posted November 18, 1999 01:24 PM         

PRILLED AN-FUEL OIL (Cap sensitive)

DETONATION VELOCITY

Confined = 4600 M/sec.

Unconfined = 3200-4600 M/sec.

DETONATION PRESSURE - 490,000-1,000,000 P.S.I.

SENSITIVITY - One #8 blasting cap will initiate detonation in charges larger than 2.25 inches, but similar untreated prills will not detonate.

USE-

BLASTING - Useful in blasting due to the fact that it is easy and very inexpensive to prepare. This prilled form of the usual ANFO explosives is attractive to the blaster because in nearly all applications this type of prilled ANFO explosive will have a higher detonation rate and therefore an increased performance over it's counterpart.

DEMOLITION - See PRILLED AN-FUEL OIL

MUNITIONS - See PRILLED AN-FUEL OIL

This is a very interesting development of the ANFO explosives. While being very simple it effectivel sensitizes the fertilzer grade of AN when mixed with diesel, so that one blasting cap will detonate the resulting mix. It makes use of the tendancy of e ven small amounts of water to effect the crystalline structure of the prills in such a way that effective density is lowered. This, in conjunction with available fuel, yields an explosive that is cap sensitive. This is one of the most simple cap sensitive explosive compositions in this book.

This procedure really should be performed of all prilled AN explosives. This lowers the actual density of the prills. Giving an optimum density for the proper absorbtion of most ANFO. Compositions with 94.4% AN and 5.6% fuel oil are considered optimum. These will also be cap sensitive. The fuels in the compositians below are considered slightly higher than the ANFO explosive due to sensitivity and performance respectively. Take 40 G. of ammonium nitrate prills (fertilizer grade) and to them add 10 G. (10 cc) water. This mixture is heated to 90 degrees C. (195 degrees F.). All of the prills should dissolve. If not stir the liquid until they do. This liquid (saturated AN-water solution) is then added to a mixture of 14 G. #2 diesel and 186 G. ammonium nitrat e prills (fert. grade). This mixture is stirred and poured into a suitable container (stainless steel pan) and placed in an oven with the thermostat set at 150 degrees F. for 2.5 hours with constant supervision. Ammonium nitrate when mixed with fuels are d angerous when heated. Better and safer than this is to place these wetted prills in a desicator (laboratory drier) or in a container with a vacuum drawn on it and it's contents so as to remove the water. This vacuum method of water removal is best and will yield the highest performance mixtures. ln boiling water off the AN prills under reduced pressure porous prills are produced by the water vapor escape from inside the prills.

--------------------------------------------------------------------------------

These prills will produce cap sensitive mixtures easily with almost any liquid hydrocarbon. Fuel oil, naptha, gasoline, carbondfdisulfide and atmost anything liquid that will combust will work.

AMMONIUM NITRATE (Fert. prills)............40 G. or 14.6%

WATER....................................................10.cc or 4.0%

....................................................................................

AMMONIUM NITRATE (Fert. prills)............186G. or 74.4%

....................................................................................

GASOLINE.................................................5 G. or 2.5%

WAX (PARIFFIN).........................................9 G. or 3.1%

or

DIESEL...................................................................7 G.

ALUMINUM POWDER (400 Mesh)...........................14 G.

This procedure should work on other liquid fuels except the very volatile ones such as gasoline and the alcohols giving easily prepared cap sensitive explosive compositions. Also the substitution of 14 G. of powdered aluminum for 7 G. of the diesel will give a slightly higher performance explosive.

--------------------------------------------------------------------------------

Taken from the book
Improvized fertilizer explosives

posted November 19, 1999 10:30 AM            

------------------
"The knowledge that they fear is a weapon to be used against them." www.50megs.com/nbk2000

The reason the final explosive must have lots of air spaces in it is once the surface reaction (blast) creats a high pressure, the air bubbles reach incandescent temp and ignite all AN surrounding them. Since they are everywhere in this foamed AN, the blast progresses as a detonation wave at the speed of sound in that temperature and that density medium, which is pretty fast. In the old solid prills, this internal reaction didn't occur, and you had to have a booster that could hold the pressure on it long enough for the slower burning to occur. Same effect in black powder. A packed lump will burn slowly. FFFg will flash off in a puff due to the fire permeating the hollow spaces and lighting it all at once. There was a bubble bath additive that also can alter the solidity of prills to make AN go faster.

Know of any easily obtained sources of aluminum powder?