EXPLOSIVE ENERGY:THE CONCEPT OF BLASTING OPERATION IN MINING

Truly energy can neither be created not be destroyed but can change from one form to another. Explosive are chemical compound which at detonation releases specific joules of energy. The energy release during Blasting travels in form of shock  wave, heat energy, light energy, sound energy and gas energy. The first release is light energy followed by shock wave which is associated with heat energy.

The last release energy is the gas energy which finalize the work need to be done by Explosive charge.

Energy is defined by various scholars as the ability needs to do work. The work before Explosive during detonation is to explode rock mass, fragment rock mass, throw rock piles and to  cause other negative effects like ground vibration, airblast, and rock projection (flyrock)

Sequence of Explosive energy ULTILIZATION during Blasting

 The light energy travels faster than all others energy, it shows the initiation direction of Explosive charge detonation. 

Check this about light energy

Thou the charges are initiated by shock energy.

Checking most slow play rock Blasting videos we see first the sequence lightning which is been followed by the shock waves then sound energy.

By the reason of definition, high Explosives are those capable of detonating under the shock energy produce by cap number 8 to release shock energy faster than the speed of sound.

Shock energy perform diver functions among which include ignition of the base charge and column Explosive charge.

The shock wave from the detonator initiate the primer and detonate the Explosive column. The shock wave in a view of achieving the fragmentation work requires from Explosive, it create radial cracks into the rock mass within the design burden and spacing.

The micro-cracks are created under compression and tensile slabbing. This prepare the rock for explosion.

Rock By definition (dipping towards Bowel series reaction: The pit of temperature influence during magma grains growth)

Rocks are by definition the aggregate of many minerals. Each available rock on Earth can be categories into basically three classes;

1. Igneous rocks,

2. Sedimentary rocks, and

3. metamorphic rocks 

1. igneous rock (also called the primary rocks): is formed generally by the cooling and solidification of molten magma flowing through volcano vent from the magma chamber located legendly in the mantle. Examples are basalt (apharitic texture rocks known to be volcanic igneous rock due to it surface eruption and rapid cooling rate), granite (the most abundant rock on Earth, usually phaneritic in texture composing dominantly mica, feldspar and Quartz. Other types are pegmatite, gabbro, obsidian and pumice.

Flashing l Other rock classification 

2. sedimentary rock: formed by the reaction of diagenesis process (compaction and lithification) on deposited rock sediments. Usually deposited in beds/strata in obedient to superposition principle. Examples includes; sandstone, limestone, clay, shale among others.

3. metamorphic rocks: This class of rocks are formed by the occurrence of metamorphosis process on pre-existing rocks. This process involve the change in rock form under the influence of high temperature and pressure. Example includes; gneiss, marble, Dolomite, quartzite, schist among others.

 I choose not to dig deep in this rock of a thing so I don't end up talking for hours on rocks. Rocks are my textbook anyway we need to learn a bit about them.

I was trying to register the idea of heat functionality in rock breakage during Blasting before I was been tossed into the stope and winze of rock classification.

What I was about doing is to explain the concept of bowel series reaction which form the basic foundation for mineral formation during magma cooling.

The idea of heat energy is that, upon Explosive charge detonation, The heat energy weakens the rock Mineral grains bond. It cooks most of the rock minerals to the point of recrystallization which enables the creation of radial micro cracks by shock wave during tensile slabbing. Thou the process of heat transfer during explosion occurs very rapid. The heat cook up the grains  and create path of weakness for the waves to travel compressively and tensionally.

I keep picturing this idea in my mind untill I come to understand it during the process of breaking rocks using sledge hammer. The  small scale miners  and artisan miners (SSM & AM) call this operation knocking process. Thou it not included in mining process sequence (Drilling, Blasting, mucking, loading and haulage).

 I also read history on past old age mining approach, the miner in a bit to break rock boulders cook up the boulders with fire so as to cause particulate and grain expansion. The boulders are heated beyond the thermal spallability strength of the rock, just to enables it fracturing during hammering.

Also, in the place of thermal drilling process where by oxygen and fuel oil is burn below the drill bit  so as to cook up the rock for fast Penetration of drill bit during grinding, crushing of the rock by the bit cones/tooth.

Heat release during Explosive charge detonation aid the easy cracking and slabbing of the rock.

I will stop here about that for now.

To the gas energy, it function is to fill the created cracks and due to its high pressure nature causes explosion of slabbed and unstable rock mass.The gas energy perform the explosion and the throw of rock pile.The reason for proper Blast design is to ensure this Explosive release energies are use positively.

Some of the control factors include the powder factor, bur

The burden and spacing, the rock characteristics (uncontrollable factors), Explosive proper selection among other factors.

Thanks for reading.

If you gain anything try to comment this phase:

 "Explosive is for peace and not for war, for making money and not for terrorism" 

##Giant_Miner

WhatsApp contact:+2347031018600

ACHIEVING A GOOD BLASTING:POST AND PRE BLASTING INSPECTION IS THE KEY

Pre Blasting and post Blasting inspection for data collection and blast design is very important so as to performance a profitable and productive Blasting.

Some of the pre-blasting inspection carried out before Blasting includes;

1. Ground water condition (in-hole water check)

2. Rock face discontinuity mapping

3. Drilling parameters collection.

4. Free face checking.

1. Ground water condition (in hole water)

Water may be present in the mine either through surface inflow or underground water outflow.

Ground water condition affects Blasting materials, expecially when using a non water resistant Explosive like ANFO. This may result into MISFIRE and poor fragmentation.

All holes must be inspected and those with water should be noted.

Water tend to reduce the sensitivity of non water resistant Explosive. Explosive like Dynogel and emulsion gel and other water resistant Explosive should be use in noted water filled holes.

Hole with water can also be drained or flush by high pressurized air before charging.

2. Discontinuity mapping

Mostly in mine face and floor fractures occur due to overbreak induced by the previous Blasting. Some cracks in rock may be of wide aparture capable of stealing grain Blasting Agents and concentrating it at a point ( this may result into formation of flyrocks if the concentrated/trapped Explosive is close to the free face where burden is less).

Thou fractures may tend to appear in rock due to natural phenomenon like weathering and stress relief. The discontinuity condition of rock mass need to be checked before drilling and possibly after drilling to contain it effect on Blasting.

3. About drilling parameters, this is very important as poor drilling design will totally affect Blasting. Some of this design parameters are burden and spacing, hole Depth and hole diameter.

Imperfect hole parameters affect not only burden movement during Blasting but also affect Blasting cost, environmental safety and Blasting result.

Poor hole burden distribution affects burden movement during Blasting which tends to create the production of unwanted Blasting result. The concept of Achieving good Blasting, we need to ensure our drilling design is properly done and if possible checked on softwares like O-pit blast for outlier drill holes.

Most mining companies complain of blast overbreak and poor fragmentation. The damage created by Blasting shock waves can be contained by proper drilling design which help to optimumly ultilize Explosive energies during detonation.

Checking Bench or mine free face provided by the drilling team is also an important thing to consider during Blasting. This will help to control charge density rate at the first hole row to prevent the possibility of flyrock and other Blasting created hazard.

Some of the post-blasting inspection includes; Misfire checking, wall and roof scaling, Blasting fume and gas testing, fragmentation checking and analysis.

Get the complete detailed post-blast explanation later.

Thanks.

GIANT MINER.

WhatsApp number:+2347031018600

MINING AT PROFIT: BLASTING SAFETY AS A KEY

The main aim of mining is to secure profit.

This in most cases may be affected by mine operation cost if not properly managed.

Drilling and Blasting plays high role in ensuring profit in Mineral exploitation.

If the expenses incur on drilling and Blasting yield poor result, it tends to affect all the downstream operation cost.

It therefore good that blast design be done and monitored thoroughly by the Mine supervisor.

This is liken to safety in the mine, workers life is very important and must be given principal consideration.

Blasting must be done safely with no accident record or any form of misfire.

Explosive is dangerous when poorly handle but peaceful if well handled.

In 1960s before Alfred Nobel light up Explosive works, the use of Nitroglycerin Explosive base, TNT and puliminating Mercury & gold had cause great havoc due to there high sensitivity.

But for the discovery of Ammonium Nitrate base Explosive which are less sensitive but high exotically sensitive.

Explosive is now design to detonate under the availability of Shock wave from highly sensitive detonator and other Blasting accessories.

Conclusively;

Mine profitability is a function of;

1. Good Safety management System

2. Good mine operation system (development, drilling, Blasting, excavation, haulage & transportation)

The three key safety elements are very important to ensure mine safety.

These keys are:

1. Engineering

2. Education

3. Enforcement

Engineering safety element: This comes in the place of Engineering design, quality assurance and quantity assurance. Bench design work, mine design, blast design and other Engineering related min aspect must be given high priority.

2. Education safety element: All workers must be education on mine state view, wall stability, equipment usage and handling. Knowledge is safety: knowledge of mine operation and equipments goes a long way to remain safe in the mine.

3. Enforcement element: All safety rules, regulation, law, policy must be enforce on mine workers