The Chemistry of Powder and Explosives - Sciencemadness Dot Org

328 SMOKELESS POWDER
Ball-Grain Powder
The process for the manufacture of ball-grain powder which
Olsen and his co-workers have devised 26 combines nicely with
Olsen's process for the quick stabilization of nitrocellulose to form
a sequence of operations by which a finished powder may be
produced more rapidly and more safely than by the usual process.
It supplies a convenient means of making up a powder which
contains non-volatile solvents throughout the mass of the grains
or deterrent or accelerant coatings upon their surface.
FIGURE 81. Ball Grains (Smokeless Powder) (3X). (Courtesy Western
Cartridge Company.)
Nitrocellulose, pulped and given a preliminary or sour boiling,
may be used directly without poaching. Deteriorated smokeless
powder, containing nitro derivatives of diphenylamine and acidic
decomposition products, may be reduced to a coarse powder under
water in a hammer mill, and may then be used. Whichever is
used, the first necessity is to stabilize it by complete removal of
the acid. For this purpose, the material in the presence of water
(which may contain a little chalk in suspension or urea in solution)
is introduced into a still where it is dissolved with agitation
in ethyl acetate to form a heavy syrup or lacquer, and is treated
with some substance which is adsorbed by nitrocellulose more
readily than acid is adsorbed. It is a curious fact that nitrocellulose
is dissolved or dispersed by ethyl acetate much more readily
26U. S. Pat. 2,027,114 (1936), Olsen, Tibbitts, and Kerone; also U. S.
Pats. 2,111,075 (1938), 2,175,212 (1939), 2,205.916 (1940).