US1169384A - Apparatus for sintering and smelting ores. - Google Patents

Description

A. S. DWIGHT.

APPARATUS FOR SINTERING AND SMELTING ORES.

APPL|CAT|0N.FILED MAR-31,1910. RENEWED JUNE 12. 1915.

Patented Jan.i25, 1916.

wi-lmeooo ARTHUR S. DWIGHT, OF NEW YORK, N. Y.

APPARATUS FOR SINTERING AND SMELTING. ORES.

Specification of Letters ratent.

Patented Jan. 25, 1916.

Application filed March 31, 1910, Serial No. 552,579. Renewed June 12, 1915. Serial No. 38,809.

I '0 all whom it may concern Be it known that I, ARTHUR S.- DWIGHT, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Ap aratus' for Sinteringand Smelting Ores, 1 which the following is a specification, reference being had therein to the accompanying drawmg. 7

This invention relates to improvements in apparatus for treating ores, particularly those which are susceptible of a desulfurizing or kindred treatment and a sintering treatment, either simultaneously or successively, and of being subsequently reducedby smelting or a similar operation.

It will be noted that apparatus embodying my improvements is also adapted for the treatment of iron or other ores in which there is normally present no combustible element. When ores of this class are to be treated combustible material, such as carbon, may be artificially introduced.

Of the drawings Figure 1 is a side view partly inelevation and partly in vertical section. Fig. 2 is a plan view, a part being shown in cross section along the line 2.-2. of

may be of any preferred orm, such as a gas Fig. 1. Fig. 3 is a fragmentary cross sectional view taken along theline 3-3 of Fig. 2.

It will be understood that the apparatus presented is illustrated more or less conventionally in the drawings but in such a way that the essential parts of the construction may be readily understood by those skilled in the art. Generally considered, the devices illustrated can be considered as made up of two main parts; i

The apparatus indicated by A is especially adapted for treatment of sulfid ores, such as copper sulfid, although it is to be understood that the invention is not limited to the treatment of material of any particular type.

The apparatus A comprises a traveling conveyor 1. This conveyer 1 may be of any desired type, but I prefer to use a conveyer comprising a series ofpans, buckets or pal-- lets 2. These pallets are provided with perforated bottoms, and side walls perpendicular to the bottoms. Wheels 3, 3 are provided for each pallet and these wheels are adapted to engage with and be supported by the tracks 4 and 5. The pallets are adapted to aline with each other at the upper part of the conveyer to form a continually moving tray or platform supported by the track 4.

At its forward. end the track 1 is overlapped by the track 5 in such a way that a pallet on passing around the curved endof the track 4 will be engaged by the overlapping curved end of the track 5 on which it will be carried by gravity to the continually rotating wheel 6. This wheel is provided with teeth adapted to engage the wheels of the pallets and to thus carry the inverted pallets upward onto the track 4. A hopper 7 is provided for the reception of material and serves to direct the material onto the moving conveyor in a stream or layer of substantially uniform thickness. 1 I

8 represents an air box provided with means for exhausting the air therefrom. The top of this box is formed by the perforated bottoms of the moving pallets, and consequently as air is Withdrawn from the box by the exhausting means, it is drawn in through the perforatlons in the pallet bottoms. When there is a'layer of ore on the pallets then the'airwill be drawn downward through the interstices between the ore frag ments.

9 represents an ignitin apparatus which pipe perforated to provide a series of gas jets across the top of the ore mass or a conductor and burner for oil. The stream or layer, of ore delivered from the hopper 7 passes under the apparatus 9, and the comustible elements, such as sulfur contained in the ore, are ignited.

' It is not necessary to here describein de- I tailthevarious successive steps incident to the desulfurizing and sintermg of the ore, as these are fully described in patents issued to .A. S. Dwight and R. L. Lloyd, among them being Patent 882,517 and Patent 882,518. For the purposes of the present description, it is sufficient to say that the ore moves along with the conveying apparatus 1, and the combustion started byv the igniting device 9 moves gradually downward through the stream or layer of ore under the influence of the downward draft of air caused by the exhausting device connected with the air box 8. The combustion is entirely supported by the combustible elements, such as sulfur or carbon contained in the ore charge itself, and the lines of combustion move downward until they reach the bottom of the laye.

The heat generated by the combustion causes certain constituent elements of the ore mass to melt and un1te the layer into a homogeneous coherent porous cake. The rate of mo -tion of the conveyer 1, and the thickness of the layer ofore are so regulated that the desulfurizing and sintering processes will be completed when the moving layer reaches the point 10. As each pallet reaches the point 10, it is moved out of alinement with prises side and end walls 13, a bottom 14:

and an arched roof 15. The various parts of the furnace maybe formed of any suitable heat resisting materials which are adapted for use in connection with the ore to be treated.

In one wall of the furnace there is pro vided an aperture 16, that is relatively wide so as to be adapted to receive the end of the sinter cake 11. I prefer to so construct the conveyer 1 that the sinter cake will be fed into the furnace at a slight downward angle, the purpose of which will be hereinafter fully set forth. If desired, supporting ledges of fire brick may be formed to support the advancing sinter cake. I do not, however, at present consider these ledges necessary and have not therefore shown them in the drawings.

The bottom of the furnace is adapted for the collection and retention of a bath of matte or molten metal. A tap 17 is provided for the withdrawal of the metal from time to time. On top of the metal bath there will collect a layer of slag consisting of silicious or other material. This layer of slag is formed either from material contained nor-.

mally in the ore itself or it may be derived from fluxing Inaterialsmixed with the ore before it reaches the desulfurizing and sintering apparatus. If preferred, however, the fluxing materials can be separately introduced into the furnace by means of a hopper and chute,- such as is indicated by 18.

19 is a slag-tap adapted for the occasional or continual removal of the slag. The tap 19 may discharge into a suitable slag car, such as indicated by 20. The tap is located at such an elevation that the slag will be maintained at a level somewhat above that of the inner end of the sinter cake'll. I have found, on account of its porousnature, that the sinter cake is lighter than the slag and will consequently tend to float thereon. By submerging' the inner end of the sinter cake its tendency to break by its own weight is counteracted.

21 and 22 represent two sets of electrical contact devices arranged respectively above and below the moving sinter cake; These contact devices may be of any preferred form, but for purposes of illustration I have shown them as comprising a series of pivoted spring-pressed fingers frictionally engaging with the surfaces of the cake. These contact devices are connected by means of a suitable conductor with one terminal of an electric generator. The other generator terminal is connected with a stationary electrode or contact plate 23 located in the bottom of the furnace. This contact phteis preferably formed of carbon and by means of it electrical connection is established to the bath of metal in the furnace.

The sinter cake 11, on account of the metal contained therein, forms. an electric conductor which may have a rather high resistance, and the electric generator with which it is connected by means of the contacts 21 and and the carbon plate 23 has sufficient voltage to permit the completion of an electric connection between the end of the sinter cake and the molten metal beneath it, the current passing through the molten slag. Intense heat is generated by this action of the current and by means of it the end of the advancing cake is continually melted off. The current potential and the rate of more ment of the cake should be so adjusted relative to each other as to maintain the end of the solid cake at substantially the same part of the furnace. As the sinter cake is melted the pure metal is separated by gravity and unites itself with the mass of metal in the furnace. The slag and impurities float on top of the metal and are withdrawn through the tap 19..

The passage of the electric current through the sinter cake tends to heat it on account of the electrical resistance of the cake itself. It will be noted that the cake is subjected to four separate heating influences. First, the heat of sintering, which is retained as the cake passes into the furnace; second, the heat caused by the passage of the current through the sinter cake; third, the heat derived by conduction and radiation from the hot metal and slag; and fourth, the heat from the smelting action at the end of the cake. It will, therefore, be noted that, on account of the heating influences just referred to to which the cake is subjected before it reaches the position where the current leaves the 3 sinter-cake and passes to the molten hath within the furnace, comparatively little additional heat need be generated at this point to cause melting.

Various changes and modifications may be made in the apparatus which I have described without departing from the spirit of my invention. For instance, a sinteriug device of any of the types which are now well known may be used. Other changes vention the processes of ore treatment which I have herein set forth. These processes are described and claimed in my co-pending applications entitled respectively Sintermg and smelting ores, filed March. 31, 1910, Serial No. 552,578, and Sintering or ag lomerating'and smeltlng fine. ores'and oreearing materials, filed June 25, 1908, Serial No.

' 440,404, renewed May 12, 1913, Serial No.

What I claim is 1. In an apparatus of the class described the combination of a moving platform adapted for the conveying of a continuous layer of ore, means for sintering the ore on the platform into a continuous cake, and

means for passing an electric current through a portion of the cake adjacent its advance end, substantially as set forth.

2. In an apparatus of the class described, the combination of a means for forming and continually advancing a continuous layer of ore, means for sintering the advancing layer into a continuous cake, and means for passing an electric current through a portion of the cake adjacent its advance end, substantially as set forth.

3. In an apparatus of the class described,

the combination of a means for forming and continually advancing a continuous layer of ore, means for sintering the advancing layer into a continuous cake, means for connecting the cake intermediate its ends to one terminal of an electric generator, and an electrode connected to the other terminal of the said generator and separated from the advance endof the cake, substantially as set forth.

4. In an apparatus of the class described, the combination of a means forforming and continually advancing a continuous layer of ore, means for sintering the advancing layer into a continuous cake, a relatively stationary electrode so arranged relative to the advance end of the cake as to permit the formation of an electric connection between the end of the cake and the electrode, and means for passing an electric current through the cake intermediate its ends, substantially as set forth.

5. In an apparatus of the class described, the combination of a means for the continual formation of a continually advancing continuous cake of sintered ore, and stationarily located electrical terminals adapted to connect a part of the moving cake into an electric circuit, substantially as set forth.

the generator and separated from the advance end of the cake, substantially as set forth. I

7. In an apparatus of the class described, the combination of a means for the continual formation of a continually advancing continuous cake of sintered ore, a relatively statiohary electrode, so arranged relative to the advance end of the cake as to permit the formation of an electric connection between the end of the cake and the electrode, and means for passing an electric current through the cake intermediate its ends, substantially as set forth. e

8. In an. apparatus of the class described, the combination of a means for the continual formation of a moving cake of material adapted to be smelted, and means for connecting a substantial portion of the said moving cake into an electric circuit for the purpose of smelting it,substantially as set forth.

9. In an apparatus of the class described, the combination of a furnace, adapted for with the said molten mass, means external to 'the furnace for continually forming a continuous cake of material adapted to be smelted, means for feeding the said cake into the furnace as it is formed, and means for establishing electrical connection to the cake, and between the end of the cake and the molten mass, substantially as set forth.

10. In an apparatus of the class described, the combination of a furnace adapted for the retention of a bath of molten metal and a layer of slag on top of the metal, means for establishing electrical connection to the bath, means external to the furnace for continually forming a continuous cake of material adapted to be smelted, meansfor feeding the said cake as it is formed, into the furnace in such a way as to be partly submerged in the bath, and means for establishing electrical connection to the cake, and between the end of the cake and the molten bath-substantially as set forth.

11. In an apparatus of the class described, the combination of a sintering device, a furnace adjacent the sintering device, and adapted for the retention of a bath of molten material, an electrical connection with the material whereby an electric current is estabmolten material, means for feeding sintered lished through said material and the molten bath, substantially as set forth.

12. The combination of a smelting furnace in one wall of which is a relatively broad opening through which may be fed a mass of sinter in sheet form and which is adapted to retain a mass of molten material, a support exterior to the furnace and adjacent to the said opening across which the sinter mass passes as it is fed into the furnace, an electric contact device constituting one terminal ARTHUR S. DWIGHT. Witnesses H. I. STEHLI, C. M. @ITANLEY.

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