IMPROVEMENTS IN THE MANUFACTURE OF BLASTING POWDER
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office of
the Commissioners of Patents on the 14th September 1875. A communication
from abroad by Herrenstein Courteille, of the City and State of New York,
United States of America, Chemist.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN THE MANUFACTURE OF
BLASTING POWDER." [A communication from abroad by Herrenstein Courteille, of
the City and State of New York, United States of America, Chemist.]
The chief purpose of this Invention is to produce a powder for blasting, which,
while having great dynamical power that may be graduated for mining purposes,
shall possess the quality of being non-explosive in the open air or by concussion or
friction, at the same time greatly reducing the cost of manufacturing and com-
pleting the product in from one to two hours when amalgamated under this
process.
The said Invention consists in a compound of the following ingredients; namely,
nitrate of soda or saltpetre, sulphur and charcoal, which form the chief elements or
base; and with these I combine peat, metallic sulphates, as well as coal of a hard
nature, and the oils or fats of animals, or tar of any kind, which produces the
equivalent results to the oleaginous matter. These ingredients comprise the com-
pound and are put under process in bulk. While the proportions of these ingre-
dients may be slightly varied, yet experiment has shown that the following have
proved the best for the purpose, varying from the minimum to the maximum,
according to the strength desired.
For manufacturing one hundred pounds the proportions will be, nitrate of soda
or saltpetre, sixty to seventy-five pounds; sulphur, ten to twelve pounds; charcoal,
seven to ten pounds, peat and hard coal, nine to twelve pounds, combined metallic
sulphates, two to four pounds; and oleaginous matter, animal or vegetable, refined
or crude, one to three pounds. Tar in any form will answer the purpose of such
oily matter.
All the solid matters are pulverized and mixed together with the metallic
sulphates. These are all subjected to the action of steam in an open vessel until
thoroughly saturated when the direct application ceases. With this I combine the
action of external heat by superheated steam, the vessel being provided with a
double bottom for that purpose. The effect of this combined heating action is to

page_text: bring the mixture to a uniform solution and perfect incorporation of the materials,
and effect an entire vaporization of the liquid by prolonging the external heat
until the compound becomes dry, which occupies a period of about thirty minutes.
During the vaporization of the liquid the temperature of the heating element in
the double bottomed vessel is being slowly reduced from 250° to 150° Fahrenheit.
This reduction is made to ensure perfect safety in the drying process.
When nearly dry I take the mass out and put it on a drying platform of metal
heated by steam or hot air, and under this action in about fifteen minutes the
powder is ready for packing.
The employment of peat, charcoal, and hard-coal-makes-the-powder_but_slightly
inflammable or of slow combustion, and the combination with these of the metallic
sulphates and the oily matters makes the powder non-explosive in the open air and
by friction and concussion, and at the same time increases the strength when it is
confined in the chamber of a mine. Were it not for the external application of
heat simultaneously with the direct application of steam the process would be
prolonged and slow, and the incorporation of the ingredients would not be so
perfect.
The chemical reaction which occurs when the compound has been in ebullition
for a period of fifteen minutes consists in swelling or a developement in bulk
to an increase of about one third of its volume; and this action would be defective,
and the product in consequence less efficient, were it not for the application of
internal and external heat. The superheated steam avoids the use of fire and all
danger arising therefrom, and hastens the process.
In the manufacture of powder by this improved process all danger of explosion
is avoided, human life relieved from constant jeopardy, rates of insurance and
transportation diminished, security given to miners, and mining rendered more
renumerative.
In practice I have found that the combination of charcoal with peat and hard
coal produces the best result in rendering the combustion less instantaneous (for
blasting powder a matter of great importance), and the combination of these with
the sulphates of metal gives the best effect in rendering the compound inexplosive
in the open air and by concussion and friction; and I am not aware that these
materials have been combined in any known process for the manufacture of powder,
nor that oils or fats have been employed in their natural condition with them. In my
process these materials are treated at once, and the process is completed in one
operation, as stated, and not carried on under separate operations.
An essential feature of this Invention is the dispensing with the use of glycerine
and yet obtaining a strong powder by the combined action of the peat and hard
coal with charcoal, metallic sulphates, and oils, making a new compound by a very
cheap and quick process for producing the powder.