Improvements in the Manufacture of Gunpowder.
Year: 1896

page_text: Date of Application, 14th Nov., 1896-Accepted, 30th Jan., 1897
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Gunpowder.
We, CAMILLE MORTIER, Chemical Engineer, of Bilbao, and HENRY ARTHUR
SANDON, Engineer, of Portugalete, near Bilbao, both in the Kingdom of Spain,
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 :-
The present invention has reference to the manufacture of a new gunpowder by
the mixture of the trinitrocresols with a suitable proportion of nitrate of potash, or
other nitrate, and with or without other ingredients.
We know that there have been ballistic explosives invented and used, in the
manufacture of which the salts of trinitrophenol (picrates) or of trinitrocresol
(cresylates) enter as organic ingredients, but these powders are as a rule very
dangerous in the process of manufacture on account of the facility with which the
said salts detonate by shock or by friction, either alone or associated with oxidants,
with or without charcoal.
Besides this it has been recognized that in spite of the addition of charcoal the
powders so obtained have always had a violent local action, and consequently
their employment has been abandoned, in spite of whatever other advantages they
may have possessed.
We are the first to have found a safe and practical method of employing
picric acid itself or its homologues the trinitrocresol (trinitro-cresylic acid), as
distinguished from their salts and of adapting their explosive properties when
mixed with suitable proportions of nitrate of potash, or other nitrates, to be used
in firearms for sporting or war purposes.
An important point in our process is the association of an oleaginous substance
for waterproofing our powder. We are aware that several substances of different
chemical constitution have been employed for a similar purpose such as paraffin wax,
animal or vegetable wax or fat, oils, resins, shellac or indiarubber, but we find that
stearic acid (or commercial stearin) has physical properties which render it
specially available for this purpose. This substance added in suitable proportions,
before or after the granulation, permits of modifying the speed of combustion of
the explosive and of obtaining a powder the time of combustion of which may
be exactly equal to that taken by the projectile to traverse the barrel of the
firearm.
The principal characteristics of our explosives so produced are Ist-Great safety
with notable economy of time in the manufacture,-2nd-High ballistic force-
3rd-Speed of combustion graduated at will, and 4th-Uniformity of results in
their employment.
The formula we employ varies according to the nature of the arm, but as
examples we give the following:
A. For sporting powder and for pistols and revolvers :-

page_text: B. For war powder, rifles of "Gras" system and cannon of small calibre :-
Trinitrocresol -
T
20 parts by weight.
The process of manufacture of our powders is as follows:-With the particularity
that all the operations are carried on in the dry state:
1. The ingredients, with the exception of the trinitrocresol and of the stearic
acid, are triturated together in a revolving iron cylinder, by means of bronze balls
inserted loose with the charge.
2. When this trituration is judged sufficient the contents of the iron cylinder are
transferred to another revolving cylinder of wood, inside which a number of loose
wooden balls are allowed to revolve, and the trinitrocresol is then added and the
revolving operation continued.
3. When this mixing is finished the powder is carried to the hydraulic press and
there pressed into slabs, which are afterwards granulated by being passed between
bronze rollers.
4. The grains being obtained, they are transferred to a polishing drum where a
certain proportion of stearic acid, preferably in a powdered form, is introduced.
The rotating motion of the drum produces heat by friction; the stearic acid
melts and in this state forms itself into a coating to each grain and gives it a bright
polish, being sufficient to protect against all damp and to prevent the evaporation
of the trinitrocresol contained in the powder.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. A powder consisting of a mixture of trinitrocresols (always to the exclusion
of their salts) and a nitrate of potash or other nitrate, with or without the addition
of charcoal, and coated with stearic acid.
2. The process of manufacture as above described for ensuring the uniform
mixing of the above ingredients with great safety in their treatment.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.