IMPROVEMENTS IN SMELTING ZINC ORES, AND IN FURNACES EMPLOYED FOR THIS PURPOSE
Year: 1858

page_text: LETTERS PATENT to Maximilien Schaffner, Civil Engineer, of Eisenach,
for the Invention of "IMPROVEMENTS IN SMELTING ZINC ORES, AND IN
FURNACES EMPLOYED FOR THIS PURPOSE."
Sealed the 3rd June 1859, and dated the 11th December 1858.
PROVISIONAL SPECIFICATION left by the said Maximilien Schaffner at the
Office of the Commissioners of Patents, with his Petition, on the
11th December 1858.
I, MAXIMILIEN SCHAFFNER, Civil Engineer, of Eisenach, do hereby declare
the nature of the Invention for "IMPROVEMENTS IN SMELTING ZINC ORES, AND
IN FURNACES EMPLOYED FOR THIS PURPOSE," to be as follows:-
According to this Invention the calamine or other zinc ore to be reduced is
placed in a large chamber or muffle, around which a flue from a furnace passes.
The top of this chamber is formed of hollow bricks, and the bottom of fire
blocks or tiles, which rest on masonry at the two sides, and are also supported
between the sides with perforated supports; the blocks or tiles at the bottom
of the chamber or muffle form the top of a flue from a furnace, and the
products of combustion from the furnace enter this flue at one end of the
chamber, and pass on beneath the chamber to its other end, where the flue
rises up,
and the products of combustion then pass back above the chamber
through the hollows in the bricks forming its top to a chimney, by which

page_text: means the chamber is sufficiently heated to volatilize the zinc. At one side of
the chamber there are holes through which the zinc ore is introduced into the
chamber; these holes are closed air-tight when the furnace is in operation.
From the chamber or muffle pipes descend to a condenser in which the zinc is
deposited in a liquid state, and can be ran off, when desired, through a small
tap hole; from this condenser pipes pass to another condenser, which arrests
the metal which passes away with the gases in the state of dust. From the
second condenser a pipe in which there is a valve passes to the chimney, so that
by opening or closing this valve the gases may be drawn more or less quickly.
from the chamber or muffle. In the chimney below where the pipe from the
condenser enters there is a sliding register, which, when the operation of
smelting the zinc ore is nearly completed, is all but closed, and the gases from
the furnace are caused to pass into the chamber or muffle through pipes which
pass from the furnace to the chamber, the passages through which pipes are at
other times closed by registers. The gases first aid in reducing the ores, and
afterwards serve to empty the muffle of the vapours of zinc. In place of
passing the gases from the furnace through the muffle, carbonic oxide 'may be
produced in a separate generator, and passed through the muffle. The furnace
may in a similar manner be made to heat two muffles, which may either be
placed side by side or end to end.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Maximilien Schaffner in the Great Seal Patent Office on
the 11th June 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MAXIMILIEN
SCHAFFNER, Civil Engineer, of Eisenach, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of December, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Maximilien Schaffner, Her special licence that I, the said Maximilien
Schaffner, my executors, administrators, and assigns, or such others as I, the said
Maximilien Schaffner, 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 "IMPROVEMENTS

page_text: IN SMELTING ZINC OBES, AND IN FURNACES EMPLOYED FOR THIS PURPOSE," upon
the condition (amongst others) that I, the said Maximilien Schaffner, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly 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 immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Maximilien Schaffner, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
According to this Invention the calamine or other zinc ore to be reduced is
placed in a large chamber or muffle, around which a flue from a furnace passes.
The top of this chamber is formed of hollow bricks, and the bottom of fire
blocks or tiles, which rest on masonry at the two sides, and are also supported
between the sides with perforated supports; the blocks or tiles at the bottomn
of the chamber or muffle form the top of a flue from a furnace, and the
products of combustion from the furnace enter this flue at one end of the
chamber and pass on beneath the chamber to its other end, where the flue
rises up, and the products of combustion then pass back above the chamber
through the hollows in the bricks forming its top to a chimney, by which
means the chamber is sufficiently heated to volatilize the zinc. At one side
of the chamber there are holes through which the zinc ore is introduced into
the chamber; these holes are closed air-tight when the furnace is in operation.
From the chamber or muffle pipes descend to a condenser in which the zinc
is deposited in a liquid state, and can be run off, when desired, through a
small tap hole; from this condenser pipes pass to another condenser, which
arrests the metal which passes away with the gases in the state of dust. From
the second condenser a pipe in which there is a valve passes to the chimney,
so that by opening or closing this valve the gases may be drawn more or less
quickly from the chamber or muffle. In the chimney below where the pipe
from the condenser enters there is a sliding register, which, when the operation
of smelting the zinc ore is nearly completed, is all but closed, and the gases
from the furnace are caused to pass into the chamber or muffle through pipes
which pass from the furnace to the chamber, the passages through which pipes
are at other times closed by registers. The gases first aid in reducing the ores,
and afterwards serve to empty the muffle of the vapours of zinc. In place of
passing the gases from the furnace through the muffle,. carbonic oxide may be

page_text: annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal vertical section (through the line C, D, Figure 4)
taken through the centre of the fireplace, the hearth, the muffle, and the
chimney of a furnace for reducing zinc ores constructed according to my
Invention; Figure 2 is a transverse vertical section (through the line E, F,
Figure 1) taken through the muffle, the flues above and below the muffle, and
through the pipes which conduct the vapours of zinc to the condenser;
Figure 3 is a vertical section (through the line A, B, Figure 1) taken
through the fireplace and the flue leading to the chimney; Figure 4 is a
horizontal section through the muffle, the doors for charging the muffle, and
through the openings in which are fitted the pipes for conveying the vapours
to the condenser; Figure 5 is a horizontal section through the fire (through
the line M, N, Figure 1); Figure 6; one side view of the furnace, shewing the
condenser; Figure 7, the other side view of the furnace, shewing the openings
for charging the muffle. a, a, is the fireplace; b, b, the muffle, the bottom of
which is formed by fire blocks or tiles, which rest on the supports b¹, and on
the masonry at the two sides; c, c, are the channels which conduct the flame
under the muffle, which are formed by the above-mentioned supports 6', these
supports are perforated to prevent an unequal distribution of the flame under
the muffle; the top of the muffle is formed of hollow fire-bricks d, d, the
hollow in the bricks being arranged to form a portion of the flue of the
furnace. The products of combustion pass from the fireplace beneath the
bottom of the muffle through the channels c, c, to the end of the muffle, they
then pass up through the passage c¹ into the hollow passages in the fire-
bricks d, d, and through these passages to the chimney; the bricks d, d, are
fitted together as shewn in the Drawing, to prevent the vapours of zinc
passing through the top of the muffle into the hollow passages in the bricks
forming the flue above the muffle; f,f, are passages for admitting air above
the fuel on the firė-bars; and g is the fire-door. A mixture composed as for
the zinc furnaces now used of calcined calamine or other zinc ore and small
charcoal or coke is introduced into the muffle through the four openings a¹ in
the side of the furnace (see Figure 7). The first of theso doors is larger than

page_text: the others, so that fire-tiles for repairing the bottom of the muffle may be
introduced through it. When the zinc ore, has been introduced into the
muffle, these openings are closed by cast-iron plates, the edges around the
plates being made tight by clay, sand, or otherwise. Figure 6 shews the side
of the furnace on which the condensor is situated. The muffle is provided
with four openings on this side, which are provided with bent earthenware
pipes a² (of the same kind as those employed in a silician furnace), through
which the vapours of zinc descend into à sort of basin k, where the zinc is
deposited in a liquid state, and can be run off through a small tap hole 7. The
gases, which are formed in the muffle pass through this condensor and from
its two ends through.iron pipes r, r, into a second condenser B of sheet iron,
and then into the chimney. The second condensor B is for the purpose of
retaining the metal which is carried with the gases in the state of a grey dust.
The communication of the condensor with the chimney is for the purpose of
establishing a more or less quick draft to facilitate the passage of vapours of
zinc from the muffle, and also for preventing a draft from the chimney to the
muffle through the flue which passes around the muffle. At the end of the
pipe which connects the second condensor with the chimney there is a register
by which the degree of draft through the condensors may be regulated.
Towards the end of the operation the register S in the chimney is all but
closed, and the registers.s, s, which before closed the passages o, o, from the
fireplace into the muffle are opened to admit into the muffle the carbonic
oxide from the fire; these gases first serve to reduce the ores, and then serve to
empty the muffle of the vapours of zinc which it. may contain. In order that
the workman may know when to admit the gases from the fire into the muffle,
there is in each of the iron doors which close the openings a¹ into the muffle,
a small hole, so that the workınan may observe how the reduction of the ores
is going on; and when the workman observes that the formation of zinc
vapours is slackening, he all but closes the register s and opens the registers 8, s.
The operation being terminated, the doors a¹ into the muffle are opened so as
to empty the muffle. The pipes leading to the condensor are not removed
except when they require cleaning or renewing. Figures 8 and 9 shew respec-
tively a longitudinal vertical section and a horizontal section of another
arrangement of furnace. In this arrangement the flue from the furnace in
place of passing around the muffle in the direction of its greatest width, as in
the arrangement just described, passes around it in the direction of its least
width. The openings a in the muffle for the introduction of the ore are
formed in the largest side of the muffle as shewn, and the openings a* for
conveying the vapours of zinc to the condensor are placed at the two ends.

page_text: Figures 10, 11, 12, and 13, shew different sections of an arrangement of zinc
furnace, in which one fire is arranged to heat two muffles by flues from the
fire passing around the muffles. In these Figures the same letters of reference
indicate similar parts to those marked by the same letters in the Figures above
described.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I am aware that zinc
ores have before been reduced by being placed in a chamber or muffle heated
by a flue from a furnace passing around it, and also that the gases coming
from the fire have before been passed through the muffle during the whole
operation of reducing the ore, I do not therefore claim the same, but what I
claim is,
First, the constructing the bottom of the muffle of fire blocks or tiles, and
the top of the muffle of hollow bricks, the blocks or tiles forming the top
of a flue from a furnace and the hollows in the bricks forming a continuation
of the flue.
Second, the passing the vapours from a zinc furnace through two condensers,
in the first of which the zinc is deposited in a liquid state, and in the second in
.the state of powder.
Third, the passing the gases from the fire' through the muffle at the end of
the operation for the purpose of completing the reduction of the ore, and
afterwards for emptying the muffle.
And lastly, the heating two muffles placed either side by side or end to end,
by means of one fire, as herein described.
In witness whereof, I, the said Maximilien Schaffner, have hereunto set
my hand and seal, this Sixth day of June, in the year of our Lord One
thousand eight hundred and fifty-nine.
MAXIMILIEN SCHAFFNER. (L.S.)