US1433353A - Process for treating ores to sinter them - Google Patents

Description

A. s. DWIGHT. PROCESS FOR TREATING ORES T0 SINTER THEM.

APPLICATION HLED MAY 20, I912.

l ,,%3,35 3:. Patented Oct. 24 1922,.

process or method of treating ore as will be ARTHUR S. DWIGHT, 915 NEW YORK, N. Y., ASSllIGrNOlEi. T0 DWIGT d5 LLOYD METAJLE' LURG-ICAL COMPANY, OF NEW YORK, N. Y., A CURPORATION OF NEW JERSEY.

PROCESS FOR TREATING OBES TU'SfN'JllER 'JEHlEllllE. v

llriginal application filed December 23, 1907, Serial No. M7360, Divided and application 'filed April 22, i

1912, Serial No. 692,548. Divided and-this application filed May 20, 1912. Serial No. 698,467.

To allwkom it may concern:

Be it known that l, ARTHUR SJDWIGHT, a citizen of the United States, residing at New York, in the county of New York and State ofNew York, have inventedcertain new and useful Improvements in Processes for Treating Ores to Sinter Them, of which the following is a specification, reference being had therein to the accompanying drawr ngs.

' This invention relates to improvements in the art or method of treating ores, it being more particularly intended for use in the treating of ores which are susceptible of having combustion carried on therein after an initial igniting of the ore mass has been edected, for instance such as the ores of the sulfid class which can be desulfurized and sintered at one and the same operation.

I have heretofore exploited and perfected means for igniting ores for such treatment which utilize jets of gas, and have employed such devices to a large extent;' an example of such means being illustrated in my Patent 916,391 of .llfarch 23, 1909. But under many circumstances it is desirable to subject the surface of the ore to be ignited to a more intense heat, and to better direct and apply the heat employed for igniting purposes than is possible when using open jets of gas such as illustrated and described The present 1nhereinafter set forth, so as to secure a good initial ignition of the ore under all circumstances and conditions of use.

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For the purpose of illustrating how the invention may be carried out if have presented in the accompanying drawings, more or less conventionally, a mechanism for supplying, transporting and sinte ing a mass of ore material, and finally deliv ring "it in sintered cakes or masses, such as shown and describedin my Patent No. 1,027,119, dated May '21,, 1912.

1 do not in this caseIclaiin the igniting mechanism-illustrated in the drawings, claims therefor, including claims'based onthe specific mechanism illustrated in Figs. 2 and. 3, have been presented by me in my application No.;692,548 I a division of the a plication on which was based my aforesaid atent No. .1, 27,110,and

'- which application some of the parts of. the apparatus adjacent to the firing or igniting region.

Fig. 3 is a cross section on the line Illlll of Fig. 1.

F igQ t. is a longitudinal sectional view, on a larger scale thanthe other views, illustrating another form of the invention.

For the purposes hereof it is merely sufficient} to note that, in the drawings, A

represents an air suction box, 'ovcrwhich' travelthe ore-supporting cars or pallets B. Each of these carries .one or more grate sections C, suitably supported. Each car 'or pallet is mounted upon wheels D adapt- Ed tfi travel upon tracks or guides, shown at K indicates a hopper or feeding receptacle which is supplied with the ore, initially, and

from which it is delivered in charges or in a stream to the cars or pallets B as they travel below it.-

.The cars or pallets, after receiving their A charges, move past the igniting mechanism, .where the combustable elements of the charges are ignited, and then travel over the air chamber Aduring which travel an internal combustion within and throughout.

the charges of material being treated takes place, while the particles thereof are maintained in a quiescent state with reference to each other, so that when they come to the end of this portion of their treatment the said charges have been each changed froma' mass of pulverulent particles to' sintered, agglomerated or coherent mass. At

the end of the track section F they reach the downwardly curved guide-at F with which the wheels of the pallets successively engage. From this part of the guide-wayfthe pallets or'cars move to the inclined and returning part'of the track or guide-way at F", along which they travel in inverted positions. At H there are lifting and: power transmitting wheels, adapted to engage with the pallets or cars and carry them upward to the track section, F, and then by a pushing action imnot part forward travel to-them, causing them 60. which is arranged ascreen Q or other suit to move across the open end of the air box I A. The wheels H are rotated by the belt T connected with their shaft. At U there is an air forcing apparatus, here shown as a suction fan connected by a trunk or duct at J with the air' box A, and adapted toexhaust the air from the latter, causing currents of air to pass downward throu h the ore on the pallets or cars, as shown by the arrows in Fig. 1. These air currents maintain chamber indicated by Y. It may be located at any suitable place and is shown as placed at the side of the ore-holdil ng and transporting apparatus. 'Preferably it has a grate, as shown at y, upon which a bed of burning coal or suitable fuel can be maintained, as shown aty'.

The hot products of combustion are carried from the fire chamber Y and are caused to impinge upon the'top surface of the ore body. This is effected in the construction s'hownby means of a flue Y leading from the fire chamber and extending across the body of the ore, and having an opening such that the flame and the products of coinbustion from the fire bed at y can be caused to impinge upon the ore surface and cause the combustible elements thereof to become inflamed. The flue terminates in an upwardly turned leg or pipe Y which may finally dis- L most 7 circumstances, be employed with' charge the products of combustion from the igniter at any suitable oint.

igniter of this c aracter can, under greater economy than one which depends uponthe use of gas, and, moreover, can" be employed in regions and at places where gas is not obtainable, and where a desulfurizing and "sintering apparatus of the present sort would be prohibited if dependent thereon. And again, the volume and intensity of the flame and products of combustion from the fire chambercan be varied to meet difierent conditions in the ore; as, where the latter is of a more inflammable character, the fire in the fire chamber can be correspondingly reduced; and where the ore is more refractory and vless 'combu stible, a more'intense .com-

- ,bu'stion can be provided in the fire chamber.

" In Fig-41 have illustrated a difl'erent form; of igniter. for burning solid fuel from that illustrated 2 and 3. It conslsts of a'brazier Q" across the bottom of able perforated support for the fuel. This brazier is placed overv the movin pallets,

close to the hopper, and is particu arly well suited where charcoal is employed for ignite ing the ore. The fuel within the brazier is ignited from above, and the down draft produced by the fan U causes the hot gases of combustion from the brazier to be brought into contact with the ore, starting combustion therein. As the fuel burns the ashes drop throu h the perforated screen or fuel support and fresh fuel, fed from above, is ignited by upward radiation.

In both forms of the igniting means herein illustrated and described, there is an open bottom closure above the exposed surface. of the ore mass, arranged to be filled with the hot materials used to set fire to the ore mass. The walls of the closure confine the said hot igniting materials laterally but permit them to act, through the open bottom of theclosure, directly upon the surface of the ore mass, over an area equal to that of the open bottom of the closure. The area of this open. end or bottom is of sufficient expanse to insure a thorough and intense ignition that will not, under any circumstances met with in practice, go out after separation has taken place between the igniter and the ignited area of the ore mass, such as occurs when the ore carriers move beyond the igniter.- It is in these respects, to wit, in confining and directing the hot igniting materials to a definite area of considerable width, that the present invention is characterized, being distinguishable from the method illus tratedin earlier atents of mine, for instance, in my a oresaid Patent 916,391;

= where the igniter consists of a gas pipe perforated or provided with burner tips and so arranged as to cause a row of open or exposed igniting gas flames burning in the open to impinge upon the surface of the ore along a narrow line of quite limited area. By confining the hot igniting materials within a chamber as described, the intensity of the available heat employed for igniting is increase and 'is more easily controlled and direct d than is possible when ignition is secured from gas burned in the open. By applying the igniting heat to a sufiiciently wide area of ore at one and the same instant of time, I' am able to insure practically perfeet i nition of the entire ore surface treated, inclu ing as well those areas which do not quickly ignite, by reason of a local deficiency of the combustible constituent of the mass, as those which take fire more readily. Furthermore, the said arrangement prevents dissipation of the heat developed for igniting purposes, by wind or other natural movements of air across the apparatus, as is experienced' when-open, undirected and unprotected igniting flames are used.

It will be observed that thechamber in which the hot igniting materials are confined and the heat directed to the desired area of the ore surface, is provided with a supply du t o that theremay be maintained within ILA-33,353

the chamber a constantly renewed supply of the said hot igniting materials. In the form of apparatus illustrated in Fig. 3 this duct is the flue between the fire chamber Y, and open-bottom closure over the ore mass; While in the form illustrated in Fig. 4 it consists of the upper portion of the brazier Q, such portion serving the double function of a holder for the reserve body of charcoal or other solid fuel, and also as a directing flue for the air that, uniting with the fuel in combustion, supplies the hot igniting materials.

The currents of air that are induced to pass'transversely through the body or bed of ore operate to draw more or less of the hot gaseous materials from within the enclosing chamber of the igniter into direct contact with the ore mass, and thus assist in preventing their dissipation.

I do not in this application claim the specific form of'igniter illustrated in Fig. 4: of the drawings, as that is made the subject of a separate application filed, on the th day of March, 1912, Serial No. 685,910, as a division of my application filed March 23, 1909 on which 'my aforesaid Patent 1,027,110

, issued.

What I claim is 1. The herein described process of treating metal-bearing ore, with which is commingled acombustible substance, to cause it to be sintered, which consists in forming a thin pervious layer of the said mass, applying to a relatively broad area of the upper surface thereof a laterally defined body of materials heated to a temperature sufficient to ignite the-said combustible substance of the mass while the particles thereof are maintained in a state of quiescence, and passing air through the mass to continue the combustion therein started by the said ignition.

2, The herein described process of treatin metalfbcaring ore, with which is commingled a combustiblesubstance, to cause it to be sintered, which consists in forming a thin pervious layer of the said mass, applying to a relatively broad area of the. upper surface thereof a laterally defined body of hot igniting gaseous materials, drawing the said hot gaseous materials into intimate contact with the-ore by aircurrents caused to pass through the body of the ore to insure a good surface ignition and continuing combustion of the ore mass apart from the said hot surface igniting materials to complete sinte-ring throughout the entire mass.

3. The herein described process of treating metal-bearing ore, with which is commingled a combustible substance, which consists in forming a thin pervious layer of the said mass upon a perforated holder therefor, applying to a relatively broad area of the upper surface thereof at one and the to be sintered, which consists in forming a thin pervious layer of the said mass, and igniting the upper surface thereof by a laterally defined and constantly renewed body of hot igniting materials, temporarily employed, from which body are drawn into intimate contact with the surface portion of the ore the said hot materials by means of induced air currents caused to pass through the mass.

5. The herein described process of treating metal-bearing ore, with which is commingled a combustible substance, in order to sinter it, which consists in forming a thin pervious layer of the said mass, heating at one and the same instant of time a sharply 1 laterally defined, covered, and relatively broad area of the upper surface of the said mass to a temperature sufficient to ignite the said combustible substance of the mass, and continuing, apart from the igniting means, the combustion of the said combustible substance throughout the mass from the surface ignited to the opposite surface, while the particles of the mass are maintained in a quiescent state, the said combustion being maintained and assisted by means of induced currents of air caused to pass through the ore mass.

6. The herein. described process of treatin metal-bearing ore, with which is commlngled acombustible substance, to cause it to be sintered, which consists in successively forming a series of separated, relatively thin, pervious masses thereof, uniformly igniting the said masses of ore at their exposed surfaces, one after another, by applying thereto a relatively broad and laterally defined body of hot igniting materials, and continuing the combustion thus started throughout each mass of material, and apart from the igniting materials, until each mass has been completely sintered throughout, such continued combustion and sintering taking place while the particles of each mass are maintained in a condition of quiescence.

In testimony whereof I affix my signature, in presence of two witnesses.

ARTHUR S. DWIGHT.

Witnesses:

HENRY J. STEHLI, Lorne H. HYDE.

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