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104 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is optimum fragmentation? |
3)Optimum fragmentation varies from operation to operation. |
1)No fines 2)Uniform Fragmentation 3)Optimum fragmentation varies from operation to operation 4)No oversize |
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What is the most efficient way to use explosives? |
2)Minimize energy expended on making airblast, ground vibrations, and flyrock 3)Maximize energy used to break rock to requirements |
1)Use the lowest cost explosives available 2)Minimize energy expended on making airblast, ground vibrations, and flyrock 3)Maximize energy used to break rock to requirements 4)Expand the blasting pattern |
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The goals of the course include |
4)You will be knowledgeable in the subject and be confident and able to design blasting shots
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1)To learn how to break rock as finely as possible. 2)You will have blown up a lot of stuff 3)Get a good grade 4)You will be knowledgeable in the subject and be confident and able to design blasting shots |
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Why is the use of explosives important to our economy? |
1)If we didn't have explosives many raw materials would be very expensive. 2)Drilling and blasting is the least expensive way of breaking solid rock 4)If it's hard rock you have to use explosives to break it so you can economically mine it. |
1)If we didn't have explosives many raw materials would be very expensive. 2)Drilling and blasting is the least expensive way of breaking solid rock 3)The amount of explosives sold is an important part of our GNP 4)If it's hard rock you have to use explosives to break it so you can economically mine it. |
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The purpose of explosives is so we can easily: |
1)Dig it 2)Load it 3)Crush it 4)Haul it |
1)Dig it 2)Load it 3)Crush it 4)Haul it |
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Who invented dynamite? |
1)Alfred Nobel |
1)Alfred Nobel 2)Ascanio Sobrero 3)William Bickford 4)Lamont Dupont |
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The course objectives include: |
3)Obtain an understanding of explosives and explosive products and the ability to apply this to the breakage of rock in an environmentally acceptable and safe manner. |
1)Being able to break rock as small as possible 2)Limiting flyrock 3)Obtain an understanding of explosives and explosive products, and the ability to apply this to the breakage of rock in an environmentally acceptable and safe manner. 4)Breaking rock so it can be loaded, hauled and crushed effectively. |
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Match the following event to the cause in fragmentation process: 1)Crushing around the hole 2)Fractures extend to the free face 3)Rotation of fragments 4)Crushing and grinding in moving muckpile |
1-C 2-B 3-D 4-A |
A)Secondary fragmentation B)Gas pressure C)Shock wave D)Momentum |
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Detonation Velocity is dependent on? |
1)Charge Diameter 2)Priming 3)Confinement 4)Explosive Type |
1)Charge Diameter 2)Priming 3)Confinement 4)Explosive Type |
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Which of the following explosives has the least water resistance? |
5)ANFO |
1)Slurries 2)40% strength dynamite 3)Both 1&2 4)Emulsions 5)ANFO |
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Explosives are not affected by freezing temperatures. |
False |
True False |
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The Relative Bulk strength of an explosive |
1)Is relative to ANFO |
1)Is relative to ANFO 2)Is the weight to the cartridge or package 3)refers to its sensitivity 4)refers only to bulk products 5)is the speed at which it detonates |
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A moderate variation of the amount of fuel oil in ANFO will affect |
1)Sensitivity 2)Velocity 3)Production of Fumes 5)Energy |
1)Sensitivity 2)Velocity 3)Production of fumes 4)Density 5)Energy |
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Which is the highest density explosive product? |
3)Cast Booster |
1)Emulsion 2)ANFO 3)Cast Booster 4)High-Density ANFO 5)Water Gel |
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In wet blast holes which of the following apply? |
1)The hole should be dewatered if possible 3)Explosive density should be greater than 1 4)A water resistant explosive should be used |
1)The hole should be dewatered if possible 2)Explosive density should be less than 1 3)Explosive Density should be greater than 1 4)A water resistant explosive should be used |
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Which of the following statements is incorrect regarding propagating ground? It... |
5)Reduces Misfires |
1)results in improper fragmentation 2)can lead to dead pressing 3)Causes high levels of vibrations 4)negates the effect of delays 5)reduces misfires |
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Permissible explosives |
1)are classified for use in coal mines 2)produce no (very low) flame 4)are used in underground operations that are classified as gassy |
1)are classified for use in coal mines 2)produce no (very low) flame 3)are low (deflagrating) explosives 4)are used in underground operations that are classified as gassy |
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Nonel compromises which of the following? |
5)A hollow tube with a dusting of HMX or aluminum |
1)A waded tube filled with black powder 2)Cap and detonating tube 3)A group term for any non-electric system 4)A mixture which detonates at 7 km/sec 5)A hollow tube with a dusting of HMX or aluminum |
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Non-electric systems are safe to use in the presence of which of the following? |
2)Stray Electricity |
1)Welding equipment 2)Stray electricity 3)Impact/shock 4)Open Flame |
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The all fire current of a standard electric cap is: |
2) 250milliamps |
1)150 milliamps 2)250 milliamps 3)100 milliamps 4)125 milliamps 5) 1 amp |
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Nonel can be cut and spliced where? |
2)Only on the lead in line |
1)Down the hole 2)Only on the lead in line 3)On 25/500 EZ dets near the surface connector 4)Between rows |
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If 10 blasting caps are wired in parallel and each blasting cap is 3 Ohms, the total resistance of the circuit will be____Ohms. |
0.3 Ohms |
For Parallel Resistance Req=1/(1/R1+1/R2+1/R3+...) |
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Which of the following are correct about safety fuse? |
1)Its burning rate varies with moisture content and age 4)Its burning rate varies with altitude 5)It is designed to burn at 40 seconds per foot |
1)Its burning rate varies with moisture content and age 2)It provides very accurate delays 3)It is a very safe system to use 4)Its burning rate varies with altitude 5)It is designed to burn at 40 seconds per foot |
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The safety factor when using a "Blaster's" multi-meter to check an electric blasting cap is |
2)10 |
1)20 2)10 3)50 4)2 5)5 |
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Electronic detonators are accurate to 1 micro-second. True/False? |
False |
True False |
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Commercial detonating cord contains which of the following explosives? |
4)PETN |
1)Black Powder 2)NG 3)TNT 4)PETN 5)HMX |
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If 20 blasting caps are wired in series and the resistance of each blasting cap is 2.5 Ohms, the total resistance is ____Ohms. |
50 Ohms |
Resistance in Series Req=R1+R2+R3+... |
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A good starting place for powder factor in bench blasting is: |
1)0.5 lb/ton |
1)0.5 lb/ton 2)1 lb/ton 3)2 lb/ton 4)0.2 lb/ton |
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The most effective way to produce smaller rock is to: |
2)Increase powder factor |
1)Use LP delay series detonators 2)Increase powder factor 3)Decrease bench height 4)Increase subdrill |
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Having too high a face height can result in: |
2)Flyrock 3)Toe 4)Poor breakage 5)Drilling inaccuracies |
1)Powder factor too low 2)Flyrock 3)Toe 4)Poor breakage 5)Drilling inaccuracies |
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Which post-blast phenomenon is the key indicator of insufficient delay on the back row of a bench blast? |
4)Rock from the blast on the bench behind the shot |
1)Backbreak 2)Flyrock 3)Low muckpile profile 4)Rock from the blast on the bench behind the shot |
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Bench blasting is the most common form of blasting because: |
1)It is easy to drill vertical holes 3)There is a free face to afford easy breakage 4)It is low cost blasting |
1)It is easy to drill vertical holes 2)None of the answers shown are correct 3)There is a free face to afford easy breakage 4)It is low cost blasting |
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The jointing and bedding in a limestone ledge will |
4)All of the above |
1)Determine the suitability for jetty stone 2)Control the face profile 3)Determine the best blasting direction 4)All of the above 5)None of the above |
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The most complete fragmentation occurs: |
3)Around the explosive |
1)Areas of increased burden 2)Around the stemming 3)Around the explosive 4)Between holes |
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The rules of thumb for minimum delay period are: |
1)3 ms per meter of burden intra row 3)3 ms per foot of burden row to row 4)1 ms per foot of burden intra row |
1)3 ms per meter of burden intra row 2)25 ms row to row 3)3 ms per foot of burden row to row 4) 1 ms per foot of burden intra row |
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When using delays in a blast, which of the following are correct? |
1)There are optimum delay periods for fragmentation 2)Using delays reduces ground vibrations 3)There are optimum delay periods for minimum vibration |
1)There are optimum delay periods for fragmentation 2)Using delays reduces ground vibrations 3)There are optimum delay periods for minimum vibration 4)The optimum delay period is 25 ms |
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If a large void is encountered during drilling, the hole should be loaded as follows: |
5)Load though the void with stemming, reprime above the deck, and continue loading |
1)Use stick explosive 2)Load the hole with the normal weight of explosives 3)Load the hole to the normal level with explosives 4)None of the above 5)Deck through the void with stemming, reprime above the deck, and continue loading |
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Oversize will be a problem if the blast hole spacing is X times the joint spacing. Pick correct description of X below: |
2) 2 to 3 |
1)Over 10 2) 2 to 3 3) Under 0.5 4) 1 |
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The fragmentation process includes: |
1)Tensile reflection at the free face 2)Dynamic shock wave fracturing 3)Movement 4)Gas pressure induced radical fracturing |
1)Tensile reflection at the free face 2)Dynamic shock wave fracturing 3)Movement 4)Gas pressure induced radical fracturing |
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Increasing degrees of freedom in blasting results in increased fragmentation. |
True |
True False |
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Having a face height too low normally results in: |
2)Powder factor too low 3)poor breakage 5)Flyrock 6)Stemming ejection |
1)Tow 2)Powder factor too low 3)Poor breakage 4)Drilling inaccuracies 5)Flyrock 6)Stemming ejection |
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Primers should: |
4)All of the above |
1)Only be assembled at time of use 2)Not be tamped or slit 3)Not have cartridges above 4" in diameter dropped on them in the blast hole 4)All of the above 5)None of the above |
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For bench blasting a 4 inch hold loaded with ANFO, the burden and spacing should be: |
3) 8x12ft |
1) 20x20ft 2) 6x6ft 3) 8x12ft 4) 12x18ft 5) 4x6ft |
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The column density of a 3.5 inch hole loaded with bag ANFO is how many pounds per foot of hole? |
2) 3.5 |
1) 2.5 2) 3.5 3) 0.5 4)1.5 |
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Oversize found in the middle of the muck pile is most likely a potential sign of: |
4) A misfire |
1)Excessive subdrill 2)All answers shown are correct 3)Poor stemming 4)A misfire |
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Hard toe is caused by: |
1)Bad drilling 2)Insufficient energy at the bottom of the hole 3)Misfires 5)Too high a burden at the toe |
1)Bad drilling 2)Insufficient energy at the bottom of the hole 3)Misfires 4)Too much powder on the last row 5)Too high a burden at the toe |
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For blasting massive rock, which is the most important rock strength? |
3) Tensile |
1)Shear 2)Triaxial 3)Tensile 4)Compressive |
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Persons assigned to securing a blast site during blasting operations should be: |
4) All of the above |
1)Trained 2)Properly equipped 3)Have knowledge of procedures 4)All of the above 5)Be licensed |
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Under combined MSHA and OSHA regulations the drilling of holes next to holes being loaded or already loaded is only allowed at a distance farther than: |
3) 50 ft 4) 30 ft if barrier is used |
1)None of the listed answers are correct 2) 25 ft 3) 50 ft 4) 30 ft if a barrier is used 5) 100 ft |
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Under MSHA regulations, vehicles carrying explosives must be: |
1,2,3,4,5 all correct |
1)Equipped with sides higher than the explosive transported 2)Have dry chemical fire extinguishers 3)Equipped with non-sparking cargo space 4)Secured while parked with the brakes set, the wheels chocked, and the engine shut off... 5)Maintained in good condition |
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If a misfire is suspected, the blaster should first |
1)Wait for fifteen (15) minutes unless safety fuse is being used |
1)Wait for fifteen (15) minutes unless safety fuse is being used 2)Investigate the misfire as soon as possible 3)Pull on any leg wires or tubing to determine if it is still attached to anything 4)Contact his explosives supplier |
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Which of the following causes the most fatalities in blasting? |
5)Failure to clear the area |
1)Rough handling of explosives 2)Drilling into undetonated explosives 3)Blasting caps prematuerly exploding in magazines due to static electricity 4)Improper insertion of blasting caps into primers 5)Failure to clear the blasting area 6)Transporting electric blasting caps |
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The principle hazard associated with the initiation systems is: |
4) Lightning |
1)Blast hole deviation 2)Radio Frequency energy 3)Storage 4)Lightning 5)Smoking |
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If a blast is delayed more than 72 hours then |
1)The operator shall notify the appropriate MSHA district office |
1)The operator shall notify the appropriate MSHA district office 2)The operation shall be shut down until the blast is fired 3)A penalty will be assessed 4)The blasting certificate of the blaster shall be suspended 5)All listed answers are correct |
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The person most likely to be injured during a blast is: |
2)Blaster |
1)Shot crew 2)Blaster 3)Equipment operator 4)Foreman |
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Flyrock is caused by: |
6)All the above are causes of flyrock |
1)Insufficient burden 2)Mud seams and cavities 3)Improper timing 4)Stemming that doesn't hold well 5)Mud capping 6)All the above are causes of flyrock |
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Under MSHA regulations "the area where explosive material is handled during loading including..." is defined as the |
4)Blast site |
1)Blast pattern 2)Shot 3)Blast area 4)Blast site |
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Type 5 magazines are |
1)Drop trailers or bulk product bins |
1)Drop trailers or bulk product bins 2)Permanent and bulletproof 3)Portable and bulletproof 4)Temporary day boxes |
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What is the maximum diameter of blast hole allowed under MoDOT regulations? |
3) 4 inch |
1) 2 inch 2) 3 inch 3) 4 inch 4) 6 inch 5) 9 inch |
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Using OSM guidelines, what is the scaled distance that should be used when blasting between 301 and 5,000 ft from a structure (w/o seismic monitoring) |
3) 55 |
1) 65 2) 75 3) 55 4) 50 |
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Which of the following can be stored in an explosives magazine with class "1.1" explosives? |
3)Non-sparking tools necessary for magazine operation |
1)Empty explosive cases 2)Unmixed two component explosives 3)Non-sparking tools necessary for the magazine operation 4)None of the listed answers can be stored with 1.1 explosives 5)Any valuable equipment such as a chainsaw 6)Gasoline 7)Class 1.1 detonators |
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ATF regulates the: |
1)Sale of explosives 4)Storage of explosives |
1)Sale of explosives 2)Use of explosives on the property/job site 3)Transportation of explosives 4)Storage of explosives |
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What is the minimum distance permitted for smoking or open flame from explosives? |
3) 50 ft |
1)There is no minimum distance 2) 100 ft 3) 50 ft 4) 25 ft 5) 10 ft as long as the explosives are covered or in a mag |
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To transport explosives on a public road in a vehicle that requires DOT placards, the driver is required to have: |
1,2,3,4 are all correct |
1)A CDL with appropriate hazardous material endorsement 2)Fire extinguishers 3)A shipping manifest 4)A written route plan |
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DOT regulates the: |
1)Transportation of explosives on public roads 2)Assignment of explosives 1.1,1.4,1.5 labeling |
1)Transportation of explosives on public roads 2)Assignment of explosives 1.1, 1.4, and 1.5 labeling 3)All transportation of explosives 4)Separation of mags |
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For the storage of explosives and blasting agents, which of the following is correct? |
E) Both C & D |
A)All mags must display explosives signs B)No storage mag should display explosives signs C)Explosive mags should not display explosives signs with the exception of type 5 mags D)All explosives storage areas should have a perimeter signs displayed in such a way that a bullet passing through a sign noes not have a clear line of sight to a mag E) Both C & D |
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Missouri state regulations require the reporting of any storage of explosives above |
5) 100 lb |
1) 1,000 lb 2) 2 cases 3) 300,000 lb 4) 10,000 lb 5) 100 lb |
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If the closest structure is 400 ft from your blast and you want to maintain a scaled distance of 50, what is the max allowable charge per delay that you can detonate? |
4) 64 lb |
W= (D/Ds)^2 1) 8 lb 2) 48 lb 3) 50 lb 4) 64 lb 5) 80 lb 6) 400 lb |
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The ploys you are likely to experience in a court case are: |
1)Your blaster has no respect for other peoples property 2)Your blaster is incompetent 4)Your blaster was negligent |
1)Your blaster has no respect for other peoples property 2)Your blaster is incompetent 3)You did not have a blasting permit 4)Your blaster was negligent |
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If you are blasting within 1500 ft of the closest structure and your maximum charge weight per delay is 225lb, your scaled distance is: |
5) 100 |
Ds=D/(W)^1/2 1) 15 2) 20 3) 40 4) 50 5) 100 |
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Pre-blast surveys are: |
1)Best performed by a qualified, experienced vibration or engineering consultant or company 2)Useful to establish the condition of nearby buildings before blasting 4)Only mandatory by federal law for the permitting of new mining operations under OSM control |
1)Best performed by a qualified, experienced vibration or engineering consultant or company 2)Useful to establish the condition of nearby buildings before blasting 3)Not required anywhere in the blasting industry 4)Only mandatory by federal law for the permitting of new mining operations under OSM control |
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The cost of a pre-blast survey for an average residential structure (in Missouri 2002) is: |
3) $200-400 |
1) $50 2) $100-150 3) $200-400 4) $500 5) $1000 |
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To best protect yourself form unwarranted damage claims you need: |
5)Both accurate blasting records and seismograph records |
1)Accurate blasting records 2)Seismograph records of your blasts 3)Low vibration explosives 4)An ATF approved mag 5)Both accurate blasting records and seismograph records |
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You are required to maintain a scaled distance of 50 and you have 100 lb delay in your regular blast pattern. You can come up to ____ft from neighboring houses before you have to modify your blast design. |
500 |
D=Ds * W^1/2 |
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Blast vibration studies have shown that residential structures are sensitive to |
3) A combination of PPV and Frequency |
1)termites 2)Peak Particle Velocity (PPV) only 3)A combination of PPV and frequency 4)Frequency |
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The OSM guidelines state a scaled distance of ___should be used for blasting 450 ft from a structure if seismic monitoring is not used. |
55 ft |
Distance SD 0-300 ft 50 301-5000 ft 55 5001 + 65 |
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Pre-Blast surveys are useful for new operations, but are a double edged sword with regard to: |
1)New Housing 2)Existing blasting operations |
1)New Housing 2)Existing blasting operations 3)Trenching near public buildings 4)People who don't want them |
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When filling out a blast record, the following should be completed: |
1,2,3,4,5 all correct |
1)All lines filled in with none left blank 2)Have number of holes, maximum pounds per delay, and sequencing 3)Have sketch of blast with its exact position 4)Signed by blaster 5)Dated with time of blast |
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If the house is 500 ft from a blast, the air blast will arrive __seconds after the first ground vibrations. |
0.5 |
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Ways to reduce airblast include: |
1)Elimination of det cord 4)Good explosives confinement 5)Avoid blasting during temperature inversions |
1)Elimination of detonating cord 2)You can't 3)Reduced stemming 4)Good explosives confinement 5)Avoid blasting during temperature inversions |
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Most people can easily tell the difference between ground vibrations and air blast. |
False |
True False |
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When setting up seismograph, the geophone should be placed: |
2)Buried in the ground or weighted down by sandbags to insure proper coupling with the soil |
1)As near the blast as possible 2)Buried in the ground or weighted down by sandbags to insure proper coupling with the soil 3)Inside the house 4)On a driveway or slab pathway in front of the house if possible |
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In trenching when dealing with overburden, which of the following is correct? |
1)Treat dirt as 1/2 rock if there is more dirt than rock 3)Treat water as half rock 4)Treat dirt as rock if there is more rock than dirt |
1)Treat dirt as 1/2 rock if there is more dirt than rock 2)If there is more rock than water, ignore water 3)Treat water as half rock 4)Treat dirt as rock if there is more rock than dirt |
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Oversize found in the middle of muck pile is a potential sign of: |
3) A misfire |
1)Excessive subdrill 2)Poor stemming 3)A misfire 4)All the listed answers are correct |
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You have a 10 ft trench with 6 ft of dirt. How much rock equivalent do you have to use for your calculations? |
7 ft |
Dirt>Rock calculate dirt as 1/2 rock and add to rock amt |
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The recommended max charge weight in lb/yd^3 for drilled boulders is: |
A) .25 |
A) .25 B) 1 C) 2 D) 5 |
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When trench blasting close to houses: |
1)Matting should be used |
1)Matting should be used 2)Tell the neighbors to duck 3)Each stick of dynamite must be separately primed 4)Only electronic caps may be used 5)All listed answers are correct |
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You have a line of 4" pre-split holes and 6" production holes. How near in feet can the production holes come to the pre-split? |
6 ft |
12 x production hole diameter |
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A reasonable range of powder factor for trenches (in lb/yd^3) is: |
C) 2-5 |
A) 0.25-1 B) 1-2 C) 2-5 D) 5-10 |
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A french drain is: |
1)Is blasted the same as normal trench 3)Has excess material above grade dozed away 5)Is used in mining for combination of drainage and access 6)Can be used as a sump |
1)Is blasted the same as a normal trench 2)Is only blasted in France 3)Has the excess material above grade dozen away 4)Is excavated to full depth 5)Is used in mining for combination of drainage and access 6)Can be used as a sump |
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Which of the following is incorrect about pre-splitting? |
4)It is shot on a high delay period within the main blast |
1)it is shot before the main blast 2)A single charge can be loaded at the bottom of the hole 3)Detonating cord is often used 4)It is shot on a high delay period within the main blast |
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The max drill depth for pre-splitting vertical holes is |
3) Dependent on the type and condition of your drill rig |
1) 50 x hole diameter 2) 100 x hole diameter 3)Dependent on the type and condition of your drill rig 4) 30 ft |
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The following are common problems associated with burn cuts: |
1)Borehole deviation 3)Deadpressing 4)Sympathetic Detonation |
1)Borehole deviation 2)Cutoffs 3)Deadpressing 4)Sympathetic detonation |
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The Swedish design philosophy for burn cuts is: |
1)Use expanding squares 2)Stop when burden reaches stoping hold burden 3)Fire sequence from middle out |
1)Use expanding squares 2)Stop when burden reaches stoping hold burden 3)Fire in sequence from middle outwards 4)Fire center square on instant delays |
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The optimum center to center for a loaded hole and the relief hole in a burn cut is___times the diameter of the relief hole. |
1.5 |
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Which of the following are correct recommendations for V cuts? |
2)Use instant and low millisecond delays in the cut 3)Use dynamite as primers |
1)Use emulsion as primers to avoid sympathetic detonation 2)Use instant and low period millisecond delays in the cut 3)Use dynamite as primers 4)Use ling delay periods for the cut |
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Common underground cuts include: |
1)Burn Cut 2)Fan Cut 3)Under Cut 4)V Cut |
1)Burn cut 2)Fan cut 3)Under Cut 4)V Cut 5)Drag Cut |
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Causes of Oversize in Muckpile |
1) Already defined in the face 2)Cap Rock 3)Drill hole deviation High Toe 4)Misfire 1-4)Geologically Controlled: Block size too big |
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Scaled Distance Formula |
Ds=D/W^1/2 |
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Burden Equation |
Ash's Equation Kb=30(SGex/1.4)^1/3(160/Wtrk)^1/3 SG = density of explosive (g/cc) Wt = Weight of rock (lb/ft^3) B = dx * Kb dx = diameter of explosive |
Range of Kb = 25-35 |
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Spacing |
S = B x (1.4 to 2) |
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Rules of thumb Quarries/Surface W/ ANFO |
Density = 0.8 g/cc Powder Factor = 1lb/yd^3 Face Height = 100-120 Hole Dia Face Height = 4 x burden Burden = 24 x Hole Dia Spacing = 36 x Hole Dia |
Stemming = .7-1.4 Burden Say = Burden Size = 1/8 Hole Dia Subdrill = 1/3 Burden No subdrill if bottom of face at bed plane |
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Rules of thumb Quarries/Surface W/ Emulsions & Blends |
Density = 1.25 g/cc Burden = 30 x Hole Dia Spacing = 42 x Hole Dia |
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Decking |
Dry Hole use 6 x Diameter Wet Hole use 12 x Diameter |
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