Improvements in the Manufacture of Explosives.
Year: 1898

page_text: Date of Application, 7th Sept., 1898
.Complete Specification Left, 7th June, 1899-Accepted, 5th Aug., 1899
Improvements in the Manufacture of Explosives.
I, WILLIAM HENRY CROMIE, of 3, Pump Court, in the County of Middlesex,
Gentleman, do hereby declare the nature of this invention to be as follows: :-
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This invention relates to the manufacture of gun-powder from nitro-cellulose.
The said nitro-cellulose is obtained by steeping cotton in a mixture of nitric
acid and sulphuric acid. By regulating the strength of the acid mixture and
the temperature of working, I obtain a new and hitherto unknown form of nitro-
cellulose which is physically and chemically homogeneous, and does not consist
of a mixture of the so-called insoluble and soluble varieties of, nitrated cotton.
This new form of nitro-cellulose, which contains from 12:44%, to. 125% of nitrogen,
is not affected by alcohol, is capable of being completely dissolved in an excess
of a mixture of alcohol and ether, while with a small quantity of the solvent it
can be thoroughly or, if desired, partially, gelatinized.
***The gelatinized or partially gelatinized product can be shaped by mechanical
means into the form of grains, small pieces. or laminae, and is dried in the ordinary
way either under atmospheric pressure or in vacuo.
Dated this 6th day of September 1898.
I, WILLIAM HENRY CROMIE, of 3, Pump Court, in the County of Middlesex,
Gentleman, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement;-
-
This invention relates to the manufacture of gun-powder from nitro-cellulose.
It is based on the discovery that by regulating the strength of the acid mixture
and the temperature of working, it is possible to obtain a new and hitherto un-
known form of nitro-cellulose, which is physically and chemically homogeneous
and does not consist of a mixture of the so-called insoluble and soluble varieties
of nitrated cotton.
According to the methods heretofore ordinarily employed in the manufacture
of gun-powder from nitro-cellulose, the said nitro-cellulose consisted of a mixture,
in greater or less proportion, of the insoluble and soluble varieties of nitrated
cotton. This gave rise to two defects, for if the insoluble variety were present
in greater proportion, recourse was then necessary to a solvent of the nature of
Price 8dı

page_text: acetone, which produces an unreliable gun-powder for large guns as it is liable
to give high and occasionally dangerous pressures; while on the other hand, if
the soluble variety predominates, although the bulk of the powder could be
dissolved by a mixture of ether and alcohol, the whole of the insoluble nitro-
cotton present would not be affected by the solvent and in consequence thereof
the keeping qualities of the powder would not be at all satisfactory.
To obviate these defects I proceed as follows:-
-
Instead of the ordinary acid mixture I use a mixture containing 58 per cent.
pure sulphuric acid, 29 per cent. pure nitric acid, and 13 per cent. water.
The cotton to be nitrated is immersed in the acid mixture in the proportion
of 1 lb. of cotton to 30 lbs. of acid mixture, or thereabouts, for ten minutes. The
excess acid is then pressed out of the cotton charge in the usual way and the
charge placed in pots for twenty-four hours to complete nitration. Washing and
boiling are performed as for ordinary gun-cotton, but during nitration the tem-
perature is maintained at 70° Fahr.
The nitro-cellulose so produced contains from 1244 to 125 per cent. of nitrogen.
It is capable of being completely dissolved in an excess of a mixture of ether
and alcohol, while with a small quantity of the solvent it can be thoroughly
gelatinized. The gelatinized product can be shaped by mechanical means into
the form of grains, small pieces, or laminae, and is dried in the ordinary way
either under atmospheric pressure or in vacuo. The density of the dry, finished
powder is 162 or thereabouts.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is:-
The process of producing a nitro-cellulose, containing a high per-centage of
nitrogen, which consists solely of soluble nitrated cotton and is not a mixture
of the soluble and insoluble varieties, but can be completely dissolved by a mixture
of ether and alcohol, and on gelatinization by means of that solvent produces a
gun-powder of great purity and density, substantially as specified.
Dated this 6th day of June 1899.