Improvements in and Means or Apparatus for the Extraction of Metals from Metallic Ores or Matters Containing Metals.
Year: 1890

page_text: Date of Application, 7th Nov., 1890
Complete Specification Left, 10th July, 1891-Accepted, 22nd Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in and Means or Apparatus for the Extraction of
Metals from Metallic Ores or Matters Containing Metals.
I, NICHOLAS LÉBÉDEFF of 22 Nine Line, Vassily-Ostroff St. Petersburgh in
the Empire of Russia, Mining Engineer do hereby declare the nature of this
invention to be as follows :-
In the Specification accompanying my application for a Patent dated May 2nd
1889, No. 7353 I have described a process for obtaining or extracting metals from
ores or metalliferous materials by exposing the ores or materials in a molten or
liquefied condition to the action of reducing gases injected at a point below the
surface of the bath.
According to my present invention the reducing gases are also caused to act upon
the materials below the surface but in place of injecting the gases through tubes or
the like I allow them to pass through walls or partitions of plumbago or other
materials capable when heated of allowing the said gases to pass through them by
diffusion. The ores or metalliferous materials may be contained in a crucible or
other chamber or receptacle which may be entirely or partly constructed with a
mixture of graphite and a binding agent such as is commonly employed in the
manufacture o plumbago crucibles so that a wall of this substance is interposed
between the body of reducing gases and the materials under treatment.
The ore or
metalliferous materials being brought to a molten or liquid condition by the applica-
tion of external heat and the addition if necessary of any suitable fluxes but
without the addition o coal or carbon are maintained in this condition and there-
after the reducing gases pass through the walls of the crucible or chamber and
reduce the metal. The slag or impurities can then be run off and the metal
removed separately.
The preliminary melting of the charge may be carried out either in the same
crucible or chamber as that in which the reduction is effected or in a separate
furnace.
The receptacle or chamber may be of any suitable form and dimensions and any
suitable construction of furnace or producer may be employed for generating the
reducing gases which pass by diffusion through the walls of the crucible or chamber
containing the molten or liquefied materials, but generally I prefer to allow the
reducing gases to have access to a space beneath the bottom as well as at the sides
so as to ensure the proper passage of the gases into the whole of the molten or
liquefied charge.
Care must be taken to render the materials molten or liquid and if needed suitable
luxes are added.
In treating fusible oxides such as oxide of lead or magnetic oxide of iron for
xample it is not necessary to add a flux. When dealing with infusible oxides such
s peroxide of iron or of chromium alumina and the like they must be dissolved in
nelted fluor spar for example.
When the metallic oxides are associated with different rocks or gangues such as
ime, clay or quartz for example the corresponding fluxes are added in accordance
vith the ordinary or known rules.
This process is applicable to the extraction or separation of all descriptions of
etals from their gangues or other impurities with which they may be associated in
heir natural or other condition. In practice the operation is conducted as follows in
rder to obtain aluminium for example.
The alumina being dissolved in fluor spar is subjected to the reducing process in
plumbago crucible surrounded by reducing gases which act upon its contents

page_text: through the crucible and reduce the aluminium to the metallic state. In order that
this metal owing to its lightness may not rise to the surface of the bath where it
would be oxidized I take precautions to diminish the specific gravity of the molten
mass by the addition of double fluorides of aluminium and potassium and lower
its melting point by the addition of cryolite or other fluorides as in the known
processes for extracting aluminium by electrolysis. By these means the metallic
aluminium is reduced and caused to sink to the bottom of the crucible without the
aid of electricity.
The crucibles or receptacles in which the materials are treated may be of any
suitable construction and materials provided that they comply with the conditions
herein before set forth.
For operations on a large scale 1 prefer to employ a reverberatory furnace and
construct the hearth or bed on which the materials are treated of relatively thin
slabs or plates of plumbago prepared in a similar manner to plumbagc crucibles
for example and I lead the reducing gases into a chamber or flues underneath the
bed so that they act by diffusion through the heated slabs or plates and reduce the
metal contained in the materials placed thereon.
Any other suitable construction of furnace may be employed enabling reducing
gases to act by diffusion through highly heated walls or partitions of plumbago
carbon or like material upon the molten or liquefied materials containing the metal
to be obtained.
Dated this 7th day of November 1890.
NICHOLAS LEBEDEFF.
COMPLETE SPECIFICATION.
Improvements in and Means or Apparatus for the Extraction of
Metals from Metallic Ores or Matters Containing Metals.
I, NICHOLAS LEBEDEFF of 22 Nine Line, Vassily-Ostroff St. Petersburgh in
the Empire of Russia Mining Engineer do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
In the Specification accompanying my application for a Patent dated May 2nd
1889 No. 7353 I have described a process for obtaining or extracting metals from
ores or metalliferous materials by exposing the ores or materials in a molten or
liquified condition to the action of reducing gases injected at a point below the
surface of the bath.
According to my present invention the reducing gases are also caused to act
upon the materials below the surface but in place of injecting the gases through
tubes or the like I allow them to pass through walls or partitions of plumbago
or other materials capable when heated of allowing the said gases to pass through
them by diffusion. The ores or metalliferous materials may be contained in a
crucible or other chamber or receptacle which may be entirely or partly constructed
with a mixture of graphite and a binding agent such as is commonly employed in
the manufacture of plumbago crucibles so that a wall of this substance is interposed
between the body of reducing gases and the materials under treatment.
The ore or metalliferous materials being brought to a molten or liquid condition
by the application of external heat and the addition if necessary of any suitable
fluxes but without the addition of coal or carbon are maintained in this condition
and thereafter the reducing gases pass through the walls of the crucible or chamber
and reduce the metal. The slag or impurities can then be run off and the metal
removed separately. The preliminary melting of the charge may be carried out
either in the same crucible or chamber as that in which the reduction is effected or
in a separate furnace.
The receptacle or chamber may be of any suitable form and dimensions and
any suitable construction of furnace or producer may be employed for generating

page_text: the reducing gases which pass by diffusion through the walls of the crucible or
chamber containing the molten or liquified materials but generally 1 prefer to allow
the reducing gases to have access to a space beneath the bottom as well as at the
sides so as to ensure the proper passage of the gases into the whole of the molten
or liquified charge.
It being essential to the success of the operation to obtain thorough fluidity of
the mass under treatment it is necessary to exercise care in the selection of the
fluxes employed. When treating fusible oxides such as oxide of lead or oxide of
magnetic iron a flux is not required. When treating infusible oxides such as per-
oxide of iron or chromium, alumina or other analogous oxides it is preferable to
dissolve them in molten fluor spar. In case the metallic oxides are associated with
rocks or minerals such as limestone clay or quartz for example corresponding fluxes
are to be added in accordance with known rules of metallurgy.
The process may be employed for the reduction of any metals whose oxygen
combinations admit of being reduced to a molten condition but in order to collect
or separate these metals it is necessary that their density or specific gravity should
be greater than that of the other constituents of the bath otherwise they will float
upon the surface of the latter and become oxidised.
In the extraction of aluminium for example by means of my invention the process
is preferably conducted as follows:-
The aluminium being dissolved in fluoride of calcium is subjected to a reducing
reaction in a plumbago crucible or other receptacle or chamber composed of
materials possessing the same properties as graphite with regard to the passage of
the gases. This receptacle is surrounded by a reducing flame or gases which act
upon its contents through the substance of the receptacle or crucible and reduce
the aluminium to the metallic state. In order that this metal owing to its lightness
may not float on the surface of the bath where it would be oxidised I take pre-
cautions to diminish the specific gravity of the molten mass by the addition of double
fluoride of aluminium and potassium and lower its melting point by the addition of
cryolite or other fluorides as in the known processes for extracting aluminium by
electrolysis. By these means metallic aluminium is enabled to be obtained without
the aid of electricity.
The crucibles or receptacles in which the materials are treated may be of any
suitable construction and material provided that they comply with the conditions
hereinbefore set forth.
For operations on a large scale I prefer to employ a reverberatory furnace
and construct the hearth or bed on which the materials are treated of relatively
thin slabs or plates of plumbago prepared in a similar manner to plumbago crucibles
for example and I lead the reducing flame or gases into a chamber or space under-
neath the bed so that they act by diffusion through the heated or incandescent
slabs or plates and reduce the metal contained in the materials placed thereon.
The accompanying drawing represents by way of example an arrangement of
apparatus that may be employed in carrying out my invention in practice. In this
drawing Figure 1 represents in a longitudinal vertical section taken along the
line 1-2-3-4-5-6 Figure a furnace for treating ores according to my
invention. Figure 2 represents a portion of the apparatus in horizontal section on the
line 7-8 Figure 1 and Figure 3 illustrates a portion of the flues in transverse
section on the line 9-10 Figure 2.
This furnace is constructed with an outer casing a of brickwork or masonry
enclosing a melting or reducing chamber A communicating with flues
which a supply of air is introduced and with flues & for the admission of the gases.
g through
The flue d is connected through orifices e with a space or spaces f underneath a
series of slabs composed of graphite or material permeable to the gases as herein-
before described and supported upon partitions c Figures 1 and 3. B (Figure 1)
represents a mass of liquefied materials undergoing treatment in the chamber Á
apon the slabs b.
These materials which may be melted or liquefied either before or after they

page_text: are placed in the chamber A are acted on by the air and gases which are
supplied through the flues and impinge on the surface of the said materials
as in an ordinary reverberatory furnace." A portion of these gases is caused to pass
through the orifices e into the space or spaces underneath the graphite botton b
and acts upon the materials B from below by passing through the said bottom by
diffusion as hereinbefore explained.
Any other suitable construction of furnace may be employed enabling reducing
gases to act by diffusion through highly heated walls or partitions of graphite or
other analogous material upon the molten or liquefied materials containing the
metal to be reduced.
I am aware that graphite or plumbago crucibles have before been used as recep-
tacles employed in obtaining metals by mixing their ores with wood charcoal,
coke, anthracite or the like and subjecting them to a reduction process not involving
the liquefaction of the ores but my present process consists on the contrary in
employing crucibles or receptacles of graphite or the like for containing the oxygen
combinations of metals brought to a molten condition and treated without the
addition of carbon with reducing gases that pass through the graphite or the
like.
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
claim is.
1. The process for reducing metals from their oxygen combinations brought to
the molten condition (with or without the addition of fluxes) consisting in subjecting
them without addition of carbon, to the reducing action of the gases of the reducing
flame of the furnace which pass into the bath by diffusion through any receptacle
composed of graphite (or other material capable of allowing the gases to pass by
diffusion) which contains the melted bath all substantially as hereinbefore
described.
2. A furnace constructed with a hearth or bottom composed of slabs of graphite
substantially as hereinbefore described with reference to the accompanying drawings
and for the purpose set forth.
Dated this 3rd day of I.... 1901
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.