Black powder products

Sulfur is used with charcoal as a fuel component in -> Black Powder. Sublimated sulfur is not completely soluble in carbon sulfide and contains traces of sulfuric acid the use of sublimated sulfur for black powder production is therefore not permitted. 

CaO has been found to react with concentrated Cl-contaming hydrocarbons at around 400°C (8, 9). These reactions have been studied under flow conditions with low concentration for practical use (16, 17). A functionalized CaO is reactive with diluted DCF at 450°C (16). The functionalized CaO was prepared by decomposing calcium citrate under N2 flow at 800°C. The black powder product (160 m /g), composed of CaO and amorphous carbon, was pelletized, packed into a flow reactor, and contacted with a N2 flow containing 2% DCF at 450°C. The reaction products at the outlet were analyzed as a function of time and are shown in Figure 14.4. If the complete reaction... 

Black Powder. Black powder is mainly used as an igniter for nitrocellulose gun propellant, and to some extent in safety blasting fuse, delay fuses, and in firecrackers. Potassium nitrate black powder (74 wt %, 15.6 wt % carbon, 10.4 wt % sulfur) is used for military appHcations. The slower-burning, less cosdy, and more hygroscopic sodium nitrate black powder (71.0 wt %, 16.5 wt % carbon, 12.5 wt % sulfur) is used industrially. The reaction products of black powder are complex (Table 12) and change with the conditions of initia tion, confinement, and density. The reported thermochemical and performance characteristics vary greatly and depend on the source of material, its physical form, and the method of determination. Typical values are Hsted in Table 13. 

The performance of black powder is critically dependent on the degree of intimacy of the components in the product. The manufacture of black powder is essentially a procedure for bringing the ingredients into maximum mutual contact. A detailed flow chart for the conventional process is presented in Figure 10. 

Powdered-product collection, as in pneumatic conveying the spray drying of milk, eggs, and soap and the manufacture of nigh-purity zinc oxide and carbon black... 

The first definite production of plutonium metal was made in November, 1943 by Baumbach and coworkers (1958). Approximately 35 micrograms of PuFi in a small thoria crucible in a high vacuum was reacted with barium metal at 1400 C to yield plutonium metal. The metal was found to have a silvery lustre, a density of about 16 grams j>er cubic centimeter and it rapidly absorbed hydrogen at about 210 C to form a black powder subsequently identified as PUH3 (a proof that metal had been produced). 

Pd NPs were isolated as a black powder from [Pd2(dba)3] under hydrogen pressure at room temperature in THF in the presence of 1 (Pd/1 = 1/0.2) byproducts, dba and its hydrogenated products, were eliminated by pentane washings (Scheme 2). This methodology leads to reproducible synthesis and nearly mono-disperse particles of small size [54]. 

A technical grade of silver difluoride (approximately 85%) is available from Harshaw Chemical Company. Better grades of silver difluoride are available and may be employed. It is important that the silver difluoride be a black powder. If the material is light brown and lumpy, a lower yield of product may be obtained. Normally, the contents of a 1-lb. can (approximately 435-470 g.) are employed. 

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. 

Autoignition of fresh charcoal, but not gunpowder prepared from it, is known to have happened in the black powder industry. (Optimum charcoal for gunpowder production is well short of being fully carbonised). 

Potassium perchlorate (KP KCIO4) is a weU-known oxidizer, used as an oxidizer component of black powder. Since KP produces potassium oxides and condensed products, the high molecular mass Mg of the combustion products is not favorable for its use as an oxidizer in rocket propellants. A mixture of 75 % KP with 25 % asphalt pitch was used as a rocket propellant named Galcit, which was the original prototype of a composite propellant in the 1940 s. Potassium chlorate (KCIO3) is also a crystalline oxidizer, and although it has a lower oxygen content compared... 

Though the oxidation potentials of potassium nitrate (KN KNO3) and sodium nitrate (SN NaN03) are high, both metal nitrates generate combustion products of high Mg, Thus, the specific impulse becomes low when KN or SN is used in a rocket propellant KN and SN are used as major ingredients of explosives and in pyrotechnics. KN is a weU-known material as a major component of black powder. 

Black powder —> gaseous products -I- solid products -I- heat... 

From equation (2.8), the gaseous reaction products are seen to be 3CO2, 3CO and 2N2. Therefore, the reaction produces 8 moles of product gases from 4 moles of KNO3 (404 g) plus 7 moles of charcoal (84 g) plus 1 mole of sulfur (32 g) which is equivalent to a total of 520 g of black powder. 

Assuming the reaction of black powder given in equation (2.8) is at constant pressure if only pressure-volume work is considered, the enthalpy change for the reaction at the temperature concerned is equal to the sum of the enthalpies of the products minus the sum of the enthalpies of the reactants [equation (2.17)],... 

Normally, the standard state is the most stable state at one atmosphere pressure and at the given temperature. Most tabular data, as used for the calculation of reaction temperatures, are given at 0 °C or 298 K. The overall calculation for the heat of reaction of black powder at different temperatures is simplified by using tabulated data of the enthalpy function. Hr — for the reaction products, since no enthalpy measurements can be made in the sense of an absolute quantity. 

Table 2.3 lists the molar internal enthalpies of black powder reaction products such as CO2 where Cp values are the molar heat capacities of the products at constant pressure. Using these, it is possible to estimate the heat of reaction at a particular temperature by assuming two temperature values and summing up the internal enthalpies for the reaction products multiplied by their corresponding number of moles as in Table 2.4. 

Further use of tabulated data (such as those in Table 2.3) enables an estimate to be made of the temperature of the reaction of black powder. Using equation (2.18), the standard enthalpy change may be calculated from the standard heats of formation of the reactants and products as in equation (2.20). 

Figure 2.10 Estimate of the heat of reaction for the 77 17 6 black powder composition from the sum of the product enthalpies at two reference temperatures.

R.J. Blau, G. Chen et al, Moisture Resistant Black Powder Substitute, Methods for Its Production in Granular Form and the Resulting Ballistic Properties , AICHE Annual Meeting, San Francisco, CA, Nov 16-21, 2003. 

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