HOW IT WORKS?
Blast drilling is carried out to give access to blasting materials that can be used to fragment the rocks, this enabling the removable of the material either as waste or as ore to go through the crushing plant.
|Application||Used to allow the blasting chemicals to be placed for blasting the rock, either for access or stope..|
|Quality||Important to keep alignment and depth control|
|Drilling speed||Slow rotation speed 10 to 30 RPM, capable of between 10 — 30 M/hr|
|Hole depth||Very dependant on the stope design and the method of extraction, for access these asre usually between 3 -6mts|
|Hole size||Usually between 2” and 4” Diameter|
|Flexibility||The flexibility is mostly around the ability to work in confined areas and be able to manoeuvre safely.|
|Cost||Cost varies depending on rock hardness and the ability and cost of running the equipment.|
|Time||Usually these rigs have a high production rate, usually giving an average of 100 metres per shift.|
|Technique||This very much depends on the mine design, does it have the access for a complete rig on tracks, or do they havre to use man portable.|
|Challenges||To be able to discuss with the mine operators on best methodology for their mine before they commit to an antiquated system.|
|Products & Solutions|
Blast hole drilling is so called because it is used to drill holes for blasting, the system should be fully capable of recording the drilling parameters. The rig uses either a Down Hole Hammer or Top Hammer Rotation unit, this depending on the rig ability and the rock strength.
Using the Down Hole Hammer with a fully moving rig system, the tool is always on the rotation unit, normally with a shorter drill pipe. To set up the drill rig requires instrumentation to give the angle (if required) and direction of the hole, once set up drilling commences with proper dust controls in place, usually water is used with the air to kill the dust
As the hole progresses, drill pipe from the carrousel (or similar device) are added until hole depth is achieved. Or if using Man Portable equipment, the pipe are added by personnel.