Blasting agents consist of mixtures of fuels and oxidizers, none of which are classified as explosive. Nitrocarbonitrate is a classification given to a blasting agent under the U. S. Department of Transportation regulations on packaging and shipping. A blasting agent consists of inorganic nitrates and carbonaceous fuels and may contain additional nonexplosive substances such as powdered aluminum or ferrosilicon to increase density. The addition of an explosive ingredient such as TNT changes the classification from a blasting agent to an explosive. Blasting agents may be dry or in slurry forms. Because of their insensitivity, blasting agents should be detonated by a primer of high explosive.

Ammonium nitrate- fuel oil (ANFO) has largely replaced dynamites and gelatins in bench blasting. Denser slurry blasting agents are supplanting dynamite and gelatin and dry blasting agents. The most widely used dry blasting agent is a mixture of ammonium nitrate prills (porous grains) and fuel oil. The fuel oil is not precisely CH2, but this is sufficiently accurate to characterize the reaction. The right side of the equation contains only the desirable gases of detonation, although some CO and N02 are always formed. Weight proportions of ingredients for the equation are 94.5 percent ammonium nitrate and 5.5 percent fuel oil. In actual practice the proportions are 94 percent and 6 percent to assure an efficient chemical reaction of the nitrate.

Uniform mixing of oil and ammonium nitrate is essential to development of full explosive force. Some blasting agents are premixed and packaged by the manufacturer. Where not premixed, several methods of mixing in the field can be employed to achieve uniformity. The best method, although not always the most practical one, is by mechanical tier. A more common and almost as effective method of mixing is by uniformly soaking prills in opened bags with 8 to 1O percent of their weight of oil. After draining for at least a half hour the prills will have retained about the correct amount of fuel oil.

Fuel oil can also be poured onto the ammonium nitrate in approximately the correct proportions as it is poured into the blasthole. For this purpose, about i gal of fuel oil for each 100 lb of ammonium nitrate will equal approximately 6 percent by weight of oil. The oil can be added after each bag or two of prills, and it will disperse relatively rapidly and uniformly.

Inadequate priming imparts a low initial detonation velocity to a blasting agent, and the reaction may die out and cause a misfire. High explosive boosters are sometimes spaced along the borehole to as sure propagation throughout the column. In charge diameters of 6 in. or more, dry blasting agents attain confined detonation velocities of more than i2,000 fps, but in a diameter of 1- 1/2 in., the velocity is reduced to 60 percent.

Advantages of insensitive dry blasting agents are their safety, ease of loading, and low price. In the free-flowing form, they have a great advantage over cartridge explosives because they completely fill the borehole. This direct coupling to the walls assures efficient use of explosive energy. Ammonium nitrate is water soluble so that in wet holes, some blasters pump the water from the hole, insert a plastic sleeve, and load the blasting agent into the sleeve. Special precautions should be taken to avoid a possible building up of static electrical charge, particularly when loading pneumatically. When properly oxygen- balanced, the fume qualities of dry blasting agents permit their use underground. Canned blasting agents, once widely used, have unlimited water resist-ance, but lack advantages of loading ease and direct coupling to the borehole.

The specific gravity of ANFO varies from 0.75 to 0.95 depending on the particle density and sizes. Table 3-6 shows how confined detonation velocity and charge concentration of ANFO vary with borehole diameter. Pneumatic loading results in high detonation velocities and higher charge concentrations, particularly in holes smaller than 3 in. (otherwise such small holes are not usually recommended for ANFO blasting).

Baratol

Baratol is a composition of barium nitrate and TNT. TNT is typically 25-33% of the mixture with 1% wax as a binder. The high density of barium nitrate gives baratol a density of at least 2.5. Early implosion atomic bombs, like the Gadget exploded at Trinity in 1945, the Soviet's Joe 1 in 1949, or India in 1972, used an Composition-B [RDX-TNT mixture] as the fast explosive, with baratol used as the slow explosive.

Composition A

Composition A is a was-coated, granular explosive consisting of RDX and plasticizing was. Composition A is used by the military in land mines and 2.75 and 5 inch rockets. Comp A-3 explosives are made from RDX and wax. Composition A-3 is a wax-coated, granular explosive, consisting of 91% RDX and 9% desensitizing wax. Composition A-3 is not melted or cast. It is pressed into projectiles. It is nonhygroscopic and possesses satisfactory stowage properties. Composition A-3 is appreciably more brisant and powerful than TNT; its velocity of detonation is approximately 27,000 fps. It may be white or buff, depending upon the color of the wax used to coat the powdered RDX. Composition A-3 is used as a fillerinprojectiles that contain a small burster cavity, such as antiaircraft projectiles. It can be used as compressed fillers for medium-caliber projectiles.

Composition B is a mixture of 59% RDX, 40% TNT, and 1% wax. The TNT reduces the sensitivity of the RDX to a safe degree and, because of its melting point, allows the material to be cast-loaded. The blast energy of Composition B is slightly higher than that of TNT. Composition B is nonhygroscopic and remains stable in stowage. It has an extremely high-shaped-charge efficiency. The velocity of detonation is approximately 24,000 fps, and its color ranges from yellow to brown. Composition B has been used as a more powerful replacement for TNT in loading some of the rifle grenades and some rocket heads. It can be used where an explosive with more power and brisance is of tactical advantage and there is no objection to a slight increase of sensitivity. While no longer used in newer gun projectiles, some older stocks may be found with Composition B main charges.

Factors for Equivalent Weight of Composition B Explosive Equivalent:

Composition B-3

During the development of a series of melt-castable explosive formulations devoid of TNT, non-TNT formulations yielded self-heating temperatures significantly lower than predicted. In other tests, Composition B (59.5% RDX, 39.5% TNT, 1% wax) demonstrated an exceedingly low self-heating temperature that ultimately results in a violent final reaction. It is often processed above its self-heating temperature, yet it is safely processed in 300-gallon melt kettles. Researchers subjected Composition B and its individual energetic components to one-liter cook-off testing. They expanded their investigations to include neat TNT, neat RDX (HRDX), an insensitive RDX (IRDX) essentially absent of microinclusions and voids, and Composition B-3 (60% RDX, 40% TNT) made with IRDX. Following analysis of these tests, researchers also tested an HRDX/TNT (13% HRDX, 87% TNT) mixture.

Neat TNT is thermally destabilized by the presence of RDX, either HRDX or IRDX, indicating that RDX is the trigger in the thermal decomposition process associated with Composition B (HRDX) and Composition B-3 (IRDX). The reaction violence of both neat HRDX and Composition B made with HRDX were exceedingly violent, with either partial detonation or detonation occurring. Additionally, researchers observed that the reaction of Composition B-3 (IRDX/TNT) was more violent than either neat TNT or neat IRDX. Once again, they hypothesized that solubilized RDX in molten TNT was the source of the effect. They believe the high-quality, defect-free crystals of IRDX were modified by a dynamic equilibrium in molten TNT, with IRDX solubilized and reprecipitated as ill-defined, voided crystals similar to HRDX. They suspect these ill-defined RDX crystallites present at cook-off temperatures were the source of the reaction violence at cook-off.

Composition C-3

Composition C-3 is one of the Composition C series that has now been replaced by C-4, especially for loading shaped charges. However, quantities of Composition C-1 and Composition C-2 may be found in the field. Composition C-1 is 88.3% RDX and 11.7% plasticizing oil. Composition C-3 is 77% RDX, 3% tetryl, 4% TNT, 1% NC, 5% MNT (mononitrotoluol), and 10% DNT (dinitrotoluol). The last two compounds, while they are explosives, are oily liquids and plasticize the mixture. The essential difference between Composition C-3 and Composition C-2 is the substitution of 3% tetryl for 3% RDX, which improves the plastic qualities. The changes were made in an effort to obtain a plastic, puttylike composition to meet the requirements of an ideal explosive for molded and shaped charges that will maintain its plasticity over a wide range of temperatures and not exude oil.

Composition C-3 is about 1.35 times as powerful as TNT. The melting point of Composition C-3 is 68°C, and it is soluble in acetone. The velocity of detonation is approximate y 26,000 fps. Its color is light brown. As with Composition B, Composition C is no longer being used as a gun projectile main charge. However, some stocks may still be in service with Composition C-3 used as a main charge.

Composition C-4 / Comp C-4 Plastic Explosive

The plasticized form of RDX, composition C-4, contains 91% RDX, 2.1% polyisobutylene, 1.6% motor oil, and 5.3% 2-ethylhexyl sebacate.

The Demolition charge M183 is used primarily in breaching obstacles or demolition of large structures where large charges are required (Satchel Charge). The charge assembly M183 consists of 16 block demolition charges M112, four priming assemblies and carrying case M85. Each Priming assembly consists of a five-foot length of detonating cord assembled with two detonating cord clips and capped at each end with a booster. The components of the assembly are issued in the carrying case. The demolition charge M112 is a rectangular block of Composition C-4 approximately 2 inches by 1.5 inches and 11 inches long, weighing 1.25 Lbs. When the charge is detonated, the explosive is converted into compressed gas. The gas exerts pressure in the form of a shock wave, which demolishes the target by cutting, breaching, or cratering.

Using explosives provides the easiest and fastest way to break the frozen ground. However, the use of demolitions will be restricted when under enemy observation. Composition C-4, tetrytol, and TNT are the best explosives for use in northern operations because they retain their effectiveness in cold weather. Dig a hole in the ground in which to place the explosive and tamp the charge with any material available to increase its effectiveness. Either electric or nonelectric circuits may be used to detonate the charge. For a foxhole, 10 pounds of explosive will usually be sufficient. Another formula is to use 2 pounds of explosive for every 30 cm (1') of penetration in frozen ground.

DMDNB

DMDNB (2-3 dimethyl, 2-3 dinitrobutane) is a new, military unique compound used as a tagant in C-4 explosive. Therefore there is no OSHA or ACGIH standard. However, USACHPPM's Toxicology Directorate did a study to determine an Army Exposure Limit. There is no toxicological data for DMDNB's effects on the human body, but tests were done on laboratory animals and they showed a reversible liver hypertrophy in rats that were exposed to DMDNB. An exposure level was determined and a one thousand fold safety factor was used to lower the Army exposure level to 0.15 mg/m^3. (At this level there are no warning properties, i.e. smell, taste, etc.)

Composition H6 / COMP H6

H-6 is an Australian produced explosive composition. Composition H6 is a widely used main charge filling for underwater blast weapons such as mines, depth charges, torpedoes and mine disposal charges. The M21 AT mine is 230 millimeters in diameter and 206 millimeters high. It weighs 7.6 kilograms and has 4.95 kilograms of Composition H6 explosive.

In weapon applications, computational models require experimental data to determine certain specific output parameters of H6 to predict various underwater blast scenarios. To this end, the critical diameter dc, which is the minimum diameter which will sustain a stable detonation, and the limiting value of the velocity of detonation at infinite charge diameter D-infinity, were determined for unconfined cylinders of H6.

Cyclotol [Composition B]

Cyclotol, which is a mixture of RDX and TNT, is an explosive used in shaped charge bombs.

CXM-6

On 30 August 1999 Holston Army Ammunition Plant restarted production of new explosives to fill an order for Composition CXM-3. This is the first new explosive production by Royal Ordnance North America (RONA) as the operating contractor at Holston. CXM-3 will be supplied to Atlantic Research Corporation to fill warheads for the Tomahawk missile system. RONA is also planning to produce other RDX and HMX products, including approximately 800,000 pounds of Composition C-4, by the end of December.

Detasheet is a plastic explosives, manufactured by DuPont containing PETN with nitrocellulose and a binder. It is manufactured in thin flexible sheets with a rubbery texture, and is generally coloured either reddish/orange (commercial) or green (military). In use, it is typically cut to shape for precision engineering charges.

Source: http://www.globalsecurity.org/military/systems/munitions/explosives-compositions.htm