz, (approximately in a range between 1 and 300 Hz, which can be higher depending on sonic head frequency production capabilities) which can be further varied with borehole mining of various subsurface sites in different ways depending on multiple factors, e.g. mineral type, nozzle type and oscillating rates of a particular type of sonic drill head. Logistical analysis will in part determine the working parameters with each site to be within constraints of the equipment.
The goal of this inventive mining process, which as a total system plan and methods may herein be referred to as Hice Hydro-mining, is to provide an improved system design and methods for subterranean fluidic jet mining not present in prior art using a sonic core drilling rig's sonic head as a pulsing energy source in combination with a water pumping member as a hydraulic source adding high-pressure and—high water volume with sonic mining tools adaptable to use with the inventive system's design and methods in order to generate sonically pulsed jetting streams to fracture and disaggregate mineral subsurface targets more efficiently and in a commercially economic manner, excavating slurry while providing simultaneous eductor extraction of slurry through a borehole annulus with a minimized potential for slurry blockage using a single partially cased borehole and recovery of slurry concentrates with use of a sump member and sonic core barrel. The system and methods use preferably two laterally-directed diametrically opposed pulsed jetting nozzles incorporated in a pulsed jetting sub-coupling tool attached axially between a shoe rock bit having a downwardly directed pulsed jetting nozzle and a transition rod that connects the sub-coupling to a sonic rod string using intermittently spaced eductor couplings with sonically pulsing jets to facilitate slurry recovery through the annulus space, performed through a single and partially cased borehole. A method is provided for recovering slurry fragments too heavy to be removed by eductor siphon function that uses the advantage provided by a sonic core barrel of retrieving sump trap contents quickly and without getting stuck. This total system and methods may also be expanded by adding additional sonic casing members to the sonic casing string in conjunction with adding more eductor couplings to the sonic rod string to facilitate deeper and denser slurry recovery using a one borehole mining system plan and method. Another method is provided with the pulsed jetting system and methods for use of an independent eductor mechanism for increasing extraction rates of slurry, which may optimize high-efficiency subsurface excavation rates and used as an adjunctive method for slurry extraction by the efficient pulsed jetting apparatus design provided by the invention. General advantages of the invention over prior art are several, but generally speaking it provides improved efficiencies in slurry production, borehole mining economics and eco-friendliness, especially because of its variable energy-sizing potential with various efficient sonic drill rig platforms and adaptable apparatus and methods of applying pulsed jet mining to increase production rates, given the variable mining situations that are available.
The following table lists the part numbers and part descriptions as used herein and in the figures attached hereto:
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It should be understood that the jetting members, including the sonic rod 15 and rod string 15, transition rod 14, sub-coupling 13 and shoe rock bit 12 herein, include nozzle and threading incorporations with variations in type, shape, size, material content with one member being comprised of parts or of all inventive jetting members so that one inventive jetting member may perform the function of two or more sonic jetting members, and thereby can be of variable construction to adapt to the particularities of corresponding sonic drill rigs, sonic drill heads, sonic rods and casing, and pump elements but are all permutations of similar function and intent are contemplated as being representative and consistent with the inventive sonically pulsed jetting system plan and methods presented with multiple permutations implicit.
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While the inventive system and claims have been described and illustrated in detail, it is to be understood that this is intended by way of illustration and example only and is not to be limited to such illustrations and examples. To those skilled in the art to which this invention pertains, many modification and adaptations thereof will suggest themselves. Accordingly, it should be understood that the specific disclosures and descriptions contained herein are to be taken in an illustrative sense and that the scope and spirit of the invention is not to be limited thereby except in accordance with the accompanying claims.
1) A sonically pulsed hydraulic jetting system assembly intended to be used with a commercial sonic drill rig with movable tower attachments for subterranean modulated low-frequency (equal to or less than 300 Hz) for sonically pulsed jet borehole mining having a sonic drill head, wherein the sonic drill head can be securely attached to a relatively elastic sonic rod, to which the system is attached and functions when adaptably attached by hydraulic conduit to a high pressure high volume operating pump system with a water reservoir, and within a borehole that is at least partially cased, comprising:
- a. At least one or more transition rod members that is generally tubular having a top end for attachment to the bottom end of a sonic drill rod, in tubular fluid communication with the sonic drill string functioning to minimize stress between the sonic drill water flow stream and the sonically pulsed hydraulic jetting system assembly by applying additional weight to the system as well as by incorporating in its internal structure such as guide vanes to reduce flow turbulence supporting the sub-coupling nozzles to generate more coherent sonically pulsed jetting bolts, having a bottom end for attachment to the pulsed jetting sub-coupling;
- b. At least one or more sub-coupling members that is generally tubular with one or more convergent-type nozzles, e.g. quartic with guide vanes, directed laterally for pulsed jetting with a top end attached to a transition rod or may also be otherwise attached to a sonic drill rod directly and a bottom end attached to a pulsing rock bit or may be manufactured to incorporate the structures of the shoe rock bit, so that the sub-coupling member may have qualities of all three components of the system assembly structurally incorporated into one sonically pulsed jetting system and rock bit apparatus attached to the bottom end of a sonic rod string, but is preferably a separate sonic jet mining component for increased variability;
- c. a sonically jet pulsing shoe rock bit member having at least one downwardly directed convergent pulsing jetting nozzle to cut and agitate rock and slurry relative to a sump member oriented beneath the sonically pulsed jetting system assembly and having one or more crushing plates or wedges to crushingly fragment large rock fragments or boulders by moving the rod string and attached rock shoe bit with at least one downwardly pulsing jet, up and down and in rotation to generate rock-fracturing torque and compression force from the sonic drilling rig as well as by using the immediately oriented jet pulsing effect, having a top end for secure attachment to a sonically pulsed jetting sub-coupling;
- d. at least one or more sonically pulsed eductor coupling members being substantially aligned in the sonic rod string, attaching a sonic rod above and a sonic rod below, having one or more sonically pulsed jetting nozzles directed upwardly, having associated partial chambers to be used for eductor siphon function, used within the annulus in association with sonic casing and hydraulic gradient forces generated within the mining cavity to facilitate lifting of slurry through the annulus to the surface;
- e. an elastic sonic rod or rod string that is adaptably attached on its top end to a sonic rod attached to a spindle of a sonic drill head that oscillates at a low frequency (usually less than or equal to 300 Hz) facilitating pulsing energy transfer into a high-pressure high-volume fluid column moving through the tubular sonic rod open-ended hydraulic system that will include in fluidic tubular communication at least one rod with a sonically pulsed hydraulic jetting system assembly, that includes a pulsed jetting eductor coupling, transition rod, pulsed jetting sub-coupling and pulsed jetting shoe rock bit or any combination, for receiving high-pressure and high volume fluid flow from a pump member with at least one check valve as well as simultaneously transferring adjustably tunable oscillating energy from a sonic drill head member through its spindle with sonic energy wave transfer through and from the elastic (generally meaning to be deformable but not deformed permanently) sonic rod or sonic rod string and its fluid column generating pulsed water jets through the eductor coupling's one or more jetting nozzles into the fluid filled annulus from the interfaced internal fluidic column, also resulting in pulsed fluid volume streaming from the sonically pulsed rock shoe bit and sub-coupling nozzles;
- f. a sonic casing member or combination string of sonic casing members, elastic or inelastic, to be used for emplacement in the ground, with adding or subtracting casing sections to a casing string and recovery by a sonic drill rig and secured to the surface but independent of the sonic drilling rods, used to facilitate slurry extraction using at least one sonically jetting eductor coupling member positioned within the casing's internal space in tubular attachment and alignment with at least one sonic drill rod, facilitating the benefit of sonically jet pulsed mining using the sonically pulsed hydraulic jetting system assembly plan and methods, having its top most end usually above the surface of the ground, its bottom end oriented above or within proximity of the subsurface mining targeted mineral.
- g. a water pump member with a driver and conduit attachments allowing for communication of fluid to drill head member and sonically pulsed hydraulic jetting system assembly, presenting continuous flow high-pressure and high volume capabilities, preferably with automatic adjustment capabilities to adjust pressure and volume to jet mining variable demands, usually functioning on average per mining site between 200 psig and 2000 psig, and with a flow capacity between 20 gallons and 2000 gallons of water per minute depending upon and being variable with the objectives attached to the pulsed jet mining operation, though these are only estimations of pumping parameter required using various situational constraints by equipment and are not intended to be limiting but representing a common effective range for applying the sonically pulsed hydraulic jetting system assembly to perform subsurface mining production of slurry from a targeted mineral source with efficiency, but specific parameters will be dictated by the analysis and constraints of each mining site's situation and logistics;
- h. a sonically pulsed jetting borehole mining system combining high-volume fluidic column's hydraulic energy from a surface pumping member as well as simultaneously transferring of relatively low-frequency sonic oscillation energy waves from a sonic drill head member into an attached inelastic or elastic sonic rod or rod string that interfaces with a pressurized water column and attachable sonic pulsed jet mining apparatus generating a subsurface sonically pulsed jetting mining system and methods, to be called Hice Hydro-mining.
2) A system of claim 1 wherein the pulsed sonic rod and sonically pulsed jetting system assembly fluidly communicates to a conduit attached to a pumping mechanism with at least one check valve interposed in relatively inelastic conduit that prevents oscillation energy from the sonic drill head and drill head spindle to communicate fluid transfer back toward the high-pressure liquid pump mechanism that supplies reservoir fluidic material to the elastic sonic rod and rod string, which can contract and expand with energy wave propagation that may help generate pulsing fluid streams, to flow one way through pulsing jetting nozzles integrated into the sonically pulsed hydraulic jetting system assembly positioned below the borehole casing string with pulsed semi-discrete or discrete bolts of water delivering momentum flux into the target deposit and subterranean excavated cavity and also with eductor coupling nozzles pulsing jet streams being directed upwardly into the annulus between the sonic casing and sonic rod string using one or more eductor-type couplings to facilitate slurry lift and to minimize blockage potential of slurry flow.
3) A system of claim 1 wherein the relatively low-frequency adjustable oscillation energy is not directed into or through the casing string directly during pulsed jet mining process, with the sonic casing string being independent of the sonic rod, only having oscillating energy directed applied during its emplacement, or with adding or subtracting casing sections from the mining borehole during coring sampling operations or with removing the sonic casing from the borehole, with a sonic rod string positioned within and through the central space of the stable borehole casing string establishing a variable annulus space separating the movable sonic rod string from the generally stable sonic casing string to facilitate slurry extraction.
4) A system of claim 1 wherein differences in nozzle size, nozzle shape, guide vanes and other structural dimensional variation are used with different components and sections of the sonically pulsed jetting system assembly to generate different pulsed jetting streams with different effects as determined by task performance, such as for rock fracturing or slurry lift.
5) A sonically pulsed jetting system as claimed in claim 1 wherein the members and supporting equipment and tools can be variable in design but generate similar low-frequency sonic drill head propagated sonically pulsed jetting for subsurface mining, comprising the sonically pulsed hydraulic jetting system assembly members.
6) A system of claim 1 wherein the sonic rod string is fluidly communicated to a pumping mechanism by conduit in contiguous fluid communication by conduit with a water reservoir having at least one high-pressure release safety valve and at least one one-way check valve interposed in relatively inelastic conduit between the pumping mechanism and the sonic drill head that prevents inadvertent excessive pulsed peak fluid pressures from exceeding the safety limits of the equipment.
7) A system of claim 1 wherein the pulsed jetting eductor couplings would not be added to the sonic rod string allowing only for a contiguous sonic rod string and for only pulsed jetting through nozzles located below the bottom end of the casing string and directed toward fracturing, cutting and agitating the targeted mineral into slurry.
8) A system of claim 1 wherein the sonic core drill rig has a tower mechanism to raise, lower and rotate the spindle member to which an adapter is attached and receives fluid and energy waves transferred through the adapter to a sonic rod and sonic rod string attached to the sonically pulsed jetting system assembly which can be movably raised, lowered and rotated to generate improved subsurface slurry production rates.
9) A method for mining minerals, gems and metals from a target deposit comprising the steps of identifying a target deposit examining sonic core samples, emplacement of a casing string into or to the top-most part of the deposit using a sonic core drill rig, which may be modified with additional sonically pulsed jetting system assembly facilitating features including a high-pressure and high-volume fluid pump, conduits, seals, pressure release valves, one-way check valves, and other supportive equipment, an uncased borehole extension is left beneath the casing to be used as a sump member to collect concentrated heavy debris and for progressive insertion of the sonically pulsed jetting system assembly attached to the sonic rod string to facilitate cutting and disaggregating the subsurface target minerals from the uncased borehole in 360 degrees rotation, inserting a sonic rod string having an adjustable length by adding or subtracting various sections (i.e. rods, couplings, transition rod, sub-coupling and bit members) sufficient to obtain the desirable depth for mining, into the securely placed sonic casing string that has been inserted into or to the top-most level of a subterranean mineral target deposit to be excavated, slurry generated and recovered using sonically-pulsed jet nozzles that are structurally positioned in components of the sonically pulsed jetting system assembly and structurally manufactured by 3-D printing, machined or threadably integrated within a shoe rock bit, sub-coupling and also with pulsed jetting eductor-type couplings that attach sonic rods together to facilitate slurry lift in the annulus within and through the casing string, attaching a high-pressure fluidic pumping member, with a communicating fluid reservoir, to a conduit with at least one check valve and at least one safety pressure-release valve attached to the sonic core drill rig's sonic head fluid transfer conduit system, or to a modified swivel adaptor apparatus, to allow fluid flow one way from the sonic drill head into and through the sonic rod string, inserting the sonic rod string and attached sonically pulsed jetting system assembly through the casing member string and into the borehole so that the bottom-end of the sonically pulsed jetting system assembly having laterally cutting one or more pulsed jetting nozzles to cut, fracturing and disaggregate mineral target below the casing member and juxtaposed to the targeted mineral deposit, generating fluid flow by engaging the pumping member to pump fluid into the sonic rod string while oscillating the sonic head at an appropriate frequency for energy transfer to the fluid column, rotating the resonating sonic rod string and attached sonically pulsed jetting system assembly 360 degrees or any less angulation for different excavation cavity shapes and at varying speeds while moving the pulsed jetting streams up and down in the borehole beneath the casing bottom end and against the targeted mineral matrix, fracturing and cutting matrix to form slurry, observing the lifted slurry exiting out of the annulus at the top-end of the casing string into a slurry catch box, or monitoring slurry density meters from where it is pumped by slurry pump to a processing plant, e.g. slurry box at a processing platform where the slurry is classified using one or more screens, jigs, sluices, gravity concentrators, where water separated from slurry particulate matter and is clarified using at least one hydrocyclone and/or screen that is collected in a cistern and either pumped to the clarified water reservoir or filtered by a bone char filtration system or used in further processing or to another water-holding reservoir, using a plurality of fluidic pulsing jetting nozzles and division of water with pump and sonic head adjustable cyclic volume and pressure transfers to generate multiple mining effects including lateral, either horizontal or angled, which may be on diametrically opposite sides of a sub-coupling to neutralize reactive thrust destabilization, for pulsed jetting to fracture mineral matrix and also downwardly directed pulsing jet or jets for further cutting and dispersing subterranean excavated cavity bottom slurry and sump slurry back into solution allowing greater potential for it to be lifted through the annulus by the Venturi effect from the eductor-type pulsed jetting eductor couplings with the pulsed jetting eductor nozzles oriented to partial vacuum and diffusing chambers in the annulus to facilitate lift of slurry to the top of the casing and into the slurry catch box from which slurry can be pumped using one or more slurry pumps to a processing plant for further classification and water separation with clarified or filtered water recycled back to a fluid reservoir, immediately reused at the processing platform or to be stockpiled, gravel that is classified from slurry as large, not captured in traps and separated out as gangue may be crushed by a gravel crushing machine to a uniform small size and again run through the classification processor for gravity concentrator separation of valuable minerals and elements with rejected small gravel sands collected for reinsertion into the subterranean cavity as fill, thereby completing the mining process at the site. A high hydrostatic fluid level will be monitored and adjusted automatically by a sensor, either mechanically or electronically, as needed, being maintained by a conduit and high-volume low-pressure water pump with a water reservoir source to provide for immediate insertion of fluid into the annulus' top end, with the conduit communicating for fluid emplacement through a nozzle connected to a collar secured to the top end of the casing, which also attaches the slurry catch box to the casing, to maintain effective eductor function and hydrostatic stability of the subterranean cavity.
10) A method for mining minerals, gems and metals from a target deposit comprising the steps of recovering a sump concentrate periodically using the core barrel with or without extending additional casing members, whereby a sump will be maintained on the floor of the subterranean excavated cavity during pulsed jetting subterranean excavation to trap large heavy elemental nuggets and gems and other heavy debris for recovery with a sonic core barrel, with interruption of the pulsed jet mining process, removing the sonic rod string and jet pulsed mining apparatus from the borehole, then inserting the sonic core barrel or similar barrel device on supporting sonic rods into the borehole to the sump member, coring the sump contents with or without over-coring the sump, preferably deepening the extracted sump member to seal unconsolidated concentrates within the core barrel with a cap of non-concentrate, preferably extending the depth of the sump and then removing the core-barrel and its heavy and large slurry contents from the subsurface mining site and sump member to the surface for processing.
11) A method for mining minerals, gems and metals from a target deposit comprising the steps of recovering slurry from a deeply extended deposit where extending the casing string further into the mining cavity and around the sonic jetting rod string with added sonically pulsing jetting eductor couplings to the sonic rod string is employed to facilitate improved dense slurry recovery, with periodically adding additional casing members to a casing string as needed to position the pulsed assembly deeper into a deepening mining cavity where dense slurry may gravitate and collect, with the sonic casings bottom-end extending below the top of the mining cavity's ceiling, such that a more efficient and denser slurry extraction is accomplished using a single borehole method, providing for better use of more pulsed jetting eductor couplings with adding additional sonic rods and additional casing members to function with a downwardly extended annulus into a sonically pulsed jetted excavation cavity.