Underground mining method using drilling and multi-directional blasting holes

Abstract

A method for underground mining in a rock mass comprises drilling one or more service holes from at least one surface location into the underground rock mass. Drilling a plurality of multi-directional blast holes into the underground rock mass, branching from at least one of the one or more service holes. Each of the plurality of multi-directional blast holes is loaded with one or more explosives and one or more detonators. Inserting the one or more explosives and one or more detonators from the surface. Wirelessly detonating the one or more explosives to fragment the underground ore mass. Extracting the fragmented rock to the surface through the one or more service holes.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] not applicable

[0003] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0004] not applicable

[0005] Names of the parties to the joint research agreement

[0006] not applicable Background Art

[0007] The present invention relates to the field of underground mining of minerals. Known underground mining methods require open pit mining where overburden rock is removed before mining the target ore, or the use of underground mines that can selectively mine the target ore. Underground mining requires miners to work underground and requires expensive support structures, ventilation, cooling and drainage.

[0008] As global demand for mined minerals increases, high concentrations or high-grade minerals near the Earth's surface have been mined in large quantities. Miners must either dig deeper to find high-grade minerals or mine and process large amounts of low-grade material at the surface to get to usable ore. This problem is particularly acute for copper, nickel and cobalt, which are critical to renewable energy infrastructure and the manufacture of electric vehicles.

[0009] Known mining methods use explosives placed in blast holes drilled in the area of ​​interest to blast rock into small fragments which can then be extracted to the surface and processed to remove valuable ore minerals. Blasting is generally considered the most energy efficient method of breaking rock.

[0010] As miners go deeper in search of valuable minerals, they face higher operating temperatures, water ingress, risk of rock fracture, and other geotechnical risks to underground workers. To mitigate these risks, expensive ventilation, cooling, drainage, and reinforced concrete support structures are installed at high cost.

[0011] There is a need for methods that can bring ore bodies deep underground to the surface without removing overburden or requiring miners to work underground. Summary of the invention

[0012] One aspect of the present invention relates to a method for conducting underground rock mining. The method according to this aspect includes drilling one or more service holes from at least one surface location into an underground rock mass. Drilling a plurality of multi-directional blast holes branching from at least one of the one or more service holes into the underground rock mass. The plurality of multi-directional blast holes are each loaded with one or more explosives and one or more detonators. Inserting the one or more explosives and one or more detonators from the surface. Wirelessly detonating the one or more explosives to fragment the underground ore body. Extracting the fragmented rock to the surface through the one or more service holes.

[0013] In some embodiments, after extracting a volume of fractured rock, a fluid is flowed through the fractured rock remaining in the subsurface to extract soluble or finely fractured components of the remaining rock.

[0014] In some embodiments, at least a portion of the one or more service holes are drilled to intersect in or near an area in the subsurface rock mass to be extracted. The intersection of at least a portion of the one or more service holes is used as a location reference for other drilling operations.

[0015] In some embodiments, at least one service hole is drilled relative to another borehole using magnetic ranging or electromagnetic ranging.

[0016] In some embodiments, one or more of the plurality of multi-directional blast holes are guided relative to measured geophysical properties of the subsurface rock mass using sensors disposed on the drilling assembly to optimize the location of one or more of the plurality of multi-directional blast holes.

[0017] In some embodiments, a plurality of multi-directional blast holes are navigated within a subsurface rock mass by measuring at least one property of drill cuttings collected at the surface related to mineral composition.

[0018] In some embodiments, one or more multi-directional blast holes are drilled using sensors that control directional drilling so that the hole is drilled vertically, thereby maintaining survey accuracy.

[0019] Some embodiments further include injecting tailings from the surface into the void space created after extracting a volume of crushed rock.

[0020] In some embodiments, the crushed rock is extracted via one or more service holes using a winch conveying apparatus to recover the crushed rock from the underground blast pile and move the crushed rock to the surface.

[0021] In some embodiments, the winch delivery device travels within a casing disposed within at least one of two of the one or more service holes, wherein the winch delivery device locks into the casing, and the casing is pushed into the burst pile to help fill the winch delivery device.

[0022] In some embodiments, the service hole is drilled to intersect the lowest point of the blast pile, and wherein the winch conveying apparatus includes a bottom portion having a one-way mechanism allowing for collection of crushed rock as it enters the blast pile.

[0023] In some embodiments, a winch conveying apparatus utilizes mass and a wire rope to collect material through a downward hammering action or vibration.

[0024] In some embodiments, one or more service holes include a first extraction borehole, inside which a container is deployed to extract the crushed rock, the container being deployed on a winch, and one or more service holes include at least a second extraction borehole drilled to intersect the first extraction borehole from a stope containing the crushed rock so that gravity delivers the crushed rock into the second extraction borehole, wherein the container disposed in the second extraction borehole lifts the crushed rock to the surface.

[0025] In some embodiments, movement of the crushed rock is controlled via a drill pipe or drill rod inserted into a second extraction borehole operated from the surface, whereby the drill pipe or drill rod acting within the second borehole reduces the fragment size of the crushed ore.

[0026] In some embodiments, the fractured rock is broken into smaller fragments by mechanical action of a drill pipe or wireline conveying equipment, or by inserting an explosive device into at least one of one or more service holes drilled through the subterranean rock mass, to allow the smaller fragments to be extracted to the surface via at least one of the one or more service holes.

[0027] In some embodiments, the crushed rock is extracted using a jet pump fed by concentric or parallel connected pipes in at least one of the one or more service holes.

[0028] In some embodiments, a plurality of multi-directional blastholes are drilled using a whipstock apparatus located within a tubing configured to move along and rotate within a service hole; the openings in the tubing facilitate subsequent directionally drilling of multi-directional blasthole divergences from the service hole.

[0029] In some embodiments, the pipe is moved to a starting position and orientation for drilling each of the plurality of blasthole multi-directional branches, and then after drilling each of the plurality of multi-directional blastholes from each of the blasthole multi-directional branches, the pipe is returned to each starting position and orientation to facilitate loading of explosives into each of the plurality of multi-directional blastholes.

[0030] In some embodiments, a plurality of multi-directional blast holes are drilled using an apparatus, the apparatus comprising: a pipe inserted into one of the one or more service holes. The pipe is anchored in place. The pipe comprises: a plurality of pre-cut windows to facilitate drilling of the multi-directional blast holes; a plurality of positioning devices to allow a whipstock to be installed and locked in a desired position by a corresponding one of the plurality of positioning devices to drill a set of multi-directional blast holes; and a mechanism for releasing the whipstock to allow the next in a series of multi-directional blast holes to be drilled.

[0031] In some embodiments, one or more explosives are loaded into at least one of the plurality of multi-directional blastholes using an outer tube having a diameter smaller than the multi-directional blasthole bifurcation and a flexible inner sleeve having a diameter that can expand to fill the multi-directional blasthole bifurcation. The flexible inner sleeve is inserted inside the outer tube. The inner sleeve is filled with explosives, boosters, and detonators. The outer tube and the flexible inner sleeve are advanced into the multi-directional blasthole bifurcation on the pipeline. A release mechanism is triggered to place the explosives at a desired location, and the flexible inner sleeve is released inside the multi-directional blasthole bifurcation. The outer tube is removed, leaving the explosives to expand in the flexible inner sleeve to effectively fill the entire diameter of the multi-directional blasthole bifurcation.

[0032] In some embodiments, one or more detonators are activated by a radio frequency signal having a specific identifier and fire code.

[0033] In some embodiments, the crushed rock is extracted using a pair of extraction boreholes drilled from the surface to intersect near the underground rock mass, wherein a steel cable is looped downward in one of the pair of extraction boreholes and looped upward in the other of the pair of extraction boreholes. Extraction equipment attached to the steel cable is used to lift the crushed rock to the surface by movement of the steel cable.

[0034] A method of underground mining in rock according to another aspect of the invention includes drilling one or more service holes from a surface location into a subsurface rock mass. Drilling a plurality of multi-directional blast holes branching from one of the one or more service holes. One or more of the multi-directional blast holes are loaded with one or more explosives and one or more detonators. Inserting the one or more explosives and one or more detonators from the surface. Wirelessly detonating the one or more explosives to fragment the subsurface rock mass. Extracting the fragmented rock through an existing mine shaft.

[0035] In some embodiments, a plurality of multi-directional blast holes are directed relative to measured geophysical properties of the subsurface rock mass using sensors disposed on the drilling assembly to optimize the location of one or more multi-directional blast holes.

[0036] In some embodiments, a plurality of multi-directional blast holes are navigated within a rock mass by measuring at least one property of drill cuttings collected at the surface, the at least one property being related to mineral composition.

[0037] In some embodiments, a plurality of multi-directional blast holes are drilled using a whipstock located within a tubing configured to move along and rotate within a service hole, the openings in the tubing facilitating directional drilling of subsequent blast hole multi-directional branches from the service hole.

[0038] In some embodiments, the tubing is moved to a starting position and orientation for drilling each of the plurality of blasthole multidirectional branches. The method further includes drilling a set of multidirectional blastholes from each of the plurality of blasthole multidirectional branches, wherein after drilling a set of multidirectional blastholes from each blasthole multidirectional branch, the tubing is then returned to the starting position and orientation to facilitate loading explosives into each of the set of multidirectional blastholes drilled from each blasthole multidirectional branch.

[0039] In some embodiments, a plurality of multi-directional blast holes are drilled using an apparatus, the apparatus comprising: a pipe inserted into one of the one or more service holes, the pipe anchored in an appropriate position in one of the one or more service holes. The pipe comprises: a plurality of pre-cut windows to facilitate drilling of multi-directional blast holes; and a plurality of positioning devices to allow the whipstock to be installed and locked in a desired position by the corresponding positioning devices, thereby drilling a group of multi-directional blast holes. The pipe also includes a mechanism for releasing the whipstock to allow the next one in a group of blast holes to be drilled.

[0040] In some embodiments, one or more explosives are loaded into at least one of a plurality of multi-directional blastholes using an outer tube having a diameter smaller than the multi-directional blasthole bifurcation and a flexible inner sleeve having a diameter that can expand to fill the multi-directional blasthole bifurcation. The flexible inner sleeve is inserted inside the outer tube and filled with explosives, boosters, and detonators. The outer tube and the flexible inner sleeve are advanced into the multi-directional blasthole bifurcation on the service pipe. The method also includes triggering a release mechanism to place the explosives at a desired location, wherein the flexible inner sleeve is released and expanded inside the multi-directional blasthole bifurcation; and removing the outer sleeve, leaving the explosives to expand in the released flexible inner sleeve to fill the diameter of the multi-directional blasthole bifurcation.

[0041] In some embodiments, one or more detonators are activated with a radio frequency signal having a specific identifier and fire code.

[0042] A method of underground mining in rock according to another aspect of the present invention includes drilling one or more service holes from a surface location into a subsurface rock mass. Drilling a plurality of subsurface multi-directional blast holes into the rock mass. The plurality of subsurface multi-directional blast holes diverge from at least one of the one or more service holes. The subsurface multi-directional blast holes are loaded with one or more explosives and one or more detonators inserted from the surface. Wirelessly detonating the one or more explosives to fragment the subsurface rock mass. Fluid is flowed through the fragmented subsurface rock mass to extract soluble or finely fragmented components of the fragmented subsurface rock mass.

[0043] In some embodiments, at least a portion of one or more service holes are drilled to intersect in or near a subsurface rock mass, with the intersection point serving as a location reference for other drilling operations.

[0044] In some embodiments, two of the one or more service holes are drilled using magnetic or electromagnetic ranging.

[0045] In some embodiments, sensors on the drilling assembly are used to guide the plurality of subsurface multi-directional blast holes relative to measured geophysical properties of the subsurface rock mass to optimize the locations of the plurality of multi-directional blast holes.

[0046] In some embodiments, a plurality of subterranean multi-directional blast holes are navigated within a subterranean rock mass by measuring at least one property of drill cuttings collected at the surface, the at least one property being related to mineral composition.

[0047] In some embodiments, sections of multiple subterranean multi-directional blastholes are drilled using sensors that control directional drilling to drill vertically, thereby maintaining survey accuracy.

[0048] Some embodiments further include injecting tailings from the surface into the subsurface via at least one of the one or more service holes after extracting the volume of the fractured subsurface rock mass.

[0049] In some embodiments, the fractured subsurface rock mass is extracted using a jet pump fed by nested or parallel connected pipes disposed in at least one of the one or more service holes.

[0050] In some embodiments, a plurality of subterranean multi-directional blastholes are drilled using a whipstock located within a tubing configured to move along and rotate within a service hole, wherein openings in the tubing facilitate directionally drilling multi-directional blasthole divergences from the service hole.

[0051] In some embodiments, the pipe is moved to a starting position and orientation within the service hole for drilling each of the plurality of blasthole multi-directional branches. After drilling each of the plurality of multi-directional blastholes, the pipe is returned to each starting position and orientation to facilitate loading explosives into each of the plurality of multi-directional blastholes drilled from each blasthole multi-directional branch.

[0052] In some embodiments, a plurality of multi-directional blast holes are drilled using an apparatus comprising: a pipe inserted into at least one of the one or more service holes and anchored in an appropriate position in the at least one service hole, wherein the pipe comprises a plurality of pre-cut windows to facilitate drilling one or more of the plurality of underground multi-directional blast holes. The pipe further comprises a plurality of positioning devices to allow the whipstock to be installed and locked in a desired position in the at least one service hole by a corresponding positioning device to drill a set of a plurality of underground multi-directional blast holes. The pipe further comprises a mechanism for releasing the whipstock to allow the next in a series of multi-directional blast holes to be drilled.

[0053] In some embodiments, one or more explosives are loaded into at least one of a plurality of underground multi-directional blastholes using an outer tube having a diameter smaller than the diameter of the multi-directional blasthole bifurcation and a flexible inner sleeve having a diameter that can expand to fill the multi-directional blasthole bifurcation. The flexible inner sleeve is inserted inside the outer tube. The flexible inner sleeve is filled with explosives, boosters, and detonators. The outer tube and inner sleeve travel into the multi-directional blasthole bifurcation on the delivery pipeline. A release mechanism is triggered to place the explosives at a desired location, the flexible inner sleeve is released and expanded inside the multi-directional blasthole bifurcation, and the outer sleeve is removed, leaving the explosives expanded in the flexible inner sleeve to fill the diameter of the multi-directional blasthole bifurcation.

[0054] In some embodiments, one or more detonators are activated with a radio frequency signal having a specific identifier and fire code.

[0055] Other aspects and possible advantages will be apparent from the following description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A side view showing the general method of underground mining by drilling and multi-directional blasting holes.

[0057] Figure 2 Several views of a movable casing multi-purpose multi-directional whipstock apparatus and drilling rig are shown.

[0058] Figure 2A A movable whipstock is shown within a pre-cut fixed casing having multiple multi-directional window exits.

[0059] 3A and 3B show views of a loading tube for explosives.

[0060] Figure 4 A side view showing the extraction method using a bucket transported by a wire rope winch.

[0061] Figure 4A A detailed view of the extraction bucket conveyed within the casing is shown.

[0062] Figure 5A side view of an extraction machine using a hydraulic jet pump is shown.

[0063] Figure 6 A side view of the extraction method using a crane and multiple shafts is shown.

[0064] Figure 7 Shown are side views and details of two boreholes set up for extraction machinery using the wire loop method.

[0065] Fig. 7A and 7B A side view and detail of the use of a cutting device to create two borehole loop systems are shown, respectively. Figure 7B Also shown are details of the extraction machinery using the wire loop method via two drill holes.

[0066] Figure 8 Post-mining in-situ leaching diagram is shown. DETAILED DESCRIPTION

[0067] The methods and apparatus described herein enable positioning of a borehole in or near a rock mass deep underground to be extracted to the surface without removing overburden or requiring miners to work underground. The disclosed methods use new mining machines, techniques, and geometries to achieve such extraction.

[0068] The method according to the invention may be considered to be similar to keyhole surgery in orthopedics, where a small hole is used to precisely remove a problematic element from a joint.

[0069] In the case of mining, the method according to the present invention provides a step change in economic results, energy usage, personnel safety, material requirements and environmental impact. The disclosed method can access ore reserves that were previously impossible to mine safely and economically.

[0070] By sequentially creating multiple separate void spaces through blasting, and reducing waste rock removal for tunneling, tailings slurry can be reinjected into the void spaces, thereby reducing or eliminating the need for hazardous and environmentally dangerous tailings dams.

[0071] The disclosed method has the following key elements:

[0072] (A) Methods of creating initial void space to allow drilling and blasting to commence

[0073] (B) Various systems that replace underground drilling equipment with multi-directional drilling systems operated from the surface

[0074] (C) Various systems for loading explosives into multi-directional blast holes and detonating them remotely

[0075] (D) Various systems that replace underground rock removal systems with systems that operate from the surface to extract material via one or more boreholes

[0076] (E) systems for accurately positioning drilling and blasting relative to the ore body and performing grade control functions; and

[0077] (F) Specific methods for leaching low-grade ore after rock extraction

[0078] (G) Methods related to the operation of existing mine operations

[0079] In the method according to the invention, the entire extraction operation is performed using equipment operated from the surface or a previously extracted location, similar to the operations performed using drilling equipment used for drilling for oil and gas through one or more boreholes. Blasting is known to be the most cost and energy efficient method of fracturing rock in the mining industry today, and is the primary method of producing the fracturable rock that can be extracted in the method.

[0080] A typical series of mining operations are described herein. The actual geometry, engineering choices, and extraction methods selected will depend on factors such as the geology of the mineral resource, depth, rock properties of the ore and overburden, previous mine operations, and other factors. Therefore, the present invention describes non-limiting examples as an illustration of the method. At least a first "service" borehole extends into the rock or ore body underground. Such a first borehole can extend to a great depth, such as hundreds of meters or thousands of meters, to penetrate the rock or ore body. At least one borehole is enlarged in the target area (i.e., the ore body) to be as large as possible to provide void space for starting the blasting process. For example, the enlargement can be performed using a reaming device or by drilling multi-directional blast holes from the first borehole or another borehole.

[0081] As used in the present invention, the term "service" is intended to mean any activity that may be performed or carried out in a borehole, including but not limited to the movement of tools and equipment, the movement of fluids, and the movement of solids (e.g., rock fragments). The term "service" is not intended to limit the scope of activities performed in any borehole, but is only used to clearly identify the relevant borehole when necessary for the purpose of clarity of the present invention.

[0082] In some embodiments, a second service hole (used as a starting point for the blasthole) may be drilled with the bottom hole located close to the first borehole, and then multiple multi-directional branches may be drilled from the second service hole. There may be several such blastholes in a large mining operation. When the blasthole drilling is completed, explosives are inserted into each multi-directional branching blasthole. For example, the explosives are remotely detonated using a radio signal that penetrates the ground or by using a hydraulic signal. In order to effectively blast and remove rock, the explosive closest to the first borehole or any similar borehole used for extraction is first detonated. The crushed material, called a "blast pile", is then extracted through the service hole. The foregoing process is repeated, and a void space or "stope" is created. The size and shape of the stope is designed with rock stability in mind, and features such as support columns or arched roof geometry that may be left in place are used to prevent the stope from collapsing. It is well known that rock crushing by blasting is the most energy-efficient method of crushing rock, and many innovations are made to optimize efficiency by allowing high crushing through blasting using this method.

[0083] Although the present exemplary embodiment contemplates the creation of at least a second service hole as a main hole or "pilot" hole for subsequent multi-directional drilling activities, it should be clearly understood that a multi-directional blast hole as described herein may be drilled from a first service hole, where the first service hole is subsequently used for extraction activities as described further below.

[0084] The crushed rock can be extracted via an extraction device placed in the first borehole. Depending on the depth, rock properties, water level and volume to be extracted, a number of different extraction methods can be used in accordance with the present invention. The extraction device can use a pumped fluid (usually water under pressure) to lift small rock fragments in a slurry to the surface, or use a mechanical bucket that is filled via a separate shaft, or is dropped or forced into the blast pile by the bucket's weight, momentum, or pushed inside a pipe string, or dragged with a wire rope.

[0085] At the surface, any water in the extracted minerals can be separated.

[0086] The first basic innovation according to the present invention is a series of processes and machines that enable drilling and blasting functions to be performed from the surface in underground mining via one or more boreholes and a plurality of blastholes using directional drilling techniques, which blastholes can be drilled, guided, loaded with explosives and detonated in sequence from the surface. The present exemplary method can achieve a range of mine development geometries that are novel and significantly different from the geometries of currently developed mines. The methods described herein require accurate measurement of the locations of the blastholes to produce geometries and spacings that allow for effective blasting.

[0087] Other fundamental innovations include methods of efficiently and economically bringing the resulting material, which has been blasted into fragments, to the surface using hydraulic lift of a winch-delivered bucket or "bucket" or hydraulic force in a pipe string or a motive fluid (e.g., water or air). This material can be extracted through one or more service holes. The bucket or bucket can be traveled within a casing and forced into the blast pile through a pipe. In other methods, a bucket conveyed on a steel cable is used to extract the ore.

[0088] This example method will typically target high-grade ores at depths greater than 100m below the surface. Ore bodies at shallower depths may not be as economical as open pit mining. In any case, this example method may be advantageous because it reduces surface environmental impacts and risks and may allow mining in areas where existing mining methods are normally prohibited.

[0089] Ore is used to refer to the material to be extracted; this can be a mined mineral, and can include veins containing pure metals (e.g., gold and silver) as well as ores of copper, lead, zinc, cobalt, nickel or other metals. Generally, the method is expected to be most beneficial for valuable high-grade deposits deposited deeper underground, however the method can be applied to any material to be mined underground.

[0090] This example method is a completely new mining method that has not been conceived before because it requires several recent developments in mine blasting equipment and oilfield drilling equipment and their cost-effectiveness as a starting point. From the mining technology perspective, it is necessary to use remotely operated detonators that are ignited using radio frequency signals transmitted through the rock. From the oil and gas drilling industry perspective, directional drilling, multi-directional drilling, hard rock drill bits are required while drilling and may also require geosteering, short radius drilling, closed-loop directional drilling control, rotary steerable drilling assemblies and gyroscopic measurements to maximize efficiency and measurement accuracy.

[0091] On this basis, basic innovations are reflected in the following areas:

[0092] The concept of mining from the surface through multi-directional blast holes;

[0093] This multi-directional drilling and blasting operation is made possible by a novel series of drilling and blasting operations

[0094] Novel drilling and blasting geometry makes this multi-directional drilling and blasting possible

[0095] Device for effectively drilling and then reentering multi-directional blast holes

[0096] Methods to ensure blast holes are drilled in optimal locations and to ensure minimal dilution of ore into waste

[0097] Throughout the process, geophysical surveys, wireline logging, logging while drilling and other sensors will be used within the borehole to assess ore properties, rock mass properties, depth and proximity of drill hole intersections. Many technologies from oil and gas extraction are expected to be applied to the process to provide information on rock physical properties.

[0098] Device for efficiently and safely loading explosives into the multi-directional blast hole and ensuring that the explosives completely fill the cross-section of the blast hole for maximum effect

[0099] Method and apparatus for extracting crushed material or "burst pile" from the ground by hydraulic jet pumping or other pumping of suspended slurry

[0100] Method and apparatus for constructing multiple shafts and a method of recovery for extracting crushed material by lowering buckets and retrieving them from extraction points in underground blast piles by cables and hoists. The buckets can travel internally and lock into casings to force the buckets into the blast pile.

[0101] Because the disclosed method does not require complete dewatering of the area to be mined or eliminate the risk of rock fall or rock burst, it may allow mining from deposits much deeper than previously possible. It may allow mining in areas where high temperatures, toxic gases, or geotechnical instability make it too dangerous for traditional underground mining methods. The method does not require block caving and in some cases allows the extraction and replacement of ore bodies without causing severe surface subsidence.

[0102] The disclosed method may be most advantageous when mining relatively narrow, steeply dipping ore deposits in veins or stopes.

[0103] Typically, "drilling" refers to rotary drilling, which is commonly used to drill oil, gas and water wells in underground formations. The method assumes that it is performed using commonly used directional drilling equipment and methods. Generally, when these methods are adopted in this application, several differences will have lower execution costs.

[0104] For all of the underground equipment shown, it is within the scope of the present invention that a drilling equipment system similar to that used for drilling oil, gas or water wells is located at the surface to provide: means for connecting pipes in and out of the borehole, means for providing mechanical forces vertically and torsionally on the pipes, means for pumping water or drilling fluid at high pressure, and means for recovering drilling fluid, water and rock cuttings and removing them from the fluid.

[0105] First, low-cost water-based muds can be used instead of expensive drilling fluids because there is no need to weight the fluid or control fluid losses. In cases where the mine is above the groundwater level (free water level), air, foam or other low-density fluids can be used for drilling to prevent excessive losses. Second, pressure control equipment such as blowout preventers is not required because the rock to be drilled does not contain hydrocarbons or is not on an overpressure zone.

[0106] Although deep for production operations, these operations are relatively shallow compared to oil field drilling because the equipment used for lower pressures and lower temperatures can significantly reduce costs.

[0107] There may be aspects where the cost of drilling may be higher in some cases, namely the fact that minerals often occur in hard rock, either metamorphic or igneous. Hard rock drill bits and methods, such as roller cone drill bits or hydraulic hammer equipment, may be required.

[0108] Typically, "surface" refers to the surface of the earth, however this method can be used to deepen a mine from an existing excavation where people are involved in the mining process and this should be considered throughout the description. In this case, the surface can be considered to be the location where people are operating in the existing mine.

[0109] This method produces multiple stopes and reduces the waste rock typically generated to connect tunnels and drifts. In addition, hydraulically isolated and drained stopes can be used to dispose of tailings, eliminating the need for surface tailings dams.

[0110] In some cases where the minerals are soluble after blasting, the blast pile may be left in situ and extracted via leaching or solution mining processes.

[0111] The method can be used to mine remaining ore in an area that has been previously mined using conventional methods but cannot be further mined due to water intrusion, rock instability or other hazardous or economic obstacles. In such cases, multi-directional drilling and blasting can be used to create a rock blast pile, which can then be extracted by the methods described herein or using existing mine operations, using conventional methods or by in situ leaching.

[0112] The method herein contemplates the initial use of downhole equipment from oil and gas drilling with some modifications and relatively simple mechanical equipment. Once the method is established, innovations in robotics will lead to further development of robotic equipment to improve the performance of various key functions in the process. Some examples of this are listed. (i) A robotic mechanism for movement and alignment of a whipstock for drilling multiple blast holes without removing the drill rod from the hole. (ii) Safely loading explosives into blast holes with a minimum number of drill rod strokes after drilling, including moving and aligning the whipstock to insert the explosives without removing the drill rod from the borehole. (iii) Improving rock extraction efficiency using robotic loading equipment to efficiently handle loading rock and ore fragments into extraction equipment. (iv) Automating surface activities such as drilling, loading of explosives, and unloading of rock or ore from extraction equipment.

[0113] The disclosed methods are described herein as a series of steps to achieve the goal of extracting ore from an underground ore body in a safe, environmentally friendly and economically attractive manner. These descriptions relate to some but not all possible implementations described in the accompanying drawings; in some cases, the steps may have different options than those described in the drawings.

[0114] Figure 1 A side view of the general method of underground blasting of multi-directional blastholes is shown. The figure shows a simplified implementation of the method as a general case. The ore body is an inclined stratum (1), marked with a "+" shading.

[0115] The ore to be extracted may be accessed via a large diameter extraction borehole (9) drilled to depth and in this case vertically. In this case the hole is enlarged in the ore body to create an "extraction point" by drilling short multi-directional blast holes and blasting the inverted cone shaped void space (10). The material is then extracted by drilling and circulation or another extraction method as described herein. This provides an initial space allowing a larger blast pattern to start and produce fragments. A bucket device (11) also used to allow relatively long passes is used like a towline bucket or inserted into the blast pile at the extraction point (10).

[0116] exist Figure 1In the figure, reference numeral (2) is a borehole drilled from the surface by drilling equipment at the surface (15) to drill multi-directional blast holes to blast the stope. In this case, once drilling is carried out along the downward trend of the stope, the multi-directional casing assembly is placed in place (3). Multi-directional side borings are then drilled from these exit points into the ore body (4); these are loaded with explosives, and radio frequency controlled detonators are placed within the explosives, usually at the bottom (5). These are detonated in sequence, thereby blasting the rock into the smallest possible fragments. Typically, very high blast loads or "powder factors" will be used to produce minimal rock fragmentation. (6) shows the location of the previous hole that has been blasted, and (7) is the broken rock or "blast pile" left behind. (8) is the void space or stope that may be partially filled with water. The geometry is designed so that the top section of the stope 16 partially blocks the flow of the blast pile down the stope, so that there is an extraction point. This is the free surface of the blast pile, allowing the bucket equipment to operate on the blast pile without being restricted by the stresses of the broken rock above.

[0117] The bucket device (11) is a cylindrical device with several parts that repeatedly cycles up and down to extract the ore and is designed and operated to maximize the amount of rock that can be taken away with each descent. The bucket device is delivered at high speed on a wire rope from a winch at the surface (14). In this case, the bucket is lowered to the bottom of the extraction point and the rock is collected by being dragged onto the blast pile. In this case, as Figure 5 As shown in , the bucket can be inserted or pushed into the blast pile to scoop up material in the cylindrical bucket.

[0118] It is within the scope of the invention that there can be pairs of these holes so that the buckets can travel in opposite directions on a single shaft, so that the energy of the falling bucket can be recovered. It is within the scope of the invention that multiple shafts can be operated simultaneously to speed up extraction.

[0119] Still reference Figure 1 , shows an auxiliary borehole (12) drilled to cut off the extraction point. This will allow a high speed hammer (13) on a wire rope, for example, to travel down from a winch (14) and break up oversized material. In some cases, explosives may be traveled down to clear the obstruction. In addition, the drilling equipment may be used to drill out any blockages in the shaft. An auxiliary borehole (17) may be drilled to extract water from the stope using an appropriate water pumping system.

[0120] In some cases, the borehole (3) may intersect (9), (12) or (17) to provide a position reference. This may be achieved using magnetic ranging techniques.

[0121] Figure 2Several views of a removable casing multi-purpose multi-directional whipstock apparatus and drilling apparatus are shown. Reference numeral (20) is a steel pipe (similar to the casing used in oil well drilling) that is inserted into a multi-directional borehole to drill a multi-directional bifurcation that accommodates other components and is used to accurately position the window (22) and whipstock (21) to guide subsequent drilling of the multi-directional bifurcation in the desired orientation. (20) may also have a drill bit or grinder to allow it to remove debris that may fall into the borehole. In some implementations, the casing may not reach the surface and be attached to a retrievable bushing hanger, which is a mechanical device that holds the casing in place in the hole.

[0122] Reference numeral (21) is a whipstock, which is a solid body shaped to push the drill bit from the subsequent drilling path, drill out of the window and into the rock at a construction angle determined by the shape of the whipstock and an azimuth and depth determined by the position of the whipstock.

[0123] Reference numeral (23) is an anchor which may be required to push the assembly so that the gap between the window and the borehole is reduced to prevent debris from falling into the blast hole.

[0124] At the surface or some other control point, precise reference points (27) on the casing (26) are used to orient and position the assembly at depth, and the system is then securely clamped (28) to remain stationary during the sidetracking process.

[0125] Drilling is performed in multiple directions using directional drilling equipment (29) known in the art such as bend joints, motors and MWD systems.

[0126] The starting point of the system can actually be a multi-directional drill hole with one or more bifurcations, followed by a foundation of multiple multi-directional blast holes.

[0127] Typically, drilling is done from a single borehole shown in three dimensions. There is virtually no limit to how many blast holes can be drilled from a single borehole, with issues such as casing wear being the limiting factor. In the case of deep operations in hard rock, using a single borehole for a large number of multi-directional blast holes would have economic advantages.

[0128] Typically, all multidirectional blastholes in a pattern are drilled sequentially and each blasthole is left open. Explosives are inserted after the pattern is drilled to avoid any safety or regulatory issues associated with drilling near explosives.

[0129] Figure 2AA movable whipstock in a pre-cut fixed casing with multiple multi-directional windows as exits is shown. In another embodiment, a steel casing is set in a hole, and the casing has multiple positioning devices and exit holes to facilitate the setting of a mechanical whipstock and drilling multiple sidetracks at different depths and locations along the casing. The pipe can have, for example, an internal mechanical profile or a radio frequency identification (RFID) tag to accurately locate and orient the exit drilling position and direction. The mechanical profile has the following features: an directional profile that orients the whipstock at the correct azimuth, a unique profile that allows the mechanical wedge (key) in the whipstock to be set only in a single position, and a locking profile that is strong enough to allow drilling stress. There is also a release mechanism in the whipstock to remove it. In some implementations, the composite pipe can be deployed and can be fixed in place by cement to prevent the borehole from collapsing, but allow rapid drilling of the sidetrack.

[0130] Reference numeral (201) indicates a parent main borehole drilled from the earth's surface.

[0131] Reference numeral (202) indicates a casing tubular member inserted from the surface, usually made of steel, long enough to accommodate all multi-directional exit points. In this case, the casing does not move. The casing can be extended from the surface to the bottom or set in place with a "bushing hanger" commonly used in oil and gas drilling.

[0132] Reference numeral (203) indicates a plurality of outlet windows pre-cut before installation into the hole. These outlet windows can be oriented in a directional array relative to the drilled hole.

[0133] Reference numeral (204) shows an orientation guide which is a feature inside the casing, typically an internal profile that orients the whipstock assembly via a wedge (209).

[0134] Reference numeral (205) indicates a lock profile which will form with wedge (209) a "no go" for the specific side to be drilled. This profile will allow all wedges to pass except the corresponding wedge, and the corresponding wedge will prevent any downward movement, including downward movement with very high drilling forces.

[0135] Reference numeral (206) indicates a drilling assembly including a directional drilling tool and a drill bit, which will pass through the window (203) due to being deflected by a whipstock (207).

[0136] The assembly of whipstock deflector (207), whipstock (208) and wedge (209) will travel within the casing (202) and be positioned at the appropriate position in the locking profile (205) to allow drilling through the appropriate window (203).

[0137] Reference numeral (207) indicates a whipstock deflector, a steel deflector commonly used in oil and gas drilling. The whipstock may be run on a device that can be released once in position.

[0138] Reference numeral (208) denotes a whipstock orienting device that allows the whipstock to be oriented and matched to the target window. The orientation is set before traveling.

[0139] Reference numeral (209) denotes a wedge profile which is locked in the locking mechanism (205) and prevents rotation and downward movement when set. The wedge profile (209) can be removed by pulling with a preset force after drilling.

[0140] Figure 2A The foregoing system shown in will be applicable where rock mechanics or borehole quality prevents casing movement due to debris or hole collapse during drilling and blasting.

[0141] Figures 3A and 3B show a side view of a multi-directional blast hole explosive loading apparatus. After the drilling of the blast hole pattern is completed, the multi-directional hole is loaded using the following apparatus. The key goal is to selectively place a long bag or tube of explosives containing detonators and boosters in the desired blast hole, release the long bag or tube of explosives, and then the bag collapses into place, filling the entire cross-section of the blast hole. This complete borehole filling is important to achieve maximum effectiveness of the explosives. Air or water gaps will reduce the speed of detonation and shock wave coupling.

[0142] As shown in Figures 3A and 3B, at the surface, a loading tube (30) is assembled to load the required volume of explosives. The loading tube (30) is a set of internally smooth and flush tubes (35) screwed together, similar to drill pipe or casing, which can be made of metal or more likely plastic or composite materials. It is flexible enough to easily pass through the sharp turns in the multi-directional branching of the borehole.

[0143] The bottom of the loading tube (30) has a bottom nose (38) shaped to pass easily into the borehole and has a release mechanism that can be remotely released or opened to allow the loading bag to be released into the blast hole. This can be remotely triggered by a pressure pulse sequence or radio frequency signal commonly used in oil well drilling or equipment pumped from the surface.

[0144] Prior to loading the explosives, a ‘dry march’ may be carried out without the explosives to ensure the blast hole is free of debris, depending on the risk of the explosives becoming stuck.

[0145] In some implementations, the release mechanism may be at the top of the stowage bag and the bottom nose may be part of the bag or passive.

[0146] Inside the tube is placed a long loading bag (31) that has a diameter larger than the pipe and can be folded and fixed to slide easily inside the loading tube. The material is chosen so that the friction between the bag and the tube is low, or a lubricant is added.

[0147] In some implementations, the bag may be an expandable tube or other device for providing the same function. In some implementations, there may be no bag and the waterproof explosive emulsion may be injected directly.

[0148] Once hung and fully assembled at the surface, detonators (36) and booster (37) (as required) are placed in loading bags and then an explosive slurry such as ANFO, emulsion or other liquid, gel or granular explosive is loaded through a hose or from a silo or hopper.

[0149] When the loading bag is filled, it is closed and the explosive loading tube is delivered into the hole using the drill rod. At the multi-directional bifurcation, the tube passes easily because its diameter is smaller and more flexible than the drilling assembly used to drill the test hole.

[0150] Once the explosives are at the desired depth, the bottom nose is released and the loading bag is slid into the hole, if the mixture is chosen to be denser than water, it may alternatively be hydraulically pumped into place.

[0151] The tube is withdrawn and the "plugging" material (40) is pumped down the drill pipe.

[0152] If the whipstock is not set correctly, a plug (not shown) may be placed on top of the explosive to prevent the drill bit from re-entering the hole. This may help obtain regulatory approval but is not functionally required.

[0153] Multiple charges or "layers" may be loaded sequentially into the same blast hole.

[0154] This operation is performed sequentially to load all wells.

[0155] Various release equipment and salvage equipment used in oil well drilling can be used to release and retrieve equipment if it becomes stuck.

[0156] Figure 4 Shown is a side view of a winch operated bailing system with extraction points directly from the blast pile for extracting rock and ore.

[0157] Reference numerals 1 to 17 show Figure 1 The same elements as those explained above. Reference numeral (9) is one or more boreholes drilled from the surface. The holes will follow a trajectory to reach the desired extraction point in the ore at the desired point.

[0158] In this figure, a single extraction borehole is shown. In some cases, pairs of boreholes are drilled to deploy a pair of bailing buckets on opposed winches connected by a common shaft, thereby using the weight of one bucket to assist in lifting the loaded bucket out of the shaft. The common shaft has a clutch to allow the bottom bucket to be vibrated into the blast pile.

[0159] The extraction point can be enlarged from a normal circular diameter by repeated reaming to form a vertically oriented elliptical borehole into the stope, thereby creating space for the blast pile to flow freely. It can also be created by drilling multiple blast holes from the borehole 9.

[0160] Reference number (507) indicates the bailing equipment or bucket and is a cylindrical body connected to a steel cable with the following features: a hard-faced scoop at the bottom to dig into the blast pile; the cylinder may have a hinge mechanism to allow deployment in a relatively tight curvature at a construction angle in the borehole. Reference number (508) indicates a hatch that closes and holds the rock when pulling out of the hole and a release mechanism for safe unloading at the surface.

[0161] Reference numeral (509) indicates a jar assembly to hammer the bucket into the blast pile and fill the bucket using the up and down movement of the winch.

[0162] The bucket (507) and vibrating assembly (509) are transported at high speed from a winch at the surface using a wire rope (510).

[0163] A second shaft type (12) may be drilled to allow a high speed wireline hammer (13) to be lowered to break up oversized rock in the extraction point. Explosives (e.g., shaped charges) may be inserted through the shaft and manipulated with a robotic arm and used to blast oversized rock and unblock the flow of the blast pile.

[0164] In most cases, a shaft 17 is drilled to intersect the stope at its lowest point to extract water via a submersible pump. In some cases, soluble ore may be extracted via circulating water through the blast pile to increase the rate of ore extraction. In some of these cases, not all of the blast pile is extracted, and such water extraction may prove to be an economical method of recovering soluble material that is being mined but cannot be extracted.

[0165] Figure 4A Shown is a side view and detail of an extraction machine using a bucket on a wire rope inside a casing for applying force.Instead of a simple wire rope device, the following equipment will replace the bucket (507), vibrating assembly (509), (510).

[0166] The wire rope conveying equipment can be run from the surface in a pipe or casing (512) which will extend in the borehole. Typically, the pipe (512) is a jointed pipe that travels with the drilling equipment or similar lifting device. The diameter of the casing (512) is as large as possible without sticking or excessive friction. Within this pipe, a bucket assembly (514) will travel on the wire rope (513) to allow the explosive pile to be quickly retrieved to the surface.

[0167] The bucket assembly is a cylindrical device with a hatch (519) to allow the burst pile to be captured. The hatch (519) opens when pushed down into the burst pile and closes when lifted with material behind it.

[0168] The system enters the explosion pile in the extraction point. The extraction point can be as referenced Figure 4 Constructed as explained.

[0169] The bucket latches (516) into the casing so that the casing can be used to press down into the blast pile to fill the bucket with material. There is a hard shovel on the casing shown at (517) or on the bucket to push into the broken rock. The latch is released, allowing the bucket on the wire rope (513) to be pulled to the surface, emptied and traveled back into position.

[0170] The sequence of operations is that the casing is first raised above the blast pile. Second, the bucket travels down into position and locks, and then the casing is lowered into position, filling the bucket with material. The casing is then raised and the latch is released (in this case by pulling on a steel cable), and the bucket is pulled to the surface and emptied. This process is repeated over and over, extracting the ore at the maximum rate.

[0171] The casing is held in some kind of drilling equipment or lifting system that allows the casing to be moved up and down as described above. It may also be advantageous to be able to rotate the casing. It may also be advantageous to circulate water or air through the casing.

[0172] Figure 5 A side view of an extraction machine using a hydraulic pump is shown. In implementations where blasting can break up the rock sufficiently to extract small particles of rock without much crushing or drilling, the ore material can be extracted through a single borehole using a hydraulic venturi or jet pump as shown in this figure. This method may be limited to relatively shallow depths due to depth and hydraulics.

[0173] One or more extraction boreholes (51) may be drilled from the surface to a low point in the ore body to be extracted. Before blasting the first blast, the borehole is enlarged as much as possible to create void space for effective blasting.

[0174] The crushed rock and ore (50), also known as a "blast pile" in mining, is blasted by a multi-directional blasting method and collapses in the cavity created by the blasting process.

[0175] A series of pipes are lowered into the borehole (56). At the bottom is a drill bit or crushing device that can use rotation or vertical motion to crush the broken rock to be extracted. In this implementation, a combination of rock characteristics and blasting effectiveness dictates that this is an efficient process. The drill bit will wear over time and can be replaced by pulling the entire assembly out of the hole.

[0176] This process can be aided by high pressure water jets from pipe (53), which are common in oil well drilling. The pulverized material enters the inlet of a venturi jet pump (55) through a small passage (54).

[0177] The inner conduit (56) is an inner tube (59) that acts as a conduit for rock and water to flow to the surface.

[0178] The driving force comes from high-pressure water pumped downward in the annulus between the inner and outer pipes.

[0179] The jet pump (55) is used to convert the energy of the high pressure water outside the inner pipe into a pressure that drives the mixture of rock and water to the surface. The jet pump can travel on the inner pipe and can be removed and replaced by pulling out the inner pipe.

[0180] The motive fluid pressure is pumped at the pressure and rate required to bring the fluid and cuttings to the surface.

[0181] Compressed air may be injected along a separate line into the inner string at a point (57) to provide air lift, ie, by reducing the hydrostatic pressure, to allow the venturi to operate at high velocities and greater depths.

[0182] As water and rock are extracted, the "burst pile" will fall into the hole 51 and continue to be crushed and extracted.

[0183] It is common in blasting that up to 20% of the material may be in the form of fine particles which can be extracted without comminution. In some cases, high grade ore is preferentially present in fines and can be beneficially extracted without comminution by the flow and pumping of groundwater or injected water. In this case, different configurations of pumps can be used.

[0184] The fluid level in the stope can be controlled to increase bottom hole pressure, thus helping to lift material out of the hole, or to lower it to have a gravity drain with more water and fine material.

[0185] Figure 6A side view of an extraction method using a crane and multiple shafts is shown. The main figure shows a side view of three extraction shafts from left to right: a drainage borehole (709), an extraction borehole (707), and a crushing / feeding borehole (703) and crushing / feeding borehole (701) hardware within (704). The foregoing apparatus may have an advantage over previous embodiments in that larger materials up to the diameter of the elevator and feeder may be extracted and processed at the surface, rather than crushed downhole as in previous methods. All apparatus are installed from the surface via directional drilling. In this example method, four separate shafts are drilled:

[0186] 1. An extraction shaft (707) of sufficient diameter to lift the bucket of crushed rock to the surface. In most cases this is the maximum diameter of all the shafts drilled.

[0187] 2. A crushing and feed shaft (701) which serves the purpose of blasting and providing the initial void space for the conduit into the extraction shaft. The crushing and feed shaft will intersect the extraction shaft to allow the crushed ore to fall into the bucket;

[0188] 3. Drainage shafts (709) are drilled to accommodate pumps and piping to remove water from the extraction shaft, allowing ore to be pulled by winches in the air-filled shaft. At least one will intersect the extraction shaft to remove water; and

[0189] 4. Multi-directional blasthole shafts for drilling blastholes. This may be drilled to intersect the main crushing and feed shafts, allowing precise relative positioning.

[0190] A drainage shaft is drilled into the extraction shaft to drain the water. A water pump, such as an electric submersible pump, is installed and run at the end of the pipe. The water will contain a high amount of solids, so select a pump with a high solids tolerance.

[0191] The elevator bucket (705) typically has wheel pulleys to reduce friction and wear on the borehole wall. The borehole can be open hole without casing or with steel or other casing if desired. Minimizing the need for casing is economically advantageous. The elevator bucket (705) has a "mouth" to catch as much falling rock as possible. The elevator bucket (705) is loaded with material falling from the feeder / crusher hole. A second elevator bucket is below the elevator, which can be engaged by a mechanism on the wire rope or drill pipe and winched out on the wire rope cable (706) when full.

[0192] The function of the feed and crush borehole (701) is to allow the surface operated drilling / crushing / pushing equipment (703) to break the rock through the restricted diameter (704) and then through a section of pipe into the extraction shaft and elevator. The feed and crush borehole (701) is drilled from the surface and intersects the extraction shaft below the ore body and blast pile (702).

[0193] The assembly (704) is inserted to stop just before the intersection of the borehole. It is secured by an open hole packer (standard oil field equipment). In the top of it is a replaceable tube, which is a hard material used to crush the rock and also to control the diameter of the rock passing. The grinding / crushing assembly acts on this equipment. Its diameter is smaller than all restrictions downstream of it to prevent blockages. The drill pipe is inserted from the surface and can perform the following actions: drill through the "blast pile of broken rock", crush the rock and force it through a controlled diameter, and in the case of a blockage, a small diameter spear can be inserted to clear all the material.

[0194] When the elevator bucket (705) is full of material, the drill rod closes the gap between the drill rig (703) and the ore body (702) to prevent the flow of broken rock and allow the elevator to circulate to the surface without too much debris falling into the hole.

[0195] An alternative to the apparatus shown at (703) and (704) is a rotating helical assembly which, when rotating in one direction, forces material into the extraction shaft. If stationary, the material would be prevented from falling into the extraction shaft as the bucket travels to and from the surface.

[0196] Figure 7 , Fig. 7A and Figure 7B Shown is a side view and detail of the extraction machinery using the wire loop method via two drill holes. Figure 7 A side view of a pair of extraction boreholes drilled down to a point where ore is to be extracted is shown. Both holes are drilled with a diameter sufficient to extract the ore. The two holes can be drilled as pilot holes and then expanded to a larger size. A first vertical shaft (801) is drilled to the desired point and its position is confirmed by precise measurements. A second vertical shaft (802) is drilled to intersect the first hole at a selected distance below the desired extraction point. The hole is drilled to intersect in the first vertical shaft (801) by precise measurements or magnetic positioning methods using magnetic or electromagnetic equipment.

[0197] After the two service holes are drilled and successfully intersected, a wire rope cable (803) is inserted into the borehole (801) and a cable (804) is inserted into the borehole (802). Mechanical or magnetic methods (805) are used to make the first cable grab the second cable.

[0198] Fig. 7AAn abrasive cutting method is shown applied to form a path between two boreholes. A pair of cable winches (806) are used to pass an abrasive cutting assembly (808) back and forth on a solid cable to cut a path (809) between the two boreholes. Rollers or friction reducing devices (807) may be used to reduce friction and allow for more efficient cutting and reduced cable wear.

[0199] Figure 7B A dual borehole system is shown as an extraction method for a mining process. An ore bucket (810) is transported throughout the pair of boreholes on a strong steel cable. Additional shafts (811) may be drilled to control ore flow and break up oversized rock. A blast pile (812) flows into the area where the pair of boreholes intersect. A wire loop allows the bucket (810) to scoop up rock (813) and be driven by a winch system (815) to bring the rock to the surface (814).

[0200] Figure 8 Schematic showing in situ leaching in a stope created by multi-directional blasting. Figure 8 In the in situ leaching process, the Figure 1 Continuation of what has been explained. The remaining multi-directional blast holes (902) have been detonated using wireless detonators. The resulting blast pile fills a large portion of the stope (903). The blast pile can be considered to be a leach pile generated underground. A fluid (904) such as water or a weak acid is pumped into the borehole and flows into the top of the stope (905). In this case, the borehole is used to drill the blast holes, but this may not always be the case.

[0201] In some cases, flow control devices may be used in the entry points to ensure even distribution of the fluid. The fluid fills most of the void spaces (910) and fills the voids and boreholes to the liquid level (911). The fluid flows through the crushed material.

[0202] At the end of the process, the liquid level can be lowered with a more powerful pump so that acid or other contaminants do not leach outside the broken stope area. Additional boreholes can be drilled to monitor and ensure that the leachate does not migrate into the groundwater.

[0203] Here is a detailed description of the sequence of key steps:

[0204] (1) Evaluation and project selection

[0205] First, the ore body is evaluated and defined through diamond core drilling or reverse circulation drilling, as is common in the industry, to assess whether the subject is suitable for the method. This can all be done from surface, and is done in most cases today.

[0206] The most favorable economic benefits of the method may be mining high-grade and valuable ores in locations where conventional methods are impractical due to rock mechanics, temperature, environmental constraints or other factors.

[0207] The ore body should have sufficient vertical amplitude to allow the blast pile to be efficiently drained to a single point or multiple points. This is possible except in the case of relatively thin and flat ore layers.

[0208] The rock mechanical properties should be evaluated to ensure that the method is effective. The drilling penetration rate should be evaluated, the borehole stability and the rock fragmentation distribution should be evaluated. The maximum stable open pit size should be determined to plan the operation.

[0209] The hydrology should be carefully assessed to determine the amount of water that may enter the stope during mining operations. In most cases, the method will use water-based drilling fluids, however, in situations where free water levels are low and fluid losses are high, the option of air drilling exists.

[0210] Before work begins, a detailed geometric and engineering plan is drawn up, taking into account the uncertainty ellipse for each borehole and the methods that can be used to locate the borehole, such as magnetic ranging and precision gyroscopic technology, which is commonly used in oil and gas drilling.

[0211] 2. Preparation

[0212] The prepared drill site is ideally located to allow for a large portion of the wellbore length to be vertical, allowing for rapid drilling and accurate measurement positioning.

[0213] Tailings can be returned to the stope at some stage of mining, however some capacity is required to store drill cuttings and tailings.

[0214] 3. Drilling holes, extraction holes and first extraction points

[0215] Based on previous surveys, nearby vertical boreholes are drilled to the lower portion of the ore body. The size of the boreholes will be optimized to quickly extract the material while being sized to be economically drilled using available drilling equipment. The anticipated borehole sizes are 12 inches to 60 inches in diameter.

[0216] In this example, drilling will be done vertically to a point at the bottom of the volume to be mined. A second hole may now be drilled and positioned alongside the first hole.

[0217] 4. Create void space

[0218] At this point, as much void space as possible will be created at the portion of the drill hole that intersects the ore body, which will be started by the hole enlarging tool. If the rock is soft, jet blasting or abrasive cutting can be used. The void space needs to be blasted to create "room" for the blast pile. In some cases, multiple sidetracks close to the first hole may be formed, and then explosives placed to enlarge the hole size.

[0219] Typically, in underground blasting, the blast size requires a void space ratio (V r ) to allow rock fragments to move. If a 10m 3 The initial gap (V0) of (10m×1m×1m) is 30m, so the next blasting can break 30m in the first blasting mode. 3 The amount of material that can be blasted grows geometrically with each blast, so that the volume V blasted on the nth blast b =V0(Vr) -n . Obviously maximize the initial void (V0) and void space ratio (V r ) is important for efficient mining operations.

[0220] At this point, one or more vertical holes may be drilled to allow for subsequent rock fracturing to occur. The goal is to intersect the extraction hole at a point that will become the extraction point. Its intersection will be guided using gyroscopic surveys and magnetic ranging tools used in oil well drilling. Vertical drilling is ideal for this function.

[0221] At this point, a smaller borehole can be drilled to allow the water to be pumped out. This can be done with a rocker pump, screw pump, or submersible pump inserted into the well. A vertical borehole is ideal for this function.

[0222] 5. Drill a multi-directional borehole to intersect the extraction borehole.

[0223] The drill holes are then drilled to allow for a multi-directional drill and blast operation. In this case, the drill will be drilled vertically down to the top of the ore body, then curved to follow the top of the ore body and finally descend to near vertical to intersect the extraction drill hole. This is again done using surveying and ranging tools. This allows the measurements to be linked so that the location of the drill holes relative to each other is known with precision.

[0224] The borehole is typically 30 cm in diameter to optimise drilling costs and explosive placement options.The first borehole drilled from the surface may be referred to as the main borehole or mother borehole.

[0225] At any time during the drilling of any borehole, in lieu of conventional drilling, core barrel or continuous coring methods may be used to provide geological information about the ore and rock.

[0226] The borehole is then plugged back to a depth where a multi-directional connection is made to drill a series of blast holes.

[0227] 6. Drilling multi-directional blasting holes

[0228] At this point, a string of steel pipe casing is extended into the hole with a whipstock, window and anchor mechanism at the end. The casing will be designed to have minimal tensile and torsional flexibility. The casing will be positioned using a measuring tool and then clamped into place. The size of the casing will minimize the risk of sticking in the borehole and is typically 25 cm in diameter. A portion of the whipstock can be made of non-magnetic material.

[0229] Since the system will be reused many times for hundreds or thousands of multi-directional blast holes, replaceable wear elements can be used to avoid wear on the casing and drill pipe.

[0230] Using directional drilling tools commonly used in oil and gas drilling, a sidetrack is then drilled by a whipstock and lands near the end of the extraction borehole. This will be positioned in the desired pattern to enable blasting into the void space created by the extraction hole. The blasthole is approximately 2-5m from the extraction borehole.

[0231] During drilling, blast hole cuttings can be analyzed for ore grade.

[0232] The drilling method may include but is not limited to the following drilling technologies: measurement while drilling tools, bending joints and drilling motors, rotary steerable drilling systems, and continuous tubing drilling.

[0233] A gyroscopic survey can be run to accurately locate the hole. Typically, the hole will be drilled vertically because the measurement error is minimal and the closed-loop control system can drill a precise and efficient vertical hole.

[0234] After drilling, the casing will be accurately marked and its position recorded, then moved and rotated as a second divergence or multi-directional drilling. This will be positioned in the desired pattern to enable blasting into the void space created by the extraction hole.

[0235] This process will be repeated until the first blasthole pattern is drilled. Typically, each blast will require 30% of the rock volume to be blasted into void space. Therefore, the first set of blastholes may be small in number; for example, 6 blastholes surrounding 2 extraction holes.

[0236] Typically, in underground blasting, the blast size requires a void space ratio (V r ) to allow rock fragments to move. If a 10m 3 The initial gap (V0) of (10m×1m×1m) is 30m, so the next blasting can break 30m in the first blasting mode. 3 The amount of material that can be blasted grows geometrically with each blast, so that the volume V blasted on the nth blast b =V0(Vr) -n . Obviously maximize the initial void (V0) and void space ratio (V r) is important for efficient mining operations.

[0237] It should be noted that the efficiency of sidetracking, drilling and loading the blastholes is critical to the overall economics of the mining process.

[0238] 7. Loading explosives into the blast hole

[0239] Once all the initial blast holes are drilled, the explosives will be loaded. The casing will be moved to position the window back to the first hole and the explosives will be placed in this hole. This operation is repeated until all holes are filled.

[0240] Referring to Figure 3, explosives, boosters and radio frequency ignited detonators will be loaded into tubular bags, in tubes at the surface for each blast hole. Such radio frequency devices that penetrate rock are available in the mining industry today. The assembly will be lowered into the hole on the drill pipe. It will be lowered into position, then the bag will be released and collapse into position, filling the desired volume of the blast hole. The fluid can circulate to actuate the release and ensure that the explosives have fallen at the correct depth. In some cases, if the blast hole is long, multiple explosive systems can be loaded in each blast hole. Appropriate procedures will be formulated to ensure that the operation is safe. The explosives used are likely to be pre-packaged blast tubes or waterproof emulsion explosives. In some cases, the pre-packaged explosives may have a small enough diameter to be pumped to position via the drill pipe or tube, and then the liquid explosives are pumped to the surrounding position, thereby filling the cross-section of the borehole.

[0241] Plugging materials such as gravel or drill cuttings can be circulated downward or placed in a plug on top of the explosive.

[0242] In this case, if the whipstock is not set correctly, a plug (not shown) can be placed on top of the explosive which prevents the drill bit from re-entering the hole. This may help to gain regulatory approval but is not functionally required.

[0243] Before the explosive is fired, the casing and whipstock may be removed to prevent damage, and a plug may be set to prevent fluid from spraying out of the borehole. Typically, a pump is used to pump out any water from the void space before firing to maximize the effectiveness of the explosive.

[0244] Once the first explosive pattern is loaded, it will be ignited by a series of radio signals from the surface or a transmitter in one of the boreholes. The explosives will ignite in a delay and sequence known to the blasting technician.

[0245] 8. Use cranes to extract blasted rock or "blast piles"

[0246] After the explosives are fired, the material is removed through extraction holes. There are a number of extraction methods and which one is used depends on the depth, rock type and rock fragmentation.

[0247] The key requirement is to ensure that there is free surface and void space at the extraction point so that the blast pile is not subject to confining pressure and can therefore be scooped out or removed without excessive force. This will require the geometry of the extraction point or "extraction" point to be generated using the drill and blast method of this article. Generating extraction points is common in underground mining, however in this case the extraction point must be generated by drilling from the surface.

[0248] For mechanical extraction, in one implementation, this is done with a "bucket" that travels at high speed into the crushed rock or blast pile created by explosives. The bucket will travel on a wire rope and may have a "jolt" or sliding weight that can be used to hammer the bucket.

[0249] In another implementation, the bucket travels within the casing, into which the bucket can be locked at its bottom end. Once locked, the casing can be moved at the surface and apply force to push the bucket into the blast pile, thereby filling the bucket even if the blast pile is hard, compacted, or contains oversized fragments. The bucket is an open-bottomed cylinder with a trap door or jaws that close when lifted full of rock. The bottom edge will be hardened and sharpened to optimize recovery of the broken rock.

[0250] In another method, the bucket is used in a manner similar to a drag line, where the bucket is dragged to the surface of the burst pile to fill it.

[0251] In another method, two boreholes with wire rope loops will extract the material in a continuous bucket loop.

[0252] If the rock fragments are too large to be caught by the bucket hammer, the device can be lowered into one of the drill holes. Additional explosives and / or a drilling assembly can be used to fracture the rock.

[0253] 9. Extract blasted rock using hydraulic jet pumps

[0254] The following describes the construction of an extraction borehole for extracting crushed rock using a hydraulic jet pump. The borehole is used to extract blasted and drilled material from the target ore body. This is an alternative to using the wire rope conveying bucket described previously. This may be more efficient at shallower depths of less than 150m and where the rock is easily broken into small fragments by blasting, and the hydraulics allow it to be pumped to the surface.

[0255] An extraction shaft is drilled from a point at the surface to a point at the bottom of the ore body that is considered most effective for extracting the ore. This shaft is usually of a large diameter that can be drilled economically, e.g. most cost-effective. If surface conditions do not permit, directionally drilling can be used.

[0256] The top of the shaft is slightly larger in diameter and can be capped with a steel casing to prevent loose or weathered rock from falling into the hole during the process. If the rock is unstable, permeable, has karst-like voids or has fractures, it may be necessary to cap the entire borehole to the ore body to prevent fluid loss or collapse of the borehole.

[0257] Where the borehole intersects the ore to be extracted, the hole must be enlarged to the maximum practical diameter to create void space for future blasting operations. Depending on the rock characteristics, reaming tools, water jets and other drilling methods may be used. If a 0.5m borehole is drilled, the section may be enlarged to twice that diameter.

[0258] To further increase the void space, if necessary, a smaller multi-way divergence may be drilled from the top of the ore body at a certain offset from the borehole. The borehole is usually 2-4 borehole diameters from the main borehole. Explosives are inserted into this multi-way and detonated. The diameter of this multi-way may be smaller than the main hole.

[0259] The main hole is then drilled into the crushed rock or "blast pile" produced by the previous blast. The rock fragments are circulated to the surface and the void space around the hole increases.

[0260] The borehole is then ready for extraction using the methods described in "Ore Extraction" after each series of blasting operations.

[0261] The process can be repeated to extract from multiple points with multiple drill holes, or the drill hole can be "sidetracked" or changed in depth to a new location to extract more ore or ores from a different location.

[0262] The extraction process continues until enough material has been extracted for the next blast pattern. Extraction and drilling of new blast holes can be performed simultaneously.

[0263] The methods described here will extract the ore and create void spaces, known in mining as stopes.

[0264] 10. Mining and production precautions

[0265] Additional blast holes will be drilled from the borehole for blasting. If possible, the additional blast holes are located using the same service hole and whipstock / window assembly. The additional blast holes are drilled to break as much as possible while minimizing dilution. Grade control of the drill cuttings can be performed while drilling. Wireline logging tools or surface logging while drilling can be used for grade control. Accurate measurements ensure that the spacing between holes is accurate. As more void space is created in the stope, many blast holes can be drilled, with each pattern becoming larger.

[0266] Typically, each pattern will be located higher up in the ore body, forming stopes which always descend the blast pile to the extraction point created by the extraction drill holes.

[0267] The blast is designed to minimize oversized rock clogging the extraction hole. A high performance explosive with a maximum powder factor will be used. In conventional mining operations, blast loads are limited by safety considerations due to flyrock and vibration. In this case, such considerations are much less restrictive and a much higher powder factor can be used to give the largest fragments. Smaller fragments can improve mineral recovery and reduce subsequent grinding costs and are generally considered advantageous in the mining process.

[0268] After a period of time, the boreholes used to drill the multi-directional boreholes may need to be plugged and sidetracked to a new location. In some cases, any one of the boreholes may collapse and need to be re-drilled.

[0269] The ultimate size of the stope of the void space created may be limited by rock mechanics. In this case, the rock pillars may remain intact to support the stope. In other cases, block caving may be desired and collapse of the overburden to crush the ore and extract the ore is possible. In some cases, the method may provide intervention for underground mine block caving operations that fail to achieve the desired caving performance.

[0270] The drilling and blasting process will continue, using the same boreholes and stopes / void spaces wherever possible for cost-effectiveness. In some cases, stopes may be abandoned and new stopes created to allow tailings to be injected into the void spaces, thereby reducing tailings storage at the surface.

[0271] In order to enable the same extraction point to be used for multiple stopes, sequencing involving the injection of tailings with cement can be used. In one implementation, first, fine fill material is injected into the hole for extraction. Then, a portion of the fill with added cement is poured into the stope through the blast hole. This forms a plug, and subsequently, unsolidified material can fill the rest of the stope. The unsolidified material around the extraction hole is then removed by drill pipe circulation, and a new stope can be started from the same extraction point, with the solidified portion holding the tailings material in place.

[0272] 11. Multi-directional blast hole drilling and positioning

[0273] A method is described in this section with reference to other methods that may be disclosed in the accompanying figures and claimed as alternative methods.

[0274] The measured positioning accuracy of a borehole is most accurate when the borehole is precisely vertical. Long deviated holes can be drilled, but the positioning accuracy decreases with horizontal deviation.

[0275] In one representation, a second borehole is drilled which will be the main borehole for a series of multi-directional blast holes and then drilled into the ore body. This will be described, but if regulations allow, it can be multiple boreholes or reuse the same main borehole as the extraction borehole.

[0276] Multi-directional blast holes are drilled from the surface, and then directionally drilled a distance from the ore body to be blasted so that the main hole is not affected by the blasting, and the curved section of the borehole can be drilled so that the blast hole penetrates the ore body in parallel.

[0277] Several bifurcations may be drilled from the borehole, however here we consider a single bifurcation. Additional bifurcations may be drilled and then each abandoned with plugs, cement or conventional open hole whipstock. In this way, the cost of drilling from the surface is incurred only once for a large stope being created.

[0278] In one embodiment, a removable and reusable multi-directional whipstock assembly is used to drill each blast hole. This is described in more detail in the accompanying drawings on a removable casing multi-purpose multi-directional whipstock device and a drilling rig.

[0279] Glossary: ​​Below is a list of technical terms used in oilfield technology and mining.

[0280] Oilfield terminology uses the term wellbore and the term borehole interchangeably.

[0281] Blast hole – A drilled hole in a mine that is eventually filled with explosives to blast and release large quantities of rock.

[0282] Geophysical Surveying - A scientific method of exploration that measures the physical properties of rock formations. Common properties studied include magnetism, specific gravity, electrical conductivity, and radioactivity.

[0283] Stope – Any excavation carried out in a mine to extract ore, other than development work. The contours of the ore body determine the contours of the stope.

[0284] Heap – Ore or rock broken apart by blasting.

[0285] Explosion pile - a pile after an explosion.

[0286] Ore - A mixture of ore minerals and gangue from which at least one metal may be profitably extracted.

[0287] Tailings – The waste material left after the target mineral is extracted from the ore. Tailings consist of crushed rock, water, and residual materials used in ore separation.

[0288] Wireless Detonator - A device that initiates explosive material without any wires or fuses connected to it. Usually a radio frequency device, such as the ORICA "webgen" device

[0289] Wellbore and borehole are used interchangeably to refer to a hole drilled using a rotary drilling assembly.

[0290] In this context, bucket is used to describe the cylindrical container used to recover ore from underground blast piles to the surface.

[0291] The multidirectional definition considered in this patent is a borehole where multiple boreholes branch off from a main borehole at a certain point in the ground. There may be multiple secondary branches from one main borehole, with additional branches subsequently drilled from each of these secondary boreholes.

[0292] Geo-Steering / Geo-Steering. The use of formation data generated by a measurement-while-drilling system to assist in drilling a wellbore to a specific target in the formation.

[0293] Drilling FluidsDrilling Mud.The drilling fluid system—often called the "mud system"—is the single part of the well construction process that remains in contact with the wellbore throughout the drilling operation.

[0294] MWD, The term MWD refers to measurements made downhole using electromechanical equipment located in the bottom hole assembly (BHA).

[0295] Directional Drilling,Directional drilling is defined as the practice of controlling the direction and deviation of a wellbore to a predetermined subsurface target or location.

[0296] Whipstock, a stiff steel ramp along which the mill turns as it cuts a hole in the side of the casing to begin sidetracking or lateral drilling of the wellbore.

[0297] A window is an exit point lateral from the parent hole, usually a hole cut in the side of the borehole to allow side drilling of the well.

[0298] The method used to obtain the measurements needed to calculate and plot the 3D wellbore path is called directional surveying.

[0299] Logging While Drilling, Logging While Drilling (LWD) refers to the addition of wireline quality formation measurements to the directional data of the Measurement While Drilling (MWD) service.

[0300] Wireline logging involves any aspect of logging that is related to using a cable to lower a tool into a borehole and transmit data. Wireline logging is different from measurement while drilling (MWD) and mud logging.

[0301] According to the principles and example embodiments described and shown herein, it will be appreciated that the example embodiments can be modified in arrangement and detail without departing from such principles. The foregoing discussion focuses on specific embodiments, but other configurations can also be envisioned. In particular, even if expressions such as "embodiments" are used herein, these phrases are intended to refer to the possibility of embodiments in general, and are not intended to limit the present invention to specific embodiment configurations. As used herein, these terms may refer to the same or different embodiments that can be combined into other embodiments. Generally, unless otherwise stated, any embodiment cited herein can be freely combined with any one or more other embodiments cited herein, and any number of features of different embodiments can be combined with each other. Although only a few examples are described in detail above, it is readily understood by those skilled in the art that many modifications are possible within the scope of the described examples. Therefore, all such modifications are intended to be included within the scope of the present invention as defined in the appended claims.

Claims

1. A method for underground mining in a rock mass, comprising: drilling one or more service holes from at least one surface location into the subsurface rock mass; drilling a plurality of multi-directional blast holes branching from at least one of the one or more service holes into the subsurface rock mass using a rotary directional drilling apparatus extending from the surface; loading a plurality of multi-directional blast holes with one or more explosives and one or more detonators using a drilling assembly extending from the surface, inserting the one or more explosives and one or more detonators from the surface; wirelessly detonating one or more explosives to fragment underground rock mass; as well as The crushed rock is extracted to the surface via one or more service holes.

2. The method of claim 1 wherein after extracting a volume of the fractured rock, a fluid is flowed through the fractured rock remaining in the subsurface to extract soluble or finely fractured components of the remaining rock.

3. The method of claim 1 , wherein at least a portion of the one or more service holes are drilled to intersect in or near an area in the subsurface rock mass to be extracted, the intersection of at least a portion of the one or more service holes being used as a position reference for other drilling operations.

4. The method of claim 1, wherein at least one service hole is drilled relative to another borehole using magnetic ranging or electromagnetic ranging.

5. The method of claim 1, wherein one or more of the plurality of multi-directional blast holes are guided relative to measured geophysical properties of the subsurface rock mass using sensors disposed on the drilling assembly to optimize the location of one or more of the plurality of multi-directional blast holes.

6. The method of claim 1 further comprising injecting tailings from the surface into the void space created after extracting the volume of crushed rock.

7. The method of claim 1, wherein the crushed rock is extracted via one or more service holes using a winch conveying apparatus to recover the crushed rock from the underground blast pile and move the crushed rock to the surface.

8. The method of claim 7, wherein at least two service holes are drilled to intersect the lowest point of the blast pile, and wherein the winch conveying apparatus includes a bottom portion having a one-way mechanism allowing the crushed rock to be collected as it enters the blast pile.

9. The method of claim 8 wherein the winch conveying apparatus utilizes mass and wire rope to collect material by a downward hammering action or vibration.

10. The method of claim 1, wherein the one or more service holes include a first extraction borehole, inside which a container is deployed to extract the crushed rock, the container being deployed on a winch, and the one or more service holes include at least a second extraction borehole drilled to intersect the first extraction borehole from a stope containing the crushed rock, wherein gravity delivers the crushed rock into the second extraction borehole, wherein the container disposed in the second extraction borehole lifts the crushed rock to the surface.

11. A method according to claim 10, wherein movement of the crushed rock is controlled via a drill pipe or drill rod inserted into a second extraction borehole operated from the surface, whereby the drill pipe or drill rod acting within the second borehole reduces the fragment size of the crushed ore.

12. The method of claim 1, wherein the fractured rock is broken into smaller fragments by mechanical action of a drill pipe or wireline conveying equipment, or by inserting an explosive device into at least one of one or more service holes drilled through the subsurface rock mass, to allow the smaller fragments to be extracted to the surface via at least one of the one or more service holes.

13. The method of claim 1, wherein the crushed rock is extracted using a jet pump fed by concentric or parallel piping in at least one of the one or more service holes.

14. The method of claim 1, wherein a plurality of multi-directional blast holes are drilled using a whipstock apparatus located within a pipe configured to move along and rotate within a service hole; the openings in the pipe facilitating subsequent multi-directional branching of blast holes directionally drilled from the service hole.

15. The method of claim 14, wherein the pipe is moved to a starting position and orientation for drilling each of the plurality of blasthole multi-directional branches, and then after each of the plurality of multi-directional blastholes is drilled from each of the blasthole multi-directional branches, the pipe is returned to each starting position and orientation to facilitate loading of explosives into each of the plurality of multi-directional blastholes.

16. The method of claim 1, wherein the plurality of multi-directional blast holes are drilled using an apparatus comprising: a pipe inserted into at least one of the one or more service holes, the pipe anchored in place, the pipe including a plurality of pre-cut windows to facilitate drilling of multi-directional blast holes; a plurality of positioning devices to allow the whipstock to be installed and locked in a desired position by a respective one of the plurality of positioning devices to drill a set of multi-directional blast holes; and a mechanism for releasing the whipstock to allow the next in a series of multi-directional blast holes to be drilled.

17. The method of claim 1, wherein one or more explosives are loaded into at least one of a plurality of multi-directional blast holes using an outer tube having a diameter smaller than the multi-directional blast hole bifurcations and a flexible inner sleeve having a diameter expandable to fill the multi-directional blast hole bifurcations, the flexible inner sleeve being inserted inside the outer tube, the inner sleeve being filled with explosives, boosters and detonators, the outer tube and the flexible inner sleeve being advanced into the multi-directional blast hole bifurcations on the pipeline; a release mechanism is triggered to place the explosives at a desired location, and the flexible inner sleeve is released inside the multi-directional blast hole bifurcations, and the outer tube is removed, leaving the explosives to expand in the flexible inner sleeve to effectively fill the entire diameter of the multi-directional blast hole bifurcations.

18. The method of claim 1, wherein one or more detonators are activated with a radio frequency signal having a specific identifier and fire code.

19. A method of underground mining in rock comprising: drilling one or more service holes from a surface location into the subsurface rock mass; drilling a plurality of multi-directional blast holes branching from one of the one or more service holes using a rotary directional drilling assembly extending from the surface; loading one or more of the multi-directional blast holes with one or more explosives and one or more detonators, and inserting the one or more explosives and one or more detonators from the surface; wirelessly detonating one or more explosives to fragment underground rock mass; as well as Crushed rock is extracted through existing mines.

20. The method of claim 19, wherein the plurality of multi-directional blast holes are drilled using a whipstock located within a tubing configured to move along and rotate within a service hole, the openings in the tubing facilitating directional drilling of subsequent blast holes multi-directionally diverging from the service hole.

21. The method of claim 20, wherein the pipe is moved to a starting position and orientation for drilling each of a plurality of blasthole multi-directional branches, the method further comprising drilling a set of multi-directional blastholes from each of the plurality of blasthole multi-directional branches, wherein after drilling a set of multi-directional blastholes from each blasthole multi-directional branch, the pipe is then returned to the starting position and orientation to facilitate loading of explosives into each of the set of multi-directional blastholes drilled from each blasthole multi-directional branch.

22. The method of claim 19, wherein the plurality of multi-directional blast holes are drilled using an apparatus comprising: A pipe is inserted into one of the one or more service holes, the pipe is anchored at an appropriate position in one of the one or more service holes, the pipe includes a plurality of pre-cut windows to facilitate drilling of multi-directional blast holes, the pipe includes a plurality of positioning devices to allow a whipstock to be installed and locked in a desired position by corresponding positioning devices to drill a group of multi-directional blast holes, and the pipe includes a mechanism for releasing the whipstock to allow the next one in the group of multi-directional blast holes to be drilled.

23. The method of claim 19, wherein one or more explosives are loaded into at least one of a plurality of multi-directional blast holes using an outer tube having a diameter smaller than the multi-directional blast hole bifurcations and a flexible inner sleeve having a diameter expandable to fill the multi-directional blast hole bifurcations, the flexible inner sleeve being inserted inside the outer tube, the flexible inner sleeve being filled with explosives, boosters and detonators, the outer tube and the flexible inner sleeve being advanced into the multi-directional blast hole bifurcations on the service pipe, the method further comprising triggering a mechanism to release to place the explosives at a desired location, the flexible inner sleeve being released and expanded inside the multi-directional blast hole bifurcations, the outer sleeve being removed, leaving the explosives to expand in the released flexible inner sleeve to fill the diameter of the multi-directional blast hole bifurcations.

24. The method of claim 19, wherein at least one of the one or more detonators is activated with a radio frequency signal having a specific identifier and fire code.

25. A method of underground mining in rock comprising: drilling one or more service holes from a surface location into the subsurface rock mass; drilling a plurality of underground multi-directional blast holes into the rock mass using a rotary directional drilling assembly extending from the surface, the plurality of underground multi-directional blast holes branching from at least one of the one or more service holes; loading an underground multi-directional blast hole with one or more explosives and one or more detonators, and inserting one or more explosives and one or more detonators from the surface; wirelessly detonating one or more explosives to fragment underground rock mass; as well as Fluid is passed through a fractured subsurface rock mass to extract soluble or finely fractured components of the fractured subsurface rock mass.

26. The method of claim 25, wherein a plurality of underground multi-directional blast holes are drilled using a whipstock located within a pipe configured to move along and rotate within a service hole; and wherein the openings in the pipe facilitate multi-directional branching of blast holes directionally drilled from the service hole.

27. The method of claim 26, wherein the pipe is moved to a starting position and orientation within a service hole for drilling each of the plurality of blasthole multi-directional branches, and after drilling each of the plurality of multi-directional blastholes, the pipe is returned to each starting position and orientation to facilitate loading of explosives into each of the plurality of multi-directional blastholes drilled from each blasthole multi-directional branch.

28. The method of claim 25, wherein the plurality of multi-directional blast holes are drilled using an apparatus comprising: A pipe inserted into at least one of the one or more service holes and anchored in an appropriate position in the at least one service hole, the pipe including a plurality of pre-cut windows to facilitate drilling one or more of a plurality of underground multi-directional blast holes, the pipe including a plurality of positioning devices to allow a whipstock to be installed and locked in a desired position in the at least one service hole by a corresponding positioning device to drill a group of a plurality of underground multi-directional blast holes, and the pipe including a mechanism for releasing the whipstock to allow the next in a series of multi-directional blast holes to be drilled.

29. The method of claim 25, wherein one or more explosives are loaded into at least one of a plurality of underground multi-directional blasting holes using an outer tube having a diameter smaller than the diameter of the multi-directional blasting hole bifurcation and a flexible inner sleeve having a diameter that can expand to fill the multi-directional blasting hole bifurcation, the flexible inner sleeve being inserted into the interior of the outer tube, the flexible inner sleeve being filled with explosives, boosters and detonators, the outer tube and the inner sleeve being advanced into the multi-directional blasting hole bifurcation on the conveying pipeline; a release mechanism is triggered to place the explosives at a desired location, the flexible inner sleeve is released and expands inside the multi-directional blasting hole bifurcation, the outer sleeve is removed, and the explosives are left to expand in the flexible inner sleeve to fill the diameter of the multi-directional blasting hole bifurcation.

30. The method of claim 25, wherein one or more detonators are activated using a radio frequency signal having a specific identifier and fire code.

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