Hydraulic Mining System for Tabular Orebodies Utilising Directional Drilling

Abstract

A mining system for extracting ore using directional chilling techniques to obtain access to the orebody. Spaced-apart roadways are formed in the ore formation, with a downhill roadway being lower in elevation than the other roadway, and the downhill roadway having a ditch therein draining downhill. A borehole is formed between roadways in the ore formation using the directional drill bit, and then the end of the drill string is equipped with a jetting nozzle. The jetting nozzle is moved within the borehole to erode the formation and mine the ore. In one embodiment, a slurry of mined ore and jetting fluid flows as a slurry down the intersection of the mined face and the floor towards a ditch formed in the downhill roadway. In another embodiment, a slurry of the mined ore and the jetting fluid flows down the borehole, and then down the ditch formed in the downhill roadway. In each case, the ore flows down the downhill roadway to a sump. From the sump, the ore is carried to the surface for transportation and eventual refining or use.

1 . A method of mining ore from a formation, comprising:
 forming an underground upper roadway and an underground lower roadway in said formation to define an ore panel therebetween;   forming said lower roadway at an elevation generally below said upper roadway, and sloping the lower roadway downhill;   locating borehole drilling equipment underground in one of said upper roadway or said lower roadway;   forming a sloping borehole with a drill string connected to said drilling equipment, said sloping borehole formed from one said roadway to the other roadway and through the ore panel to be mined, and moving the drilling equipment in the roadway each time a different sloping borehole is formed;   using a jetting nozzle attached to the end of the drill string to produce a high pressure jet of a liquid;   moving the jetting nozzle through said borehole to erode the ore panel, where the pressurized liquid forms a slurry with the mined ore; and   allowing the slurry of mined ore and liquid to flow down the lower roadway to a sump.   
     
     
         2 . The method of mining ore as described in  claim 1 , further including forming a face in the ore panel by the erosion process, and forming a floor as the face of the ore panel recedes during the erosion process, and forming the floor with the solid panel of ore on one side, and a goaf on the other side. 
     
     
         3 . The method of mining ore as described in  claim 1 , further including creating a series of enlarged holes from whence ore is removed, with pillars of the ore panel standing therebetween. 
     
     
         4 . The method of mining as described in  claim 1 , further including sloping the upper and lower roadways and forming ditches therein for the conveyance of the slurry of mined ore to the sump. 
     
     
         5 . The method of mining as described in  claim 1 , further including drilling the bore hole from the upper roadway through the ore panel to the lower roadway;
 connecting the lateral jetting nozzle to the drill string at the lower roadway;   using the drill string to move the jetting nozzle uphill toward the upper roadway, and controllably rotate the jetting bit so that an enlarged hole or face is formed in the ore panel by the jet of high pressure liquid; and   producing an ore bearing slurry by the erosion, and transporting the ore bearing slurry down the enlarged hole of the mining face created by the erosive process, to the lower roadway.   
     
     
         6 . The method of mining as described in  claim 1 , further including drilling the borehole from the lower roadway through the ore panel to the upper roadway;
 attaching a reaming system to the drill string at the upper roadway;   reaming the borehole to a larger diameter;   attaching a lateral jetting bit to the drill string; and   using the jetting bit to erode the ore panel, starting at the upper level of the borehole, where the eroded ore then flows as a slurry back down the enlarged borehole to the lower roadway.   
     
     
         7 . The method of mining as described in  claim 1 , further including using a directional bottom hole assembly attached to the drill string to enable the drilling of a directionally controlled borehole in the ore panel. 
     
     
         8 . The method of mining as described in  claim 1 , further including moving the jetting nozzle through the borehole to erode a sidewall thereof and form a face of the ore panel, and then continuing the movement of the jetting nozzle laterally across the face of the ore panel to mine the ore of the formation. 
     
     
         9 . The method of mining as described in  claim 1 , further including moving the drill string into a different borehole to mine a new slice of the ore panel. 
     
     
         10 . The method of mining as described in  claim 1 , further including forming a pillar adjacent to one said upper or lower roadway to protect the roadway from collapsing, and forming said pillar by leaving the panel intact at the location of the pillar. 
     
     
         11 . The method of mining as described in  claim 6 , further including eroding a face in the ore panel to form a shape to induce backflow of the slurry toward the borehole to mine the ore panel. 
     
     
         12 . The method of mining as described in  claim 6 , further including forming the borehole at an angle with respect to a horizontal reference so that the slurry is carried downhill by the borehole. 
     
     
         13 . The method of mining as described in  claim 1 , further including using the jetting nozzle that produces a narrow jet of high pressure liquid oriented generally in plane perpendicular to the drill string so as to permit erosion of the ore panel. 
     
     
         14 . The method of mining as described in  claim 1 , further including forming a goaf at locations where the mined ore is removed from the ore panel. 
     
     
         15 . The method of mining as described in  claim 2 , further including mining the ore panel by sweeping a high pressure liquid jet across the face of the ore panel to mine the face of the ore panel and cause the ore panel face to recede and form the sloping floor, and allow the ore bearing slurry to flow down the sloping floor along the solid ore panel of ore, away from the goaf and toward the lower roadway. 
     
     
         16 . The method of mining as described in  claim 1 , further including using a visual survey system at a mining location where the ore panel is eroded by the jetting nozzle to provide a remote video representation of the operation. 
     
     
         17 . The method of mining as described in  claim 1 , further including using an acoustic or other survey system at a mining location where the ore panel is eroded by the jetting nozzle to provide a remote representation of the operation. 
     
     
         18 . The method of mining as described in  claim 1 , further including using a survey system to provide an operator with knowledge of the orientation of the jetting nozzle. 
     
     
         19 . The method of mining ore as describe in  claim 1 , further including moving the drilling equipment downhill in one said upper or lower roadway each time mining of a slice of an ore panel has been completed. 
     
     
         20 . The method of mining ore as described in  claim 1 , further including forming a lateral roadway perpendicular to both said upper roadway and said lower roadway, said lateral roadway sloping downhill from said upper roadway to said lower roadway so that a slurry of mined ore from an ore panel located above said upper roadway can flow down said lateral roadway to said lower roadway and then to said sump. 
     
     
         21 . The method of mining ore as described in  claim 1 , further including sweeping the jetting nozzle about an arc from a floor of the formation to a roof of the formation, and moving the jetting nozzle axially along said borehole to cause a face of the ore panel to recede in the direction of movement of the jetting nozzle, and allowing the slurry to flow downhill on the floor toward the borehole and then perpendicular downhill to the lower sloping roadway. 
     
     
         22 . The method of mining ore as described in  claim 21 , further including moving the jetting nozzle downhill from one borehole to a subsequent borehole to mine subsequent slices of said ore panel. 
     
     
         23 . A method of mining ore from a formation, comprising:
 defining plural panels of ore to be mined in said formation;   forming an underground upper roadway and an underground lower roadway in said ore panel;   forming said lower roadway at an elevation lower than said upper roadway, and sloping said lower roadway downhill;   locating borehole drilling equipment underground in one of said roadways;   forming a sequence of adjacent sloping boreholes with a drill string and drill bit connected to said drilling equipment from one roadway to the other roadway and through an area of the ore panel to be mined, and moving the drilling equipment in the roadway each time a sloping borehole is formed;   using a jetting nozzle attached to the end of the drill string to produce a high pressure jet of a liquid;   moving the jetting nozzle axially through each borehole to erode a slice of the ore panel between boreholes, and eroding the ore panel with the pressurized liquid to form a slurry of the mined ore, the eroding of the ore panel forming a sloped junction where a face of the unmined ore panel joins a floor formed by the mined ore panel; and   allowing the slurry of the mined ore and liquid to flow down the sloped junction to the downhill sloping lower roadway, and then to a sump.