US404473A - Charles j - Google Patents

Description

(No ModeL) 0. J. EAMES.

PROCESS OF REDUCING IRON DIREGT FROM ITS GRES- No. 404,473. Patented June 4, 1889.

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CHARLES J EAlWlES, OF NEW YORK, N. Y.

PROCESS OF [REDUCING IRON DIRECT FROM ITS ORIES.

SPECIFICATION formingpart of Letters Patent No. 404,473, dated June 4, 1889.

, Application filed January 19, 1889- gerial No. 296,833. (No model.)

To all whom it may concern.-

Be it known that I, CHARLES J. EAMEs,a citizen of the United States, residing at New York city, in the State of New York, have invented certain new and useful Improvements in Process of Reducing Iron Direct from its Ores; and I hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled inthe'art to which it appertains to apply the The object of the present invention is to reduce iron ore by the reverberatory-fmnace methods without the use of lime or other protective coating for-the carbon used as the reducing agent. On account of the presence of free oxygen in the furnace and the rapid combustion of the carbon used as the reducing agent it has heretofore been considered impracticable to reduce iron ores by the hearth or reverberatory-furnace method without using a lime-wash or some equivalent protective coating for the carbon. In reducing high-grade ores or those containing I a small per cent. of silica the presence of lime or any equivalent matter which can act as a flux has been found to be highly objectionable, as the resultant sponge is dry and cannot be Worked successfully into bar-iron by rolls or otherwise, owing tothe brittleness of the bar due to deficiency of silica. The same characteristics present themselves when the sponge is used in the open-hearth process. The only remedy lies in replacing the silica of which the sponge has been robbed, and this is not readily accomplished.

My present pro'c'ess leaves the silica in the sponge unchanged or in its natural condition.

My invention, generally stated, consists in subjecting a layer or stratum of granulated iron ore having from thirty to forty (40) per cent. of granulated coke-breeze or granulated hard or anthracite coal intimately mixed therewith, said stratum arranged on a coke bed or hearth, to a neutral gas-flame, all as will hereinafter more fully appear.

I will now proceed to describe my invention more fully, so that others skilled in the art of metallurgy may apply the same.

For purposes of illustration and description I have shown a reverberatory furnace adapted to the purpose; but I do not herein claim the same, as it forms no part of the present invention, and any other reverberatory furnace can be readily employed.

In the drawings, Figure 1 is a longitudinal vertical section of a revcrbera'tory furnace, and Fig. 2 is a plan view with the crown removed.

Like symbols refer to like parts wherever they occur.

I prefer to work with gas, either natural or producer gas, whichever may be most convenient, as a neutral flame is most easily obtained thereby and an oxidizing flame is more easily avoided.

1 indicates the fire-chamber, into which, at or near its bottom, delivers an air-pipe 2, which should be provided with a suitable valve or damper (not shown) for controlling the volume of air admitted. If desired, a blast may be used, but is not recommended.

3 indicates the gas-pipe or gas-inlet, which may terminate in a perforated transverse or T burner, which is preferably placed at about the height of the top of the bridge-wall.

4 indicates the bridge-wall, in the top of which are arranged three or more rows of detached bricks, the bricks of the alternate rows arranged to break joints, so as to form zigzag passages for the flame. 4

5 indicates the usual reverberatory arch or crown of the furnace, and 6 the hearth-plate. The hearth should be formed by covering the hearth-plate 6 to a depth of eight (8) or twelve (12) inches with lumps of coke and then -filling the interstices between the lumps of coke with a mixture of granulated iron ore and powdered coke. The lumps should then be covered to a depth of two (2) or more inches with a layer of said mixture of granulated ore and fine coke, and a neutral or reducing flame from the fire-chamber allowed to reverberate on the mass until reduction of the iron ore occurs and agglutination takes place, after which the top layer of fine material may be compacted and dressed off by any suitable tool and a working bottom of the'desired character will be obtained.

In forming the bottom of the furnace as above described the furnace may be worked at a higher temperature than will be desirable in carrying out my process. Care, however, should be had when dressing off the bottom not to apply sufficient force to crush the lumps of coke which constitute the main bulk thereof.

In a furnace of the character described, or its equivalent, and which has a coke bottom entirely free of anything which can act as a flux for the silica contained in the iron ore, I place a layer or stratum of broken and granulated iron ore with which has been intimately mixed from thirty to forty per cent. of granulated coke-breeze or granulated hard or anthracite coal. If desired,a top dressing of granulated coke-breeze a couple inches in thickness may be spread over the mixture of iron ore and reducing agent last specified. I then producein the fire-chamber a neutral flame by means of the gas and sufficient air to induce 10W combustion, carefully guarding the quantity of air admitted, and by means of a suitable damper D in the chimney and a proper manipulation of the gas (or volume of gas admitted) I maintain sufficient pressure in the furnace at all times to prevent any leakage of the external air into the furnace over the hearth. Thus by a proper manipulation of the flame and furnace pressure I avoid any free oxygen which would consume the reducing agent.

As a result of said process I obtain a thorough reduction of the ore Without loss of its silica, and a resultant sponge, which can be readilyutilizcd in the manufactureof Wrough tiron and steel Without the necessity of adding silica or its equivalent at subsequent stages of its use.

Having thus described my invention, What I claim, and desire to secure by Letters Patent, 1s

1. The process herein described of reducin g iron ore in reverberatory furnaces, which consists in subjecting a stratum composed entirely of an admixture of granulated iron ore and granulated coke-breeze or anthracite coal and devoid of flux, said stratum arranged on a coke-hearth, to the reverberatory action of a neutral flame or neutral gas-flame in a 10W state of combustion and under sufficient pressure to prevent the entrance of air into the furnace, substantially as and for the purposes specified.

2. The process herein described for reducing iron ore in reverberatory furnaces, which consists in subjecting a stratum of admixed granulated iron ore and granulated cokebreeze or anthracite coal and devoid of flux, said stratum being arranged on a coke-hearth and covered by athin layer of coke-breeze, to the action of a neutral gas-flame under such pressure as will prevent the entrance of air into the furnace, substantially as and for the purposes specified.

In testimony whereof I aflix my signature, in presence of two Witnesses, this 19th day of January, 1889.

CHARLES J. EAMES.

itnesses:

E. 'l. WALKo, F. R. CORNWALL.

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