Year: 1899

page_text: Date of Application, 7th Dec., 1899
Complete Specification Left, 5th Sept., 1900-Accepted, 6th Oct., 1900
1, LUDWIG WENGHOFFER, Doctor of Philosophy, of Friedrichstrasse 115, Berlin,
Germany, do hereby declare the nature of this invention to be as follows:-
Contrary to the view hitherto prevalent, that it is difficult to burn aluminium
directly, I have found by experiments, that aluminium in a state of fine division,
such as aluminium powder can be burned easily.
For instance, if oxygen is made to pass over aluminium powder, a very
slight addition of heat, corresponding to the temperature of burning sulphur,
in other words, the contact with a burning sulphur match, or sulphur thread, or
with the flame of a Bunsen burner, is sufficient for igniting the aluminium.
With a continuous supply of oxygen, the combustion once started will proceed
through the whole mass, so as to burn the whole of the aluminium, and to develop
or set free an enormous quantity of heat. In a similar manner, a mixture of
aluminium powder with oxygen carriers, such as potassium perchlorate, will
immediately burn through the whole mass with great violence.
Owing to its easy combustibility when in a state of fine division, and especially
also owing to the enormous generation of heat caused by its combustion, finely
divided aluminium is specially suitable for the manufacture of high explosives.
The same may be said of finely divided magnesium and of mixtures or alloys of
aluminium and magnesium in a state of fine division, also of the carbides of the
said metals, and also of calcium carbide. These metals and their carbides have
in common the property of generating a large amount of heat by their combustion.
My experiments have shown, that all explosives containing oxygen carriers
which will support the combustion of aluminium, magnesium or carbides, and
which, by their combustion, yield large volumes of gases (the sudden generation
of which is the cause of their effect) will greatly improve in strength by the
admixture of pulverized aluminium, or carbide of magnesium or of calcium.
For instance, mixtures of pulverized aluminium with potassium perchlorate,
picric acid, potassium permanganate, nitrates and many other salts rich in oxygen,
will explode violently, when heated in a tube, and are therefore applicable as
explosives. The addition of charcoal, sulphur and other substances yielding
gaseous products of decomposition or oxydation, will enhance the explosive
effect.
Instead of oxygen-yielding substances, such as chlorates, perchlorates, per-
sulphates, permanganates, chromates, peroxides, nitrates, organic nitro-compounds
etc., liquid oxygen or liquid air may be employed, which not only produce the
combustion of the aluminium, magnesium, or of the carbides mentioned above,
but are also rapidly gasified by the great heat of combustion of the metal or
carbide, and thereby enormously expanded.
The effect of the metals and carbides mentioned above, which are capable of
combustion when mixed with oxygen carriers or free oxygen, for instance, in the
shape of liquid oxygen, is therefore based primarily on the enormous and sudden
expansion of the gases which are present in the mixture, or formed by the decom-
position of compounds contained in the same, or by the oxidation of suitable

page_text: admixtures, such as charcoal, organic matter, or sulphur. A secondary cause, is
the reducing capacity of the said metals and carbides, which renders them available
for the manufacture of explosives from substances, which have not hitherto been
used for this purpose, or only under exceptional circumstances, for instance, sodium
sulphate. Such substances, when reduced by aluminium etc., yield products of
decomposition, which are entirely or partly gaseous. A mixture of pulverized
aluminium with sulphate of sodium or of potassium may be used as an explosive.
The gases produced and expanded by the combustion of explosives containing
aluminium, magnesium, or mixtures or alloys of these metals, or their carbides
or calcium carbide, may be divided into the following categories:
1. Gases present originally, such as air and oxygen.
2. Gases of decomposition, for instance oxygen derived from potassium chlorate.
3. Gases of oxidation or combustion, for instance, carbonic acid and sulphurous
acid produced by the combustion of charcoal and sulphur.
4. Gases of reduction, for instance sulphurous acid produced from sodium
sulphate.
improvements relating to explosives.
I, LUDWIG WENGHOFFER, Doctor of Philosophy, of Friedrichstrasse 115, Berlin,
Germany, 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:--
Contrary to the view hitherto prevalent, that it is difficult to burn aluminium
directly, I have found by experiments, that aluminium in a state of fine division,
such as aluminium powder can be burned easily.
For instance, if oxygen is made to pass over aluminium powder, a very
slight addition of heat, corresponding to the temperature of burning sulphur,
in other words, the contact with a burning sulphur match, or sulphur thread, or
with the flame of a Bunsen burner, is sufficient for igniting the aluminium.
With a continuous supply of oxygen, the combustion once started will proceed
through the whole mass, so as to burn the whole of the aluminium, and to develop
or set free an enormous quantity of heat. In a similar manner, a mixture of
aluminium powder with oxygen carriers, such as potassium chlorate, will
immediately burn through the whole mass with great violence.
Owing to its easy combustibility, when in a state of fine division, and especially
also owing to the enormous generation of heat caused by its combustion, finely
divided aluminium is specially suitable for the manufacture of high explosives.
The same may be said of finely divided magnesium and of mixtures or alloys of
aluminium and magnesium in a state of fine division, also of the carbides of the
said metals, and also of calcium carbide. These metals and their carbides have
in common the property of generating by their combustion a large amount of heat.
My experiments have shown, that all explosives containing oxygen carriers
which will support the combustion of aluminium, magnesium or carbides, and
which, by their combustion, yield large volumes of gases (the sudden. generation
of which is the cause of their effect) will greatly improve in strength by the
admixture of pulverized aluminium, or carbide of magnesium or of calcium.
For instance, mixtures of pulverized aluminium with potassium-chlorate,
picric acid, potassium permanganate, nitrates and many other salts rich in oxygen,

page_text: will explode violently, when heated in a tube, and are therefore applicable as
explosives. The addition of charcoal, sulphur and other substances yielding
gaseous products of decomposition or oxidation, will enhance the explosive
effect.
Instead of oxygen-yielding substances, such as chlorates, perchlorates, per-
sulphates, permanganates, chromates, peroxides, nitrates, organic nitro-compounds
etc., liquid oxygen or liquid air may be employed, which not only produce the
combustion of the aluminium, magnesium, or of the carbides mentioned above,
but are also rapidly gasified by the great heat of combustion of the metal or
carbide, and thereby enormously expanded.
The effect of the metals and carbides mentioned above, which are capable of
combustion when mixed with oxygen carriers or free oxygen, is therfore based
primarily on the enormous and sudden expansion of the gases which are present
in the mixture or formed by the decomposition of compounds contained in the
same, or by the oxidation of suitable admixtures, such as charcoal, organic matter,
or sulphur. A secondary cause is the reducing capacity of the said metals and
carbides, which renders them available for the manufacture of explosives from
substances which have not hitherto been used for this purpose, or only under
exceptional circumstances, for instance, sodium-sulphate. Such substances, when
reduced by aluminium etc., yield products of decomposition, which are entirely
or partly gaseous. A mixture of pulverized aluminium with sulphate of sodium or
of potassium may be used as an explosive.
The gases produced and expanded by the combustion of explosives containing
aluminium, magnesium, or mixtures or alloys of these metals, or their carbides
or calcium carbide, may be divided into the following categories:-
1. Gases present originally, such as air and oxygen.
2. Gases of decomposition, for instance oxygen, derived from potassium chlorate.
3. Gases of oxidation or combustion, for instance, carbonic acid and sulphurous
acid produced by the combustion of charcoal and sulphur.
4. Gases of reduction, for instance sulphurous acid produced from sodium
sulphate.
In all these cases the effect of the aluminium, magnesium, aluminium carbide,
magnesium carbide, and calcium carbide is based on the great quantity of heat
suddenly liberated by the combustion of these metals and carbides, which heat
causes a sudden and enormous expansion of the gases generated by the combustion
of the explosive.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. Explosives composed of finely divided aluminium or magnesium or mixtures
or alloys of these metals or their carbides or calcium carbide on one hand, and
one of the materials already used in the manufacture of explosives, or other
materials which liberate gases when heated with the said metals or carbides, on
the other hand, substantially as described.
2. The manufacture of explosives by mixing finely divided aluminium or
magnesium or mixtures or alloys of these metals, or their carbides, or calcium
carbide, with a material adapted to liberate gases when heated with the said
netals or carbides, including materials hitherto used in the composition of
explosives, substantially as described.
Dated this 5th day of September 1900.
FAIRFAX & WETTER,
Agents,
37 and 39, Fssex Street, Strand.