Improvements in and connected with the Manufacture of Explosives.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with the Manufacture of Explosives.
I, JOSEPH OKELL, of 93, Portsdown Road, Maida Hill, in the County of London,
Gentleman, do hereby declare the nature of this invention (a communication
from Hermann Pipitz, Chemist, of Marchegg, near Vienna, Austria), to be as
follows:-
This invention relates to the manufacture of smokeless explosives, such as gun-
powder suitable for military rifles, artillery powder, and sporting powder. It consists
in an improved process for the manufacture of nitro-cellulose suitable as raw material
for explosives, and in processes for the manufacture of various kinds of powder by
means of the nitro-cellulose thus obtained.
For producing nitro-cellulose I take blocks of wood, preferably alder wood, from
which the bark has been removed, and soften the said blocks by steaming or by
prolonged steeping in water, in order to facilitate further treatment. Subsequently
I produce short shavings, by means of a suitable machine cutting across the grain.
These shavings are then relieved of acid by boiling with soda solution, about a
hundred parts (by weight) of shavings being boiled from two to three hours in water
containing about two parts of calcined soda and two parts of caustic soda.
After the shavings have been carefully washed, they are exposed to steam at a
pressure of 3 to 4 atmospheres for about 15 minutes, in order to destroy the
albuminoids, subsequently they are again boiled and carefully washed. In order to'
destroy the colouring matter, the shavings, when still moist, are steeped in #L
chloride of lime solution containing about 8% of chloride of lime, then again boiled,
carefully washed and dried.
The cellulose obtained as described is now nitrated by subjecting it to the action
of a mixture of sulphuric and nitric acid for about two hours. This is preferably
effected in a nitrating pot or in a series of nitrating pots, a third of the quantity of
the acid mixture intended for such a pot being first poured into the same, after
which the corresponding quantity of cellulose and the rest of the acid mixture is
gradually added in small instalments.
The acid mixture employed consists preferably of one part by weight of nitric acid
having from 1.49 to 1.50 specific gravity, and three parts of sulphuric acid of
about 1.84 specific gravity; about 11 parts of the acid mixture are employed for one
part of cellulose. Care should be taken during the nitrating process, that the tem-
perature will not exceed about 21 degrees Cent.
The nitrated cellulose is relieved of the excess of acid by pressure, and then
carefully washed. In order to remove any trace of free acid, that may have remained,
the nitro-cellulose is subjected to the action of a 2 per cent. soda solution for several
hours, then well washed and compressed.
The nitro-cellulose thus obtained constitutes an intermediate product which is
used in the manufacture of various kinds of powder.
The composition of each kind of powder and the process for its manufacture
differ according to its special purpose, that is to say, whether it is to be used

page_text: for military rifles, artillery, or sporting rifles, or for blasting purposes. Sporting
powder differs again according to its application for bullets or for small shot.
Powder for military rifles is produced as follows:—
Before treating the nitro-cellulose with soda-solution as described above, it is dried
at a temperature between 40 and 50 degrees C., until the moisture contained in it
does not exceed from 5 to 8%, and then it is reduced to very fine powder.
Subsequently, about 100 parts (by weight) of this powder are placed in a
suitable mixing vessel, together with a mixture of about 78 parts (by weight) of
sulphuric ether, 12 parts of absolute alcohol and 10 parts of acetone, and the
whole is rapidly mixed so as to form a pasty mass which is allowed to stand
about ten minutes, while preventing the access of air. Subsequently the mass
thus obtained is rolled into sheets of about 1 or two millimetres thickness, then
provided with longitudinal and transverse grooves by means of a grooved roller,
so that the mass can be easily broken into grains by hand.
If these grains are rapidly placed in a still heated by means of a water bath, from
50 to 60 per cent. of the liquid mixture mentioned above may be recovered by dis-
tillation. After this has been done, the grains are placed in an acid mixture similar
to that which has been used for the nitration of the cellulose, and are left in this
mixture about 10 hours, while periodically stirring. The proportions are about 4 parts
of acid to one part of the grains. Subsequently the grained powder is separated from
acid by a centrifugal machine, then carefully washed, then subjected to a mixture of
about 3 to 5 parts of caustic ammonia in 100 parts of water, again washed and
dried.
The grained powder thus treated is then placed in a boiling solution of 1 part of
potassium nitrate and about 5 parts of barium nitrate in about 60 parts of water, left
therein for about 15 minutes, and then dried, after which the product thus obtained
is mixed with a 5% collodion solution, about 15 parts of collodion solution being
taken for every 100 parts of the product. The ether contained in the collodion may
be subsequently recovered by distillation.
The grain powder is now condensed or compressed by means of a cylinder in the
manner well known, the desired quantity of powder grains being weighed off and
exposed to a suitably high pressure, until the powder forms a coherent cake, which,
however can be caused to crumble into grains by slight manipulation.
Finally the powder is polished in suitable drums or other receptacles, with the aid
.of about part of finely scraped paraffin added to 100 parts of the powder.
The process for the manufacture of artillery powder is as follows:-
After the cellulose has been nitrated, relieved of superfluous acid by pressure and
then washed, as described above, the press cakes of nitro-cellulose, when still moist,
are mixed with ammonium nitrate or potassium nitrate (saltpetre) and barium
nitrate between rollers or under edge runners, and the mixture is dried, until it
contains only about 5 per cent. of moisture. In the same manner and in the same
proportion as described above, this mass is now incorporated with the mixture of
sulphuric ether, alcohol and acetone mentioned above, then relieved of the super-
fluous solvent by distillation, and then divided into grains by means of smooth rollers
and grooved rollers which grains, however, are much larger than those of the rifle 4
powder. Finally the grains are compressed and polished, as has been described in
the case of rifle powder.
The composition of this powder varies according to the size of the grains. For
instance, I may take 80 parts of nitro-cellulose, 5 parts of saltpeter (ammonium or
potassium nitrate) and 15 parts of barium nitrate. Instead of this, however, I may
employ from 80 to 88 part of nitro-cellulose with 10 to 12 parts of nitrates, or
75 parts of nitro-cellulose with 25 parts of nitrates.
Sporting powder for bullets is obtained by intimately mixing the moist press
cakes of nitro-cellulose with ammonium bichromate or with potassum nitrate between
rollers or under edge runners, and then drying the mixture until it contains less 5
that 5% of liquid. The proportions of this mixture are approximately 94 parts of
cellulose (calculated as being dry) to one part of ammonium bichromate and 5 parts

page_text: of potassium nitrate. The mass thus obtained is again treated with the mixture of
ether, alcohol and acetone in the same manner and in the same proportion as in the
process described above, and then subjected to distillation.
The subsequent graining, compressing and polishing take place as described above,
except that slightly more paraffin (1 per cent.) is used for polishing.
For making sporting powder suitable for sinall shot, the press cakes of nitro-
cellulose are mixed with barium nitrate (about 18 per cent.), potassium nitrate
(about 3 per cent.) and a solution of gum tragacanth in water (about 2 per cent.),
care being taken that the mixture contains for every 100 parts of dry substance
about 105 to 110 parts of water. In this way a plastic mass is obtained, which is
then placed on fine meshed sieves and divided into small pieces. The latter are then
rounded by grinding in suitable drums and subsequently dried between 40 and 50
degrees C.
Dated this 5th day of September 1898.
FAIRFAX & WETTER,
Agents for the Applicant.
Improvements in and connected with the Manufacture of Explosives.
I, JOSEPH OKELL, of 93, Portsdown Road, Maida Hill, in the County of London,
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 various kinds of gunpowder from
nitro-cellulose or nitro-lignose, and to a special process for obtaining structureless
nitro-cellulose or nitro-lignose suitable as raw material for gunpowder.
The object of this invention is the economical manufacture of smokeless gun-
powder which combines great ballistic power with a high degree of stability and
safety.
The improvements chiefly consist in an improved process for coating and finishing
army rifle powder and artillery powder after granulation, also in a special manufacture
of sporting powder for shot guns, from structureless nitro-cellulose and a binding.
substance which is not a solvent of nitro-cellulose, preferably gum tragacanth, and in
certain details of procedure or series of operations and compositions of matter, as will
be hereafter more fully described and specified by the claims.
For producing nitro-cellulose I take blocks of wood, preferably alder wood, from
which the bark has been removed, and soften the said blocks by steaming or
by prolonged steeping in water, in order to facilitate further treatment. Subse-
quently I produce very fine shavings, from 1-5 to 1-3 millimetres thick, by
means of a suitable machine cutting across the grain. These shavings are then
relieved of acid by boiling with soda solution, about a hundred parts (by weight)
of shavings being boiled from two to three hours in water containing about
two parts of calcined and two parts of caustic soda. After the shavings have
been carefully washed, they are exposed to steam at a pressure of 3 to
4 atmospheres for about 15 minutes, subsequently they are again boiled and carefully
washed. In order to destroy the colouring matter, the shavings when still moist are
steeped in a chloride of lime solution containing about 8 % of chloride of lime, then
again boiled, carefully washed and dried.
The cellulose obtained and purified as described is now nitrated by subjecting it to
the action of a mixture of sulphuric and nitric acid. This is preferably effected in a

page_text: nitrating pot or in a series of nitrating pots, a third of the quantity of the acid mixture
intended for such a pot being first poured into the same, after which the corresponding
quantity of cellulose and the rest of the acid mixture are gradually added in small
instalments.
The acid mixture employed consists preferably of one part by weight of nitric acid
having from 1.49 to 1.50 specific gravity and about three parts of sulphuric
acid of about 1.84 specific gravity; about 11 parts of the acid mixture is employed for
one part of cellulose, and the mixture is allowed to act for about two hours, care
being taken that during the nitrating process the temperature will not exceed about
21 degrees Cent.
The nitrated cellulose is relieved of the excess of acid by pressure, and then
carefully washed. In order to remove any trace of free acid that may have remained,
the nitro-cellulose is subjected to the action of a 2 per cent. soda solution for several
hours, then well washed and compressed.
The nitro-cellulose thus obtained constitutes an intermediate product suitable for
the manufacture of various kinds of powder.
The composition of each kind of powder and the process for its manufacture differ
according to its special purpose, that is to say, whether it is to be used for military
rifles, artillery or sporting rifles. Sporting powder differs again according to its
application for bullets or for small shot.
Powder suitable for military rifles is produced as follows:---
Before treating the nitro-cellulose with soda solution as described above, it is dried
at a temperature between 40 and 50 degrees C., until the moisture contained in it
does not exceed from 5 to 8 %, and then it is reduced to very fine powder.
Subsequently, about 100 parts (by weight) of this powder are placed in a suitable
mixing vessel, together with a mixture of about 78 parts (by weight) of sulphuric
ether, 12 parts of absolute alcohol, and 10 parts of acetone, and the whole is rapidly
mixed so as to form a pasty mass which is allowed to stand for about 10 minutes,
while preventing the access of air. Subsequently the mass thus obtained is rolled
into sheets of about 1 to 2 millimetres thickness, then provided with longitudinal
and transverse grooves by means of a grooved roller or rollers, so that the mass can
be easily broken into grains by hand. If these grains are rapidly placed in a still
heated by means of a water bath, from 50 to 60 per cent. of the liquid mixture
mentioned above may be recovered by distillation. Although I prefer the
granulation by means of grooved rollers as described, other suitable methods of
granulation may be adopted.
After this has been done, the grains are placed in an acid mixture similar to that
which has been used for the nitration of the cellulose and are left in this mixture
about 10 hours, while periodically stirring. The proportions are about 4 parts of
acid to one part of the grains. Subsequently the grained powder is separated from
acid by a centrifugal machine, then carefully washed, then subjected to a mixture of
about 3 to 5 parts of caustic ammonia in 100 parts of water, again washed and
dried.
The grain powder thus treated is then placed in a boiling solution of one part of
potassium nitrate and about 5 parts of barium nitrate in about 60 parts of water, left
therein for about 15 minutes, and then dried, after which the product thus obtained
is mixed with 5% collodion solution, about 15 parts of collodion solution being taken
for every 100 parts of the product. The ether contained in the collodion may be
subsequently recovered by distillation.
The grain powder is now condensed or compressed by means of a cylinder in the
manner well-known, the desired quantity of powder grains being weighed off and
exposed to a suitably high pressure, until the powder forms a coherent cake, which,
however, can be caused to crumble into grains by slight manipulation.
Finally the powder is polished in suitable drums or other receptacles, with the aid
of about one part of finely scraped paraffin added to 100 parts of the powder. Instead
of paraffin, a corresponding quantity of stearin or similar heavy hydro-carbon may be
employed, and instead of ordinary collodion, known substitutes for the same may be

page_text: used, the principal feature being, that powder grains of highly explosive material are
first coated with a dense and coherent film of less explosive or inert material, then
compressed, and finally coated with a smooth waterproof and slowly burning outer
film.
The process for the manufacture of artillery powder is as follows:-
After the cellulose has been nitrated, relieved of superfluous acid by pressure, and
then washed, as described above, the press cakes of nitro-cellulose, when still moist, are
mixed with ammonium nitrate or potassium nitrate (saltpetre) and barium nitrate
between rollers or under edge runners, and the mixture is dried, until it contains
5 per cent. of moisture. In the same manner and in the same proportion as described
above, this mass is now incorporated with the mixture of sulphuric ether, alcohol and
acetone mentioned above, then relieved of the superfluous solvent by distillation, and
then divided into grains by means of smooth rollers and grooved rollers, which grains,
however, are much larger than those of the rifle powder. Finally the grains are
compressed and polished, as has been described in the case of rifle powder.
The composition of this powder varies according to the size of the grains. For
instance, I may take 80 parts of nitro-cellulose, 5 parts of saltpetre (ammonium or
potassium nitrate) and 15 parts of barium nitrate. Instead of this, however, I may
employ from 80 to 88 parts of nitro-cellulose with 10 to 12 parts of nitrates or
75 parts of nitro-cellulose with 25 parts of nitrates.
Sporting powder for bullets is obtained by intimately mixing the inoist press cakes
of nitro-cellulose with ammonium bichromate or with potassium nitrate between rollers
or under edge runners, and then drying the mixture, until it contains less than 5% of
the liquid. The proportions of this mixture are approximately 94 parts of cellulose
(calculated as being dry) to one part of ammonium bichromate and 5 parts of potassium
nitrate. The mass thus obtained is again treated with the mixture of ether, alcohol
and acetone in the same manner and in the same proportion as in the process
described above, and then subjected to distillation.
The subsequent graining, compressing and polishing take place as described above,
except that slightly more paraffin, (1 per cent.) is used for polishing.
For making sporting powder suitable for small shot, the press cakes of nitro-
cellulose are mixed with barium nitrate (about 18 per cent.), potassium nitrate (about
3 per cent.), and a solution of gun tragacanth in water (about 2 per cent.), care being
taken, that the mixture contains for every 100 parts of dry substance about 108
to 110 parts of water. In this way a plastic mass is obtained, which is then placed
on fine ineshed sieves and divided into small pieces, the latter are then rounded by
grinding in suitable drums and subsequently dried between 40 and 50 degrees C.
If a low gas pressure is desired, I increase the quantity of gum tragacanth to
3 per cent. and add to the mixture 2 per cent. of vaseline.
A small quantity of vaseline (from 2 to 5 per cent.) or other oleaginous body may
be used also in the composition of the other kinds of gunpowder, for producing special
effects.
The process described above for the manufacture of structureless nitro-cellulose or
nitro-lignose is applicable also to other ligneous raw materials, such as peat fibre,
straw, hemp, flax, the said fibrous materials being pressed into blocks sufficiently
hard, that they can be cut into fine shavings, which are subsequently relieved
of non-ligneous admixtures or elements by treatment with water and suitable
chemicals.
The process described above for obtaining or preparing cellulose or lignose suitable
as a raw material for the manufacture of nitro-cellulose is applicable also for the
manufacture of chemical products other than nitro-cellulose, and I propose to claim
this extension in a separate application for a patent.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In the manufacture of gunpowder mainly consisting of nitro-cellulose. the

page_text: process of coating and finishing the powder grains, which consists in first coating
them with collodion and driving out the superfluous solvent, then condensing or
compressing the powder, and finally coating it with paraffin, substantially as
described.
2. In the manufacture of sporting powder mainly consisting of nitro-cellulose, the
application of structureless nitro-cellulose, in combination with an adhesive liquid or
binding substance such as a solution of gum tragacanth, in lieu of a gelatinizing
medium or solvent, substantially as described.
3. In the manufacture of gunpowder mainly consisting of nitro-cellulose, the
repeated nitration of the powder after granulation, substantially as and for the purpose
described.
4. The various processes described above for the manufacture of rifle powder,
artillery powder, and sporting powder.
5. The various kinds of gunpowder composed of structureless nitro-cellulose or
nitro-lignose, binding material, and oxygen carriers, substantially as described and in
the proportions specified.
6. Granulated gunpowder mainly composed of a highly explosive core, a less
explosive or inert inner coating, and a waterproof and slowly burning outer coating,
substantially as described.
7. The process for the manufacture of structureless nitro-cellulose or nitro-lignose
from wood, substantially as described.
Dated this 4th day of July 1899.
FAIRFAX & WETTER,
Agents, 37 and 39, Essex Street, Strand, London.