Process and Apparatus for Reduction of Iron and other Oxide Ores and for Fusion and Purification of the Produced Metals.
Year: 1890

page_text: I ate of Application, 7th May, 1890
Complete Specification Left, 6th Feb., 1891-Accepted, 14th Mar., 1891
PROVISIONAL SPECIFICATION.
A Process and Apparatus for Reduction of Iron and other Oxide
Ores and for Fusion and Purification of the Produced Metals.
I, JACQUES DÉSIRE DANTON, of No. 23, Boulevard de Strasbourg, Paris, France,
Engineer, do hereby declare the nature of this invention to be as follows
:-
This invention relates to the reduction of ores, particularly those of iron, and the
fusion and purification of the produced metals, the process and apparatus being
especially applicable in localities where ores exist in comparatively smallquantities,
not such as warrant erection of great smelting works.
For reducing the ores, I pass them down an annular column surrounding a central
column supplied with hot deoxidating gases; the walls of the annular ore column
are perforated so that the hot gases pass from the central column luterally through
the ore to an annular space surrounding the ore column, whence the waste gases
are led off, their heat being utilised if desired. The ore is fed in at the top of the
annular column and the reduced material is withdrawn by lateral apertures at the
bottom. The heat of the gases is moderated so that they cannot effect fusion of
the metal. Instead of constructing the reducing apparatus of circular or polygonal
form with a central gas space and an annular ore space surrounding it, there may
be a series of gas spaces in line, each having an ore space on each side of it, and
beyond each of these a flue to carry off the waste guses..
The apparatus may be made of considerable height, and the central column or
gas space may be blocked about midway by a moveable baffle so that the gases pass
Erom the lower part of this space laterally out through the ore into the outer space,
and return thence laterally in through the upper portion of the mass of ore to the
upper part of the central space whence they escape. The gases may be obtained
from a separate producer, or the producer for each apparatus may be arranged in
it lower part. Also, when the apparatus is arranged as last described, the gases
returning inwards through the upper portion of the ore may have their temperature
reduced by admission of air to pass with them.
By subjecting the ore to the action of gases consisting mostly of carbonic oxide,
at temperatures from 250° to 550° C., the pores of the ore become charged with
pulverulent graphite resulting from decomposition of the carbonic oxide, and thus
attain a condition favourable for their reduction and subsequent fusion. When the
ore is in pulverulent condition I mix it with bituminous coal or, when the coal is
not bituminous, I add petroleum or tar, and subject the mixture, preferably under
pressure, in closed vessels to the action of hot gases which in this case need not be
of deoxidating character.
The ore charged as above described with graphite, or the pulverulent ore treated
in admixture with coal, may be reduced as it descends the annular column of the
apparatus, and the produced metal may be fused at the bottom under a blast from
suitable tuyères.
In order to purify or improve the quality of the fused metal it may be received
u ladles or in furnace beds or converters lined with the mixture of the pulverulent
ore and coal or of the ore charged with graphite. Or the fused metal may be
poured down in a shower while these matters or other purifying agents in powder
are blown against it.
Dasad thin 7th day of 1800
ABEL & IMRAY,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION
A Process and Apparatus for Reduction of Iron and other Oxide
Ores and for Fusion and Purification of the Produced Metals.
1.JACQUES DESIRE DANTON, of No. 23, Boulevard de Strasbourg, Paris, France,
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 :-
This invention relates to the reduction of ores particularly those of iron, and the
fusion and purification of the produced metals, the process and apparatus being
especially applicable in localities where ores exist in comparatively small quantities,
not enough to warrant erection of great smelting works.
The accompanying drawings represent various forms of apparatus by which the
process can he carried on.
Figure is a vertical section of a furnace, which may be of circular or polygonal
form in plan, divided into these cocentric compartments, a central compartment G
which receives the reducing gases, an annular compartiment m having perforated
walls to this the ore is supplied by the opening O at the top and from it the material
operated on is withdrawn by doors pp, and an outer aminlar compartment a into
which pass the gases after they have passed through the ore and from which they
are discharged by the pipes t." These gases before being discharged may heat air
pipes. The gas may be produced elsewhere, but preferably it is produced in the
bas of the central compartment where the fuel is blown by tuyeres e supplied with
air or with air and steam according as carbonic oxide or water gus is desired, or
a mixture of them. The gas ascends the central compartment and passes laterally
through the ore, effecting reduction.
Figure 2 is a transverse section of a horizontal furnace acting in a similar manner.
Here is the central compartment supplied with gas, mis the ore compartment
with perforated walls, bare air or water pipes heated by the gases before their
discharge. This furnace may he of considerable length and may be divided by
partitions into several furnaces each supplied with ore through an opening O at the
top, and discharged by doors p below.
Figure 3 shews a modified form of furnace. In the gas producer there are
cooling pipes by which the temperature of the gas can be regulated, and there is a
stopper which can he raised or lowered so as to determine the height through
which the gas passes to the ore. After passing through the ore the gases may
either escape by the pipes or may pass back through the ore to the central
chimney T.
Figure 4 shows a furnace of cupola kind, having suspended in its middle a
refractory pipe forming the central compartment G, round which there is an
annular compartment m supplied through with ore or reduced ore which descends
to a central part where it is subjected to the blast of tuyeres r. By means of a
hopper tube T fiel or other carburating materials may be supplied to descend
through G, while the gases ascend and pass away by the flue S to be utilized for
burning or reducing. This arrangement is especially adapted for dealing with
friable or pulverulent material which the gases cannot readily penetrate.
Figure 5 shows a furnace where both reduction and fusion are effected. The ore
supplied at o descends in the compartment and at the bottom is subjected to the
blast at v.
Fuel or carburating material or fluxes may be supplied by T, which is
then closed. The gases produced at the bottom ascend in G, pass through the
perforated walls and the ore and escape by the pipes 7.
For ore which has not
undergoue preliminary carburation, the furnace Figure 5 should be made of
considerable height and should be provided with pipes as shewn in Figure 3 for
cooling the gases.
With apparatus such as I have described I effect reduction and fusion of ores
under the following conditions :-

page_text: Generally the ore should be subdivided into small fragments so as to expose
large surface for action, but not pulverized, unless the special arrangements for
dealing with pulverized ore are adopted. It is better to reduce by gas than by the
admixture of solid carbon which involves high temperature and partial fusion; and
the reduction should be effected at moderate heat by prolonging the period during
which the gas acts, Carbonic oxide applied at temperatures between 2.50° and
550° C. to oxide ores becomes decomposed, one portion of its carbon taking up
additional oxygen and passing away as carbon dioxide, another portion penetrating
the ore and becoming deposited in its porcs ready to operate in the final portion of
the reducing process. This deposit of carbon may be termed graphitisation.
Instead of or in addition to carbonic oxide, other reducing agents may be employed,
coal gas, water gas and other compounds of hydrogen, even carbonaceous smoke,
which supercarrates the gases and increases the amount of deposited carbon.
The pressure and temperature of the reducing gases may often with advantage be
varied to suit different qualities of ore. By causing the gases to pass laterally as in
the furnaces above described I avoid the action of carbonic acid on the upper layers,
such as takes place when the gases have to pass vertically through the whole
height of the charge. When the ore is in pulverised condition it is mixed intimately
with caking coal dust, and the mixture is subjected in a close vessel preferably
under pressure to a slow distillation terminated by firing; thus the ore is reduced
and coagulated as a kind of coke which can be readily fused. Instead of thus
treating pulverised ore, it may be placed in a high closed vessel and subjected to
sudden pressure from below upwards of a fluid which holds in suspension the
particles of metal and gangue, and the latter by reason of its lightness is discharged
above by a stop cock giving passage to a small stream surrounded by gas. By
blowing in a fluid of high reducing quality such as petroleum vapour, reduction and
separation of gangue are readily effected.
For reduction of other ores, the process begins with firing as the first phase, then
graphitisation is promoted, the second phase, the temperature is then gradually
raised but not to fusing point, and the graphite in burning completes the reduction,
third phase. The ore may be partially reduced and graphitised by stopping at the
second phase. Fusion may follow or may accompany reduction. In order to avoid
introduction of carbon dioxide with flux, I employ quick lime.
The refining of the molten metal is effected immediately on its being tapped, and
it consists of two periods. First the molten metal is made to descend in a shower
in a heated chamber having perforated walls, and during its descent is exposed to
munierous streams in all directions of air carrying in suspension any powders suitable
to the metal. Silica thus applied produces a slag which can be run off and which
facilitates elimination of phosphorus. Secondly, the bath of molten metal is run
into a moveable melting pot or crucible previously lined with old plate and refining
material obtained by pugging suitable powders with lime paste. The metal being
heated, its refinement is completed according to the nature of the agents employed,
and it is run in ingots, which may ultimately be incorporated with their plate
moulds.
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 I
claim
1. The reduction of ore without contact with solid carbon by subjecting it in an
annular compartment to the action of reducing gases passed laterally through it.
2. The graphitisation of ore by subjecting it, after first firing, under temperature
not exceeding 350° C. to gas containing carbonic oxide, by decomposition of which
carbon in form of pulverised graphite becomes deposited in the pores of the ore.
3. Effecting partial or complete reduction of ore by gradual increase of
temperature but not up to fusion.
4. The reducing apparatus illustrated by Fig. 3 in which the reducing gases are
made to pass first laterally outwards then laterally inwards through the ore.

page_text: 5. The arrangement, when desired, of cooling tubes in the lower part of the
central compartment for regulating the temperature of the reducing gases by means
of air or water in the tubes.
6. The fusion of reduced and graphitised ore in a furnace of which the central
vertical part may be empty in order to relieve the ore from the injurious action of
carbon dioxide and to melt pulverulent ores.
7. Effecting both reduction and fusion in one apparatus consisting of a vertical
rencing furnace with lateral distribution of the reducing gases, terminating at the
bottom with a melting compartment subject to blast.
8. The direct refinement of molten metal by its reception in a moveable melting
pot previously lined with refining material.
9. The reduction of pulverulent ore mixed with eaking coal dust in a close vessel
preferably under pressure and the separation of its gangue, with or without reduction,
by an ascending current of fluid, which may be reducing or not, in a high elosed
vsel, discharging the gangne,
10. Refining molten metal by exposing it while it descends in a shower to currents
of compressed air in which are suspended suitable refining powders.
11. The use of pulverulent ore for forming with lime lining for refining
apparatus, especially the moveable melting pots, and the beds of refining furnaces.
12. The application of the process and apparatus above described to all iron ores,
and oxide ores generally such'ns those of manganese nickel, cobalt and to slags.
Dated this 6th day of February 1891.
ABEL & IMRAY,
Agents for the Applicant.