An Improved Safety Explosive, and Method or Process of Manufacturing the same.
Year: 1893

page_text: Date of Application, 23rd Oct., 1893-Accepted, 2nd Dec., 1893
COMPLETE SPECIFICATION.
An Improved Safety Explosive, and Method or Process of
Manufacturing the same.
I, WILBRAHAM EVELYN-LIARDET of St. Kilda Street, Elstemwick, in the
Colony of Victoria, Chemist, 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 has been devised to provide the public with an improved safety
explosive and which whilst being efficient in the highest degree and economical in
its use may be prepared at a minimum cost. The invention has reference to that
class of explosives known as safety explosives, that is to say which do not explode
by the mere application of an ordinary flame or spark.
The ingredients employed by me to make such explosive and the method or the
process of manufacturing the same is substantially as follows :—
To carry this invention into effect I prepare the materials preferably, but not
arbitrarily in the following manner-Tar of any approved kind is placed in a tank
of any capacity said tank having beneath it a furnace to supply heat thereto, the
tank is also provided with three taps or cocks on one of its sides, that is to say-
one cock near the bottom, a second one higher up and a third above that again, so
that were a tank three feet square to be used, one tap would be near the bottom,
the second tap ten inches above and the third fifteen inches above the second and
eight inches from top, so that in the event of the lighter portion of the tar boiling
over, the cock at that point may be opened and such tar allowed to be drawn off into
any suitable vessel.
Heat having been applied in the furnace and the tar raised preferably to
260 degrees Fahrenheit at the level of the centre cock the tar is removed and
mixed in any suitable vessel with picric acid in the proportions preferably of
one third of picric acid to two thirds of the tar at the aforesaid heat of about
260 degrees Fahrenheit or in equal parts-i.e.-half tar and half picric acid;
the picric acid will then be dissolved into the tar and is then styled by me "prepared
tar" and at ordinary temperature the mixture thus formed will be brittle and have
a smooth glossy appearance like jet.
Sawdust, (preferably wood meal or mealed leaves of the fir) is placed in a mixer
jacketed by boiling water.
To 1 lb. of fine sawdust, wood meal or ground fir leaves (while hot), 2 lbs. of the
"prepared tar" is added. The prepared tar should be made liquid by heating it in
a suitable vessel and gradually adding it to sawdust or meal when it will mix and
when cool can be sieved out fine or ground to constitute what I term "prepared
sawdust."
Chlorate of potassium is then fused until one third of the oxygen is thrown off
making per chlorate of potassium, and this is ground or pulverized.
The materials for my improved explosive having been thus made are mixed in
the following manner and proportions.
The per-chlorate of potassium is heated in a steam jacketed pan to 220 degrees
Fahrenheit and while hot the "prepared sawdust" is added, and mixed into it
while hot until the mass becomes black which it does in about fifteen to twenty
minutes if well mixed.
The mass is then placed upon sieves, allowed to chill, shaken or rubbed through
and the finished explosive will have the appearance of ordinary well manufactured
gunpowder.

page_text: An alternate formula and method by which I make a good explosive is as
follows:-
Chloride of sodium or common salt, having no hydro-scopic properties is ground
fine; one pound avoirdupois of such salt is saturated with one ounce of diluted
picric acid and one third, two thirds or one half, of chlorate of potassium
is then added to the mixture. Then dry in a jacketed pan and add one ounce of
magnesia carbonate, and when the whole is quite dry add the " "prepared sawdust
in the proportions preferably, but not. arbitrarily, of 75 parts of the mixture to
25 parts of the prepared; but before the ingredients last named are associated I
prefer to store the finished materials for a few days.
"
Both forms, hereinbefore described, can be exploded under water with the
ordinary fulminate cap whilst in dry ground the cap can be omitted and
the ordinary fuse used.
As a substitute for "dynamite" and "gelatine" or "nitro-glycerine" compounds
it will be found by use to possess greater strength and to be less subject to climatic
changes or exudations and to be perfectly free from objectionable fumes and is
undoubtedly stable.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is-
1. In explosives-The combination of picric acid with prepared tar and with an
admixture of sawdust or vegetable meal as and for the purposes hereinbefore set
forth and explained.
2. In explosives-The combination of picric acid, chloride of sodium and
prepared tar with an admixture of sawdust or vegetable meal as and for the
purposes hereinbefore set forth and explained.
3. In methods or processes of manufacturing explosives-The method or process
hereinbefore described consisting of associating coal tar whilst hot with a pro-
portion of picric acid and with the mixture so produced impregnating sawdust or
other analogous absorbent raising the whole to about 212 degrees Fahrenheit then
cooling the mixture and passing it through a sieve, then adding to the sifted
product a certain proportion of per-chlorate of potassium at the same time heating
the mass as the perchlorate of potassium is being added until the whole mixture
assumes a black color and again passing the whole through a sieve substantially as
and for the purposes set forth.
Dated this 23rd day of October 1893.
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.