Blasting operation is one of the most important operation, looking from the capital influence on operation cost, the important of Blasting result on downstream operations and the place of safety. Most mine and quarries are not sensitive enough to understand the principle of Blasting operation and it significant in mine profit margin, because all Blasting is Blasting to them provided the ore ore industrial rock mass is broken down.
Some of the blast design by operators in common quarries around Africa and others continent where small scale miners and Artisanal miners dominate are extremely poor and give low Explosive Energy ultilization.
It has been proved by many research that poor blast Design with lack of agreement between the blast parameters like burden, spacing, stemming length, subdrill among others will definitely produce poor fragmentation with high environmental illness such as ground vibration, airblast, noise, flyrock among others.
Giant Africa mines expecially Nigeria mines like Dangote, BUA, Freedom Quarries, Fanalou Quarries, Geo-works Quarries, Stoneworks Quarries among others are making great different compare to other local Quarries handled by ASM. This Giant mines have great mine plans and design that help them in striking balance between the hypertensive parameters.
But nevertheless, most of them still under use Explosive energy and still haven't balance the variance effect between the controllable factors (burden, spacing,hole diameter, Stemming, e.t.c) and the uncontrollable factors (rock strength, discontinuity nature of rock mass, chemical property of rock among others).
Blasting operation is capital intensive as I had earlier explained in one of my published write up, the Effect of poor Blasting is not restricted to just loading and transportation but also stretch wings to downstream operations like crushing, grinding and Separation because libration begins from Blasting as Explosive energy not only break rock but also weaken the intermolecular bonds in rock grains.
Previous years ago I meant one of the giant blasterman in Akoko Edo local government of Edo state Nigeria, I was quest to ask him why using ANFO as the column charge and the reason for using it in abundant?
He replied as with this that, ANFO is a strength breaker Explosive, thou it is a low Explosive or better still Blasting agent, it assist and sustain High Explosive energy within the rock mass and ensure it saturate and weaken rock strength. This will reduce work on the processing machine by aiding easy comminution process.
Why air decking is likely going to yeild result that Stemming material decking!!!
Many never sieze from asking me this question concerning the reason why I think air decking will give better Blasting than solid material decking.
Talking about decking in Blasting operation we refer to the situation where innert material is place within explosive charge to reduce charge delay and also produce diversifer stand for the explosive wave.
At the point of detonation, explosive charge initiate generate fast waves which travels at a speed greater than the speed of sound in more than Seven times (>2100m/s), the wave energy perform the Major function of microfracturing (Slabbing). At the point of initiation, the waves are released to complete propagation after getting to the free face. The use of air decking (air bag) definitely provides closer free face medium for the shock waves which makes it reflects back quickly to support the lateral waves after longitudinal wave collision. In other words, the resulting wave generate from the air bag after collision support the rate of fracturing beyond the crushing zone. This support increase in fragmentation and proper breakage of the rock mass.
It also help to provide higher confining which gives the charge more avenue to release more explosion gas for casting and fragmenting.
In conclusion, Air bag help in the reduction of explosive charge weight per blast, reduce the maximum instantaneous charge per delay which directly minimize the blasting operation cost.
It also support good fragmentation; this advantage is important since theain aim of blasting is to get sufficient Run-off-mine at low cost for profitable production.
Also, good fragmentation assist in the minimizing of dilution and challenge of unexpected increase in transportation cost from mime2mill.
Finally, safety has always been the watch word and first thing on the dial of mining industry. It is of no doubt that blasting is one of the most dangerous operation in mining operation cycle due to the high energy involved. Such energy as that release form explosive can be destructive if not safely utilize and can be devastating if poor use. The use of Air bag is one of the cheapest way to ensure the safe and profitable use of explosive.
Remember, Mining the ore safe is better than mining it profitably when the mining act and condition is unsafe. Ensure bis safe and profitable to avoid any for of accident which is the end product of hazard. Eradicating principal hazard to avoid principal threatening condition works like magic for those mining industries that put all mining safe and profitable strategy in place.
Maje safety first.
Thanks and Happy mining
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