From: AHAHMA%kontu.utu.fi@ssyx.ucsc.edu
Subject: ANFO
Date: 6 Mar 90 10:44:09 GMT

Fertilizer and oil is one of my favorite mixtures. I haven't even
calculated how many hundred kilograms I've consumed. The fertilizer is
cheap and readily available. As a drawback its brisance is low.
However, that doesn't matter, if one kilogram is not enough I take two
or five or ten. It is still cheaper than using some high explosives
like pentrite or similar.

The fertilizer in Finland contains 75..80 % of ammonium nitrate, the
rest being dolomite earth. It doesn't matter at all, although the
safety instructions on the bags tell: This fertilizer won't burn or
explode under any conditions..  Well, that's not actually true, it does
react, if it is ground a little and mixed with 4 % of oil. The best oil
available is waste motor oil. It is the cheapest, it doesn't stink is
the mixture and it ignites the best. The best of all, think about the
the environmental problems involved in waste oil! This is the way how
to get rid of such problems! I use a 5.5 % mixture, calculated on pure
ammonium nitrate. More oil means difficulties with the ignition and a
bad smelling cloud of smoke after the explosion.

The problem is only to get a strong boost to set the mixture off. You
need at least 30 grams of TNT or stronger to ignite the unconfined
stuff. If confined, it can be ignited even with explosives of a lower
brisance. Usually I take 20 to 30 grams of octogen and the ignition is
100 % sure. Another "problem" with unconfined charges is the minimal
amount. You have to take at least 5 cm thick layer in every directions
around the detonator to get a sure ignition.  That means about a
kilogram. A kilogram makes a blast that can be heard 7 km away upwind.
I know, I have been told that after I had made some tests..

The minimal charge problem doesn't arise with confined charges, i.e.
buried into ground, underwater charges etc. On the other hand, these
make less noise and that's why you can use more stuff at one time.
Underwater explosions are my favorite, they don't make noise, but look
very spectacular and beautiful.  Underground blasts are nice too, but
you have to have a good shelter against falling stones. For example, a
4 kg charge in 1 meter depth in sand threw about 4 cubic meters of sand
200..300 meters away. The crater was about 4 meters wide and 2.5 meters
deep. The ignition was carried out with delay fuse, which is readily
available here. (Just walk into a store and buy some 10 meters).

3P

From: AHAHMA%kontu.utu.fi@ssyx.ucsc.edu
Subject: ANFO
Date: 30 May 90 16:15:12 GMT

>I have not dome any work don sintering/melting explosives.  Does anyone have
>experience with AN/FO mixtures, especially in confinement and initiation?

ANFO must be either very tightly confined or used in big amounts to function
properly. If not confined, the critical diameter for fertilizer (80 % AN) is
about 5 to 7 cm. That means you have to take at least a sphere of 10 to 15 cm
in diameter and place the detonator in the middle. In practice it means only
charges over one kilogram work. And the detonator must be 20 grams of TNT or
some more brisant explosive.

If the ANFO is confined, the critical diameter is smaller and even charges
under 0,5 kg can be detonated completely. Also the grade of the AN affects the
initiation. The best is prilled (spray dried) AN, which has a large surface
area and a lot of pores in the prills. If the AN is ground or dense particles,
it will be much more difficult to ignite - like the fertilizer. 

The sensitivity can be increased with additives, such as nitroglycol, TNT,
aluminum dust, other high explosives. Adding 4 % of EGDN will make any AN cap
sensitive; the excess oxygen released can be used up by adding a solid fuel,
for example carbon black or sugar. However, these mixtures are closer to
dynamites than ANFO.

ArNO
    2

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Realize what you are doing
Date: 13 Dec 1995 18:22:49 GMT
Organization: Consulting Chemist

In article <ACECBC3A9668D0C3@dialup-a2-7.mel.netspace.net.au>,
petert@netspace.net.au (Peter Tilmanis) says:

>In article <49t87i$5ha@geraldo.cc.utexas.edu>,
>glhurst@onr.com (Gerald L. Hurst) wrote:
>
>>Your grandfather did not learn about ANFO in WWI. It first
>>evolved into commercial use after 1948, possibly at least
> ^^^^^^^
>>partly as a consequence of the Texas City explosion.
>
>Evolved from where, may I ask?  The military, perhaps?

Not from the military.

In the 1950's Various mine and quarry operators began playing 
with mixtures of AN and just about any fuel one can think of, 
often using little knowledge of chemistry. Some mixes shot 
better than others and some actually made production shots.

Melvin Cook, the author of "The Science of High Explosives," 
credits himself with having reduced the formulation to the now
standard mixture of AN and #2 fuel oil.

The established powder companies resisted the move to ANFO
because it was not in their perceived best economic interests
to sell a 2.5 cent/lb material in place of the more expensive
dynamites. They also reasoned that a non-water-proof blasting
agent would create too many misfires and that the low density 
of the ANFO mixes would not generate sufficient bore-hole 
pressure.

As the move toward ANFO use gained steam, manufacturers 
responded by improving the physical properties of AN prills 
intended for use as blasting agents. They also developed
water-resistant packaging materials for wet-hole use as well
as numerous types of primers and boosters.

Not long after the rise in popularity of ANFO, there began 
a parallel development of AN water-gel slurry explosives. 
Again, Mel Cook, with considerable justification, takes a 
great deal of credit for the associated technology.

Related to the water-gels are the emulsion explosives first
introduced successfully by the Atlas Powder company in the 
early seventies. These materials shoot at very high 
velocities as commercial blasting agents go and they have 
good temperature stability. The emulsions are also made as 
cap-sensitive explosives for use in applications which
previously required dynamite or other high explosives.

Both the water-gel slurries and the emulsions may be viewed
as "wet ANFO" combined with a lot of additional technology.

Jerry

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Realize what you are doing
Date: 14 Dec 1995 18:05:30 GMT
Organization: Consulting Chemist
Lines: 24

In article <BILLW.95Dec14032820@puli.cisco.com>, billw@puli.cisco.com
(William ) says:

>    Both the water-gel slurries and the emulsions may be viewed
>    as "wet ANFO" combined with a lot of additional technology.
>
>I guess that's not QUITE as bad as saying "modern microprocessors can
>be viewed as "treated sand" combined with a lot of additional technology".

No, it is not that bad. The analogy of "wet ANFO" is often
reasonably accurate from both the standpoints of chemical
analysis and reaction mechanism.

Jerry

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: Could anyone explain what it is?
Date: 21 Dec 1995 17:49:35 GMT
Organization: Consulting Chemist
Lines: 20

In article <htAENxM.dosl4@delphi.com>, dosl4@delphi.com says:

>Alex Gostevskikh <alexg@nbnet.nb.ca> writes:
> 
>>Can anybody explain what the gelling agent does
>>in ANFO and who makes it?
> 
>The answer is self-evident -- ANFO=Ammonium nitrate/fuel oil. Many
>sources for fuel oil. The purpose is to sensitize the ammonium nitrate,
>which is otherwise
>stable.                    Kind Regards,  Bierstin.

There is no gelling agent in ANFO -none is required.

There are numerous thickeners, such as guar gum which are used
in aqueous ammonium nitrate slurries.

Jerry

*Experience tends to make me very suspicious of Gerald's assertions:-)*
--Bruce Hamilton

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: OKC Bombing recalled by OKC resident - I don't believe two bombs
Date: 17 Oct 1995 04:11:27 GMT
Organization: Consulting Chemist
Lines: 43

In article <riveroDGJoMr.Mzv@netcom.com>, rivero@netcom.com (Michael
Rivero) says:

>In article <45sprs$2br@news.cis.okstate.edu>
>randle@osuunx.ucc.okstate.edu () writes:
>
>>...  Hell, why would you lug a barrel of ANFO around when you could use 
>>a pocketful of C-4.

C-4 is certainly more brisant, but for heaving and air blast effects
ANFO can hold its own pretty well.

>  There are many very real applications where a low velocity explosive
>is far more useful than a high velicity one. In simple terms
>it's the choice between moving something and penetrating it. Let's say a
>truck has flipped over blocking the road and you're about to get strafed.
>C-4 will punch a hole up through the truck, but leave pieces still on the road.
>A low velocity explosive will create a volume of combustion gases which will 
>pick up the truck as a whole unit and toss it off the road in a single piece.

There's only a grain of truth in what you write. It's true that C-4 
is a good hole-puncher, but it can also heave rather well. If you don't
want a hole with your heave, just stand the explosive off slightly or
buffer the target. High explosives generally produce as much or more
gas than low ones, because the latter more often contain metal salts.

>  And don't forget that the thunder and flash of low velocity explosives have 
>a greater psychological effect on the enemy than the "crack" of C-4.

How so? There are fast explosives which make a good boom and there are
explosives which shoot at two stable but very distinct velocities with
exactly the same sound effects. In my experience the sound is related
to the explosion temperature but not to the velocity.  In particular,
it seems that aluminum, even in modest quantities, adds a lot of noise
to HE.

>  Finally, you can make ANFO from pillaged supplies a lot easier than you can
>make C-4.

That's true, but you probably still need to knock over
a magazine to get a blasting cap and primer:)


Jerry

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: sci.chem
Subject: Re: Decomposition of Ammonium Nitrate
Date: 30 Dec 1995 04:29:05 GMT
Organization: Consulting Chemist
Lines: 29

In article <4c226m$ntr@usenet.ucs.indiana.edu>, "John C. Huffman"
<huffman@indiana.edu> says:

>mdudley@brbbs.brbbs.com (MARSHALL DUDLEY) wrote:
>>If you heat ammonium nitrate it decomposes. I believe that 2 NH4NO3 will
>>decompose into 2 N2, 4 H2O and O2.  Is this correct?  If this is correct,
>>then at what temperature does decomposition take place?
>>
>>Marshall
>
>At ca. 210C decomposes mostly into H2O and N2O.  Remember Texas City?

At 210C, yes, but in the texas city explosion it is more likely
that the reaction looked something like this:

8NH4NO3 -> 5N2 + 4NO + 2NO2 + 16H2O

Not counting the loss of nitrogen oxides to fuel impurities.

A trace of organics would have had an enormous effect on the
energy release. Both the above equation and the low temperature
decomposition to N2O yield only about 130 kcal/kg (approximate)
whereas the mixture with 5.7% fuel oil delivers over 1000 kcal/kg.

Like gunpowder, AN does not explode to yield its lowest energy
products. In the presence of fuel oil though, not only the 
theoretical maximum energy increases but also the efficiency in
producing the optimum low-energy products (H2O, N2 and CO2).

Jerry (Ico)

Newsgroups: rec.pyrotechnics
From: tam@quest1.questconsult.com (Timothy Melton)
Subject: Re: Sci Project On Ammonium Nitrate
Date: Tue, 2 Jan 1996 14:26:32 GMT
Followup-To: rec.pyrotechnics

>If Ammonium Nitrate is so safe can you explain Texas City, 1947.  Where 9
>million pounds of it blew up from 2 ships in the harbor and killed 510
>people?  (the investigations determined no outside initiator)

AN is quite safe.  It is extremely hard to initiate without being
intimately mixed with a fuel.  It is, in fact, so difficult to initiate
that blasting powder was used to break up large concreted masses of AN and
AN+ammonium sulfate mixes in Oppau, Germany in the 1920's.  This was done
over 16,000 times without a mishap.  

Texas City was caused by the having the AN prills in intimate contact with
a fuel (the prill coating used back then was paraffin wax).  In addition,
the prills were packaged in paper sacks.  Given sufficient self confinement
(enough that the heat cannot escape) the AN could (and obviously did)
detonate.  The keys here are the fuel and the self-confinement.  Without
these the accident never could have happened w/o stong initiation.

Oh, by the way, after blasting the AN/AS mix over 16,000 times in Oppau, 
the whole mass (~4500 tons) was initiated at about 7:30 a.m. on September
21, 1921.  The explosions destroyed the plant and approximately 700 
nearby houses, and killed 430 persons.  AN is safe unless you REALLY abuse
it.  

Tim



-- 
Tim Melton                    tam@questconsult.com
Quest Consultants Inc.        http://www.questconsult.com/
P.O. Box 721387               (405) 329-7475
Norman, Ok 73070-8069         Fax: (405) 329-7734

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: blowing stumps
Date: 18 Mar 1996 03:07:19 GMT

In article <314CB10F.38B4@olympus.net>, Glenn Smith <gsmith@olympus.net> says:

>Raymond M. Kacmar wrote:
>> 
>> Need to blow some stumps, have used commircial explosivis to do it
>> before, but have a surplus amount of AN fertilizer. Can I use it to make
>> some ANFO to do the job? Any info welcome(precentages, safty info ect.)
>
>        I've used two cups undiluted antifreeze to a 5gal bucket of 
>prills. For best penetration, snap a cap on the bucket with a fitting, 
>and pull a partial vacuum on it(bucket will partially collapse), holding 
>it for 5min. When the vacuums released, the glycol is really sucked into 
>the prills. Much snappier than diesel fuel. Unfortunately, I've had 
>almost no sucess detonating charges of this less than 8" in diameter. And 
>that's with several ounces of double-based powder as a booster! Hope you 
>have BIG stumps...the stuff just doesn't support detonation in small 
>quantities.
>        One asshole with a Ryder truck and the fun's spoiled for 
>everybody.

This "recipe" for ANFO is nonsense. The use of double base powder
also makes no sense. There is no reason to believe that a given
batch of smokeless powder would shoot with a cap. Sucking a partial
vacuum on a bucket of prills sounds like something Rube Goldberg
thought up and would only be useful for crumpling buckets.

ANFO only requires that the fuel and oxidizer be reasonably well 
mixed. The oil will penetrate the prills thoroughly over a period
of an hour or so via its wetting action.

Antifreeze is not a good fuel, and most certainly not as good as the
much cheaper fuel oil. Antifreeze (ethylene glycol) has less than
half the heat of combustion of an equal weight of fuel oil. The 
mixture with antifreeze would also change for the worse with time 
because of the solubility of the AN. 

Any ANFO that requires 8" diameter to shoot is really inferior
junk. When we speak of 8" in testing ANFO, we mean a LONG column
at this diameter. One borehole would take several crumpled buckets.

If you are thinking of using ANFO for stumping, get better 
information from a more reliable source than UseNet. Some people
here often speak authoritatively about things they do not
know anything about.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics,alt.engr.explosives
Subject: Re: Who know's anything about mixing Amonium Nitrate with fuel?
Date: 3 May 1996 05:49:32 GMT

In article <4m9hpf$cqm@odo.PEAK.ORG>, billn@PEAK.ORG (Bill Nelson) says:

>This is bogus. If the mixture contained that much fuel, you would be
>lucky to be able to initiate it with anything.
>
>The best mixture is about 7% oil, if I remember correctly. 
>
>If necessary, I could look up the ratios for the best sensitivy and for
>the best oxygen balance. But maybe Jerry or Norman will save me the effort.

We always recommended 5.7% number 2 fuel oil.  If you make the rough
assumption that the formula of fuel oil is CH2 then the oxygen balanced 
mix based on formula weights (AN = 80, CH2 = 14) calls for a ratio
of 3*80:14. The % fuel thus works out to 100*14/(240+14) = 5.5%. If the
fuel were polyethylene, this percentage would be just right since
the two terminal H's on the long chains don't do much to change the
basic CH2 empirical formula.

Of course aliphatic fuel oil components have much shorter chains than 
PE so the average H:C ratio is a bit higher than 2.0. On the other hand, 
fuels are loaded with aromatics like benzene or its cousins that can 
have empirical H:C ratios at or below 1:1. The latter species dominate 
our fudge factors in this case so we adjust the final ANFO to 5.7% in 
deference to unsaturated molecules.


Just for kicks, let's pretend we want to make benzene ANFO. Now the
ratio becomes 2.5*80:13 (Huh? what'd he do?:)) and the fraction of fuel
in the balanced blasting agent becomes 100*13/(2.5*80+13) = 6.1%.

All of the above, of course, assumes you wanted mainly CO2 in your 
product gases and not CO - which is generally considered a very good
idea :)

3NH4NO3 + CH2 --> 7H2O + CO2 + 3N2 (he probably cheated and it doesn't 
				    balance)

2.5NH4NO3 + CH --> 11/2H20 + CO2 + 5/2N2 (Now I'm sure he's cheating)

Multiply by two if it pleases.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: Who know's anything about mixing Amonium Nitrate with fuel?
Date: 8 May 1996 08:20:04 GMT

In article <trimmDr0BoE.Coo@netcom.com>, trimm@netcom.com (Gary M.
Watson) says:

>In article <4mc6pc$8mo@geraldo.cc.utexas.edu> glhurst@onr.com (Gerald
> L. Hurst) writes:
>
>>In article <4m9hpf$cqm@odo.PEAK.ORG>, billn@PEAK.ORG (Bill Nelson) says:
>>
>>>This is bogus. If the mixture contained that much fuel, you would be
>>>lucky to be able to initiate it with anything.
>>>
>>>The best mixture is about 7% oil, if I remember correctly. 
>>>
>>>If necessary, I could look up the ratios for the best sensitivy and for
>>>the best oxygen balance. But maybe Jerry or Norman will save me the effort.
>>
>>We always recommended 5.7% number 2 fuel oil.  If you make the rough
>>assumption that the formula of fuel oil is CH2 then the oxygen balanced 
>>mix based on formula weights (AN = 80, CH2 = 14) calls for a ratio
>>of 3*80:14. The % fuel thus works out to 100*14/(240+14) = 5.5%. If the
>>fuel were polyethylene, this percentage would be just right since
>>the two terminal H's on the long chains don't do much to change the
>>basic CH2 empirical formula.
>
>How do these adjustments affect sensitivity to detonation?  Does
>proper oxygen balance imply maximum sensitivity?  And how does
>the sensitizers such as aluminum or anhydrous methanol affect
>the calculus?  I note that the Kinestick people used nitromethane
>and finely powdered ammonium nitrate to make a cap-sensitive
>blasting stick akin to dynamite that does not require the usual
>booster of TNT that one associates with traditional ANFO concoctions.
>It is possible that the Kinestick contains aluminum or some
>other powder and the red fluid tube contains some kind of alcohol
>or whatever, but this is not what the salesman told us.
>
>Thanks for any light you can shed on this, Jerry.

Maximum sensitivity in ANFO occurs at about 2% fuel oil, maximum energy 
at 5.7%.  Aluminum sensitizes the mix and has been used in conjunction
with other semi-energetic fuels like dinitrotoluene to make cap-sensitive
explosives such as "moleculite."  Methanol is slightly sensitizing to
ANFO type formulations, but not much - and it would really ruin the
solid for storage because of AN solubility.  Also, MeOH has too low a
flashpoint for blasting agent use.

Kinepak (e.g. kinestick) does not use aluminum and contrary to 
popular belief the solid is not straight AN nor is the liquid straight
NM.  Alcohol is not used in the liquid, but it does contain other fuels
to improve the oxygen balance and optimize energy output.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: anfo
Date: 2 Mar 1997 09:14:16 GMT

In article <00001fe7+00004172@msn.com>, GARRET2@msn.com (GARRET
LECOMPTE) says:

>would somome please tell me what would be the difference between 
>using a pipe bomb instead of a blasting cap to detonate anfo. wouldnt 
>a pipe bombs shockwave be stronger than a blasting caps shockwave? 
>why wouldnt it work? please help.

Most ANFO is insensitive to a blasting cap or a typical pipe bomb.  
Commercial ANFO requires more pressure than is generated by a typical 
pipe bomb and also requires a larger charge than the gram or so of HE 
found in a blasting cap.

HE such as that used in caps can generate pressures of up to 2-4
million psi.  Pipe bombs vary, but usually produce less than 5%
of the potential pressure of HE.

In a nutshell, pipe bombs lack the necessary pressure, and individual
blasting caps lack sufficient total energy output.

Typical ANFO has a critical diameter too large to get a charge going 
with less than several grams of HE and it is best initiated with a 
good fraction of a pound or more of a cap-sensitive HE (i.e., a primer).
ANFO COULD be initiated by a pulse of not more than a few hundred 
thousand psi but it would be very difficult and a true waste of time 
for even an expert to attempt to construct an LE device capable of 
doing the job.  

If you want to initiate ANFO, the easiest way is to simply learn 
to use the material legally and buy the necessary supplies and 
equipment.

I have not discussed the limits of what CAN be done with ANFO-like
materials by altering the chemical and physical properties. This is
a subject which would cover volumes. You will likely see a lot of 
opinions on this matter but it is unlikely that any "recipes" will 
be posted in this forum by those who actually know much about 
explosives.  There is an incredible amount of very bad 
explosive-related information on the net. 

Anyone can learn about this field if they are really motivated to do 
so and spend the time to get some basic training and education, but 
there are no viable shortcuts.  Perhaps it is also true that anyone
can learn to walk a tightrope, but beginners should not start on the
high wire without a net.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Booming and Nothingness (Was Explosives vs. flash powder?)
Date: 31 Oct 1996 03:00:42 GMT

In article <558vrk$oca@news2.ee.net>, jnoonan@ee.net (jnoonan) says:

>Why then is the performance of a watergel explosive better than prill
>ANFO?  Intuitively, one would assume that the addition of water to an
>explosive would steal energy from the reaction through the heat of
>vaporization.  Blasting formulas refer to the explosive density without
>regard to the components of the explosive that is responsible fo that
>increased density.  Is the increased blasting performance provided by
>the viscosity of water, preventing gasses from escaping through the
>cracks in the strata or is all of liquid instantaniously vaporized
>during detonation?

It depends on what you mean by "performance."  A straight AN/water/FO
type of water-gel is less sensitive and less powerful than straight
ANFO because of the water.  Water always extracts an energy penalty
because it must be vaporized.  With the right additives, though, the
aqueous materials have a lot of advantages, beginning with water
resistance.

The early formulations relied on added HE, smokeless powder or finely 
divided metals for energy, sensitivity and density improvements.

There is, however, another great advantage to water-based AN systems
which arises from the complete dispersion of the oxidizer and sometimes
fuel in the aqueous medium.  ANFO is limited in its reaction rates
becuuse it must decompose in relatively large solid crystal units and
then diffuse together with the fuel to react.  Dissolved AN benefits
by not needing fusion heat input and by being dispersed on a molecular
level.  Emulsify in some fuel oil as micron-sized droplets or add soluble
fuel and you are on your way to near molecular fuel-oxidized dispersion.

This dispersion won't buy you much energy but it can allow you to wring 
out the theoretical velocity and accompanying brisance.

Naturally, you still need dispersed void for sensitivity, but in large 
holes with powerful primers you can push the loading density up way
above that of ANFO, on a weight or energy basis, and rely on other 
additives and reduced void for propagation.

Fine fuel/oil contact combined with AN supersaturation (reduced water)
can also yield high velocity and energy in reasonably dense formulations.
I am talking here about WIO emulsions.  These materials also require
void volume, but densities can run up to nearly forty percent greater
than ANFO.  Given a water content of less than, say, 15% these liquid
emulsion analogs of straight ANFO pack a lot of power into the bore hole
and they shoot at velocities up around 20,000 ft per second, which is
quite fast for commercial explosives and represents excellent shattering
power.

The viscosity of the water is unimportant.  The water is vaporized 
instantly and acts only as a gas just as the combustion product water
does.  The water adds a little gas and subtracts a little energy in
the over-all scheme, but it serves as a wonderful dispersion vehicle.

Jerry (Ico)

Subject: Re: ANFO -- Oklahoma Sugggestion
From: nreitzel@lonestar.jpl.utsa.edu (Norman L. Reitzel   )
Date: Apr 22 1995
Newsgroups: rec.pyrotechnics

In article <3n8tm1$15l@newshost.fiu.edu> larkinsg@solix.fiu.edu (Dr
Grover Larkins) writes:

   [snip]

>                            ... that an acceleration chemical may have 
>been used in the ANFO bomb -- Aluminum powder is commonly the material
>of choice ...

Dr. Larkins,

Aluminium is not in any way an "accelerator" of ANFO explosives. 

Aluminium is added to slurry explosives (not ANFO) in order to increase 
the total energy yield of the explosive, but it has the side effect of 
decreasing the velocity of detonation.  (C&E News, 1971)  In point of 
fact, substantial research was necessary in order to find formulations in 
which the energy yielded by aluminum combustion was made available within 
the time window in which the explosive operates. (DuPont, 1973, Tovex 
literature)

Moreover, aluminium (and iron, and -ESPECIALLY- magnesium) is not stable 
when mixed with ammonium nitrate.  If the aluminium is not phlegmatized, 
the mixture rapidly becomes even more hygroscopic than it is normally, 
and under proper conditions will self-ignite.  (Urbanski)  Ammonium 
nitrate is highly acidic, and will in fact dissolve quite a few metals 
very nicely, cf. Dewars' Acid (Practical Inorganic Chem, 1982).

If you want to help, great!  Try to get the info correct, though.

  ------------------------------------------------------------------------
  Norman L. Reitzel, Jr.       |    "When you live beside the graveyard,
  nreitzel@lonestar.utsa.edu   |     you can't cry for every funeral."
  Blue Water Ventures, dba.    |                     Russian Proverb
  ------------------------------------------------------------------------

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: Tovex??
Date: 11 Mar 1996 09:00:49 GMT

In article <4htbmt$klr@news.dgsys.com>, wcovexip@moose.ptialaska.net
(Bruce & Debora Gordon) says:

>Hello Jerry or other compentant Explosive Engineer.  Being up here in
>the frozen north (20°F) and trying to dig foundation footings, I have
>a need for some information concerning DuPont's product Tovex.  Could
>someone supply active ingrediant and detonation velocity?  I am having
>some luck with 1/2 to 3/4 sticks set 2 to 3 feet into the frozen
>ground.  This product seems to shatter the frozen ground structure
>well, without showering the area with loose gravel from the surface.  I
>am just curious what the active ingrediants are for Water Gell
>product's like Tovex.

Tovex is a duPont trade name that has been used on a variety of
blasting agents. Judging from the performance you quoted, which
indicates high brisance and good low temperature tolerance, I 
will guess that it is not a gel but an aqueous water-in-oil
emulsion type material. These  compositions easily hit the 19,000 
feet per second range or better depending on the particular
formulation. They are basically aqueous versions of ANFO, but
there is a lot of technology that goes in to getting the ingredients
into the right stable physical form to shoot. Chemically, these
compositions are not much different from water gels, but they 
are quite different in physical structure and performance, at
least as far as velocity and brisance are concerned.

Jerry (Ico)

From: "Gerald L. Hurst" <glhurst@onr.com>
Newsgroups: alt.engr.explosives
Subject: Re: The FO in ANFO; HE chemistry
Date: Sun, 26 Apr 1998 00:37:31 -0500

Fulmen wrote:

> Aah, then maybe you can answer a question I never have got an good
> answer too.
> I've seen a diagram depicting ANFO sensitivity and energy, with regard
> to fuel percentage. I can't find it, and don't remember the numbers.
> Can you help me there?
> And how does particle size affect this?

Maximum sensitivity occurs ar about 2% FO for normal particle size ranges.
Finer material is more sensitive for a given density and composition as one
would expect for a heterogeneous blend.  The energy output roughly triples
over the range from straight AN to oxygen-balanced ANFO.

Jerry (Ico)

From: "Gerald L. Hurst" <GHURST@austin.rr.com>
Newsgroups: alt.engr.explosives
Subject: Re: SV: Waco
Date: Fri, 29 Oct 1999 23:35:04 GMT

When ANFO is ignited in modest quantities, what usually happens is that
the fuel oil simply burns slowly (using mainly air, not AN) and
eventually melts the surface of the AN and making it it a bit crusty.
The fire usually goes out with plenty of fuel oil still trapped in the
AN.  There is only a slight contribution from AN decomposition and that
lessens rather than increases the smoke.

Very large quantities are another matter because they may wind up
detonating.  The detonation tends to produce smoke which is white,
leaning to orange-brown (from NO2) depending on the oxygen balance.  Well
ballanced ANFO seems to produce more of the orange-brown color when it is
shot in wet holes.  The color is not noticeable in small shots on the
surface.

ANFO does not produce a very heavy smoke when burned or detonated.

Jerry (Ico)

From: "Gerald L. Hurst" <glhurst@onr.com>
Newsgroups: alt.engr.explosives,rec.pyrotechnics
Subject: Re: Truck crash
Date: Sat, 27 Jun 1998 02:22:09 -0500

One can burn ANFO in reasonable quantities without risk,
but 50,000 pounds is a bit beyond reasonable.  The problem
with large quantities is that heat tends to make most explosives
more sensitive.  When you get AN up around its melting
point it gets more sensitive and when in large quantities there
is always the problem that some heavy debris from a structure
will fall and subject some of it to high impact.

Another problem lies in the fact that many liquid or liquified
explosives may become sensitive to LVD phenomena, which are
perhaps not as well unserstood as we would like.

Dave Lyle wrote:

> A few days ago, we had a tanker truck side-swipe with a retaining wall
> on one of our freeways.  The trucks fuel tank ruptured and it caught
> fire.  The driver got out OK.
>
> According to the local news, the truck was carrying 4600 gallons (47,000
> lbs) of ANFO for use at a mining operation north of here.  The
> authorities and the local media treated it like a massive explosion was
> imminent, including evacuation of a 1 mile area around the accident.
> The freeway was shut down for almost 20 hours.
>
> My understanding is that AFNO requires a detonator plus a HE booster to
> set if off, and that simply burning can not cause it to explode.  Why
> were the local officials so concerned?  Were they overreacting, or am I
> missing something?
>
> Dave