Anfo use

[Flintgreasewood]

We’re looking into the use of anfo to blast our frozen muck and gravel. No immediate help on google. Need some reliable info or links to such. Any help appreciated

[Geowizard]

Flint,

As a fellow miner, I can offer an opinion and advice.

Because everything online is searchable by anyone with an interest, this thread becomes an international resource.

A thirty second search on the subject gets you everything you need to know;

My search results;

https://www.atf.gov/explosives

Explosives are any chemical compound, mixture, or device, the primary or common purpose of which is to function by explosion. The term includes, but is not limited to, black powder, pellet powder, initiating explosives, ammonium nitrate fuel oil (ANFO) mixtures, safety fuses, squibs, mixed binary explosives, and igniters. Explosives are also present in items such as automotive air bag inflators, special industrial tools, fire extinguishers, some pest control devices, some model rocket engines, fireworks, and special effects in the entertainment industry.

Federal law generally requires anyone who imports, manufactures, deals, transports, ships, or receives explosives to obtain a federal explosives license or permit from ATF. A license allows a licensee to engage in the business of importing, manufacturing, or dealing in explosives. May 8, 2013

https://www.atf.gov/explosives/555220-t ... ing-agents

https://www.atf.gov/explosives/555220-t ... ing-agents

https://en.wikipedia.org/wiki/Binary_explosive

https://www.cga.ct.gov/2013/rpt/2013-R-0222.htm
'=============================================


Contractors;

I have a contractor that does this work in Alaska. I strongly encourage you to use a contractor for this work. He/she has the training, experience, licensing, liability insurance needed to properly evaluate your needs and carry out the job safely.

- Geowizard

[Geowizard]

Your guardian angel;

With all due respect for you and the hard work you do in meeting the challenge of mining, I would offer some simple advice. In my experience, the work to be done in mining is seldom done by an individual. We simply have too much limitation on the "horse power" we can apply to the work that needs to be done.

It takes horsepower;

Your guardian angel would suggest not working yourself into an early grave.

When the work needed exceeds the limits of human endurance, it's time to look for larger sources of power.

Rule #1;

In basic terms, the power needed has to come from a source larger than the point where the power/energy is to be applied. For example you cannot expect a 10 KW generator to supply 100 horse power.

Horsepower converted to watts:

One horsepower = approximately 750 watts. A 10 KW generator would therefore source 13 horsepower on a good day with no line losses (power losses).

Working underground as you know probably as well as anyone, involves leaving the power plant on the surface, at a safe distance from "the hole". The power cable/cord has resistance. As you apply more "load" on the generator with a 20 amp or 30 amp jack hammer, the voltage drop increases. The amount of drop = amps x resistance. The line loss increases with distance.

In my mine in Arizona, I had 2000 feet of power line. I ran three separate yellow jacket power lines. One for lights, one for power tools and a third for auxiliary power. That's a total of 6000 feet of power line. It was minimal at best.

Getting power underground;

An air compressor is the best option for running a jack hammer underground. Air pressure has little or no loss. A typical 100 horsepower compressor gives 100 horsepower to the working face. Larger jobs require larger compressors. I ran a 200 HP Shramm air compressor.

- Geowizard

[Geowizard]

One billion Horsepower;

https://www.britannica.com/technology/A ... horsepower.

Not sure what else a miner needs to know.

There are so many problems surrounding the use of explosives in the world today, that a rational small scale miner is advised to look at rational means and methods of "making hole" and advancing the drift.

In my opinion, "rational" means exerting the appropriate amount of force to move an object.

How much force is needed?

Stick around, there's more!

- Geowizard

[Geowizard]

Not my monkey;

It's not my monkey, but... I would offer a practical pneumatic solution.

Sullair:

https://america.sullair.com/en/products ... akers#tabs

185 series Tier 4 air compressor:
185 cfm
100 psi
49 HP/ 36.5 kW

375 Series Tier 4 Final Portable Air Compressor
375 - 425 cfm
150 - 200 psi
122 - 157 hp 91-117 kW

Pavement Breakers:

Standard T-Handle Pavement Breakers

MPB-90A
Air Consumption: 62 cfm
Blows per Minute: 1380
Bore & Stroke: 2 7/16" x 5 9/32"
Weight: 92 lbs
Length: 27 1/2"
MPB-60A
Air Consumption: 48 cfm
Blows per Minute: 1360
Bore & Stroke: 2 5/32" x 5 5/32"
Weight: 69 lbs
Length: 26 1/2"
MPB-35C
Air Consumption: 49 cfm
Blows per Minute: 1200
Bore & Stroke: 1 3/4" x 5 5/16"
Weight: 39 lbs
Length: 25 1/2"

Rent or buy;

My personal approach is to rent equipment.

Your infrastructure;

On the surface, pressure hose to connect the compressor to a rigid air pipe. The pipe runs downhole to a valve with pressure hose fitting, An inline air/water filter is an added accessory.

- Geowizard

[Geowizard]

Contributory negligence;

Most forum readers don't contribute.

Here's why;

Mining is inherently dangerous. It is possible that someone may get injured in the process of digging a hole.

Accident/injury lawyers make a living chasing ambulances. In our modern litigious society, our world is finding more and more people are becoming "victims". Victims of accidents and injuries are sought by attorneys for the obvious purpose of finding a financial remedy to the injury.

Those that contribute to an injury become a party to the injury. Who were the contributors? unfortunately, in today's modern world, most people avoid even having a conversation. Having a conversation on SAFE alternatives to otherwise high risk forms of doing things is important.

Safety officials working around mining operations always focus on things that produce energy. Electrical power, hydraulic power and pneumatic power, mechanical power. explosives are all methods using energy that affect safety. It is incumbent that everyone involved in mining be proactive in discussing the inherent dangers and possible activities that may compromise safety.

- Geowizard

[Geowizard]

Electric power loss;

I like easy to remember numbers.

It happens to be a fact that 10 AWG wire has a resistance of 1.0 ohms per 1000 feet.

A 10 AWG extension cord running 100 feet has a 200 foot length circuit. That's 200/1000 x 1.0 = 0.20 ohms. As mentioned before, the voltage loss (line loss) = current x resistance. A 10 amp current will cause a 2 volt drop in the line voltage.

Running 2000 feet into a mine is a 4000 foot circuit. That works out to a 4.0 ohm circuit. With a 10 amp load, the voltage drop (line loss) equals 10A x 4 ohms = 40 volts. Bump up the load to 20 amps = 20A x 4 ohms = 80 volts of line loss.

- Geowizard

[Jim_Alaska]

I have always been amazed at people that take no thought for the length of wire or cord they are going to use for whatever purpose. In many cases it is a home owner, they think nothing of running three to four hundred feet of fifty to one hundred foot cords. Most of the time the cords themselves are way too thin. Some do this to the point of not just losing line voltage, but even go to the extreme of overheating and "FIRE". Not to even mention burning out electric motors on any equipment they are using.

[Joe S (AK)]

Yeah - ever since I retired from the service I haven't touched an electric set-up (and haven't actually missed it). Among Ammo Troops ANFO just wasn't ever used since High Explosives were the norm and ANFO is just a "polite", modern, rendition of the low tech, low brisance, fertilizer/diesel "Farmer Dust-Up". It was often just reserved to blow stumps in the past but now used in hard rock mines.)

As a point of fact, when a choice was available, non-electric fuzing was almost always preferred for single or multiple shots since detcord with their electric or non-electric initiators were far more reliable. Running the wires involved in an electric shot was a specific weak point, so using wires, along with a "Hell Box", were universally found to be less reliable and were usually reserved only for exceptional circumstances requiring exact timing of the shot rather than overall reliability.

We never had to worry about voltage drop from the specialized wire we used since 12 volt batteries were commonplace. Of course, we had both styles of Hell Boxes if needed, too.

The electrical theory is, always, interesting - however - unless branching into hard rock mining is somehow in your future it seems to be of somewhat less operational use here for the dredgers, highbankers and shaker plant or trommel operators.

Unless you've had coffee made with a little C-4, well, you haven't done it all. We "Ammo Troops" really did know how to have a good time when far away from the Maddening Crowds.

- Joe -
39 years, 3 months, USAF

[Geowizard]

Branching into permafrost;

Cases like we find here related to the subject of mining permafrost require a recognition of mining methods beyond the scope of city slicker placer mining. You ain't on the beach in Oregon no mo.

So, the conventional old school wisdom is bring in the big guns!

There's a point where enough is enough. In my cyber-search on the topic, most of the writing is from another place and another world. That world existed back on planet Earth in the 1940's 50's and 60's.

Need a bigger hole? Bring in more explosives!

Too many other inhabitants of Alaska want the peace, solitude and quiet that is found in remote places. You can hear a rifle shot ten miles away. There are a few that work in road building for the State of Alaska that shall go un-named that have access to things the rest of the world doesn't. They are relics from that past world and place where you could buy a box of dynamite at the local hardware store and some caps.

The rules have changed;

We are part of a new agenda that forbids the use of certain controlled firearms and related fireworks, and you guessed it, explosives. See my reply at the top of this thread for reference.

- Geowizard