Grain coat Graphite

Coating of proplnt grains with graphite, as often practiced, serves not only as an eliminator of static electricity, but also as a deterrent also ... 

The supported Ni catalysts (5 wt.%) for H2S oxidation were prepared by incipient wetness impregnation of the two supports, i.e. SiC grains and graphite felt coated with carbon nanofibers, with an aqueous solution of Ni(N03)2.6H20 (Merck). After drying overnight at 120°C, the catalysts were calcined at 350°C for 2h in order to decompose the nitrate salt and to form the nickel oxide. The corresponding sulfidic catalysts were obtained by sulfidation of NiO by reaction with a H2S/He flow at 300°C. 

DuPont in the U.S. developed about 1909, a smokeless powder from cotton of relatively low nitrogen that was quite soluble in ether alcohol. A small amount of diphenylamine was used as a stabilizer. After forming the grains and removing the liquid, a coating of graphite was added to make the smokeless powder that was used in the U.S. Other double-base types contain about 25% nitroglycerin. Cotton lint for nitration has been replaced by purified wood cellulose. 

Infallible Propellant. A double-base proplnt consisting of NC (13.25%N) 59.25, NG 40.00 DPhA 0.75%, coated with graphite. Grains 0.055 inch in diam Sl 0.007 inch thick when subjected to 65.5° Surveillance Test and 120°... 

The ball-grain powder is then processed in the conventional manner, i.e. being weighed (11), polished and coated with graphite (12), blended in towers (13), similar to those described above (pp. 628-629), and stored (14). 

CA 26,1125,2320 2867(1932) [NH4C104 or AN (coated with graphite, rosin, paraffin, sand, charcoal, TNT, NC or carbohydrate) mixed with grains... 

Coating smokeless proplnts with graphite usually achieve the following purposes a)aids in removal of static electricity b)acts as burning deterrant c)acts as a lubricant and d)prevents caking or cohesion of the proplnt grains... 

Figure 71. Sweetie Barrel. (Courtesy Western Cartridge Company.) The moist and mixed ingredients of bulk powder, tumbled in this apparatus, take on the form of grains. Similar equipment is used for sugar-coating pills and for applying a deterrent coating or a graphite glaze to grains of colloided smokeless powder.

Schwab Powder. An older Austrian rifle proplnt consisting of solid grains (0.75mm OD) of NC coated with graphite. The charge was 2,75g muzzle velocity 600m/sec with a bullet weighing 15.8g press 1300 atms Ref Daniel (1902), 709... 

Some propint grains are glazed or coated lightly with graphite to decrease the accumulation of static electricity during handling, and to increase the bulk d thru better packing. This... 

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