Improvements in or relating to Explosives.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by
the decision of the Comptroller General of the 13th day of December 1898.
PROVISIONAL SPECIFICATION.
Improvements in or relating to Explosives.
We, WILLIAM GREAVES, Chemist, and EDMUND MILLS HANN, Civil Engineer,
both of Aberaman, near Aberdare, County of Glamorgan, Wales, do hereby de-
clare the nature of this invention to be as follows:-
The object of this invention is to obviate as far as possible the danger attend-
ing the use of ordinary gunpowder, and explosives of that class, whether loose
or compressed, for blasting in fiery and dusty mines, for it is well known that
the flame produced by gunpowder casily ignites not only explosive gases but
coal dust.
Our invention consists in adding to the gunpowder or explosives of that class
a suitable quantity of one or more of the following salts, acids or salts thereof-
oxalic acid, formic acid, tartaric acid, acetic acid, the alums, the carbonates of
ammonium, soda or potash, the sulphates of ammonium, soda or potash and the
chloride of ammonium. The salt however we prefer to employ is the ammonium
salt of oxalic acid or ammonium oxalate as it possesses the following advan-
tages:-
1. It commences to decompose at a low temperature and in so doing absorbs
a large amount of heat.
2. It gives off a large volume of a mixture of gases which mixture is incom-
bustible and a non-supporter of combustion.
3. No solid particles are formed during the decomposition.
Thus it largely reduces the temperature of explosion of the accompanying gun-
powder whilst not perceptibly diminishing its useful effect.
We find that for ordinary blasting in coal mines, 15% of the ammonium
oxalate added to gunpowder makes a good, safe and flameless explosive and pre-
vents the ignition of dust, but we do not bind ourselves to this proportion which
for other objects might be varied.
Generally it may be stated that the higher the proportion of the salt employed
the greater the degree of safety but the weaker the explosive effect.
In manufacture the ingredient may he added at any convenient stage of the
mixing process, but we prefer to add it as early as possible for the following
reason: That whilst the mixture when confined and detonated gives effects
similar to ordinary gunpowder yet when burnt in the open air it burns at a

page_text: BOILT & WADE,
Agents for the Applicants.
Improvements in or relating to Explosives.
We, WILLIAM GREAVES, Chemist, and EDMUND MILLS HANN, Civil Engineer,
both of Aberaman, near Aberdare, County of Glamorgan, Wales, do hereby de
clare 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: .
The object of this invention is to obviate as far as possible the danger attend-
ing the use of ordinary gunpowder, and explosives of that class, that is of powders
which are similar in their action or composition to gunpowder, or whether they
are made with or without free or combined sulphur and whether they contain
ordinary saltpetre or other substituted oxidizing agents, whether loose or com
pressed, for blasting in fiery and dusty times, for it is well known that the
Hame produced by gunpowder easily ignites not only explosive gases, but coul
dust.
Our invention consists in adding to the gunpowder or explosives of that class
a suitable quantity of ammonium oxalate or common alum or a mixture of the
two. The salt however we prefer to employ is the ammonium salt of oxalic acid
or ammonium oxalate as it possesses the following advantages:
1. It commences to decompose at a low temperature and in so doing absorbs
a large amount of heat.
2. It gives off a large volume of a mixture of gases which mixture is incom-
bustible and a non-supporter of combustion.
3. No solid particles are formed during the decomposition.
Thus it largely reduces the temperature of explosion of the accompanying gun-
powder whilst not perceptibly diminishing its useful effect.
We find that for ordinary blasting in coal mines. 15, of the ammonium
oxalate or common alum added to gunpowder makes a good, safe and flameless
explosive and prevents the ignition of dust, but we do not bind ourselves to this
proportion which for other abjects might be varied.
Generally it may he stated that the higher the proportion of the salt employed
the greater the degree of safety but the wenker the explosive effect.
-
In manufacture the ingredient or ingredients may be added at any convenient
stage of the mixing process, but we prefer to add it as early as possible for the
following reason: That whilst the mixture when confined and detonated gives
effects similar to ordinary gunpowder yet when burnt in the open air it burns at a
similar rate to damp powder and the safety of the process of manufacture is
thereby increased.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that
what we claim is:- -
1. A safety and flameless explosive formed by the misture with gunpowder or
other explosive of that class of ammonium oxalate substantially as specified.

page_text: 2. A safety and flameless explosive formed by the mixture with gun powder or
other explosive of that class of common alum substantially as specified.
3. A safety or flameless explosive formed by the mixture with gunpowder or
other explosive of that class of a combination of ammonium oxalate and common
alum substantially as specified.
Dated this 28th day of November 1896
WILLIAM GREAVES.
EDMUND MILLS HANN,
Boult & Wade,
Agents for the Applicants.