Improvement in Explosive Compounds.
Year: 1888

page_text: COMPLETE SPECIFICATION.
Improvement in Explosive Compounds.
1, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, l'atent Agent, do hereby declare the nature of this invention and in
what manner the samo is to be performed, which has been communicated to me from
abroad by Arden Seymour Fitch, of 57 Temple Court, in the City of New York,
County and State of New York, United States of America, Solicitor, to be particularly
described and ascertained in and by the following statement:—
The object of my invention is to produce an explosive compound for blasting
purposes, composed essentially of ordinary granulated black blasting powder and
nitro-glycerine, which is absorbed by the black powder, and in which the grains or
particles of the powder will have their absorption capacity augmented and after
absorbing the nitro-glycerine, retain their granular form and structure.
Heretofore in combining nitro-glycerine with the granules of ordinary black
blasting powder, the addition or absorption of the nitro-glycerine has caused the
disintegration of the granulated powder and has reduced the mixture to a pasty,
sticky, or deliquated mass, which as such, has been unserviceable as a true powder;
and to remedy this the grains of the powder, which is to receive the nitro-
glycerine, have heretofore been hardened and polished and thus rendered practically
non-absorbent; or such grains have been coated or varnished with a non-absorbent
and fluid resisting material; the treatment in either case being for the purpose of
preventing the absorption by the powder-granules of the nitro-glycerine, and to
ensure the adherence of the nitro-glycerine thereto, when added, as an external
coating only. But any of such prevailing treatments of a granulated powder prior
to the mixture therewith of nitro-glycerine and as a preparatory step thereto, are
necessarily comparatively costly and laborious and involve increased risk in the
process of manufacture.

page_text: By means of my hereinafter described invention 1 am enabled to obviate the
necessity of a tedious, expensive and comparatively dangerous preparation of the
grains of the granulated powder to prevent their disintegration after the combination
therewith of the nitro-glycerine; and I fabricate a blasting powder in which the
grains of the powder are not artificially hardened or polished, nor coated or varnished
with a non-absorbing substance, in the course of manufacture, but said grains have
their absorption capacity increased, and when they have absorbed nitro-glycerine will
not be thereby disintegrated or deliquated, but will retain their original form and
structure, thus constituting as a completed compound a granulated powder, which is a
high explosive.
In carrying out my invention I employ the usual ingredients of ordinary black
blasting powder for the granulated powder, namely charcoal, sulphur and a nitrate,
as of sodium. To these ingredients I add, a certain quantity of starch in the form of
a paste as hereafter set forth and all these named ingredients, when mixed as
hereinafter described, granulate as presently specified, and the resulting powder I
combine with nitro-glycerine as hereinafter set forth.
In fabricating this powder, I proceed as follows:-The starch is first converted into
a paste or jelly by being dissolved and then treated with boiling water. With this
paste there is then thoroughly incorporated the ingredients of ordinary black blasting
powder, constituting the gas-producing material, namely a mixture of charcoal, finely
ground, sulphur, when used, and a nitrate, such as sodium, potassium or ammonium
nitrate. The mass being thus mixed in a wet state there is no risk attending the
operation. The mass when thoroughly mixed is spread out, or rolled into sheets, and
dried and then broken up or granulated, in the ordinary manner.
The relative proportions of the charcoal, sulphur and nitrate may be substantially
those of ordinary black blasting powder, and should of course be preferably, such as
will effect a perfect combustion of the carbon in the mixture, on explosion. I find
that the following proportions produce a good and effective result:-Seventy-three
(73) paris, by weight, of sodium nitrate; twelve (12) parts of charcoal and ten
(10) parts of sulphur. I take five (5) parts of starch, by weight, and make the
same into paste with eighteen (18) or nineteen (19) parts of water. Into the paste,
heated, I stir and thoroughly mix the mixture of the charcoal, sulphur and nitrate.
The mass is then spread out in sheets, dried and granulated in the manner usually
employed in the manufacture of black powder.
The mass of the gas-producing material with which has been combined the starch
paste, as described, will, when the water of the paste is dried out or evaporated, he of
à honey-combed or cellular structure, the water as it evaporates leaving fine or
capillary interstices or cells extending throughout the mass, and the starch of the
paste being left incorporated in the mass.
When this dried mass is granulated, the granules will possess a greater absorptive
capacity owing to their cellular structure, than is possessed by grains of ordinary
black powder formed of the usual ingredients in the customary manner. I have found
that this granulated powder possesses the peculiar characteristic that the grains while
possessing the increased absorptive capacity stated are not affected in form and
structure, nor deliquated, by the absorption of nitro-glycerine; but, that, upon being
mixed with nitro-glycerine and absorbing it, they will retain their full granular
form and structure, and the resultant mixture will maintain itself as a granulated
powder.
I find that the mixture of ten (10) parts of nitro-glycerine with ninety (90) parts
of the described granulated powder will constitute an effective high explosive,
especially adapted for use in blasting. The proportion of the nitro-glycerine in
the completed compound may however be increased or decreased, depending upon the
strength and quickness of detonation desired. In mixing the nitro-glycerine with the
granular powder care should be taken, that by stirring or rolling the powder in or
upon the nitro-glycerine, the latter is uniformly distributed to and upon the grains, so
that the absorption may be substantially uniform in all the grains.
I am aware that starch has been heretofore used as an ingredient of explosive

page_text: compounds, and hence I do not intend to claim broadly herein the use of starch as an
ingredient. But its employment heretofore as an ingredient of black blasting powder
has been solely as a substitute for a greater or less portion of the carbonaceous
material therein, and wholly with a view to economy in cost, and the explosive
produced has been of an exceedingly low grade. Furthermore, when heretofore
employed in a high explosive as an ingredient of the mixture of substances which
absorbed nitro-glycerine, its employment, both as regards its proportion in the mixture,
and the substances with which it has been admixed, differs materially from its use in
my invention, and with a totally different result; the resulting completed explosive,
after the absorption of nitro-glycerine having been, in such cases, a plastic or semi-
plastic mass, resembling in permanent structure the several kinds of dynamite, and
not a granulated powder.
I do not employ starch in my described compound as the equivalent of any portion
of the carbon, nor in fact as a true ingredient of the gas-producing material of the
granulated powder. Starch being slower in combustion and thus less effective as a
gas-producing substance in an explosive, its presence in any considerable proportion
is not desirable in a compound intended to be a high explosive. But starch, as I
employ it, in my described invention, performs the sole function of rendering the
mass of the gas-producing material with which it is combined, as a paste, cellular or
honey-combed in structure, when the water of the paste is evaporated, and preserves
and maintains the granular structure of the grains when the same have absorbed
nitro-glycerine, and the starch is present in my compound in so comparatively a small
a quantity or proportion that its presence does not practically affect the character of
the compound as a high explosive. I am not aware that any one has heretofore
combined starch with the gas-producing material of ordinary black powder in substan-
tially the proportions stated and thus produced.a granulated powder which is cellular
or honey-combed in structure, and therefore of increased absorptive capacity, and
which when permitted to absorb nitro-glycerine will retain and preserve its granular
form.
I am furthermore not aware that a high explosive has been heretofore fabricated
composed of ordinary black blasting powder with the ingredients of which has been
combined starch in the manner herein set forth and forming an absorbent granular
powder, together with nitro-glycerine, absorbed by the granules, and in which
resulting and completed explosive the granules of the powder owing to the presence
of the starch therein, while being absorbent as stated, will maintain their granular
structure after such absorption of nitro-glycerine, and do not in consequence of such
absorption disintegrate or deliquate.
It is obvious that the proportions of the ingredients of the ordinary black powder
in my compound may be varied within the limits specified, and also that sulphur
may be omitted, the remaining oxidant such as nitrate of soda being then propor-
tionately increased; and furthermore, that such carbohydrates, as, for example,
dextrine or flour of cereals containing starch in sufficient quantity as will, by the
presence thereof in the mixture produce the described cellular structure of the grains
and maintain the granular character of the powder in the final compound, after the
nitro-glycerine has been absorbed by the granules, may be used in place of starch
as a paste in my compound.
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. An explosive compound consisting of a mixture of charcoal, and an oxidant, as
nitrate of sodium, with which is combined starch, in about the proportions named,
and forming an absorbent, granular powder, together with nitro-glycerine absorbed
by the powder-granules, said granules being maintained as such, and constituting a
granular powder after said absorption of nitro-glycerine, and adapted for use in such
granular form, substantially as described.

page_text: 2. As an article of manufacture, an absorbent granular powder composed of
charcoal, an oxidant, as nitrate of sodium, and starch, combined in about the pro-
portions and in the manner specified, and constituting a powder the granules of which
are cellular or honey-combed in structure, and adapted to absorb nitro-glycerine and
to maintain their granular form after such absorption, as set forth.
3. In the manufacture of an explosive compound the process of producing a
granular powder which consists in combining starch, dissolved and boiled in water
as paste, in about the proportion named, with the gas-producing ingredients of black
powder, as, for example, charcoal and an oxidant as sodium nitrate, and then evapo-
rating the water of the paste from the mass, whereby when the dried mass is
granulated, the resulting granular powder will consist of granules which are cellular
or honey-combed in structure, and which are adapted to absorb nitro-glycerine and
will maintain their granular form subsequent to such absorption, as set forth.
Dated this 22nd day of May 1888.