Improvements in the Manufacture of Explosives.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Explosives.
We, ARTHUR TREVOR DAWSON, of No. 28, Victoria Street, Westminster, in
the County of London, Superintendent of Ordnance Works, and JOHN KARSTAIRS,
of Messrs. Vickers Sons and Maxim's Works, Crayford, in the County of Kent,
Consulting Chemist, do hereby declare the nature of this invention to be as
follows:-
This invention relates to the manufacture of explosives consisting mainly of
urea, ethyl alcohol and nitric acid.
As urea is obtained cheaply from urine, we prefer to use that substance which
we concentrate by evaporation to about 1/10th of its volume, we add ethyl
alcohol or a mixture of ethyl and methyl alcohol and then nitric acid in small
doses. The proportions of these substances may be varied according to the
strength of explosive required. Thus for a strong explosive the proportions may
be by weight. About 6 parts of concentrated urine, 4 parts of ethyl alcohol and
6 parts nitric acid; for a weak explosive the proportions may be about 9 parts of
concentrated urine, 1 part of ethyl alcohol and 5 parts of nitric acid. Explosives
of various strengths may be obtained by using proportions intermediate to those
stated above.
We concentrate the mixture, preferably at a low temperature in vacuo, until
crystals are formed; we decant the liquid and after drying the crystals we
pulverise them. In order to prevent the action of damp or chemical reactions
which would render the explosive dangerous, we knead up the pulverised crystals
with from 5 to 15 per cent. of their weight of caoutchouc dissolved in naphtha
or other solvent, and, after thoroughly incorporating the caoutchouc solution
and the explosive, we press. the mixture into cakes, in which form the explosive
may he employed, as for instance for torpedoes. For other uses, we disintegrate
the cakes and then in order to adapt the material for granulation we grind it up
with solution of rosin or resinous gum to a pasty consistence, which after drying
we granalate in the usual way.
Where urea can be obtained cheaply, a saturated solution may be employed
instead of concentrated urine. Instead of caoutchouc; gums of like nature may be
used, but caoutchouc is to be preferred.

page_text: Improvements in the Manufacture of Explosives.
We, ARTHUR TREVOR DAWSON, of No. 28, Victoria Street, Westminster, in
the County of London, Superintendent of Ordnance Works, and Joux KARSTAIRS,
of Messrs. Vickers Sons, and Maxim's Works, Crayford, in the County of Kent,
Consulting Chemist, 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 explosives mainly from urea,
ethyl alcohol and nitric acid. From these substances we obtain a new crystallised
product which serves as the basis of our new explosives.
In order to set forth our invention and the method of carrying it into effect
we will describe the practical process of manufacturing it from urine which at
present is the cheapest source of supply for urea. We use by preference human
urine and before it becomes fetid we concentrate it by evaporation to about one
tenth of its original volume. We prefer that the temperature during concentra-
tion should not exceed 60° C.
The concentrated urine contains about 40% of carbonaceous matter a consider-
able proportion of which is urea the rest being mostly uric acid, albumen, glucose
and oxalate of calcium. It is then mixed with about one third of its volume of
what is known as methylated spirit being a mixture of ethyl and methyl alcohol
in the proportion of about 9 to 1. In giving such proportions the ethyl alcohol
used is taken to have a specific gravity of about 83.
To this mixture of concentrated urine and alcohol nitric acid of a specific
gravity of 1.45 or rather more is added very slowly: The quantity of acid added
at each time should by preference not be more than one-hundredth part by
volume of the mixture. This operation is continued till the total weight of
acid added is about two-fifths of the total weight of the mixture of urine and
alcohol to which it is added.
White needle-form crystals gradually separate. They are removed from the
liquid and dried at a temperature not exceeding 25° C. These crystals are
soluble in 1.5 times their weight of water at 20° C. and twice their weight
at 4° C. They are slightly soluble in alcohol but quite insoluble in liquid hydro-
carbons. Heated to 150° C. they give off nitric fumes and if kept at that
temperature they explode with great violence. They are quite stable for several
days in a fairly dry atmosphere but if kept longer they first crumble to pieces
and then rapidly decompose.
In order to make our new explosive we grind these crystals when perfectly
dry to a fine powder and mix this with caoutchouc dissolved in naptha, or other
convenient solvent. The amount used is from 5 to 15 per cent. of the weight of
the crystals. When the mixture is thoroughly complete the solvent is as far
as possible removed by evaporation and the remaining pasty mass is pressed into
cakes blocks or other suitable form. These do not change on being kept but
remain quite unaltered. They are not affected by temperatures up to 100° C..
but above that temperature the caoutchouc undergoes change. They are not
affected by any degree of moisture present in the atmosphere.
We have described above the method we prefer for making our explosive but
it may be varied in many respects. For instance ethyl alcohol can be used if
it can be obtained cheaply enough or larger quantities of methyl may be added
to it. Instead of caoutchouc other hydro carbons may be used to mix with
the powdered crystals but we prefer caoutchouc. Smaller quantities of alcohol

page_text: and nitric acid in proportion to the urea may be used if a weaker explosive is
desired but the proportions stated are those which give the best results.
Where urea can be obtained cheaply a saturated solution of urea may be used
instead of concentrated urine.
If granulated powder is required we disintegrate the blocks obtained as above
described and grind the fragments with a solution of rosin or resinous gum to
a pasty consistency and after drying granulate in the usual way.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. The novel crystallized substance or substances suitable for use in explosives
resulting from the process herein above described.
2. The production of a crystallized substance or crystallized substances suitable
for use in explosives from urea nitric acid and ethyl or methyl alcohol substan-
tially as herein above described.
3. The novel explosive manufactured from urea nitric acid ethyl or methyl
alcohol and caoutchouc or its equivalent substantially as described.
4. The herein described process for manufacturing explosive substances.
011
1000
กาลก
day
1000
I A 99ས ་་ས་
זנותת
ABEL & IMRAY,
Agents for the Applicants.
ABEL & IMRAY,
Agents for the Applicants.