TNT development

Explosive, Canadian. An aqueous slurry of AN and TNT, developed by Canadian Industries Ltd in collaboration with inventors M.A. Cook and H.E- Famam has been used for open pit blasting at Iron Ore Co of Canada s Knob Lake operations in Newfoundland. The fluid character of the material enables it to be loaded efficiently into bags or directly into the borehole without a container. Because of its high density (1.4) and good water resistance, it. can be loaded... 

During World War II a continuous process for nitrating toluene to TNT developed by J. Meissner [19] and patented in 1941 was introduced at the Schlebusch factory in Germany. The nitration unit consisted of 5 nitrators and 4 separators, as shown in the schematic diagram in Fig. 86. Both the nitrators and the separators... 

The RDX particle size distribution must be carefully controlled to produce castable slurries of RDX and TNT having acceptable viscosity. Several classes of RDX are produced to satisfy requirements for the various pressed and cast RDX-based compositions. A continuous process for medium-scale production of RDX has been developed by Biazzi based on the Woolwich process (79,151—154). 

R. L. Goldstein, "Recent Developments in the Optimisation and Control of Nitration in the Continuous Manufacture of TNT," in Symposium on... 

An enzyme-linked immunosorbent assay (eflsa) has been developed for the detection of residues on hands. As Httle as 50 pg of TNT can be detected (126). Liquid chromatography/thermospray negative-ion tandem ms has been successfully used to detect picogram levels of explosives in post-blast debris (127). 

Example The combustion process in large vapor clouds is not known completely and studies are in progress to improve understanding of this important subject. Special study is usually needed to assess the hazard of a large vapor release or to investigate a UVCE. The TNT equivalent method is used in this example other methods have been proposed. Whatever the method used for dispersion and pressure development, a check should be made to determine if any govern-mentaf unit requires a specific type of analysis. 

Methods for vapor cloud explosion blast prediction based on TNT equivalency are widely used. Over the years, many authors, companies, and authorities have developed their own procedures and recommendations with respect to issues surrounding such predictions. Some of the differences in these procedures include the following ... 

The TNT blast data used A substantial scatter in the experimental data on high-explosive blast can be observed which is due to differences in experimental setup. Although often referenced differently, most recommendations can be tracked back to ground burst data developed by Kingery and Pannill (1964). 

Although it recognized that much higher values have been occasionally observed in vapor cloud explosion incidents, the U.K. Health Safety Executive (HSE) states that surveys by Brasie and Simpson (1968), Davenport (1977, 1983), and Kletz (1977) show that most major vapor cloud explosions have developed between 1% and 3% of available energy. It therefore recommends that a value of 3% of TNT equivalency be used for predictive purposes, calculated from the theoretical combustion energy present in the cloud. 

The equivalent charge weight of TNT is calculated on the basis of the entire cloud content. FMRC recommends that a material-dependent yield factor be applied. Three types of material are distinguished Class I (relatively nonreactive materials such as propane, butane, and ordinary flammable liquids) Class II (moderately reactive materials such as ethylene, diethyl ether, and acrolein) and Class III (highly reactive materials such as acetylene). These classes were developed based on the work of Lewis (1980). Energy-based TNT equivalencies assigned to these classes are as follows ... 

On the basis of an extended experimental program described in Section 4.1.3, Harris and Wickens (1989) concluded that overpressure effects produced by vapor cloud explosions are largely determined by the combustion which develops only in the congested/obstructed areas in the cloud. For natural gas, these conclusions were used to develop an improved TNT-equivalency method for the prediction of vapor cloud explosion blast. This approach is no longer based on the entire mass of flammable material released, but on the mass of material that can be contained in stoichiometric proportions in any severely congested region of the cloud. 

If, on the other hand, a vapor cloud s explosive potential is the starting point for, say, advanced design of blast-resistant structures, TNT blast may be a less than satisfactory model. In such cases, the blast wave s shape and positive-phase duration must be considered important parameters, so the use of a more realistic blast model may be required. A fuel-air charge blast model developed through the multienergy concept, as suggested by Van den Berg (1985), results in a more realistic representation of a vapor cloud explosion blast. 

Conventional TNT-equivalency methods state a proportional relationship between the total quantity of flammable material released or present in the cloud (whether or not mixed within flammability limits) and an equivalent weight of TNT expressing the cloud s explosive power. The value of the proportionality factor—called TNT equivalency, yield factor, or efficiency factor—is directly deduced from damage patterns observed in a large number of major vapor cloud explosion incidents. Over the years, many authorities and companies have developed their own practices for estimating the quantity of flammable material in a cloud, as well as for prescribing values for equivalency, or yield factor. Hence, a survey of the literature reveals a variety of methods. 

Equation (7.4.3) was developed from data on tlie liigh explosive, trinitrotoluene (TNT). 

Table 7-26 [49] has been developed by ratio of relative heats of explosion. For close explosion, i.e., (Z < 3.0 ft./lb / ) and for shapes other than spherical, the TNT equivalent factor can be much greater than those from relative heats of explosion [49]. 

N 16.47%, OB to C02 —103.4%, triclinic needles (from ale). prisms (from acet), mp 238.2°, bp expl at 415°, d 1.48g/cc. Insol in w, si sol in hot ale eth, misc in hot acet benz. Can be prepd by treating mesitylene with a mixt of. nitric sulfuric acids in the cold (Refs 2 3). Blanksma (Ref 4) prepd it by dissolving mesitylene in sulfuric acid, partial sulfonation taking place, and then adding the soln to nitric acid, with the pptn of trinitio-mesitylene. Kholevo (Ref 6) nitrated mesitylene with nitric acid 27, sulfuric acid 69, water 4% to yield white crysts. The expl power of trinitro-mesitylene is less than PA (Ref 9), and it develops a bomb press 84% that of TNT (Ref 8), Its impact sensitivity is 52% that of TNT (Ref 7), and it expls at 415° (Ref 5)... 

A new compn was developed consisting of RDX 35.9, NC (1-2.6% N) 24.5, NG 22.8, DNEtB 10.0, DBuPh 6.6 DPhA 0.2%. It was tough and thermally stable, relatively non-hygroscopic, and insensitive to friction, impact and rifle fire. It was also superior to TNT in rate of detonation and brisaiice. A relatively simple and non-hazardous procedure was developed for its manuf. Another formulation variation was TNT 35, Comp A-3 35, M-l proplnt powder 20, and DNEtB or TEGDN 10%. This was hard and tough at room temp, but softened at 65° (Refs 1 3)... 

TNT appears to have been first prepd by Willbrand (Ref 2) in 1863 and its prepn was further developed by Beilstein Kuhiberg (Ref 3). By the beginning of this century it was already in general use as a military expl... 

In all, the board submitted 32 recommendations as a result of its investigation. They include additional training for personnel in nitration and purification areas to enable them to cope with such emergency situations. The board also recommended the development of sensing equipment to uncover possible hazardous conditions earlier in the TNT manufacturing process . 

Water pollution can be mitigated by aeration of the wash streams formed in the sellite treatment of TNT. Further control can be achieved by incineration of the red water . However, the oxides of nitrogen and the Na2S04 ash thus formed can be troublesome. A recently developed scheme of converting this ash to Na2C03 and H2S, which can then be recycled to form sellite, looks promising... 

Its rate of detonation, as detd by the Dautriche method, was about the same as that of TNT (6880m/sec). Its sensitivity to impact, as detd in Fr, was considerably lower than for PA, but according to tests conducted in Engl, TNPht was more sensitive than PA (Ref 8). When pellets of TNPht (d 0.25g/cc) were fired in a manometric bomb, the pressure developed was 2490kg/sq cm, as against 3230 for PA... 

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