Improvements in or relating to Safety Tamping for Explosives used for Blasting Operations in Coal and other Mines, and in Apparatus for use in connection therewith
Year: 1898

page_text: Date of Application, 23rd May, 1908
Complete Specification Left, 29th June, 1898—Accepted, 6th Aug., 1898
word may
Complete Specification Left, 29th June, 1898-Accepted, 6th Aug., 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Safety Tamping for Explosives used
for Blasting Operations in Coal and other Mines, and in Apparatus
for use in connection therewith,
I, EDWIN STANLEY CLARK, of Oak Alyn, near Wrexham, in the County of
Denbigh, Colliery Owner, do hereby declare the nature of this invention to be as
follows:-
This invention has for its principal object a safety tamping for gunpowder or
other explosives in quarrying or mining operations which will not only absorb
or utilise heat generated by the explosion and thus prevent ignition of a gaseous
or coal dust atmosphere or both combined, so as to greatly reduce the smoke or
fumes and neutralise the same when charged with nitrous or other corrosive or
deleterious fumes. The health of the miners working in mines will also be greatly
improved where my invention is used owing to their not having to breathe the
deleterious compounds. I have found that if mono-carbonate or mono-sulphate
of an alkali metal or other hydrated salt of an alkali having a large quantity of
water of crystallisation or other water very loosely but chemically combined with
it, be formed into solid blocks or prisms so as to expose the greatest amount of
surface to the products of explosion and is placed with the charge of explosive
in the bore hole as the case may be, or if a thin cylinder of such salt be placed
round the charge, and blocks or prisms of the salt be interspersed or embayed with
the explosive, or perforated blocks of the salt be placed in front of the explosive,
or if the salt be used in a granulated form on firing the heat of explosion dis-
associates the water of crystallisation or other water from the salt converting it
into superheated steam and thus the force of explosion is increased and the heat
of the explosion very materially lessened.
Further I find that the nitrous and sulphurous fumes which are formed by
the explosion of gunpowder nitrated or like compounds are taken up or neutral-
ised by the alkaline carbonate or other unsatisfied alkali salts left after the disengage-
ment of the steam, liberating an equivalent amount of carbonic acid. I have
found too that if perforations parallel with the axis of the bore be made in the
salt about 5 ths of an inch in diameter having walls of salt round them about
three to five eighths of an inch in thickness or the cylinder be so much smaller
in diameter than the bore as to leave a wide passage round it for the gases to pass
through or embayments or passages be formed in the sides of the cylinder longi-
tudinally or any two or all of these provisions be adopted, the pro-
ducts of explosion instead of blowing the tamping out undecomposed
enter the holes or passages and entirely disassociate the water from the salt with
the utmost rapidity producing steam and causing the alkali of the salt to neutralise
the deleterious products of combustion and reducing the temperature particu-
larly with the ammonium nitrate compounds.
The fuse comes up through the cylinders and then through the clav filling in
the usual manner. The cylinders, prisms or embayments are composed of all or
any of the highly hydrated salts of the alkali metals especially sodium. I prefer
[Price 8dI

page_text: of soda to harden it, and ferric oxide as a stain having the following composition
Mono-carbonate
Sulphate
Ferric oxide
971/10%
1%
In very inflammable mines containing much gas and coal dust, I use an amount
of salt equal to about two-thirds the weight up to the full weight of the explosive,
a short length of cylinder being placed behind and the rest in front of the
explosive, or on the side of least resistance.
In some cases the length of cylinder used is reduced and prisms of the hydrated
salt are embedded in the charge or even granules of the hydrated salt are used.
As however these salts are liable to slowly give up their water it is desirable to
coat the pieces of the hydrated salt if embayed or inserted with the explosive and
stored with it with a film of paraffin wax, india-rubber, or other waterproof
material.
The action of my material is as follows:-
The heat of the explosion decomposes the tamping, liberates the water of crystallisa-
tion and thereby forms a large volume of steam which is converted into super-
heated steam, and adds to the explosive force by the addition of this steam.
Secondly the sulphurous and nitrous fumes liberated by the explosion are neutral-
ised, the mono-carbonate is partly bi-carbonated which in turn is attacked by the
freed acids of explosives and carbonic acid is produced, all these actions and re-
actions absorbing heat but adding increased volumes of expansive gases of an
uninflammable nature, thus the deleterious effects of the sulphurous and nitrous
acids are obviated. The vapour of steam too has a remarkable effect in lessen-
ing the amount of smoke by precipitating it in the bore hole, it being almost
unperceivable when compared with a similar weight of the same explosive fired off
without my salt. Gunpowder giving off no greater fumes than high explosives.
The mode of and apparatus for making the cylinders consists in providing a
framework or tray, having bottom bars forming a grid or tray and a series of
bars filling up the space above the grid, semi-circular holes are cut out of these
bars. These semi-circles come together between each pair of bars forming circular
moulds. A tube passes through the grid at the bottom having a plate brazed or
otherwise fixed rigidly thereon entirely filling up the bottom of the mould holes.
The space surrounding the tube is filled with crushed hydrated mono-carbonate
of soda crystals preferably stained with oxide of iron or other stain and in some
instances mono-sulphate of soda is added to harden the mass. A hot solution of
mono-carbonate of soda or of sulphate of soda or a mixture of the two is poured
in and the trays are preferably run on trolleys into a freezing chamber to cool or
crystallise rapidly. When they are thoroughly cold, steam or other heat is
momentarily applied to the interior of the aforementioned tubes and to the bars
which can be made hollow for this purpose. The tubes with their surrounding
cylinders of salt can now be lifted out and the salt cylinders removed from them
and left to dry and harden. They are now ready for use.
For the purpose of
placing the cylinders in bore holes of mines I use an instrument which I call a
filler or rammer. This rammer consists of an iron rod sliding loosely in a tube
which latter is fastened to the closed end of another tube of brass. The rod has
fixed to the end of it a plunger preferably coned and a temporary cap is placed on
the brass tube for use in measuring weight of material. When required the
cylinders are placed in the brass tube and when they are to be placed in the
hole the cap is removed and the tube with its cylinders is pushed into
the hole up to the end, the iron rod is then pressed down against the cylinders
or granulated material and the tube surrounding such rod is drawn
back. The apparatus can now be withdrawn from the hole.
Dated this 20th day of May 1898.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.

page_text: Improvements in or relating to Safety Tamping for Explosives used
for Blasting Operations in Coal and other Mines, and in Apparatus
for use in connection therewith.
I, EDWIN STANLEY CLARK, of Oak Alyn, near Wrexham, in the County of
Denbigh, Colliery Owner, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:
This invention has for its principal object a safety tamping for gunpowder or
other explosives in quarrying or mining operations which will not only absorb or
utilise heat generated by the explosion and thus prevent ignition of a gaseous
or coal dust atmosphere or both combined, so as to greatly reduce the smoke or
fumes and neutralise the same when charged with nitrous or other corrosive or
deleterious fumes. The health of the miners working in mines will also be greatly
improved where my invention is used owing to their not having to breathe the
deleterious compounds.
The present application has for its object the patenting in its most complete
form of the invention protected under No. 20223 of 1897, the Complete Specifica-
tion of which is filed contemporaneously with this, and the drawings of which
will be referred to throughout this specification.
I have found that if mono-carbonate or mono-sulphate of an alkali metal or
other hydrated salt of an alkali having a large quantity of water of crystallisation
or other water very loosely but chemically combined with it, be formed into solid blocks
or prisms so as to expose the greatest amount of surface to the products of explosion
and is placed with the charge of explosive in the bore hole as the case may be, or
if a thin cylinder of such salt be placed round the charge, the external diameter
of such cylinder being less than the diameter of the bore hole, and blocks or prisms
of the salt be interspersed or embayed with the explosive, or perforated blocks of
the salt be placed in front or back of the explosive, or if the salt be used in a
granulated form on firing the heat of explosion disassociates the water of crystal-
lisation or other water from the salt converting it into superheated steam and thus
the force of explosion is increased and the heat of the explosion very materially
lessened.
Further I find that the nitrous and sulphurous fumes which are formed by the
explosion of gunpowder nitrated or like compounds are taken up or neutralised
by the alkaline carbonate or other unsatisfied alkali salt left after the disengage-
ment of the steam, liberating an equivalent amount of carbonic acid. I have
found too that if perforations or embayments substantially parallel with the axis
of the bore be made in the salt preferably about 5ths of an inch in diameter or
width having walls of salt round them, preferably about three to five eighths of
an inch in thickness or the cylinder be so much smaller in diameter than the bore
as to leave a wide passage round it for the gases to pass through or embayments
or passages be formed in the sides of the cylinder longitudinally or any two or all
of these provisions be adopted, the products of explosion instead of blowing the
tamping out undecomposed enter the holes or passages and entirely disassociate the
water from the salt with the utmost rapidity producing steam, and causing
the alkali of the salt to neutralise the deleterious products of combustion, and
reducing the temperature particularly with the ammonium nitrate compounds.
The invention is best described by aid of the drawings accompanying the Com-
plete Specification of my application for Patent No. 20,223 of 1897, in which,
Figure 1 is a cylinder of salt hereafter described used in mining operations;

page_text: Figures 2, 3, 4 and 5 other forms of cylinder or prisms and embayments;
Figure 6, section of a part of a coal mine showing a charge ready for firing;
Figure 7, a tray of moulds and moulding bars;
Figure 8, bars separating the moulds;
Figure 9, a longitudinal section showing moulds and core tubes;
Figure 10, enlarged view of core tube and mould bottom;
Figures 11 and 12, details of tool used to insert the salt in the bore hole.
Referring first to Figures 1 to 6, A is the face of a seam of coal, B bore hole,
C prop, sprags, 1) fuse, E the explosive.
FF are cylinders or prisms, that in Figure 5 being similar to that shown on a
larger scale in Figure 1 and which represents a cylinder used in a bore hole
about one and a half inches in diameter. In such I form the cylinder 14 inches
in outside diameter with a hole through the centre of about 5/ths of an inch in
diameter. Similar cylinders or prisms in triangular, semicircular and embayed
forms are shown at Figures 2, 3 and 4 respectively. is the charge of explosive.
The fuse D comes up through the cylinders and then through the clay filling in the
I is the clay filling. These cylinders, prisms or embayments,
Figures 1, 2, 3, 4 and 5, are composed of all or any of the highly hydrated salts
of the alkali metals especially sodium. I prefer mono-carbonate of soda (soda
crystals) or a mixture of this with mono-sulphate of soda to harden it, and ferric
oxide as a stain having the following compositions:-
usual manner.
Mono-carbonate of soda
Sulphate of soda
Ferric oxide
-
97%
20
1%
In an ordinary mine where there is little or no gas or inflammable dust the charge
is well shown in Figure 6. In very inflammable mines containing much gas and
coal dust, I use an amount of salt equal to about two-thirds the weight up to the
full weight of the explosive, a short length of this tamping being placed behind and
the rest in front of the explosive, or on the side of least resistance.
In some cases the length of tamping used is reduced and prisms of the hydrated
salt are embedded in the charge or even granules of the hydrated salt are used.
As however these salts are liable to slowly give up their water it is desirable to
coat the pieces of the hydrated salt if embayed or inserted with the explosive and
stored with it, with a film of paraffin wax, india-rubber, or other waterproof
material. It is desirable in most cases to leave room round the prism or cylinder
in the borehole for the passage of gases or flame, as shown in Figure 5 or (when
placed) in a round hole Figure 2. The action of my material is as follows:
The heat of the explosion decomposes the tamping, liberates the water of crystal-
lisation and thereby forms a large volume of steam which is converted into super-
heated steam, and adds to the explosive force by the addition of this steam.
Secondly, the sulphurous and nitrous fumes liberated by the explosion are
neutralised, the mono-carbonate is partly bi-carbonated which in turn is attacked
by the freed acids of explosives and carbonic acid is produced, all these actions
and re-actions absorbing heat but adding increased volumes of expansive gases
of an uninflammable nature, thus the deleterious effects of the sulphurous and
nitrous acids are obviated. The vapour of steam too has a remarkable effect in
lessening the amount of smoke by precipitating it in the bore hole, it being almost
unperceivable when compared with a similar weight of the same explosive fired
off without my salt. Gunpowder giving off no greater fumes than high explosives.
The mode of and apparatus for making the cylinders are set forth in Figures 7
to 10. In these L is a framework or tray; M bottom perforated with holes m;
Na series of hollow bars filling up the space above the bottom M; P semi-circular
holes cut out of these bars. These semi-circles come together between each pair
of bars forming circular moulds. shown in larger size in Figure 10 is a tube
..

page_text: of the mould holes P. The interiors of the frame L, bottom M (if made hollow)
tubes Q and bars N can all communicate with each other if desirable, and arrange-
ments are made for supplying them with steam when required. The spaces P
surrounding the tubes Q are filled with crushed hydrated mono-carbonate of soda
crystals preferably stained with oxide of iron or other stain, and in some instances
A hot solution of mono-
mono-sulphate of soda is added to harden the mass.
carbonate of soda or of sulphate of soda or a mixture of the two is poured in, and
the trays are preferably run on trolleys into a freezing chamber to cool or
crystallise rapidly. When they are thoroughly cold, steam or other heat is
momentarily applied to the interior of tubes Q, bottoms M and bars P. The whole
can now be inverted or the tubes Q with their surrounding cylinders of salt can be
lifted out, and the salt cylinders removed from them and left to dry and harden.
They are now ready for use. For the purpose of placing the cylinders Figure 1
in bore holes of mines, I use an instrument which I call a filler or rammer.
is set forth in Figures 11 and 12. In these, T is an iron rod sliding loosely in
a tube U. Tube U is fastened to the closed end of another tube V of brass.
Rod T has fixed to the end of it a plunger preferably coned as shown W. X is
a temporary cap placed on a tube for use in measuring weight of material. When
required the cylinders, Figure 1, are placed in tube V and when they are to be
placed in the hole the cap X is removed, the tube V with its cylinders pushed into
the hole up to the end, the rod T is then pressed down against the cylinders or
prisms and the tube U surrounding such rod drawn back. The apparatus can now
be withdrawn from the hole.
This
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 a part of this
invention is also set forth in my Patent Application No. 20223 of 1897 which was
secret at the time that the Provisional Specification of this application was filed,
and that while I am completing that application as a precaution in case of any
publication in the interim, the complete form of my invention is set forth and
claimed here and that what I claim is :-
1. The improvement in safety tamping for explosives in mines, which consists
in solid cylinders prisms or other pieces of a dry hydrated salt such as described
arranged in a bore hole with central or other passages, whereby the products of
explosion can permeate this stemming with the utmost rapidity and give up heat
in liberating gaseous products from the stemming.
2. The method of and apparatus for forming solid pieces of salt of required shape
substantially as and for the purposes described.
D
the 10th day of Tune 1898
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham, and London.