IMPROVEMENTS IN FURNACES OR APPARATUS FOR USE IN METALLURGICAL AND OTHER OPERATIONS
Year: 1877

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
FURNACES OR APPARATUS FOR USE IN METALLURGICAL AND OTHER OPERATIONS.”
A communication from abroad by La Société Anonyme des Mines du Rhin, of
Paris France
Sealed the 16th November 1877, and dated the 1st June 1877.
Sealed the 16th November 1877, and dated the 1st June 1877.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 1st June 1877.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN FURNACES OR APPARATUS FOR USE IN METAL-
LURGICAL AND OTHER OPERATIONS." [A communication from abroad by La Société
Anonyme des Mines du Rhin, of Paris, France.]
This Invention relates to an improved construction of furnace or apparatus for
economically.and advantageously treating cast iron, steel, and analogous substances,
and also for effecting other metallurgical and chemical reactions.
This furnace is characterized by the substitution of a current having a well
determined chemical character for the current of flames acting as in reverberatory
furnaces, and the employment of a steam engine in lieu of hand labor.
The accompanying Drawings show one example of the furnace.
Fig. 1 is a plan, and Figure 2, an elevation of the rakes and blast pipes combined,
the teeth of the rakes as well as the shaft and pulley by which they are operated
being shown in the latter Figure.
Figure 3 is a central section of the furnace showing the arch and hearth, and also
the footstep bearing in which the rake shaft is supported.
Figure 4-is a horizontal section of the furnace showing the grate, the air chambers,
blower, air, inlet, and heating pipes.
Figure 5 is a section on line A, B, Figure 3, to show the apertures for discharging
the matters treated as well as the central shaft ion which the rakes and blast pipes
are mounted.

page_text: The furnace is closed, and as the flames do not traverse it, the matters under
treatment, which are spread in a thin layer on the hearth, are protected from the
direct action of the gascous products of combustion, and receive the heat by
transmission.
A forced current of a constant character or composition, either from a gas holder,
generator, or the atmosphere is supplied by pumps or a blower at a through pipe a¹
to a casing b, thence through a serpentine arrangement of pipes c exposed to
the flames to a distributing chamber beneath the vertical shaft, and through the
latter to a number of perforated pipes by which it is directed upon the surface of
the matters to be treated.
The raking and discharge of the matters is effected in an automatic manner, the
former by the rotation of the shaft i, to which the rakes e and injection pipes f are
attached.
The rakes make.circular-furrows-in-the material on the hearth, and the teeth k
on the arms are all arranged at different radii, so as to each travel in a different
path, whereby an intimate working and mixing of the melted matter is effected.
The matters are discharged by means of a small scraper lowered into position for
the purpose, which collects the matters at one spot, and discharges then at an
opening that is closed by a door during the treatment.
The form of the furnace is that of a cylinder or truncated cone m set on its base.
It may be made of plate or cast iron, or constructed wholly or in part of brickwork.
The hollow shaft i is driven through a pulley 1, and is supported in a footstep n
projecting above a small chamber in the centre of the hearth. The upper part of
the shaft projects through a stuffing box P, 7, 7, in the furnace roof, a joint being
made with asbestos; o, bearing for shaft. One or more man-holes, closed like those
of gas retorts, are provided in the sides of the furnace.
The charge is introduced through a hopper.in the roof of the furnace closed by
a damper.
The air or other current, on escaping from the furnace, charged more or less with
vapors, is conducted by a bent pipe to a suitable condenser, according to the nature
of the vapors or gases to be collected.
The current may act chemically, according to its composition and character. Air
acts negatively by its oxygen; carburetted hydrogen, positively, by its two elements;
while steam will have a compound action.
This apparatus may be used as a calcining, roasting, or reducing furnace, and
even for distilling.
The current further acts physically by its caloric upon the continually renewed
surfaces, and also mechanically by carrying off the vapors produced.
The construction of the furnace may be simplified by replacing the injection
pipes by tuyeres, and the arrangement of the hearth may be modified in cases
where the substanco treated is liquid or fusible.
As an example of the mode of. employing this close furnace, I may mention its
use for the treatment of an ore containing blende, argentiferous galena, and cupreous
pyrite (mixed ore). The ore in the condition of slick is introduced through the
hopper into the furnace, the door being.closed and the hearth heated to a suitable
"temperature. By a few revolutions of the rakes the material is spread in a thin
-layer. The temperature and introduction of heated air are suitably regulated, and the
metals are sulphated. A quantity of chloride of sodium proportionate to that of the
sulphates to be transformed is then introduced: The air current, which is suspended
at the commencement of the chloruration, should then be gradually introduced, and b
the temperature raised so as to volatilize the chlorides. If preferred, superheated
steam may be substituted for the physical and mechanical action of atmospheric air.
The copper, zinc, silver, and a portion of the lead and iron in the form of chlorides
are thus carried off.
The fixed residue more or less charged with lead in the form of sulphate and 5
sulphate of soda is immersed, while hot, drained and dried, and finally treated by
the ordinary processes used in metallurgy.

page_text: When the liquids in the condenser are sufficiently charged with chlorides, the
metals are extracted therefrom in succession by known means.
In some cases two furnaces are employed in conjunction, placed at different levels.
The raw material is placed in the upper one to be sulphated, and thence passed to
the second one, where the operation is completed. In this manner each furnace is
retained at its own special temperature, and the necessity of varying the heat of
the furnace is thus avoided.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the 30th
November 1877.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN FURNACES OR APPARATUS FOR USE IN METAL-
LURGICAL AND OTHER OPERATIONS." A communication from abroad by La Société
Anonyme des Mines du Rhin, of Paris, France.
This Invention relates to an improved construction of furnace or apparatus for
economically and advantageously treating cast iron, steel, and analogous substances,
and also for effecting other metallurgical and chemical reactions.
This furnace is characterised by the substitution of a current having a well
determined chemical character for the current of gases and flames acting as in
reverberatory furnaces, and the employment of steam power in lieu of hand labor.
The accompanying Drawings show one example of the furnace.
Figure 1 is a plan and Figure 2 an elevation of the rakes and blast pipes com-
bined, the rake teeth as well as the shaft and its pulley by which the rakes are
operated being shown in the latter Figure.
Figure 3 is a central section of the furnace showing the arch 8, the hearth d, and
the footstep bearing n, in which the rake shaft is supported.
Figure 4 is a horizontal section of the furnace showing the grate, the air
chambers, blower, and the air inlet and heating pipes.
Figure 5 is a section on line A, B, Figure 3, to show the apertures for discharging
the matters treated, as well as the central shaft i on which the rakes and blast
pipes are mounted.
"
The furnace is closed, and as the flames do not traverse it, the matters under
treatment which are spread in a thin layer on the hearth d, are protected from the
direct action of the gaseous products of combustion, and receive the heat by
transmission.
A forced current of a constant character or composition, either from a gas holder
or generator, or from the atmosphere, is supplied by pumps or by a blower at ȧ
through pipe a¹ to a casing b, thence through a coil or serpentine arrangement of
pipes c exposed to the flames, to a distributing chamber beneath the rake shaft i
and through the latter, which is tubular, to a number of perforated pipes which
radiate therefrom, and by which it is directed upon the surface of the matters to
be treated.
The raking and discharge of the matters is effected in an automatic manner,
the former by the rotation of the shaft i, to which the rakes e are also attached..

page_text: The rakes e make circular furrows in the material on the hearth d, and their
teeth on each arm are so arranged as to travel in different paths to those of
the preceding teeth, whereby an intimate working and mixing of the melted matters
is effected.
- The matters are discharged by means of a small scraper lowered into position for
the purpose, which collects the matters at one spot and discharges them at an
opening, which is closed by a door when the furnace is in work.
The form of the furnace is that of a cylinder or truncated cone m set on its base.
It may be made of plate or cast iron, or constructed wholly or in part of brickwork.
The hollow shaft i is driven through a pulley 1, and is supported in a footstep n,
projecting above a small cast-iron chamber at the centre of the hearth. The upper
part of the shaft projects through a stuffing box p, q, r, in the furnace roof, a joint
being made with asbestos; o, bearing for shaft. One or more man-holes closed by
lids, like those of gas retorts, are provided in the sides of the furnace.
The charge is introduced through a hopper in the roof of the furnace closed by a
door.
The air or other current, on escaping from the furnace, charged more or less with
vapors, is conducted by a bent pipe to a suitable condenser, according to the nature
of the vapors or gasos to be collected.
The current may act chemically according to its composition and character. Air
acts negatively by its oxygen; carburetted hydrogen positively by its two elements;
while steam will have a mixed action.
This apparatus may be used as a calcining, roasting, or reducing furnace, and even
for distilling.
The current further acts physically by its caloric upon the continually renewed
surfaces, and also mechanically by carrying off. the vapors produced.
The construction of the furnace may be simplified by replacing the injection pipes
by túyeres traversing the sides of the furnace, and the hearth may be modified in
cases where the substance treated is liquid or easily fusible.
A double door may be provided if necessary to overcome the difficulty of intro-
ducing fresh solid matters, due to the pressure of the vapors produced in the
chemical treatment of ores, &c.
As an example of the mode of employing this close furnace, I may mention its
use for the treatment of an ore containing blende, argentiferous galena, and cupreous
pyrite (mixed ore). The ore in the condition of slick is introduced through the
hopper into the furnace, the doors being closed and the hearth heated to a suitable
temperature. By a few revolutions of the rakes the material is spread in a thin
layer, and the temperature and introduction of heated air being suitably regulated,
the metals are sulphatized. A quantity of chloride of sodium proportionate to that
of the sulphates to be transformed, is then introduced. The air current, which is s
shut off at the commencement of the chlorination, should then be gradually intro-
duced, and the temperature raised so as to volatilise the chlorides (if preferred,
superheated steam may be substituted for the physical and mechanical action of
atmospheric air), the copper, zinc, silver, and a portion of the lead and iron being
thus carried off in the form of chlorides.
The.fixed-residue-more or less-charged-with lead in the form of sulphate and
sulphate.of.soda,.is.immersed-while-hot-in-water or other suitable-liquid to separato
the soluble matters; it is then drained, dried, and finally treated by the ordinary
processes used in metallurgy.
When the liquids in the condenser_are_sufficiently charged with chlorides, the i
metals are extracted therefrom-successively-by-known means.
In some cases two furnaces are employed in conjunction, placed at different
levels. The raw material is placed in the upper one to be sulphatised, and thence
passed to the second one, where the operation is completed. In this manner each
furnace is retained at its own special temperature, and the necessity of varying the 5
heat of the furnace is thus avoided.
Having described the nature of the said Invention, and the manner of performing

page_text: the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is, the improved construction of furnace,
substantially as described and shown in the Drawings for the purposes specified, in
which a current of well determined chemical character is substituted for the direct
action of the flames as in reverberatory furnaces, and in which the greater part of
the hand labor is replaced by machine power, as set forth.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Thirtieth day of November, in the year of our Lord
One thousand eight hundred and seventy-seven.
AT