Explosives cast boosters

Carbon oxychloride, 22 Carbonic dichloride, 22 Carbonyl chloride, 22, 49, 75, 101, 184 5-Carboxy-l,3-diamino-2,4,6-trinitrobenzene, 6 Cast booster, 245, 248 Cast explosive, 4-5 Castable explosive, 56, 113 CDNTA, 4, 32, 58, 86, 109, 124, 169, 197. See also 3,5-dinitro-1.2.4-triazole copper salt CE, 4-5,32,58-59,86, 111, 124,173. See also Cast explosive... 

This very brief history relates the development in the commercial explosives industry of an explosive loading and initiation system that emphasized safety. An entire pattern of boreholes can now be loaded with an insensitive blasting agent primed with cast boosters... 

Pourable mixtures of -> TNT and PETN, used for shaped charges and for cast boosters (for initiation of insensitive explosives, such as ANFO). A 50 50 mixture has a density of 1.65 g/cm3 the detonation rate is 7400 m/s = 24300ft/s. 

Aromatic nitro compormds, primarily 2,4,6-TNT, have long use as military explosives and commercial application in cast boosters to initiate insensitive blasting agents. In the laboratory, TNT maybe encountered as prills, flake, or a cast solid ranging in color from light yellow to brown. Acetone solutions of TNT slowly develop a pink color and red is produced with ethanolic KOH. Numerous TLC systems have been described for the identification of TNT, usually with visualization by alcoholic KOH. TLC or GC-MS identification of minor products, other isomers of TNT or DNT, provides information to establish a potential common source. The use of isotope ratio MS is now being explored for this purpose. GC or LC-TEA readily identifies TNT. Combinations of TNT and NH4NO3, known as Amatols , have been used as military explosives to conserve TNT and could be encountered in old military ordnance. 

High explosives—explosive materials that can be caused to detonate by means of a No. 8 Test Detonator. Typical examples include dynamites, cast boosters, and certain emulsions, water gels, and slurries. 

Division 1.1—explosives that have a mass explosion hazard. Typical examples are dynamite, detonator (cap) sensitive emulsions, slurries, water gels, cast boosters, and mass detonating detonators. 

Picric Acid and Ammonium Picrate. Picric acid (PA) (2,4,6,-trinitrophenol) was the first modem high explosive to be used extensively as a burster ia gun projectiles. It was first obtained by nitration of iadigo, and used primarily as a fast dye for silk and wool. It offered many advantages when compressed, it was used as a booster for other explosives, and when cast (melting poiat 122.5°C) served as a burster ia shell it was stable, iasensitive, nonhygroscopic, relatively nontoxic, and of high density when cast, and could be made economically by simple nitration. 

If no other sources exist, artillery and mortar shells, bombs, land mines, and other munitions may be cannibalized for the high explosives they contain. These munitions usually contain cast explosives, which require extra strong blasting caps or boosters to detonate. However, some of the simpler cannibalization techniques will be discussed. 

Pentaerythritol tetranitrate (PETN) (3) is a powerful explosive which exhibits considerable brisance on detonation (VOD 8310 m/s at = 1.77 g/cm ). It is the most stable and least reactive of the common nitrate ester explosives. The relatively high sensitivity of PETN to friction and impact means that it is usually desensitized with phlegmatizers like wax and the product is used in detonation cord, boosters and as a base charge in detonators. Pentaerythritol tetranitrate can be mixed with synthetic polymers to form plastic bonded explosives (PBXs) like detasheet and Semtex-IA. A cast mixture of PETN and TNT in equal proportions is known as pentolite and has seen wide use as a military explosive and in booster charges. The physical, chemical and explosive properties of PETN commend its use as a high explosive. 

A number of important explosives contain nitramino functionality in conjunction with nitrate ester or C-nitro functionality. A-Nitrodiethanolamine dinitrate (DINA) (7) is a powerful explosive which can be melt-cast into charges. A,2,4,6-Tetranitro-A-methylaniline (tetryl) (8) exhibits high brisance (VOD 7920 m/s, d = 1.73 g/cm ) and has found application in both detonators and boosters, in addition to being a component of some composite high explosives. 

Type 94M (Explosive) (Navy). A cream-yellow expl compn consisting of Trinitroanisole 60 RDX 40%. Its cast d was 1.64 Brisance by Cu Cylinder Crusher Method 107% PA Expln Temp 216° Friction Sensitivity 40—50 kg (max pressure betw two rubbing surfaces for no explns) Impact Sensitivity 13 cm (max for no explns with 5-kg wt) Power by Ballistic Mortar 112% PA Rate of Deton by Dautriche Method 7700 m/sec. Originated as powerful expl for loading Torpedo Warheads but this use was discontinued due to its sensitivity to Sympathetic Detonation. Later uses included Shaped Charge Grenades and as a Booster Surround (Ref 1, p 32 as Type 94 Ref 5, p 379 as Type 94M)... 

The two principal loading techniques are casting and pressing. All expls in common military use can be pressed, however, those that are castable are usually cast because of the greater convenience and flexibility of this process. As a rule of thumb, main bursting charges of large cal munitions are cast while small explosive components (initiators to boosters) are pressed... 

Amatol, developed by the British during the first World War, is made by mixing granulated ammonium nitrate with melted trinitrotoluene, and pouring or extruding the mixture into the shells where it solidifies. The booster cavity is afterwards drilled out from the casting. The explosive can be cut with a hand saw. It is insensitive to friction and is less sensitive to initiation and more sensitive to impact than trinitrotoluene. It is hygroscopic, and in the presence of moisture attacks copper, brass, and bronze. 

Note Most TNT blocks arc made of pressed explosive, which can be reliably detonated by a commercial number 8 blasting cap. Cast TNT has a much higher density than the pressed block and is therefore more powerful but also harder to detonate. Cast TNT requires the equivalent of a military J-2 blasting cap or a booster. Cast Pentolite is sensitive to a number 8 blasting cap. 

SENSITIVITY - Sensitive to one 6 blasting cap at densities of. 95 G/cc or less. This foamed cast explosive is sensitive to a dynamite booster at a density of 1.25 or less. These figures are applicable at a charge diameter of 2 inches (5 cm.) or greater. 

The second formula is the best, performance wise, but is not as stable in even short term storage as is the first. In the second formula the emulsifier is not essential, but will yield a more cap sensitive explosive and will ensure a better mixture of the molten salt and the aluminum fuel. This process will produce cast charges of a densities 0.68-1.34 and in a 2" diameter charge will be sensitive to a blasting cap at a density of. 95 G/cc or less. Similar compositions, that are unfoamed, will not be cap or even booster sensitive, unless strong confinement and very large boosters are used. 

High deton pressure boosters such as Pentolite or Tetryl are used as detonators Refs l)Cook (1958), 316-21 2)M.A.Cook H.E.Farnam, Jr, CanP6053l4 (I960) 8t CA 55, 9879 (1961) (Explosive slurries) 3) L.A.Burkardt W.S.McEwan, USP2992088 (1961) CA 55, 26447 (1961) (Explosive Sluny casting) 4)Encycl of Expls, Vol 4, (1969),p D547-L R (Detonation in Slurry Explosives)... 

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