Apparatus and method for fracturing a hard material

Abstract

Apparatus 10 for fracturing a hard material 24 includes a loading head 12 provided with a guide tube 14 for receiving a cartridge 16 containing a charge of energetic material. A flexible elongated conduit 26 is advanced and retracted through the tube 14 via a reel 88. The conduit 26 is also in communication with a stemming loader 30 which holds a supply of particulate stemming material. Tube 14 is supported by a carriage 70 which is able to slide along a member 52 by operation of a rod 76 and cylinder 78. A motor 60 is also coupled to the member 52 to effect rotation of the member 52 and thus tube 14 about an axis A which is parallel to a hole 18 drilled in the material 24. By appropriate operation of the motor 60 and rod 76, the tube 14 can be moved into and out of alignment with the hole 18. When the tube 14 is moved into alignment with the hole 18, cartridge 16 is loaded into the tube 14 and pushed through the tube 14 into the hole 18 by advancing the conduit 26. Particulate stemming material from the loader 30 is then injected through the conduit 26 into the hole 18. Tube 14 and conduit 26 are then retracted from the hole 18 and subsequently moved out of alignment therewith. The cartridge 16 may then be initiated to cause fracturing of the material 24.

The claims defining the invention are as follows:  
     
         1 . An apparatus for fracturing a hard material, said apparatus including at least: 
 a loading head provided with a guide for receiving a cartridge containing a charge of energetic material, and guiding said cartridge into a hole formed in a face of a hard material to be fractured;    a system for advancing said cartridge along said guide to a toe of said hole; and,    a stemming loader for loading a particulate stemming material into said hole through said guide.    
     
     
         2 . The apparatus according to  claim 1  wherein said system for advancing said cartridge includes a flexible elongated member having a first end which abuts an end of said cartridge distant said hole, and a device for advancing and retracting said flexible elongated member.  
     
     
         3 . The apparatus according to  claim 2  wherein said flexible elongated member is a conduit and constitutes a part of said stemming loader, said stemming loader further including a stemming injector for injecting particulate stemming material into a second end of said conduit.  
     
     
         4 . The apparatus according to  claim 3  wherein said stemming injector includes a blower for blowing said particulate stemming material into and along said conduit.  
     
     
         5 . The apparatus according to  claim 1  further including an alignment mechanism for moving said guide into and out of alignment with said hole.  
     
     
         6 . The apparatus according to  claim 5  wherein said alignment mechanism rotates said loading head about an axis parallel to an axis of said hole, to move the guide into and out of alignment with said hole.  
     
     
         7 . The apparatus according to  claim 5  wherein said alignment mechanism slides said loading head along an axis perpendicular to an axis of said hole, to move the guide into and out of alignment with said hole.  
     
     
         8 . The apparatus according to  claim 5  further including a drilling system for drilling said hole, said drilling system including a rail and a drill slidably mounted on said rail, wherein said alignment mechanism is supported on said rail.  
     
     
         9 . The apparatus according to  claim 1  wherein said loading head includes a stemming bar which can be moved into and out of alignment of said hole for insertion into said hole to support said particulate stemming.  
     
     
         10 . The apparatus according to  claim 9  wherein said stemming bar includes a transmitter for transmitting a signal into said hole for operating an initiator or a detonator contained in said cartridge.  
     
     
         11 . A method of fracturing a hard material, said method including the steps of: 
 providing a guide for receiving a cartridge containing a charge of energetic material;    aligning said guide with a hole formed in a face of a hard material;    inserting the cartridge into said guide;    advancing said cartridge along said guide into said hole;    injecting particulate stemming material through said guide into said hole; and,    initiating said energetic material.    
     
     
         12 . The method according to  claim 11  including the step of advancing said guide into abutment with said face of said hard material.  
     
     
         13 . The method according to  claim 11  wherein said step of advancing said cartridge includes pushing said cartridge along said guide.  
     
     
         14 . The method according to  claim 13  wherein said step of pushing includes advancing a length of a flexible elongated member into said guide to push said cartridge along said guide into said hole.  
     
     
         15 . The method according to  claim 14  wherein said step of injecting particulate material includes forming said flexible elongated member as a conduit and blowing said particulate stemming material through said conduit into said hole.  
     
     
         16 . The method according to  claim 15  including a step of retracting said conduit from said hole as said particulate material is blown into said hole.  
     
     
         17 . The method according to  claim 11  including a step of attaching said guide to a drilling system which includes a rail and a drill mounted on said rail and supporting said guide on said rail.  
     
     
         18 . The method according to  claim 11  including the step of providing an alignment mechanism for moving said guide into and out of alignment with said hole.  
     
     
         19 . The method according to  claim 18  including a step of providing a stemming bar coupled to said alignment mechanism, moving said guide out of alignment with said hole; and moving said stemming bar into alignment with said hole and into abutment with said particulate stemming in said hole.