Improvements in the Manufacture of Explosives.
Year: 1893

page_text: The decision of the Chief Examiner, acting on behalf of the Comptroller, of the
21st day of March 1895, allowed, under Section 18 of the Patents, &c. Act, 1883
an Amendment of this Specification.
Date of Application, 8th Dec., 1893
Complete Specification Left, 20th July, 1894-Accepted, 25th Aug., 1894.
[Communicated from abroad by CARL PIEPER, of 3, Hindersinstrasse, Berlin, in
the Empire of Germany, Civil Engineer.]
:
Improvements in the Manufacture of Explosives.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
This invention relates to the manufacture of explosives, which, besides other
active ingredients, such as nitro and nitrohalogen compounds contain nitrates, with
or without the addition of inactive substances, and has for its object to impart to
these explosives greater power and also increased safety.
According to the said invention one or the other or all of the active ingredients
are separated during the production of the mixture from their solution in a suitable
solvent or a mixture of such solvents by evaporation, suction or the like.
It is expedient to use for this purpose a mixing apparatus adapted to be heated
and which may be so arranged that the explosives are produced directly in the form
suitable for use.
The improved method may be carried into practice in various ways. For example,
all the active ingredients of the mixture may be dissolved, the solutions mixed and
then evaporated; or one ingredient of the mixture may be dissolved and the other
ingredients mixed with the solution; or all the ingredients in the undissolved state
may be mixed with the solvent of one ingredient or a mixture of solvents of more
ingredients. Moreover, the quantity of the solvent may be such that only a portion
of the corresponding ingredient will be dissolved. It must, however, always be
borne in mind that the object of the present invention will be achieved the better
the greater the quantity of solvent, because the intimacy and fineness of the
intermixture depend upon the quantity of particles successively separated out from
their solution.
In order to attain homogeneousness and great power it is generally necessary in
the treatment of the substances, particularly in the evaporation of the solvents, to
keep the temperature below the melting point of the nitro or nitrohalogen
compounds, which may be done by evacuation.
Explosives produced according to the said method are considerably more powerful
than those made of the customary guhr and gelatine dynamites, while the manu-
facture is much less dangerous. They are very safe in use and are themselves
proof against moisture or may he protected therefrom by suitable additions or other
means. It should be specially pointed out that the most effective explosives
produced according to this method possess the important properties of exploding
even after long storage with the well-known dynamite cap having 0.54 grammes of
priming, and of not being ignited by coal dust explosion nor by fire damp.
The general good qualities, such as safe manufacture and manipulation and

page_text: extremely great. power, of the explosives prepared according to the improved
method render them also very suitable, either by themselves or mixed with other
explosives, for use in projectiles.
Dated this 9th day of December 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in the Manufacture of Explosives.
1, HENRY HARRIS LAKE of the Firm of Haseltine, Lake & Co. Patent Agents,
45 Southampton Buildings in the County of Middlesex 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 which among the
essential active ingredients contain nitro or nitrohalogen hydrocarbons iu
combination with ammonium nitrate.
The object of the said invention is to impart to these explosives an increased
explosive power with additional security, and ignition by means of lighter
detonating charge or detonating caps.
'
The said explosives, which are generally known as safety explosives, are usually
produced by introducing into the molten nitro compounds the ammonium nitrate
with or without the addition of other substances and by kneading with continued
heating or until the compound has cooled.
It is evident that under these circumstances the hydrocarbon will enclose the
nitre crystals but will not impregnate them. Experience shows that these and
similar processes do not give homogeneous products, the molten substances being
always more or less irregularly distributed.
If the heating be carried so far as to also melt the ammonium nitrate, there
will on the one hand be danger according to the kind of hydrocarbon, while ou
the other hand the ammonium nitrate dissociates already below this temperature
and besides giving rise to losses, produces unreliable and inferior products.
Nevertheless ouly a simultaneous melting of the said component-substances
enables them to be intimately mixed and as such melting cannot be effected, this
explains the frequent non-homogeneousness of the explosives obtained by the melting
process, as shown by the published results of firing. Now in order to obviate such
losses caused by the mode of manufacture, and to obtain moreover thoroughly
homogeneous substances, the inventor uses a solvent. That is to say one or the
other or all the active ingredients are separated during the production of the
mixture from their solution in a suitable solvent or a mixture of such solvents by
evaporation, suction or evacuation (application of a partial vacuum) or the like.
The solvent may also be capable of taking up further additions.
This mode of preparing intimate mixtures by separating out the component
substances from a solution by evaporation is not new in itself but it is new to use
the same for preparing safety explosive.
The high value of this improved method of manufacturing the before-mentioned
explosives is hereinafter set forth.
This process further enables to make use throughout of such low temperatures
that no decomposition of the ammonium nitrate need be feared.
It is indubitable, and it is not only confirmed by the eye and further
investigation, but particularly by the effect that even the best disintegration and
mechanical mixing cannot possibly bring two or more substances so close together
and so intimately unite them as when they are separated from evaporating

page_text: By this
liquid being continually stirred or otherwise maintained in movement.
exceedingly fine division of the hydrocarbons in the ammonium nitrate is obtained
such a high degree of security as has not heretofore been known, and also the
certain ignition by lighter detonating charges (detonators, detonating caps or
detonating primers).
When evacuating during the evaporation in order to be able where necessary,
to keep the evaporating temperature suitably below that of the respective melting
point, the parts of the mixture precipitated from the solution will be intimately
united, penetrating each other as it were.
If for instance nitro hydrocarbon which melts say at 60 degrees centigrade were
dissolved in conjunction with ammonium nitrate, and the solvent evaporated say at
70 degrees centigrade the use of the same would posses a smaller value. The nitro
compound would remain liquid and after the evaporation would surround the
crystals similarly as in the melting process.
The quality of such explosives may even be recognized by the colour if the
composition be known, the yellow colour of the nitro hydrocarbon growing the
more pale by the white colour of the nitre (ammonium nitrate), the lower
the temperature.
It has also been ascertained that the action becomes greater on the one haud the
more completely the substances are dissolved and on the other hand the lower the
evaporating temperature remains below that of the melting point of the nitro
compound, which shows that they were precipitated in the solid form.
The process may be variously modified as regards the mode of carrying it into
effect. The before-mentioned two parts of the mixture, namely the ammonium
nitrate and nitro hydrocarbons, may be wholly or partially dissolved, the solutions
mixed and then evaporated; or with the solution of one of them the other
(additional substances being mixed therewith if desired) is intimately mixed; or
the said substances are mixed in the undissolved state with a solvent suitable for
both, or with a mixture of suitable solvents which may also be capable of dissolving
additional substances. If necessary or advantageous the dissolutions may be
effected by warming at the reflux cooler.
During the mixing operation heat is applied, and in the distillation or evaporation,
which may be directly combined with this operation or joined to the same, is carried
out by the aid of a vacuum (evacuation) if, having regard to the above-mentioned
grounds, this should be deemed expedient.
It is advisable to use a mixing apparatus adapted to be heated and which may
be so arranged that the explosives are obtained directly in the form suitable for
use.
In order to demonstrate the increased action of the safety explosives prepared
by this process I will give an example which proves how very much it differs
advantageously from the melting process with the subsequent further disintegration,
which comes nearest to it as regards the quality, durability and effectiveness of the
explosives obtained.
(I.) To 9 per cent. of molten nitronaphthalene was added, while stirring
energetically, 91 per cent. of very finely pulverized, dried and heated ammonium
nitrate and further thoroughly worked.
10 grammes of this product gave in Trauzel's explosion meter, charged with
15 grammes of dry sand and caused to explode by a detonating cap No. 7, on an
average 335 cubic centimetres, that is to say, subtracting the existing bore of
35 cubic centimetres, a space of 300 cubic centimetres.
(II.) 9 per cent. of nitronaphthalene was intimately mixed with 91 per cent. of
very finely pulverized, dry ammonium nitrate, then an ample quantity of methyl
alcohol was added, and the whole worked for some time at 50 to 55 degrees
centigrade.
Afterwards the alcohol was evaporated, the energetic movement and the
evacuation being continued, and the perfectly dry and finished preparation was
caused to explode as stated under I.

page_text: The result on the average was a net space of 367.5 cubic centimetres,
corresponding to an additional effectiveness of 22.5 per cent.
The explosive produced according to II therefore, although its composition is
exactly like I as regards the percentages, has a considerably greater effectiveness.
Further tests were made which gave similar advantageous results, for example:
(III.) Roburite (dinitrobenzol and ammonium nitrate) were purchased in the
market and carefully dried in the bulk in the fresh state.
(IV.) An equal quantity as stated under III was treated with alcohol as in
Example 11. In analogous firing trials made with these preparations every
10 grammes of roburite III resulted in 287 cubic centimetres net space, whilst
roburite IV resulted in 377 cubic centimetres, this being equal to an additional
effectiveness of 31.36 per cent.
Other explosives prepared according to this invention with nitrated phenols,
nitrated toluols, uitrated toluidines and the like show a similar superiority.
In some cases it has been ascertained that the product obtained by this process
is as much as 50 per cent. more effective than that obtained by the ordinary
disintegrating and melting processes.
According to this process explosives are produced the effects of which con-
siderably exceed the best guhr- and gelatine-dynamites. At the same time the
manufacture of the same is far less dangerous; the products are absolutely safe
in use and are effectively protected against the reception of moisture, either by
themselves or by the addition of known appropriate substances or by the employ-
ment of other known means used for the same purpose.
It should be specially observed that the explosives produced by this method
possess the important property of exploding even after long storage with the
ordinary dynamite detonating charge No. 3 weighing (54 grammes, and of which will
not being ignited by coal-dust explosion or by fire-damp. This property constitutes
an enormous advance, for all the so-called safety explosives heretofore put on
the market necessitate exploding caps with a detonating charge weighing even
up to 2 grammes either to explode at all, or at least to obtain satisfactory
effects. Apart from the much higher price and the consequent greater expense
of blasting, the handling of these heavy exploding caps endangers the life of the
miner far more than any of the explosives proper. The general good qualities
such as manufacture and handling without danger, extremely high explosive
power and the like, of the explosives prepared by the present process render them
suitable, either by themselves or mixed with other explosive substances, for filling
hollow projectiles or shells.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what 1 claim is :
1. The process of rendering explosives which contain as essential ingredients or
among the essential ingredients ammonium nitrate and nitro or nitrohalogen hydro-
carbons or their derivatives, more powerful by separating the before mentioned
ingredients wholly or partially, and if desired together with other substances, from
a solution by evaporation (evacuation or the like) of the solvent, substantially as
described.
2. The form of carrying out the process described in the first claim, characterized
by the fact that during the evaporation of the solvent, which may be aided by
evacuation, the temperature is kept below the melting point of the nitro compounds
employed, substantially as and for the purpose described.
Dated this 20th Iul. 1904
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.