Improvements in the Manu tre of Explosives
Year: 1896

page_text: Improvements in the Manu
tre of Explosives.
GEORGE GUILLAUME ANDRÉ of Glenlean Argyllshire and CHARLES HERBERT
CURTIS of 74 Lombard Street London Explosive Manufacturers, do hereby
declare the nature of this invention to be as follows:-
This invention is designed to provide as safety or flameless explosive especially
suitable in fiery or dusty mines. Since our invention relating to "Improvements in
the manufacture of explosives" for which we have applied for Letters Patent
under No. 23443 of 1895 we find by experiment that by the use of the ingredients
hereinafter mentioned and approximately in the proportions hereinafter referred
to we obtain in a high degree sensitiveness to detonation while safety of the
explosive when used in an inflammable atmosphere is considerably increased. Our
invention is not liable to be exploded by fire flame friction or blows but requires
explosion by detonation. To effect complete detonation we use detonators of the
character and strength known in the trade as No. 6 or No. 7, for large blasts we
prefer the latter but for all ordinary shots that is not exceeding 1 lb. weight the
former is sufficient.
We have found that wood meal and starch containing as they do a very large
proportion of the elements of water which serve to lower the temperature of the
explosive and render it safer in an atmosphere mingled with fire damp or loaded
with coal dust form an excellent combustible in explosives of the safety class.
Though wood-meal is more easily oxidisable than starch and gives consequently a
higher degree of sensitiveness to the detonator the latter has the advantage due to
its less easily combustible character of rendering the explosive incapable of being
ignited and burned in case of the detonator tailing either from insufficient strength
or any other cause to effect proper detonation. This quality is a very desirable one
in a safety explosive.
We have found by experiments that the four requisite qualities namely easy and
perfect detonation, low temperature of explosion, great rending power and incom-
bustibility under the conditions above mentioned are, as a combination given in
their highest degree when the explosive is made up approximately in the proportions
hereinafter inentioned.
Our invention consists therefore of producing an explosive compound consisting of
wood-meal or other suitable material of a like character and starch and ammonium
nitrate approximately in the proportions hereinafter mentioned or of wood-meal or
other suitable material of a like character and starch ammonium nitrate and the
addition of a very small quantity of potassium nitrate approximately in the
proportions hereinafter mentioned.
We find by experience and experiments that the best proportions for thus making
a safety flameless explosive of great power is

page_text: Wood meal
Starch
Ammonium nitrate
Potassium nitrate -
4.0 lbs.
3.5 lbs.
90-0 lbs.
2.5 lbs.
These proportions may be subject to slight variations without departing from
our invention.
These materials are mixed or incorporated in a drum with wooden balls in the
usual manner without the addition of any liquid or the application of heat or in any
other suitable manner and the result is an explosive having the advantage of great
safety and absence of flame and especially suitable for use in fiery and dusty mines
and of the requisite power.
THEO. MCKENNA,
Agent.
Improvements in the Manufacture of Explosives.
GEORGE GUILLAUME ANDRÉ of Glenlean Argyllshire and CHARLES HERBERT
CURTIS of 74 Lombard Street, London, Explosive Manufacturers 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 is designed to provide a safety or flameless explosive especially
suitable in fiery or dusty mines. Since our invention relating to "Improvements
in the manufacture of explosives" for which we have applied for Letters Patent
under No. 23443 of 1895 we find by experiment that by the use of the ingredients
hereinafter mentioned and approximately in the proportions hereinafter referred to
we obtain in a high degree sensitiveness to detonation while safety of the explosive
when used in an inflammable atmosphere is considerably increased. Our invention
is not liable to be exploded by fire flame friction or blows but requires explosion
by detonation. To effect complete detonation we use detonators of the character
and strength known in the trade as No. 6 or No. 7-for large blasts we prefer the
latter but for all ordinary shots, that is, not exceeding 1 lb. weight the former is
sufficient.
We have found that woodmeal and starch containing as they do a very large
proportion of the elements of water which serve to lower the temperature of the
explosion and render it safer in an atmosphere mingled with fire damp or loaded
with coal dust form an excellent combustible in explosives of the safety class.
Though woodmeal is more easily oxidisable than starch and gives consequently a
higher degree of sensitiveness to the detonator the latter has the advantage due to
its less easily combustible character of rendering the explosive incapable of being
ignited and burned in the case of the detonator failing either from insufficient
strength or any other cause to effect proper detonation. This quality is a very
desirable one in a safety explosive.
We have found by experiments that the four requisite qualities namely easy and
perfect detonation low temperature of explosion great rending power and incom-
bustibility under the conditions above mentioned are as a combination given in
their highest degree when the explosive is made up approximately in the
proportions hereinafter mentioned.

page_text: Our invention consists therefore of producing an explosive compound consisting
of woodmeal or other suitable material of a like character and starch and ammonium
nitrate approximately in the proportions hereinafter mentioned or of woodmeal or
other suitable material of a like character and starch ammonium nitrate and the
addition of a small quantity of potassium nitrate approximately in the proportions
hereinafter mentioned.
We find by experience and experiments that the best proportions for thus making
a safety flameless explosive of great power i
ntion.
These materials are mixed or incorporated in a drum with wooden balls in the
usual manner without the addition of any liquid or the application of heat or in any
other suitable manner and the result is an explosive having the advantage of great
safety and absence of flame and especially suitable for use in fiery and dusty mines
and of the requisite power.
The finished explosive may be made up into suitable cartridges in the usual way
by filling it into metal cases or paper cases waterproofed.
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. In a safety or flameless explosive compound the combination of wood-meal
or other suitable material of a like character and starch and ammonium nitrate
substantially in the proportions as hereinbefore described.
2. In a safety or flameless explosive compound the combination of wood-meal or
other suitable material of a like character and starch ammonium nitrate and
potassium nitrate substantially in the proportions as herein before described.
Dated the 1st day of March 1897.
THEO.
MCKENNA,
17 & 18 Basinghall Street, Loudon, Agent.