Black powder analysis

D. R. Mouta and co-workeis, Mayards Analysis of the Final Design of the Improved Black Powder Process, Vols. 1—2, Rpt. J6329, Illinois Institute of Technology, Chicago, 1963. 

Occasionally a colorless solution was obtained at approximately — 50°. In most eases the reaction mixture contained a small quantity of fine suspended black powder (presumably copper metal). Examination of the reaction mixture at this stage by hydrolysis of a sample at —35° and gas chromatographic analysis demonstrated the presence of approximately 10% of 2,4-hexadienes [predominantly the (E),(E)-isomer],... 

An alternative mode for dehydrobenzoannulene decomposition was recently reported by Vollhardt et al. [58]. Non-planar hybrid 81, prepared in low yield via cyclodimerization of known triyne 82 [Eq.(3)], reacted explosively at ca. 250°C to give a nearly pure carbon residue. Solvent extraction of the black powder failed to yield soluble materials such as fullerenes however, analysis of the residue by TEM showed formation of bucky onions and bucky tubes [59], in addition... 

For onsite analysis, the examination of the vast number of samples necessitates the use of quick, reliable, field portable equipment that can rapidly, quantitatively verify the many chemically different types of ammunition, explosives, and pyrotechnics. The most common suite of analytes to detect is large, consisting of very chemically different compounds and usually occurs at trace levels in complex environmental matrices. This suite encompasses smokeless powders, black powders, and numerous propellant and energetic formulations. Detection should also be sought for common decomposition products of these explosives such as the methylanalines, aminonitrotoluenes, nitrotoluenes, mono- and dinitoroglycerines, and the nitrobenzenes under on-site conditions. 

Thermal analytical techniques such as thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC) have all been successfully employed in studying the pyrotechnic reactions of energetic materials such as black powder, as well as of binary mixtures of the constituents. 

The thermal analysis of black powders used for different purposes and containing differing proportions of ingredients can give an indication of the system stoichiometry by virtue of the rate and magnitude of measured exothermic events. 

References on Examination of Dynamites and of Other Blasting Explosives (practiced in USA) 1) W.O. Snelling C.G. Storm, The Analysis of Black Powder and Dynamite , USBurMines Bull 51(1916) 2) C.G. Storm, The Analysis... 

A powdered sample for analysis may be prepared safely by grinding granulated black powder, in small portions at a time, in a porcelain mortar. The powder may be passed through a 60-mesh sieve and transferred quickly to a weighing bottle without taking up an appreciable amount of moisture. 

Further hydrolysis proceeds much slower with very small heat evolution (for R = Et and Bun its value is zero within the accuracy of the experiment, while for R = Pr1 it does not exceed 20% of the overall reaction heat). Composition of the hydrolysis products for all h values approximately corresponds to Ti01s(0R) yR0H, where y = 0.15-1 depending on the nature of alcohol and concentration of alkoxide. Solvating alcohol in the hydrolysis products was confirmed by chemical analysis and IR spectroscopy of the products of their thermal decomposition. Residual carbon on thermal treatment in air is eliminated in two steps — at 300°C with formation of amorphous black powder and then in the process of crystallization at 400 to 500. A mixture of anatase and rutile is usually thus formed, calcination at higher temperature gives pure rutile. 

Analysis of the combustion products of a particular brand of black powder gave the following results56 42.98% of its weight as gases, 55.19% solids, and 1.11% water. Analysis of the solid products (percent by weight) and of the gaseous products (percent by volume) is as follows ... 

In previous casework in which the majority of the FDR particles contained potassium and sulfur, frequently at high levels, it was thought that the ammunition responsible probably contained black powder. In most of the cases the type of ammunition was not known, whereas in others the sampling and analysis of the residue from the interior of the spent cartridge cases confirmed the presence of black powder. 

A selection of old ammunition was tested to confirm that the propellant was black powder. Results of a representative selection of SEM/EDX analysis of the undischarged black powder are presented in Table 20.8. 

The practical consequences of these studies was the discovery that solutions suitable for ion chromatography must be diluted before CZE. This analytical strategy was tested with pipe bomb fragments experimentally prepared with different explosive mixtures (potassium chlorate-Vaseline, black powder, smokeless powder, a mixture of black and smokeless powders) and detonated. Fragments from bombs were extracted with water, filtered, and analyzed. Dual-ion chromatography and CZE analysis were carried out with concordant results. 

Concling [7] recently gave an interesting review on burning black powder and pyrotechnic compositions. He presented diagrams of differential analysis of the behaviour of potassium nitrate, sulphur and their mixture when heated. Figure 84 shows a diagram of KNO,+S mixture. 

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