US1329055A - Mektuei - Google Patents

Description

e. JAKOV A-MERTURI. PROCESS OF DIRECTLY ANO COMPLETELY TRANSFOBMING AND REDUCING IRON OIIES INTO IRON, STEEL, OR CAST IRON. APPLICATION FILED OCT. I6. 19!]- 1,329,055. Patented Jan. 27, 1920.

-- I 'INVENTDIX 625/01 filg'va-Mrfurz UNITED STATES PATENT OFFICE.-

GASPARD JAKOVA-MERTURI, OF'IPARIS, FRANCE.

PROCESS OF DIRECTLY AND COMPI JETELY TRANSFORMING AND REDUCING IRON ORES INTO IRON, STEEL, OB CAST-IRON.

Specification of Letters Patent.

Patented Jan.27, 1920.

Application filed October 16, 1917. Serial No. 196,870.

To all whom it may concern:

Be it known that I, GASPARD JAKovA- Mnnroni, a citizen of Albania, Scutari of Albania, and resident of Paris, France, have invented a new and useful Process for Directly and Completely Transforming and Reducing Iron Ores into Iron, Steel, or (last-Iron, which process is fully set forth in the following specification.

The present invention comprises an improved process for directly and completely transforming iron ores into iron, steel or cast iron.

- According to the usual blast furnace treatment, which is followed almost exclusively for the production of iron, the efiiciency is quite high; but there is, in reality, no iron obtained, but only carbid of iron, which must be transformed into iron or steel by subsequent fusion. The ordinary blast furnace can be divided into fourzones, viz:

1. The zone of fusion of the metal and slag, and of combustion of the coal, the temperature varying from 1500 to 2000 C. in the vicinity of the twyers.

2. The zone of carburizing of the iron, and of formation of slag, this zone having a temperature of 1000 to 1500 C.

3. The zone of reduction by carbonic oxid in the part of the stack, where the temperature varies from'SOO to 1000 C.

4. The zone of desiccation, right at the top of the stack, in which zone the temperature does not exceed 400 C.

It follows, therefore, that the conventional blast furnace may be regarded as operating as a gas producer, producing poor gas having an excess of carbonic oxid. In the zone of the twyers, where there is an excess of air,this carbonic oxid is peroxidized and converted into carbonic acid (CO but the latter, in passing over the upper layers of ore, which are heated to ncandescence, is converted into carbonic combines with the metal produced, giving cast iron instead of iron.

According to the improved process forming the object of the invention, the mixing of the ore and coal is entirely doneaway with, as well as the direct combustion of the coal in a furnace in contact with the ore. The process is based on direct combustion of carbonic oxid and of hydrogen in such a hydrogen in suitable proportionsl-dn which I case steel, more or less carbureted, is obta1nedor a current of almost pure hydrogen, the latter resulting 1n the productlon of nearly pure iron owing to thedecarburizing and deoxidation of the metal.

To obtain these results, there are employed both a gas producer capable of alternatively producing rich and poor gases, which are collected in separate holders, and a hydrogen gas producer and its holder. These producers may take any of the known forms, and, hence, their structural details are immaterial. -The ordinary type of blast furnace may be utilized, or one may be built specially with all possible improvements required for the installation of the gas producers and their holders or gasometers.

Once the producers and their gas holders areinstalled, the blast furnacecan be fed with ironv ore and flux in the usual manner,

without any admixture of coal; but in commencing operatlon for the first time, a certain quantity of coke is placed in the bottom of the stack to fire the gas. The supply of gas (carbonic oxid and hydrogen) is still continued, after firing has been completed, in the desired proportions according to whether more or less highly carburized steel is'to be obtained, 7 I

It is already known that the ordinary blast furnace actually operates like a gas producer in thatit produces a poor gas, the proportions of the combustible gas being about 90% of carbonic oxid and 10% of hydro and that by reason of this excess of car nic oxid, which is regarded as the sole reducing agent for the iron ore, the change of the ore into metal is produced by percarburizing it. It is also known that in consequence of the above, there is obtained only cast iron or percarburiaed iron. Now, if in completcl doing away with the mixing of coal with t e ore in the present rocess, there is supplied to the producers in t e blast furnace the sam proportion of about 90% of carbonic oxid and 10% of hydrogen (poor 8), cast iron will be obtained exactly as in the blast furnace. Hence, the higher is raised the hydrogen content in the mixture of the two es, the less rich in carbon will be the metal that is obtained, so that if a mixture is emplo ed which contains from 30 to 50% of hy' rogen, a steel of medium hardness can be obtained.

0n the other hand, it is well understood that there is no necessity for delivering to the body of the blast furnace an excessive rtion of hydrogen, because the ore will converted into iron; and if the temperature is net high enough in the stack to melt the metallic iron, bodies of iron will be produccd which will actually interfere with the of the furnace.

when it is desired to obtain metallic iron, the steel produced in the stack is allowed to cool in the crucible; and there is supplied to the crucible a current of oxygen which completely deearburizes and deoxidizes the metal obtained. The novel characteristic of the operation resides in the fact that the action of the carbonic oxid in the process is modified'by the hydrogen, because just as the carbonic acid tends to take hold of and percarbnrize the metal, so the hydrogen op- 9. its action and decarburizes the metal, rming volatile hydrocarbons.

These reactions, the deoxidation and decarburizi'ng by the hydrogen, may be demonstrated bythe two experiments following (12} A current of hydrogen directed against sesquioxid of iron at from 300 to 500' produces pyrophoric metallic iron;

('17) A current of hydrogen directed a inst molten cast iron at high temperature,

it and produces volatile hydrocarbons.

The accompanying drawing shows a diamatic view of one form of apparatus r carryi-n out the improved process.

In said rawing, o indicates generally a blast furnace of any suitable or preferred type, and b a gas generator or gasogene, the fatter having connected to it pipes c and c for respectively delivering poor and rich gas to the pumps e and e', which compress the gas and force it into the holders f and f, provided with manometers q and g, the ga 'ng through coolers d and d before reaching the pumps. The gas is stored in rich and poor gas passing throu h them,

suitable regulating valves h and h eing interposed in the said pipes c and 0 between the meters and the holders.

Similarly, j indicates a suitable apparatus for generating hydrogen, from which a pipe 1' leads to a holder lproviided with a manometer m. A pump k is connected in the pipe 1- and serves, like the pumps 6 and e, to compress the gas and force it into the holder 1, from which latter it can be supplied to the crucible of the furnace by way of a pipe r, the pipe 1" havin a regulating valve n and a meter 0 connects in it.

Hence it follows that in the. former case definite amounts of rich and poor gas-that is, mixtures of carbonic oxid and hydrogenand of pure or almost pure hydrogen, can be supplied to the blast furnace. For example, if a mixture of 30% of hydrogen and of carbonic oxid is desired, it can be obtained by mixing 1 cubic meter of poor gas (90% of carbonic oxid and 10% of hydrogen) with 1 cubic meter of rich gas (50% of carbonic oxid and 50% of hydrogen), and in the same way mixtures can be obtained which contain from 90% of carbonic oxid for 10% of hydrogen, to 10% of carbonic oxid for 90% of hydrogen. With the first proportions mentioned, cast iron is obtained, as the blast furnace actually shows; and the more the hydrogen content is increased. the less the metal is carbnrizcd, until finally steel is ohtained, the current of hydrogen injected into the crucible of the furnace through the pipe 1" serving to decarburize and deoxidize the steel.

According to the present process, then, there may be obtained at will in any blast furnace equipped with suitable producers and gas holders, cast iron steel or iron, according to the proportions of the gas (carbonic oxid and hydrogen,) which is burned in the stack or in the crucible; moreover, extra-hard or very soft steel can be obtained, that is to say, steel more or less highly carburized.

The process possesses the following advantages 1. It avoids the mixing of the iron are with coal, with a resultant saving of fuel, because the coal leaves ashes which fuse and form slag;

2. It results in a saving of fuel in general, because the gas is supplied in the necessary quantity and with an injection of air sufficient for fusion, without any waste;

3. In place of the coal, other fuels such as pit coal, turf, lignite or wood can be used, which renders possible the treatment of the ore at the mine itself, thus reducing the cost of transportation and of'the metal obtained;

4. It enables cast iron, or almost pure iron, or steel carburized to any desired degree to be obtained at will in the blast furnace;

5. It enables the treatment of other ores of easily oxidizable and non-volatile metals in the same way, among which ores may be specially mentioned copper ore which can give a metal almost as pure and as good quality as electrolytic copper, the metal being treated finally in the crucible by means of a strong current of pure hydrogen to completely deoxidize it;

6. It is also suitable for the treatment of tungsten ores, either calcareous scheelite (tungstate of lime) or Wolfram. (tungstate of iron and manganese) without passing them directly through tungstic acid; and when it is desired to obtain extra high speed steel, it is sufiicient to add iron ore to the tungsten ore according to the proportions of the alloy to be obtained.

I claim as my invention:

1. The herein-described process of treating iron ores in a blast furnace, which comprises the step of burning in the furnace containing the ore unmixed with fuel, a mixture of poor gas containing substantially 90% of carbonic oxid and 10% of hydrogen and rich gas containing substantially 50% of carbonic oxid and 50% of hydrogen supplied in suitable proportions, from separate gasogenes, and varying the relative proportions of the said poor and rich gases according to whether cast iron or steel is to be obtained.

2. The herein-described process of treating ores of easily-oxidizable and non-volatile metals in a blast furnace, which comprises the step of burning in the furnace containing the ore unmixed with fuel, a mixture of poor gas containing substantially 90% of carbonic oxid and 10% ofhydrogen and rich gas containing substantially' 50% of carbonic oxid and 50% of hydrogen supplied in suitablev proportions from separate gasogenes, and varying the relative proportions of the said poor and rich gases according to whether cast iron or steel is to be obtained.

3. The herein-described proces of treating iron ores in a blast furnace, which comprises the'steps of burning in the stack of the furnace containing the ore unmixed with fuel, a mixture of poor gas containing substantially 90% of carbonic oxid and 10% of hydrogen and rich gas containing substantially 50% of carbonic oxid and 50% of hydrogen supplied from separate gasogenes in proportions suitable for obtaining steel; and of injecting a current of hydrogen into the crucible of the furnace to decarburize and deoxidize the steel.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

GASPARD J AKOVA-MERTURI.

Witnesses:

EMILE LEOBRET, CHAS. P. PRESSLY.

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