The Chemistry of Powder and Explosives - Sciencemadness Dot Org

BULK POWDER 289
was called E C. powder (Explosives Company), and consisted of
nitrocotton mixed with potassium and barium nitrates with the
addition of coloring matter and small amounts of other organic
material. It was made into grains which were hardened by being
partially gelatinized with ether-alcohol. A separate company was
organized to develop the invention, and the manufacture was
started at Green Street Green, near Dartford, in Kent.
Schultze powder and E. C. powder are known as bulk sporting
powders, either because they are loaded by bulk or because, for
the same bulk, they have about the same power as black powder.
Bulk powders burn quickly. They are used in shot guns, in hand
grenades, in blank cartridges, and occasionally in the igniter
charges which set fire to the dense colloided propellent powder
which is used in artillery.
Bulk powders are made in considerable variety, but they consist
always of nitrocellulose fibers which are stuck together but
are not completely colloided. Some contain little else but nitrocellulose;
others contain, in addition to potassium and barium
nitrates, camphor, vaseline, paraffin, lampblack, starch, dextrine,
potassium dichromate or other oxidizing or deterrent salts, and
diphenylamine for stabilization, and are colored in a variety of
brilliant hues by means of coal-tar dyes. In the United States
bulk powders are manufactured by one or the other of two processes,
either one of which, however, may be modified considerably;
the materials are incorporated under wooden wheels,
grained, and partially gelatinized, or the grains arc formed in a
still where a water suspension of pulped nitrocellulose is stirred
and heated with a second liquid, a solvent for nitrocellulose which
is volatile and immiscible with water.
Three typical bulk powders arc made up according to the
approximate formulas tabulated below. The nitrogen content of
Nitrocellulose
% N in nitrocellulose
Potassium nitrate
Barium nitiate
Starch
Paraffin oil
Diphenylamine
84 0
1315
75
75
10
87 0
1290
60
20
40
10
89 0
1290
60
30
10
the nitrocellulose is an average secured by mixing pyrocellulose
and guncotton. A batch usually amounts to 200 pounds, 100
10