International Mining | AUGUST 2019 sting Dan Gleeson looks at innovations in the explosives and blasting sector with one eye on automation and wireless detonation procedures EXPLOSIVES BLASTING FRAGTrack is designed to improve productivity and optimise drill and blast through the integration of fragmentation data into the drill
Drilling Blasting of Underground Stopes Generally speaking long flat breast holes will break more ground per foot of hole and per pound of explosive used than vertical holes because they have a free underface to break to also they will not scatter the broken ore as much as vertical holes
Dec 21 2015Blasting is also used to remove pockets of unwanted material that are preventing mining machines and personnel to get to the seam containing the materials of interest Unmanned drill rigs will drill holes at pre-determined depths and positions on a blast face to ensure that a particular size fraction is achieved and that little of the overburden is liberated with the blasting to reduce material handling
This mode of blasting is often termed "stand-up" blasting The blast patterns used in blasting the coal are smaller with smaller diameter holes generally being used Hole diameters for coal blasting may range from 127 - 254 mm (5 - 10 inch) Often a separate dedicated drill rig is used for coal blasting
The holes are drilled in a pre-mapped order at the locations and depths loaded into the system The drill is precisely guided to the proper hole coordinates for accurate hole location Upon reaching the desired depth it retracts the drill string then jacks and propels to the next hole
Mining - Mining - Blasthole stoping When the dip of a deposit is steep (greater than about 55) ore and waste strong ore boundaries regular and the deposit relatively thick a system called blasthole stoping is used A drift is driven along the bottom of the ore body and this is eventually enlarged into the shape of a trough At the end of the trough a raise is driven to the drilling
The realities and facts of hot hole blasting in coal mines With the monitoring tip now in position Blast Eye can be activated by pulling out the detatchable tab The unit is now on guard At 60C Blast Eye will sound a discontinuous alarm which immediately alerts bench personnel that a once safe hole is now hot
As the name suggests drilling and blasting works as follows A number of holes are drilled into the rock which are then filled with explosives Detonating the explosive causes the rock to collapse Rubble is removed and the new tunnel surface is reinforced Repeating these steps until desired
Blast technician Andy Riutta measures a hole in the blast pattern in the main pit of Cortez Hills Two drills square off a blast pattern at Cortez Hills Blast technician Andy Riutta tosses part of an explosive device near a hole as he makes the rounds to each of the shot holes on a blast pattern at Cortez Hills
Stemming is a material that is put inside of a blast hole to help prevent gases from escaping While stemming is typically put in the top of a blast hole it can also be used to help bridge mud seams or weak layers Improperly placed stemming can greater decrease fragmentation size
RESPEC's explosives engineering division specializes in solving critical drilling-and-blasting issues safely and effectively The team combines their advanced knowledge of drilling and blasting with experience in mine planning and operations to provide a unique turnkey approach to improving drilling-and-blasting operations with a focus on improving overall mining unit costs
Blasthole Drilling is a drilling technique whereby a hole is drilled in the rock surface up to certain depth and then explosives are loaded to induce cracks on the hard surface of the inner geology formation for further deep drilling This hole which is meant for loading explosives is known as a blasthole
Backbreak – Rock broken beyond the limits of the last row of holes in a blast synonymous with overbreak Base Charge – The main explosive charge in the base of a detonator or a heavy charge at the base of a column of presplit powder Battered Production Holes – The row of production holes closest to presplit line drilled at the
In opencast mining where blasting is employed for excavation the overall cost effectiveness of the production operations is compatible with optimization of drilling and blasting parameters Rock fragmentation depends upon two groups of variables rock mass properties which cannot be controlled and drill-and-blast design parameters that can be controlled and optimized
blasting agents used in large-scale surface mine blasting do not detonate properly in boreholes of 1-inch diameter or less (ISEE 1998) If the blasting agent is diluted by mixing with drill cuttings at the top or bottom of the borehole it may not detonate properly and excessive quantities of toxic fumes may be produced (Sapko 2002)
The Underground Stemming products were designed as simple effective and easy to use products to give greater control over underground blasting operations Jeff holds a number of patents and patent applications on the designs Jeff is a member of the Australian Institute of
Transverse longhole stoping typically utilizes In-The-Hole (ITH) or top-hammer drills capable of creating holes of 75mm-200mm diameter (3-8 inches) Drilling is generally carried out from the top sill in a ring drilling or parallel drilling pattern drilling towards the bottom sill access
Blast Hole Casings Request a Quote Custom made blast casings with no minimum order size makes Yazoo the clear choice for mining and blasting contractors Water Guard Blast Hole Casings from Yazoo Mills In the blasting and mining industries time is never on anyone's side The jobs are plentiful and need done as quickly as possible
(2) In seismic blasting the blaster of record must ensure that each electric blasting circuit is tested after the blast hole is loaded with explosives and before a plug is placed into the hole (3) If the electric blasting circuit is equipped with an electric detonator or electric igniter the
EXCAVATOR MOUNTED BLAST HOLE DRILL is a versatile hydraulic drill rig mounted on a TATA EX 200 LC Excavator (or equivalent) with onboard compressor suitable for blast hole drilling in mines can be easily accessible to drill on bench as well as below the ground level construction works canal works and solar projects
Blast Hole Charging Underground mining involves four basic stages drilling blast holes pumping explosives into these holes (charging) blasting and removing the broken rock (mucking) Blast hole charging involves the placement of a primer-detonator assembly at the end of a flexible hose and inserting the hose into a blast hole
Blasting aCCessories Blasting Switch Blasting Switch (Complete) Incorporates all essential safety features required when firing from power lines The box is painted red to be clearly seen is lockable to prevent tampering and is durable to with stand the underground environment item number UP002294 Blasting Switch Repair Kit
With mining reserves trending to lower grades the need for accurate precise and representative sampling of exploration drilling and production blast holes has become more critical It has not been too long ago where mines sampled every 5th or so holes and assayed those samples
Auger Mining Equipment 33 Blasting 123 Borehole Survey Equipment 22 Core Drills 19 Core Splitters Saws 10 Diamond Drilling 68 Directional Drilling Equipment 23 Drilling Equipment 633 Mud Rotary Drilling 6 Production Drilling 20 Raiseboring 8 Roof Bolters 8 Roof Scalers 2
The Southern African Institute of Mining and Metallurgy 6th Southern African Base Metals Conference 2011 R Hawker and D O'Connor Page 323 KEEPING OPEN OF UNDERGROUND BLAST HOLES R Hawker Minova Australia D O'Connor Minova RSA Abstract Underground mining of base metals like copper often uses massive mining methods such as sublevel open stoping
Jul 19 2010Place sandbags tightly around the hole A good blast will just crack the rock Too much charge or placing the hole too near a rock face will result in 'air burst' where rock flies into the air This is dangerous and wasteful Too little charge or placing the hole too far away from a rock face will result in almost no rock breakage
blast has to be separately cleaned on the surface after excavation of the previous blast Hole locations then have to be individually surveyed and marked holes drilled explosives and initiators loaded and the blast fired Each of these actions takes considerable time A new mining method
For 30 years our Group has been supplying high quality ceramic clays to both domestic and International markets The Smart Stem was developed in reponse to the Mining Industry's need for a safe effective and simple blast hole stemming solution Chat Online What is Blasthole Drilling? -
In normal blasting all holes do not blast at the same time Bench blasting is normally carried out as short delay blasting The firing pattern has to be designed so that each blasthole has free breakage The firing sequence of a chevron pattern can radically alter the drilled burden and spacing into the blasted or effective burden (Be)
In large-scale mining operations it is possible to use blast hole diameters of up to 400 mm while in a small scale construction operations a blast hole diameter of 30 mm may be the best choice Normally the rock calls for 0 4 kg of explosive per cubic meter to be well fragmented
During the initial mining ofthe weathered cap ofthe orebody the pattern of drill holes varied from blast to blast The placing ofindi-vidual holes and the make up of blasts were dictated by the topo-graphy and the success of the results wasdependent onthequality and experience ofthe drilling and blasting
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