US1280221A - Method of sintering ores. - Google Patents

Description

E. I. HEILIVIAN.

METHOD OF SINTERING ORES.

APPLICATION FILED JAN. 3. 191a Patented Oct. 1, 1918.

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METHOD OF SINTERING ORES.

Specification of Letters Patent.

Patented @ct. ll, i918.

Application filed January 3, 1918. Serial No. 210,164.

To all whom it may concern:

Be it known that I, ELMER J. HEILMAN, a citizen of the" United States, residing at Perrysburg, in the county. of Wood and State of Ohio, hav'einvented certain new and useful Improvements in Methods of. Sintering Ores, of which the following is' a speclfication. I

This invention relates to an improved method of roasting and sintering ores, such for instance as sulfur-carrying copper ores, flue dust, or the like.

It is quite common in the art to spread ore on a movable carrier, oron a fixed bed, and provide means for igniting the combustible elements to treat the ore, one instance of a movable carrier bein disclosed in Patent No. 916,391, dated arch 23rd, 1909.

In practice, difiiculty is experienced in effectually igniting the entiremass of ore, when it is subjected to forced draft to assist that the layer of ore is thick, and becomes packed and closes the interstices and prevents the free passage of air through it.

According to my. method a thin layer of ore is spread on a carrier or bed located over a draft area, and the upper surface of the ore is ignited, and with the assistance of air suction, the mass is made incandescent, and the combustible elements are consumed. On the upper surface of the thin incandescent layer of ore is delivered another, preferably thicker layer ofore, the top surface of whichis ignited, and the air suctlon serves to draw the heat through the mass and causes ignition of the combustibleelements. By this method the ore is distributed in such manner that sutlicient oxygen is in-' troduced to insureof the combustible ole ments being ignited to convert the ore body into an incandescent mass. I

The invention also comprehends improvements in the specific steps employed in carrying out the method, all of which will be hereinafter described and particularly pointed out in the claims.

. In the accompanying drawing Figure 1 is a conventional side elevation of an apparatus employing a movable carrier, illustrating one way of carrying out my improved method.

in. the before mentioned Fig. 2 is an enlarged detail section through the apparatus shown in Fig. 1.-

Fig. 3 is a detail section of another apparatus for carrying out the method.

Referring particularly to Figs. 1 and 2, 1 indicates an endless movable ore carrier, 2, 2 sprocket wheels for supporting and guiding the carrier, and 3 buckets or pallets formed with perforated bottoms for the passage of air to promote combustion. The numeral 4,

indicates an air suction box, located below the movable ore carrier, the u per edges of the box fitting snugly the edges of the buckets or pallets to form as tight joints as possible. Connected to the lower portion of the airsuction box is a duct 5, connected to an exhaust mechanism (not shown.)

As the construction thus far described is well known in the art, particularly as shown atent, it is not thought necessary to furt er describe the parts in detail.

6 indicates a hopper located above the lower part of the movable ore carrier in advance of the air box 4. This hopper con tains non-combustible materiaLsuch for instance as limestone, cinders, or the like, to be deposited on the carrier to form a hearth (if this be necessary) on which a layer of ore to be treated is deposited, as described in the patent referred to.

In advance of the hopper 6, is an ore hopper 7, the lower end of which is disposed above the top surface of the carrier or hearth at such distance as to insure the delivery of a thin layer of ore, indicated at 8, to the hearth or bed. It is important in carrying out the method that the first layer of ore be comparatively thin, for herein lies one of the steps in the process, and one which assists in the treatment of a large mass of material in a short period of time.

To ignite the upper surface of the thin layer of ore 8, a suitable burner 9, is located second ore hopper 10, the bottom of which is so located as to spread a uniform layer of ore indicated at 11, on the upper ignited surface of the lower layer of ore. In advance of the hopper 10, is a second burner 12, to ignite the upper surface of the layer may be thicker than the first layer.

the end of of ore 11. The layer of ore 11, is introduced 'to the carrier over the draft box, and onto the burning or incandescent surface of the first mentioned layer of ore, which assists in the ignition of the combustible elements, and at the same time, because of the distribution of the material, interstices are more readily formed between the particles.

The fines or reduced ore, or material be ing treated, is delivered to the carrier in superposed thin layers, two being shown each eing separately ignited on its top surface. The ore is delivered to the carrier from the two hoppers; the first layer 8, being thin, the draft in the air box a, readily draws the air from the region above the carrier through the interstices and produces an incandes cent mass. In burning the first layer of ore, it cakes, or becomes crust-like, and is formed with numerous interstices. On the top of the now crusty incandescent mass of material, at a suitable distance beyond the burner 9, the hopper 10, delivers the super- ,indicated at 11. This superposed layer of ore is immediately ignited on its upper surface, and it is simultaneously subjected to the action of the draft in the air box, the air being drawn through the interstices formed in the ignited mass below. The top surfaces of both layers of ore are now ignited, and because of the superposed layer being supported on the ignited top surface of the lower layer, the combustible elements are more readily subjected to ignition, and soon formed into a cake with numerous interstices.

The relative thickness of the first men tioned layer of ore is such that 'the entire mass will, under the action of the heat and draft, be subjected to complete treatment, notwithstanding the introduction of the superposed layer. The thin layers, and the incandescence of the mass results in the formation of ample passages for the air to freely pass to the newly introduced ore. The top surface of the superposed layer of ore is ignited in substantially the same manner, as the first or lower layer, and is treated in identically the same way, except that because of the incandescence of the mass below, and the ignition at the top, this la lyler 1e superposed layer, however, is so proportioned as to insure of complete treatment before the air box is reached. This is possible by reason of the fact that the upper surface is ignited, and the lower surface is in contact withthe ignited top surface of the lower layer, as previously stated. When the two layers are subjected to treatment, they merge into one mass. The necessary oxygen to promote combustion where the two layers come together is made possible by partially treating the layers at difierent periods. This in effect produces a zone of incandesposed layer of ore hea set cence transversely through the mass where the two layers are brought together, and as the air must pass through the body of ore, it follows that the combustion is materially augmented.

The air drawn into the box comes from the region above the mass of. ore on the carrier, which as stated, slowly travels. The air enters the mass of ore and passes down through the interstices therein, supplying the oxygen necessary for the combustion of the combustible element. It is to assist and augment this action that it has been found desirable to spread the ore as described.

Of course, after the ore has been subjected to the treatment it passes to the end of the apparatus and is discharged in the usual way. V

It is important in the treatment of ore, that the operation be accomplished in as reasonable time as possible, but this has heretofore been found impracticable because of the necessary-thickness of the mass of ore preventing the free passage of air, sufficient to promote combustion. Hence, the speed of the conveyor is either reduced, or the thickness of the layer has been made thinner. In either case, the treatment of a given quantity of ore is prolonged, but this is overcome by superposing the layers, for obviously by following this method of treatment a larger quantity of ore can be handled, than has been possible heretofore in a given time.

Thus, by'iny improved method I am onabled to successfully and rapidly treat ores in large volume. The simultaneous application of heat to the top surfaces of both the layers of ore, and the distribution, made possible by my method, absolutely insures the ignition of the combustible contents. The distribution of the ore in thin layers is desirable, as it permits of the formation of the necessary interstices between the particles of material, thus insuring of ample air to properly promote the combustion, and the consequent treatment of the ore.

To simplify the description and disclosure T have shown and described two layers of ore, but this is not to be understood as a limitation, as many more superposed layers may be introduced if found desirable. It simply involves a further distribution and. multiplication of the feeding and igniting means, as will be obvious to one skilled in the art.

Obviously, the method need not be restricted specifically to the sintering of ores, as it is evident the improvement is capable of use in reducing many other materials.

It is to be further understood thatthe method above described can be carried out in various ways, and the conventional illus tra'tion disclosed in Figs. 1 and 2, is in no out my method with an apparatus of this type a layer of ore is ignited and when partially treated, the ignition means is removed, and another layer of ore is superposed, and the ignition means is again brought into po' sition and the top surface of the ore is ignited and the treatment of the whole mass is continued.

What I claim is:--

1. The method of sintering ore which consists in spreading a layer of ore on a suitable bed and igniting the upper surface, subsequently spreading another layer of ore on the ignited surface of the first layer and igniting the top surface of the second layer, and drawing air through the ore from the region above the top thereof to promote combustion. y

2. The method ofsintering ore which consists in, spreading a layer of ore on a suitable bed and igniting the upper surface, subsequently spreading another layer of ore on a portion of the ignited first layer and the bed beyond same and igniting the top surface of the second layer, and simultaneously drawing air through both layers of ore from the region above the exposed top surfaces to pro-' mote combustion.

3. The method of sintering ore which consists'in spreading a body of ore on a suitable bed and ignitlng a zone intermediate and transverse of the body of ore and also the top of the ore b0dy,;;and simultaneously drawingair through the body of ore from the region above the top of same.

4. The method of sintering ore which consists in igniting a layer of ore and supplying 'an additional layer over the first ignited layer and igniting the second layer, and drawing air through the ore to promotecombusti'on and cause the two layers to merge into one.

5. The method of sintering ore which consists in spreading a layer of ore on a moving body, igniting one surface of the layer, spreading a second layer of ore over the ignited or partially burned surface of the first layer and igniting the upper surface of said second layer, and drawing air through both layers of ore from the ignited surfaces to promote combustion of the combustible elements.

6. The method of sintering ore which consists in superposing layers of ore, igniting the upper surfaces of the layers of ore at different points, and drawing air through said layers of ore from the ignited surfaces to promote combustion of the combustible elements in the ore.

7. Themethod of sintering ore which consists in spreading a thin layer of'ore on a suitable bed and pasing same over a suction draft to draw air from the upper surface, igniting the upper surface of the layer of ore, subsequently introducing a second layer on the ignited portion of the first layer while the air is drawn through, and igniting the upper surface of the second layer of ore while air is drawn therethrough to cocperate with the ignition of the top surfaces of the first layer of ore to promote combustion of the combustible elements.

the ignited surfaces thereof.

In testimony whereof I aflix my signature.

ELMER JOHN HEILMAN.

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