Improvements in the Manufacture of Explosives.
Year: 1898

page_text: Date claimed for Patent under Sect. 103 of Act,
}
being date of first Foreign Application (in 21st Sept., 1897
Italy),
Date of Application (in United Kingdom), 21st Apr., 1898
Complete Specification Left, 21st Apr., 1898-Accepted, 6th Aug., 1898
COMPLETE SPECIFICATION..
Improvements in the Manufacture of Explosives.
We, UGO ALVISI, Professor of Chemistry, of 12, Via Carlo Alberto, Rome, and
EMIDIO PULIFICI, Gentleman, also of 12, Via Carlo Alberto, Rome, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
-
This invention relates to improvements in the manufacture of explosives, and
has for its objects to produce an explosive which shall require a very high tem-
perature to effect its ignition, and possessing a high balistic power rendering it
particularly effective when used for explosive shells or shrapnels and for blasting
purposes generally and also a process whereby the salient ingredient of the explo-
sive may be safely and cheaply produced, and the by-products formed during the
manufacture are of commercial value.
Hitherto perchlorates have been known as strong oxidizing compounds and very
useful in explosive compositions, by reason of their possessing a greater degree
of stability than chlorates, but the cost of material and the difficulties attending
such manufacture have been so great as to prevent their being produced upon a
practical or commercial scale.
Among perchlorates, that of ammonium, besides being a powerful oxidizer
possesses as compared with other chlorates, the additional advantages of being
itself an explosive that upon combustion is resolved into gaseous products without
leaving any residuum. In some of the existing methods of manufacture of per-
chlorate of ammonium, considerable danger and waste is present, and in others,
although free from danger, the cost of production is so great as to preclude the
manufacture being carried out upon an extensive scale.
It is the object of the present invention to overcome the difficulties enumerated
and to produce the perchlorate of ammonium both cheaply and by a process in

page_text: which the by-products of manufacture are industrially useful and therefore of value
commercially
Instead of using as a basis salts of potassium, chlorate of sodium is taken and
dissolved in suitable open vessels except where it is desired to collect the oxygen
given off in which case a suitable closed vessel would be employed. The chlorate
is submitted to the action of heat until it is completely transformed into per-
chlorate and chloride, this being ascertained either by collecting the oxygen in a
suitable measuring instrument or device, or from the dense frothy appearance of
the substance. This operation which is easily regulated and quickly effected
should be carried out at intervals, and small quantities only treated. After cool-
ing, the then solidified mass consisting of chloride of sodium is removed from the
vessel in which it has been treated, and a sufficient quantity of water is added
when the perchlorate, which is deliquescent, is entirely dissolved and the greater
part of the chloride not being very soluble is left and this undissolved portion
being well pressed by suitable means, the remaining proportion of perchlorate of
sodium is recovered.
The solution containing the perchlorate of sodium is treated with a suitable
quantity of nitrate of ammonium likewise dissolved (for it is deliquescent) in a
small quantity of water so as to saturate the solution."
The two solutions being mixed and stirred, the perchlorate of ammonium is pre-
cipitated in small, fine, white crystals, and the said crystals being either subjected
to pressure in a suitable press or to a centrifugal filter or other means for effecting
a first process of desiccation, a product will be produced sufficiently pure for use
in the manufacture of explosives.
To further purify the product it is sufficient to obtain crystallization by means of
boiling water. The same water, after the salt has been precipitated by the process
of cooling, may for the sake of economy be used for further crystallizations. The
product, after leaving the press or filter, being as aforesaid of sufficient purity for
the manufacture of explosives, may be again moistened, but if further desiccation
is desired the product may be exposed to the air after being placed upon a porous
absorbent surface.
The chemical reactions which occur in the above process are as follows:-
First, by warming the chlorate of sodium and stopping the reaction at the desired
point, the development of oxygen and the formation of chloride and perchlorate of
sodium are attained. Second, by treating the perchlorate of sodium with nitrate
of ammonium is obtained by double reaction nitrate of sodium and perchlorate of
ammonium, as in the following equation:
NaCLO4 + NHÂNO3 NaNO3 + NH+CLO
In the waters used in the said process there remains a small amount of dissolved
perchlorate which if it is desired may be recovered either by evaporating them up
to a certain point in the presence of ammonia or carbonate of ammonium, but the
quantity is so small that it is not worth recovering, the more so as the perchlorate
could be recovered mixed with a little chloride of sodium which will have remained
in solution in the waters first used. In any case the separation of chloride of sodium,
perchlorate of ammonium, and nitrate of sodium may be readily effected by par-
tially evaporating the said waters.
Taking 213 parts of chlorate of sodium and 50 parts of nitrate of ammonium,
theoretically 117.5 parts of perchlorate of ammonium, which is the principal pro-
duct, and 32 parts of oxygen, 58.5 parts of common salt, 85 parts of nitrate of
sodium, which are secondary products, should be obtained, but as in the first
calcination a small amount of the perchlorate formed is destroyed, and taking into
account all the possible waste incident to the operation, a somewhat larger quan-
tity of the latter products and a little less of the perchlorate of ammonium which

page_text: ranges from about 70 to 80 parts will be obtained. By adding to the elements
above enumerated suitable proportions of sulphur and carbon, excellent explosives
for mining purposes, may be formed which when tarred may be made up into
suitable cartridges.
Some of the forms of explosive which may be obtained under this process are
as follows:-
a It is known that picric acid does not contain sufficient oxygen to burn com-
pletely the quantities of hydrogen and carbon contained in it, and that hence the
internal combustion is not complete. In order to obviate this defect, attempts
have been made to add suitable quantities of nitrate of potassium and nitrate of
ammonium or of chlorate of potassium. These compositions with the exception
of that containing chlorate of potassium resist shocks better than picric acid. The
addition of the above mentioned substances may be made not only to picric acid
but also to picrates, and with greater safety because no exchange of acids can occur
in the process of manufacture.
It is therefore advisable to add to the picric acid, perchlorate of ammonium in
proportions which may be easily determined by calculation, with the advantage
already ascertained a priori from thermochemical data that the composition will
possess a very high explosive power. In the same way perchlorate may also be
added to picrates.
b. Instead of with picric acid (trinitrophenol) it is advisable to mix the per-
chlorate of ammonium with trinitrocresol, or with the salts of the latter, and more
particularly with the salt of ammonium. To these compositions which are still
more powerful than those above mentioned, it is intended to give the name of
"C cremoniti."
The "cremoniti" would be especially suitable for fire-arms, mining, and sub-
marine operations or the like, on account of their rending or shattering power
or, where confined, of their projectile force.
c Perchlorate of ammonium, like potassium nitrate, may be used by uniting it
in a suitable proportion with sulphur and carbon, or carbon only, for the manu-
facture of gunpowder. To these new black powders it is intended to give the
name of "manlianiti."
These and compositions of a like nature may vary according to the different
ingredients used, and their respective proportions; but in each case perchlorate
of ammonium would form the basis of such compositions, the particular advan-
tages of which are the high temperature at which ignition takes place, (2400),
high balistic power, far in excess of that of other explosives at present in use for
similar purposes, and a shattering or rending power almost equal to that of pure
picric acid.
Having now particularly described and ascertained the nature of our said in-
vention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. A process of manufacture of perchlorate of ammonium having for its basis
chlorate of sodium, and the application of perchlorate of ammonium so prepared
to the preparation of explosive substances, substantially as set out in the fore-
going specification.
2. The manufacture of explosive compositions made with perchlorate of am-
monium, and nitrophenol or any compounds or any direct derivatives of the same
such as picric acid and trinitro-cresol, substantially as set out in the foregoing
specification.
3. The manufacture of explosive compositions of perchlorate of ammonium
mixed with sulphur and carbon, or with only one of these substances, substan-
tially as set out in the foregoing specification.
4. The use of perchlorate of ammonium in the manufacture of all explosive com-
positions mentioned and described in the foregoing specification.

page_text: 5. The improved process for manufacturing explosives, substantially a
described.
J. E. EVANS-JACKSON & Co.,
Agents for the Applicants.