AN IMPROVED PROCESS APPLICABLE TO THE MANUFACTURE OF ZINC
Year: 1856

page_text: LETTERS PATENT to Jacob Levi Elkin, of Jeffreys Square, St. Mary
Axe, in the City of London, Merchant, for the Invention of "AN
IMPROVED PROCESS APPLICABLE TO THE MANUFACTURE OF ZINC."-A com-
munication.
PROVISIONAL SPECIFICATION left by the said Jacob Levi Elkin at the
Office of the Commissioners of Patents, with his Petition, on the 25th
November 1856:
I, JACOB LEVI ELKIN, of Jeffreys Square, St. Mary Axe, in the City of
London, Merchant, do hereby declare the nature of the said Invention for
"AN IMPROVED PROCESS APPLICABLE TO THE MANUFACTURE OF ZINC," to be as
follows:-
In most of the methods employed in the reduction of zinc ores, and obtain-
ing by distillation this metal from the minerals in which it is contained, a
considerable portion of the metal, amounting in many cases to as much as ten
per cent. of the entire quantity, is condensed in the form of an impalpable
grey powder, generally designated as grey oxide or suboxide of zinc. This
substance, which is very rich in metal, is infusible by any ordinary process, and
in order to reduce it to the metallic state it is usually mixed with a certain
proportion of carbonaceous matter, and charged in the reducing pots to be
distilled over again, like ordinary ore, and other substances containing zinc.

page_text: The Inventor of the present process has discovered that this grey powder
consists of minute globules of metallic zinc, these globules being of a purely
spherical form. The consequence of this spherical form is, that though heated
far above the point of fusion the powder does not melt or agglomerate, the
points of contact being too small, precisely as is the case with very finely
divided mercury.
The Inventor of the present process has, however, discovered that if the
zine powder be heated to the melting point and then submitted to a certain
pressure, the spherical globules will become flattened, and the surfaces of
contact will be thereby considerably increased, and the whole will then melt
into one mass of fused zinc.
In applying this principle on a large scale it is found to succeed admirably,
and the operation for this purpose is conducted as follows:-Four, six, or
eight pots, (according to the quantity of oxide to be melted,) are placed in a
furnace. These pots are from 18 to 22 inches in height and from 6 to 10
inches internal diameter; they are made of fire clay, and are provided at the
bottom with an opening or chamber in the shape of a boot, this opening or
chamber being about three inches square and coming outside the furnace.
These cylindrical pots are placed vertically, and arranged in such a manner as
to be able to be maintained at a low white or full red heat; cach pot is
provided with a very loosely fitting fire-clay cylindrical piston attached to an
iron rod, the top of which has a cross bar handle for turning it, and admitting
of its being charged with weights.
The mode of operation is as follows:-The pots being heated, the lower
orifices thereof are stopped with clayey sand, and the pots are charged
about half full with the perfectly dry fresh powder; the pistons are put in, and
after a time the workman presses on the pistons, turning and working them
occasionally by means of the handle.
When the zinc dust is entirely melted, the piston is raised up a little and
kept in that position; the sand at the bottom orifice is then pierced, and the
molten metal allowed to run out into a ladle to be poured into ingot moulds.
If the dust has been collected and operated upon with the care that is
necessary to prevent its combustion or partial oxidation, 90 per cent. of
metallic zinc will be obtained by immediate fusion, and 10 per cent. of real
oxide, which will yield by the ordinary mode of treatment 50 per cent. of
metal, the total yield of good grey powder by the improved process being 95
per cent. instead of 75, as by ordinary distillation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jacob Levi Elkin in the Great Seal Patent Office on the
25th May 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JACOB
LEVI ELKIN, of Jeffreys Square, Saint Mary Axe, in the City of London,
Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of November, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Jacob Levi Elkin, Her special license that I, the said Jacob Levi Elkin, my
executors, administrators, and assigns, or such others as I, the said Jacob
Levi Elkin, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED PROCESS
APPLICABLE TO THE MANUFACTURE OF ZINC," being a communication from
abroad, upon the condition (amongst others) that I, the said Jacob Lovi
Elkin, by an instrument in writing under my hand and seal, should par-
ticularly describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and im-
mediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Jacob Levi Elkin, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing. statement, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon, (that is to say):-
In most of the methods employed in the reduction of zinc ores, and obtain-
ing by distillation this metal from the minerals in which it is contained, a
considerable portion of the metal, amounting in many cases to as much as ten
per cent. of the entire quantity, is condensed in the form of an impalpable
grey powder, generally designated as grey oxide or suboxide of zinc. This
substance, which is very rich in metal, is infusible by any ordinary process,
and in order to reduce it to the metallic state it is usually mixed with a
certain proportion of carbonaceous matter, and charged in, the reducing.

page_text: pots to be distilled over again, like ordinary ore, and other substances contain-
ing zinc.
The Inventor of the present process has discovered that this grey powder
consists of minute globules of metallic zinc, these globules being of a purely
spherical form. The consequence of this spherical form is, that though heated
far above the point of fusion the powder does not melt or agglomerate, the
points of contact being too small, precisely as is the case with very finely
divided mercury.
The Inventor of the present process has, however, discovered that if the
zinc powder be heated to the melting point and then submitted to a certain
pressure, or the mass stirred or agitated from time to time, the spherical
globules will become flattened, and the surfaces of contact will be thereby
considerably increased, and the whole will then melt into one mass of fused
zine. On applying this principle on a large scale it is found to succeed
admirably, and the operation for this purpose is conducted in the manner
hereafter described.
In the accompanying Drawing I have shewn various views of an arrange-
ment of apparatus in which the agglomeration of the globules of metallic
zinc is effected by means of pressure and agitation while the mass is submitted
to heat applied externally.
Fig. 1 is a longitudinal vertical section of the apparatus; Fig. 2 is a
horizontal section; Fig. 3 is a transverse vertical section; and Fig. 4' is a
side elevation.
Four, six, eight, or any convenient number of pots a, a, a, a, (according to
the quantity of oxide to be melted) are placed in a furnace. These pots are
from eighteen to twenty-two inches in height and from six to ten inches
internal diameter; they are made of fire clay, and are provided at the bottom
with an opening or orifice b (Fig. 3), which imparts to the pot or vessel some-
what the shape of a boot; this opening or orifice is about three inches square,
and communicates with the outside of the furnace, so that the molten metal
may be run therefrom when required. The cylindrical pots a, a, are placed
vertically in the furnace, and are arranged in such a manner therein as to be
able to be maintained at a low white or full red heat. Each pot a is provided
with a very loosely fitting fire-clay cylindrical piston c, attached to an iron rod d,
the top of which has a cross bar, and handle for turning it, and admitting of
its being charged with weights, as shewn at e in Fig. 1. The piston rods d
are maintained in a vertical position where required by means of a guide bar h,
in which are cut notches to receive the vertical rods d. At the upper end of
these rods there is also a winch handle f, whereby the pistons may be turned

page_text: and worked in the pots when required. The cast-iron top m of the furnace is
supported by the tubular pillars g, g. The mode of operating is as follows:
The pots a, a, being heated, the lower orifices b, b, (Fig. 3) thereof are stopped
with clayey sand, and the pots are charged about half full with the perfectly
dry fresh powder; the pistons c are put in, and after a time the workman
presses on the pistons.c, and turns and works them occasionally by means of
the handle f, a constant pressure being kept on the pistons by means of the
weights (Figures 1 and 3). When the zinc dust is entirely melted, the
piston c is raised up a little and kept in that position, as shewn in the Draw-
ings, and the sand at the bottom orifice b is then pierced, and the molten
metal allowed to run out into a ladle to be poured into ingot moulds. If the
dust has been collected and operated upon with the care that is necessary to
prevent its combustion or partial oxidization, ninety per cent. of metallic zine
will be obtained by immediate fusion, and ten per cent. of real oxide, which
latter will yield by the ordinary mode of treatment fifty per cent. of metal;
the total yield from good grey powder by the improved process being ninety-
five per cent. instead of seventy-five, as by ordinary distillation.
In Figures 4*, 5, and 6 of the accompanying Drawing, I have shewn a
modification of the Silesian method of reducing zinc orcs, and the mode of
adapting the present improvements thereto; theso Figures being drawn to
the scalo of one-tenth tho real size.
Fig. 4 is a longitudinal section of an earthen zinc pot, being fixed and
luted into the top opening of the Silesian pot. The tube, Fig. 5, is fixed at
the other extremity b of the pot, and a sheet-iron tube, Fig. 6, is placed on
this second tube. The greater part of the zinc condenses in the first tube in
the liquid state, and is raked out twice a day into a ladle. In the second
and third tubes a large quantity of zinc is condensed in the form of a grey
impalpable powder. At f in the third tube is a hole of about half inch
diameter, for the exit of the gases, and for the workman to be able, by the
insertion of an iron rod, to keep the orifice d (Fig. 5) constantly free. The
advantages of this process are found to be considerable; as the zinc does not
burn as in the ordinary process, there are much less fumes in the workshop,
and very little zinc is lost.
Having now described the Invention of "An improved process applicable
to the manufacture of zinc," that has been communicated to me by my foreign
correspondent, as aforesaid, and the means of carrying the same into effect, I
would observe that, although I have shewn and described an arrangement of
furnace and apparatus which has been found to answer the purpose and object
of the Invention, I do not mean or intend to confine myself rigidly thereto,

page_text: as it may doubtless be varied without departing from the nature and object of
the present improvements.
In conclusion, I claim as the Invention secured to me by Letters Patent,
as aforesaid, obtaining metallic zinc from grey powder, or grey oxide of zinc,
or other substanco containing that metal, in a finely divided state, by heating
such substance a little above the melting point, and then agitating and apply-
ing pressure to the heated mass, for the purpose of causing the small particles
or globules to agglomerate, so that the melted metal may be run out into
moulds or otherwise.
In witness whereof, I, the said Jacob Levi Elkin, have hereunto set
my hand and seal, the Twenty-fifth day of May, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
Tпos. NOLAN,
66, Chancery Lane.
JACOB L. ELKIN. (L.S.)