AN IMPROVED PROCESS AND APPARATUS FOR CALCINING AND DEOXIDIZING ORES AND OTHER MINERALS, AND FOR SIMILAR PURPOSES
Year: 1880

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"AN IMPROVED PROCESS AND APPARATUS FOR CALCINING AND DEOXIDIZING
ORES AND OTHER MINERALS, AND FOR SIMILAR PURPOSES." A communication
from abroad by Thomas Southan, of Wellington, in the County of Salop, now
temporarily residing at Philadelphia, Pennsylvania, United States of America.
PROVISIONAL SPECIFICATION loft by the said William Robert Lake at the
Office of the Commissioners of Patents on the 1st May 1880.
FOR SIMILAR
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patent Agents,
"AN IMPROVED PROCESS AND APPARATUS FOR
Southampton Buildings, London.
AND
DEOXIDIZING ORES
OTHER MINERALS, AND
CALCINING AND
PURPOSES." [A communication from abroad by Thomas Southan, of Wellington,
in the county of Salop, now temporarily residing at Philadelphia, Pennsylvania,
United States of America.]
This Invention relates to a process and apparatus for calcining and deoxidizing
ores and other minerals, and for similar purposes, as hereinafter set forth.
In carrying the said Invention into practice I provide a series of retorts properly
mounted on brickwork, masonry, or the like over a furnace, the retorts being
arranged one above the other and communicating with each other alternately at
opposite ends. Within each retort there is a spiral conveyer, and the end of the
shaft thereof is connected to a gear wheel, the gear wheels meshing with each
other and being driven in any suitable manner. I also provide another series of
retorts and spiral conveyers, both being similar to those first herein mentioned.
The retorts of the second series are enclosed in a water or cooling jacket, and com-
municate with the first named retorts by means of a hopper located in a discharge
chute of the said first named retoris. There is also a discharge chute to the second
series of retorts, which chute leads into a water tank; I also provide a conveyer
or clevator for discharging the matters deposited in the said tank.
The first series of retorts has a hopper, preferably common to all, each retort of
the upper row having a pipe communicating with this hopper.

page_text: In lieu of rotating the conveyers the retorts may be rotated, and by properly
connecting the conveyers to the inside of the retorts each conveyer and retort may
be rotated, the result being the same in either case.
The operation is as follows, that is to say :-
The iron ore is reduced to a fine granular state and mixed with a proportion of
fine charcoal. The mixture is introduced into the upper hopper, and thus fed to
the retorts, which are heated to a red heat. The mixture is carried to the
end of ons retort, then to the opposite end of the next retort below, and finally to
the lowermost retort to the discharge end in the chute; from thence it drops into
the next hopper and pusses through cooling troughs into the water tank, where it
is carried away by the elevator.
The mixture traverses the extent of each series of retorts both while being
heated and cooled.
The oxygen of the oro combined with the carbon of the charcoal passes out
through a pipe or opening in the first chute, and the iron ore is left in a spongy
state free from oxygon in condition for uso in charcoal fires, puddling furnaces,
and steel melting furnaces for manufacturing wrought iron and steel.
For treating chemicals, say, tho recovery of soda from the wasto liquor used in
the manufacture of paper, the liquor evaporated to a thick consistency is mixed with
saw-dust, making a friable mass containing the soda. Tho mass is passed through
the rotorts, whereby the saw-dust is burned away and the soda is left free.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 1st
November 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, and Co., Patont Agents,
Southampton Buildings, London. "AN IMPROVED PROCESS AND APPARATUS FOR
CALCINING AND DEOXIDIZING ORES AND OTHER MINERALS, AND FOR SIMILAR
PURPOSES. A communication from abroad by Thomas Southan, of Wellington,
in the County of Salop, now temporarily residing at Philadelphia, Pennsylvania,
United States of America.
"
This Invention relates to a process and apparatus for calcining and deoxidizing
ores and other minerals, and for similar purpoces.
It has long been known that oxygen may be dissociated from iron with which
it may be combined by placing oxide of iron in contact with carbon in the prosenco
of a suitable degree of heat, and preventing the access of air to the mixture, as the
oxygen under such conditions will combine with the carbon and leave the iron in a
metallic state.
It has also long been understood that iron in such metallic state while at a red
heat will absorb the oxygen of the atmosphere with avidity, but does not readily
combine with it at the ordinary temperature; but although contact at a rod heat
of oxide of iron and carbonaceous matter, cooling the metallic iron to the
temperature of the atmosphere, and isolation from the oxygen of the air until the
cooling is completed, are conditions exceedingly simple in theory, attempts to
reduce these conditions to practice have heretofore proved unsuccessful and
impracticable by reason of the imperfect reduction of the ore from the want of a
suitable apparatus for conducting the heat to all parts of the mass under treatment,
and the exposure of the metallic iron to rooxidation for want of a proper apparatus
for excluding the atmosphere therefrom until the cooling thereof.
The object of my Invention is the practical realization in an inexpensive manner
of these theoretical conditions, and it consists in a process for treating the ore in
the manufacture of metallic.iron from the oxides of that metal, and also in improve-
ments in the furnace to be used for carrying on the said process.
This furnace is illustrated in the accompanying Drawing, in which,—
Figure 1 is a longitudinal, and
Figure 2 a transverse section.
A number of sets or series of retorts or cylinders A are arranged within a
chamber constructed of any suitable refractory material. In the example given
each set is represented as composed of three retorts, arranged the one above the other,
but the number is immaterial, and it is not absolutely necessary that they should
be arranged in the same vertical plane, although this arrangement is deemed
preferable. The number of sets of retorts employed will depend upon the capacity
of the furnace, and any number of sets may be used without departing from the
principle of my Invention.
The retorts are represented in the Drawing as being heated by the products of
combustion and flame coming from the fire place B, but any other suitable mode of
heating may be used. The retorts may be constructed of any suitable refractory
material, and may be of cylindrical, semi-cylindrical, or of any other appropriate
form, but I prefer to make the same cylindrical. Each retort is provided with a
conveyor, which in the example illustrated in the Drawing is what is known as a
screw conveyer, or in other words, a shaft provided with spiral projections
revolving within and in proximity to the inner surface of the retort. The form of
the conveyer is however not material, as any other convoyer which will cause the
particles composing the mass within the retort to be thoroughly intermixed, and to

page_text: travel from one end of the retort to the other, may be substituted for the spiral
flange or blade shown in the Drawing.
In the furnaco represented in the Drawing the lowest retort of each set being
nearest the fire is subjected to a higher degree of heat than the retorts above it.
The mass conveyed through the retorts from the moment of its entrance into the
first retort to the time of its exit from the last will be subjected to a gradually
increasing degree of heat, but these conditions may be altered by changing the
relative arrangement of the retorts and the source of heat.
The mass to be treated may be introduced into the upper retort of each set by
means of a hopper K, or by any other means suitable for foeding ore or similar
substances, and the feed or flow of the mass may be regulated or adjusted by a
valve or other suitablo dovice. The hopper may be constructed to supply each and
all of the retorts at the same time.
The conveyers within the retorts may be rotated at a uniform degree of speed by
suitable gearing, or if required, the actuating mechanism or gearing, may be so
arranged that the mass to be treated will be conveyed more rapidly through one of
the retorts than through the other or others.
A number of sots or series of cooling cylinders A', similar in construction and
operation to the heating retorts herein before described, are arranged within
a water tank D in such manner that the uppermost cylinder of each set arranged
in the tank communicates with the lowermost retort of each series in the
henting chamber. The alternate ends of the retorts or cylinders of oach set
communicate with each other, and the rotations of the convoyer are so regulated
that the mass to be treated is delivered at one end of the rotort or cylinder and
conveyed to the opposite end thereof, from whonce it is again delivored to the
retort or cylinder below, or in other words, each retort or cylinder communicates
at one end with the retort or cylinder from which it receives the mass, and at its
opposite end with the rotort or cylindor in which it delivers the mass.
The lower cooling cylinder of each set arranged within the tank D communicates
by means of the passage G with the trough H. By allowing the water to rise in
the trough H above the mouth of the passago G, an hydraulic seal is formed which
excludes the outer air from the cooling cylinders. Access of the onter atmosphore
to the chamber or hopper with which the heating retorts or cooling cylinders
communicate may be provented by any of the well known devicos used for such
purposes, or by any outlet device which permits the ogress of the gases ovolved but
prevents the inflow of the outer air.
It is obvious that the apparatus above described may be applied to various
uses other than those mentioned in this Specification, none of which nced bo
particularly described, as they will be apparent from the above description of its
operation.
The apparatus is applied for my process of deoxidizing iron ores, iron oxidos,
from the hoating furnace and puddling furnace, or the manufacture of metallic iron
from the oxides of that metal, in the following manner
prefer
The retorts A are by the flame and products of combustion from the furnace B
maintained at a temperature which will impart a cherry red heat to the contents
thereof. The ore or oxide of iron is pulverized or granulated, intermixed with
about fifteen per cent. of fino charcoal, and charged into the hoppor K.
that the particles of ore pulverized or granulated should be of the size of grains of
coarse sand, but the process may be applied to larger particles, although in the
latter case a longer treatment will be required. The amount of fino charcoal may
be somewhat varied according to the chemical composition of the ore to be treated
or the amount of oxygen it contains, as the percentage of carbon used should be in
proportion to the amount of oxygen contained in the ore An excess of carbon will
lo no harm, as, owing to tho low degree of heat at which the reduction is effected,
the metallized oro will not be carburized by comoutation during tho short time it is
exposed to the carbon. Charcoal is used in preference to substances containing
much hydrogen but other carbonaceous matter may be employed.

page_text: The charge of carbon and ore having thus been prepared, intermixed, and charged
into the hopper K, care should be taken to keep the hopper full or partially full as
the charge descends into the uppermost retort.
The charge is caused by the screw or spiral flange, or other suitable conveyer, to
travel gradually and uniformly from one end of the retort to the other, the particles
of which the charge consists being made to circulate continuously among themselves
and to occupy constantly changing relations to each other, thus subjecting each and
every part of the mass to an equal and uniform temperature, and obviating
difficulties which have hitherto preverted the production of metallic iron from its
oxides in closed retorts, as for instance, the difficulty of deoxidizing the centre of
the mass, and the liability to carburize the outer surface thereof, owing to the mass
not being thoroughly and uniformly heated.
The chemical action which takes place in the retorts under these conditions is
well known. The charcoal employed is at a high temperaturo a well known
reducing agent, or in other words, a substance which readily extracts oxygen from
ores or other substances with which it is brought into contact. The retort thereof
having been heated to a proper degree for the required chemical action the affinity
of the carbon for the oxygen of the ore causes it to combine therewith, forming a
compound which escapes as a gas while the metallic iron remains in the retort. As
the gas thus generated has a tension exceeding ordinary atmospheric pressure, the
outward flow of the same from the retorts will prevent the inflow of the air into
the retorts or tho chamber or chimney communicating with them.
Although the reduction of the ore according to my Invention may be effected in
a single retort, provided it is made of sufficient length, I prefer to use a set of retorts
arranged the one above the other, as shown in the Drawing, in which retorts the
mass after travelling to the end of the first rotort falls by its own gravity through
a properly constructed passage into the second retort immediately below the first
one, and is conveyed therein in the same manner but in an opposite direction to a
passage leading to a third retort arranged below the second one, and so on through
any number of retorts which it may be deemed desirable to use.
As much of the reducing action, which commonly is ascribed directly to carbon,
is really effected through the mediation of its protoxide, or carbonic oxide as it is
sometimes called, and as this gas possesses at a high temperature the power of
reducing the oxides of iron and other metals, it is evident that it may be substi-
tuted in the retorts in whole or in part under cortain conditions for the fino
charcoal hereinbefore montioned. The reducing gas thus used may be carbonic
oxide, or may be a gas consisting of carbonic oxide and nitrogon principally, such
as is produced by a Siemens producer, and it may be introduced into the retorts by
moans of tubes or other dovicos which, either alone or in combination with tho
conveyer, will bring it into intimate contact with the heated ore.
If a reducing agent, such as saw dust or a similar substance, is onployed in the
retorts, a certain amount of reducing gas would be evolved by the heating of the
saine.
If the reduced ore or metallic iron, after having been passed through the retorts,
should be taken therefrom in a heated state, the exposure to reoxidation would be
inevitable; it therefore becomes necessary to devise some method of reducing its
temperature to that of the atmosphere without interforing with the continuous
reduction of the ore in the retorts. I effect this object by means of a set of cooling
cylinders A' provided with conveyers similar in construction to the reducing
retorts horein before described, but surrounded by a water tank. The heated and
reduced material drops from the lowermost retort into the hopper E, whence it
passes through the series of cooling chambers A' in the manner herein before
described with reference to the retorts A, to the passago G, and trough H. The
water in the trough H forms with the passage G an bydraulic seal which excludes
the air from the cooling cylinders.
Having thus fully described the said Invention as communicated to me by my

page_text: foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. The process of reducing oxides of iron to the metallic state in contact with
carbonaceous matter at a red heat in a rotort or rotorts from which air is excluded,
and in which the ore and carbonaceous matter are continuously intermixed,
substantially as described.
Second. The process of reducing oxides of iron to the metallic state by causing
them to pass through a reducing retort or retorts from which the air is excluded
into a cooling chamber or chambers from which the air is also excluded, as and for
the purposes sporified.
Third. As a part of the above described process of reducing oxides of iron to the
metallic state, the thorough and uniform heating of pulverized ore mixed with
carbonaceous matter by means of a screw conveyer rotating within a heated retort
from which the air is excludod, substantially as describod.
Fourth. The combination of a set of communicating roducing retorts arranged
within a heated chamber with a set of cooling cylinders arranged within a water
tank, as and for the purposes described.
Fifth. The cooling cylinders communicating with each other at their alternato
ends, and provided with screw conveyors, as and for the purposes described. .
Sixth. The combination of the cooling cylinders A¹, passage G, and tank I, as
and for the purposes described.
Seventh. The combination of the reducing retorts communicating with each other
at alternate ends, and having in each a rotating conveyer with the cooling retorts
communicating with each other at alternate ends, and having in each a screw
conveyer, as and for the purposes described.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this First day of November, in the year of our Lord
One thousand eight hundred and eighty.
W. ROB. LAKE.
(L.B.)