Year: 1886

page_text: Date of Application, 28th May, 1886.
Complete Left, 28th Feb., 1887.
Complete Accepted, 29th Mar., 1887
I ADOLPHE FRITSCHI of 5 Rue St. Georges, Paris, in the Republic of France,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to smelting iron and other ores by means of carbonic oxide
and to apparatus therefor.
A suitable apparatus for carrying out the invention is constructed of a shaft and a
crucible covered over with an arch or vault and provided with a sole.
The shaft is of the shape of a tower and is lined with refractory material and is
slightly narrowed at its two extremities. Its height varies according to the nature of
the ores to be treated and it is provided at its upper part with an apparatus for feeding
the shaft and for the passage of the gas the said apparatus being for the purpose of
ensuring an even distribution of pulverised ore upon the whole surface and to collect
the gases. At the lower part of the said shaft are formed two openings in which are
placed two carbonic oxide burners hereinafter described.
The sole or part of the furnace upon which the fusion or smelting is completed is
slightly inclined from the side of the crucible in order to ensure the running off of
the moulten metal and is constructed of refractory material preferably basic where
as is usually the case the mineral forms a silicious gangue. The crucible consists of
a cavity formed at the lower part of the furnace in which the metal and the dross are
melted. In the lower part thereof is formed an opening for running off the metal
and at the upper part is arranged a tap hole for running off the dross and above the
said tap-hole there is an opening for the passage of carbonic oxide previously heated
to a temperature of 800 degrees or 1000 degrees in a heat regenerating apparatus of
the Siemens or Radot class.
An opening is formed opposite the sole in which is placed a third carbonic oxide
burner serving to set the apparatus in operation and where required to fuse or melt
the scorified matters. This burner is only intended for use as an auxiliary apparatus.

page_text: The operation of the apparatus is as follows:
A small temporary grate is first placed in front of the crucible upon which grate
coal or coke is burned until the lower part becomes red hot, the grate is then removed
and the heating of the apparatus is continued by means of the three hereinbefore
described carbonic oxide burners until the whole furnace has reached the temperature
of a white heat (1800 degrees to 2,000 degrees). The heating action of the auxiliary
burner is then stopped and the combustion of the gas is allowed to procced by the
other burners the heated carbonic oxide being admitted through the opening opposite
the sole and the ore is fed at the top of the apparatus.
After this first operation of heating the apparatus there will only remain according to
the improved arrangement pure carbonic oxide from the crucible to the upper burners
and mixed gases at a very high temperature from the said burners to the upper part
of the shaft.
Where the combustion of the oxide of carbon is effected by the air the temperature
is sufficiently high to melt platinum being at the lowest computation from 1800 degrees
to 2000 degrees.
The pulverized ore the descending speed of which varies in inverse ratio to the
ascending speed of the gases is in constant contact with gases which are of a
heat, gradually increasing from the upper to the lower part of the shaft; having
arrived at the part where the upper burners are situated the ore will have attained a
like temperature to these gasses which is 1,800 degrees or at least 1,600 degrees.
From this part to the sole the ore raised to a temperature of at least 1,600 degrees
passes through an atmosphere of pure carbonic oxide being further subjected upon
the sole to the action of the said gases when an exchange of the component elements
of the two compound bodies takes place; the oxygen of the ore will combine with the
carbonic oxide and form carbonic acid the iron remaining upon the sole. This chemical
reaction is expressed by the formula Fe' 03 + 3 CO2 Fe + 3 CO².
=
It now remains to be seen whether the metal produced has a temperature exceeding
that of its melting point which is from 1,350 degrees to 1,400 degrees; otherwise
there would be one equivalent of peroxide of iron having a temperature of 1,600 degrees
in presence of three equivalents of carbonic oxide having a temperature of 800 degrees
or 1,000 degrees and it now remains to be ascertained what will be the final temperature
of the iron and carbonic acid produced after the reaction.
This temperature is ascertained by the following proportion videlicet; the sum of
the amounts of heat produced by one equivalent of peroxide of iron and by three
equivalents of carbonic oxide is equal to the sum of the amounts of heat carried off by
the two equivalents of iron produced and the three equivalents of carbonic acid, hence
the following equation:
C x 1600 +3, 0 x 800 + Q 2240 + 2 x + 3 × 0, being the
final temperature. In this formula represents the mean specific heat of one
equivalent of peroxide of iron from 0 degrees to 1,600 degrees; C = 15,00.
Crepresents the specific heat of one equivalent of carbonic oxide C-3,43.
Qrepresents the heat disengaged in the chemical reaction which is equal to the
heat disengaged by the combustion of three equivalents of carbonic oxide.
3 x 34,100 calories
132.300 minus the heat absorbed by the decomposition of
the peroxide of iron: 95,600, Q = 6,700 calories.-These 6,700 calories represent a
minimum and could be raised to 10,000 since at a temperature of 1,600 degrees the
heat of combination of the iron and of the oxygen is much lower than 95,600, never-
theless it is preferable to retain the number 6,700 in order to be within the actual sum
of the heat produced.
=
2,240 represents the latent heat of the melting point of steel. C" represents the
specific heat of one equivalent of iron or steel at a high temperature; C. 5,20.
Crepresents the specific heat of one equivalent of carbonic acid-0 = 5,00.
By introducing into the above equation the valves of C. CCC and Q it will be
found that the value of = 1,450 degrees which is a temperature much above the
melting point of steel or iron. The metal thus produced will run into the crucible.
Heat is supplied at the bottom of the shaft by means of the two upper burners for

page_text: the following purpose:-Referring to the result given by the above formula it has
been shewn that the iron produced and the carbonic acid would have a temperature
of 1,450 degrees; now according to this process the ore is heated by means of carbonic
acid and it has to be heated to a minimum temperature of 1,600 degrees; now as it is
obvious that carbonic acid heated to 1,450 degrees could not raise the temperature of
the ore to 1,600 degrees it will consequently be necessary to supply heat to this
carbonic acid gas in order to raise its temperature to from 1,800 degrees to 2,000 degrees
in order that it may yield some heat to the descending ore and that the latter may
reach the upper burners at a temperature of 1,600 degrees. For this purpose it will
only be necessary to burn in the said burners by means of air forced by a blower or
other apparatus carbonic oxide introduced under pressure into the furnace. The
quantity of carbonic oxide required to be burned is easily calculated; only three
quarters of an equivalent of carbonic oxide is required per equivalent of peroxide
treated. The upper burners which are placed at the bottom of the shaft have still
another great advantage by allowing, when an excess of air is forced in, an oxidizing
atmosphere to be formed in the shaft which eliminates the sulphur in the form of
sulphurous acid and converts the phosphorus into phosphoric acid which is not reduced
by carbonic oxide. The first injurious element namely sulphur escapes with the gases
and the second namely phosphorus remains in the dross in the form of an acid.
metal is thus obtained almost free from sulphur and phosphorus. Arsenic and other
substances are similarly eliminated.
A
As regards consumption of fuel two equivalents of iron require for their reduction
Hence
and fusion 3+ equivalents of carbonic oxide or say four equivalents.
56 kos. of iron will require 4 x 14 or 56 ks. of carbonic oxide, and the carbon consumed
at the gas producers is
- 24 kos.; for 1000 ks. of iron 430 00 or 500* 00
56 × 6
14
=

page_text: -
Improvements in Smelting Iron and other Metallic Ores and
Apparatus therefor.
I ADOLPHE FRITSCHI, of 5 Rue St. Georges, Paris in the Republic of 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 smelting iron and other ores by means of carbonic oxide
and to apparatus therefor.
A suitable apparatus for carrying out the invention is shewn in the accompanying.
drawing and is constructed of the following parts, videlicet -1. A shaft a, b, c, d,
e, f; 2, a sole e, g. 3. The crucible g, h, i, j, covered over with an arch. The shaft
has the shape of a tower and is lined with refractory material and is slightly
narrowed at its two extremities. Its height varies according to the nature of the
ores to be treated and it is provided at its upper part with an apparatus for feeding
the shaft and for the passage of the gas the said apparatus being for the purpose of
ensuring an even distribution of pulverized ore upon the whole surface and to collect
the gases. At the lower part of the said shaft are formed two openings in which are
placed two carbonic oxide burners hereinafter described.
The sole or part of the furnace upon which the fusion or smelting is completed is
slightly inclined from the side of the crucible in order to ensure the running off of
the molten metal and is constructed of refractory material preferably basic where as
is usually the case the mineral forms a silicious gangue. The crucible consists of a
cavity formed at the lower part of the furnace in which the metal and the dross are
melted. In the lower part thereof is formed an opening G, for running off the
metal and at the upper part is arranged a tap hole H, for running off the dross and
above the said tap-hole there is an opening for the passage of carbonic oxide
previously heated to a temperature of 800° or 1000° in a heat regenerating apparatus
of the Siemens or Radot class.
An opening is formed opposite the sole at F, in which is placed a third carbonic
oxide burner serving to set the apparatus in operation and where required to fuse or
melt the scorified matters. This burner is only intended for use as an auxiliary
apparatus.
The operation of the apparatus is as follows:-
:-
A small temporary grate J, C, is first placed in front of the crucible upon which
grate coal or coke is burned until the lower part becomes red hot; the grate is then
removed and the heating of the apparatus is continued by means of the three
herein before described carbonic oxide burners until the whole furnace has reached the
temperature of a white heat (1800° to 2000). The heating action of the auxiliary
burner F, is then stopped and the combustion of the gas is allowed to proceed by the
other burners at B, the heated carbonic oxide being admitted through the opening E
opposite the sole and the ore is fed at the top of the apparatus.

page_text: After this first operation of heating the apparatus there will only remain according
to the improved arrangement pure carbonic oxide from the crucible to the burners B,
and mixed gases at a very high temperature from the said burners B, to the upper
part of the shaft.
At B, where the combustion of the oxide of carbon is effected by the air the
temperature is sufficiently high to melt platinum being at the lowest computation
from 1800° to 2000°.
I shall now proceed to describe the descending course of the ore in the furnace :-
The pulverized ore the descending speed of which varies in inverse ratio to tho
asconding speed of the gases is in constant contact with gases which are of a heat
gradually increasing from A to B, and having arrived at the part where the upper
burners are situated the ore will have attained a like temperature to these gases
which is 1800° or at least 1600°. From this part B to the sole e, g, the ore raised to
a temperature of at least 1600° passes through an atmosphere of pure carbonic
oxide being further subjected upon the sole to the action of the said gases when an
exchange of the component elements of the two compound bodies takes place; the
oxygen of the ore will combine with the carbonic oxide and form carbonic acid the
iron remaining upon the sole. This chemical reaction is expressed by the formula
Fe 03 +3 CO2 Fe + 3 002.
It now remains to be seen whether the metal produced has a temperature exceeding
that of its melting point which is from 1350 to 1,400° otherwise there would be one
equivalent of peroxide of iron having a temperature of 1600° in presence of three
equivalents of carbonic oxide having a temperature of 800 or 1000° and it now
remains to be ascertained what will be the final temperature of the iron and carbonic
acid produced after the reaction.
This temperature is ascertained by the following proportion viz:—the sum of the
amounts of heat produced by one equivalent of peroxide of iron and by three
equivalents of carbonic oxide is equal to the sum of the amounts of heat carried off
by the two equivalents of iron produced and the three equivalents of carbonic acid,
hence the following equation
:-
C x 1600 + 3 x 800 + Q: = 2240 + 2 x C¹¹ + 3 × (ll x ; x being the final
temperature. In this formula C represents the mean specific heat of one equivalent
of peroxide of iron from 0° to 1600° C = 15.00.
=
3.48.
Crepresents the specific heat of one equivalent of carbonic oxide C¹
Qrepresents the heat disengaged in the chemical reaction which is equal to the
heat disengaged by the combustion of three equivalents of carbonic oxide.
=
=
3 x 34100 calories: 102.300 minus the heat absorbed by the decomposition of
the peroxide of iron 95.600. Q = 6700 calories. These 6700 calories represent a
minimum and could be raised to 10,000 since at a temperature of 1600° the heat
of combination of the iron and of the oxygen is much lower than 95600 nevertheless
it is preferable to retain the number 6700 in order to be within the actual sum of the
heat produced.
-
2240 represents the latent heat of the melting point of steel. C¹¹ represents the
specific heat of one equivalent of iron or steel, at a high temperature; C".
5.20.
Crepresents the specific heat of one equivalent of carbonic acid-05.00.
By introducing into the above equation the valves of C, C¹, C, C, and Q it will
be and that the value of x = 1450° which is a temperature much above the melting
point of steel or iron. The metal thus produced will run into the crucible.
Heat is supplied at the bottom of the shaft by means of the two burners B, for the
following purpose: Referring to the result given by the above formula it has been
shewn that the iron produced and the carbonic acid would have a temperature
of 1450° now according to this process the ore is heated by means of carbonic acid
and it has to be heated to a minimum temperature of 1600°; now as it is obvious
that carbonic acid heated to 1450° could not raise the temperature of the ore
to 1600° it will consequently be necessary to supply heat to this carbonic acid gas
in order to raise its temperature to from 1800° to 2000° in order that it may yield
some heat to the descending ore and that the latter may reach B at a temperature

page_text: of 1600°. For this purpose it will only be necessary to burn at B by means of air
forced by a blower or other apparatus carbonic oxide introduced under pressure into
the furnace. The quantity of carbonic oxide required to be burned is easily calculated;
only of an equivalent of carbonic oxide is required per equivalent of peroxide
treated. The burners B, which are placed at the hoitom of the shaft have still
another great advantage by allowing when an excess of air is forced in an oxidizing
atmosphere to be formed in the shaft which eliminates the sulphur in the form of
sulphurous acid and converts the phosphorus into phosphoric acid which is not
reduced by carbonic oxide. The first injurious clement, namely, sulphur escapes with
the gases and the second, namely phosphorus remains in the dross in the form of
an acid.
A metal is thus obtained almost free from sulphur and phosphorus. Arsenic and
other substances are similarly eliminated.
As regards consumption of fuel two equivalents of iron require for their production
and fusion 3+ equivalents of carbonic oxide or say four equivalents. Hence
56 kilos of iron will require 4 × 14 or 56 kilos of carbonic oxide, and the carbon
56 × 6
consumed at the gas producers is
24 kilos for 1000 kilos of iron 430 kilos
14
or 500 kilos.
=
3
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. In smelting iron or other metallic ores by means of carbonic oxide the use of a
shaft a, b, c, d, e, f, of refractory material provided at its upper part with a feeding
apparatus and with an apparatus for carrying off the gas and having at its lower part
with two or more carbonic oxide burners."
2. In smelting iron or other metallic ores by means of carbonic oxide the use of a
sole made from materials of special shapes according to the class of ores to be smelted
substantially as hereinbefore described.
3. In smelting iron or other metallic ores by means of carbonic oxide the use of a
crucible formed with openings for running off the metal and the dross substantially as
hereinbefore described.
4. In smelting iron or other metallic ores by means of carbonic oxide the use of
one or more additional safety apparatus for burning carbonic oxide in order to start
the furnace and when required for smelting the scoria.
5. In smelting iron or other metallic ores by means of carbonic oxide the use of
carbonic oxide previously heated to the maximum temperature produced by known
apparatus, videlicet from 1000° to 1200° C.
6. In smelting iron or other metallic ores by means of carbonic oxide the use
of two burners for raising the temperature of the gases passing up the shaft from
1800° to 2000° C so as to communicate to the ore as it descends à temperature of
from 1600° to 1800° C.
Dated the 28th day of February 1887