US1288404A - Apparatus for cleaning clayey ores. - Google Patents

Description

E. F. GOLTRA, Tfs. MAFFITT, J. u. DANA & R. w. ERWIN.

APPARATUS FOR CLEARING CLAYEY ORES."

APPLICATION FILED JAM.5.1914.

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2) I ezziozq: a2. 22m, $5. 3? iii,

E. F. GOLTRA, T. S. MAFFITT, J. D. DANA & R. W. ERWIN.

APPARATUS FOR CLEARING CLAYEY ORES.

APPLICAHON HLL D I374 5.19M.

E. F. GOLTRA, T. S MAFFITT, J. D. DANA'& R. W. ERWIN.

APPflRATUS FOR CLEARING CLAYEY ORES.

*FPLICA ION FILED JAN. 5. I914.

Patented Dec. 17, 1918.

4 SHEE S-SHEET 3.

E. F. GOLTRA, T. S. MAFFITT, J. D. DANA & R. W. ERWIN.

APPARATUS FOR CLEARING CLAYEY ORES.

APPLICAIION HLE') 1w, 5. 1914. N

Patented Dec. 1., 1918.

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I EDWARD F. GOLTRA, THOMAS S. MAFFITT, AND JESSE DANA, 'OF ST. LOUIS, MISSOURI, AND ROBERT. W. ERWIN, F WAUKON, IOWA, ASSIGNORS, BY MESNEASSIGNMENTS, TO MISSISSIPPI VALLEY IRON COMPANY, OF WILMINGTON, DELAWARE, A. CORPO- esaaca.

RATION OF DELAWARE.

APPARATUS FOR, CLEARING CLAYEY ORES. v

I specification of Letters Patent. Patnted Dec. 1?, 1918..

Application filed January 5, 1914. Serial No. 810,531.

To all whom it may concern:

Beit known that we, EDWARD F. THOMAS S. 'MAFFITT, Jnssn D. DANA, and ROBERT W. ERWIN, citizens of the United States, said GOLTRA, MAFFITT, and DANA residing at St. Louis, State of lf/lissouri, and said ERWIN residing at Waukon, Iowa, have invented new and useful Improvements in an Apparatus for Clearing Glayey Ores, of which the following is a specification.

This invention relates to apparatus for clearing ore of its gangue, and more particularly to apparatus for clearing ores containing clay as. a gangue. 15.

Some ores, such as brown hematite and certain ores of copper, contain a large per- .centage of clay and sometimes silica as a gangue. These ores exist as nodules and boulders of various sizes in the clay beds, and the clay and silica, such as flint, stone, gravel and sand, is often found inside of the lumps or boulders. Now this gangue must be separated from the ore before it can be used economically in a blast furnace.

In U. S. Patents Nos. 957,157, granted v May 3, 1910, and 961,121, granted June 14,

1910, are described a process for clearing such clayey'ore of its gangue. The process as described in said patents may be briefly summed up as follows: The ore and its gangue are heated at a temperature and for a period suflicient to render the ganguebrittie and easily separable from the ore; the

- ore and its gangue are tumbled to shake loose the gangue from the ore, and the ore and gangue are subjected to a strong air blast so as to sweep, clean and remove the gangue from the ore.

While the air cleaning process of said patents produces a merchantable ore well suited for a blast furnace," and whilethis air cleaning process will free the ore of substantially all of'its clay gangue, it will not separate the rock, flint, gravel and sand from the ore to a sufiicient extent. As stated above, this silica occurs in combination with clay as a gangue, and often occurs inside of the lumps or boulders of ore.

One of the objects of this invention therefore is to refine the apparatus described in the above patents so as to render it more eficient, so as to clear theoreof all of its and 10 feet in diameter.

for various ores having characteristics permitting its utilization, more particularly various ores containing clay as a gangue and occurring in the form of nodules in the clay, and containing considerable moisture both free and combined.

Further objects will appear from the detail description taken in connection with the accompanying drawings in which:

Figure 1 is a diagrammatical plan view of an apparatus illustrating the process ensbodying this invention,

Fig. 2 is a profile or elevation also. in diagrammatical form, a

Fig. 3 is an enlarged diagrammatical detail profile or elevation,

Fig. 4 is'another enlarged dia 'rammatical detail profile or elevation showmg the second converter, Y.

Fig. 5 is a plan showing the third converter,-

Fig.v 6 is a profile or'side elevation partly in section, of this third converter,

Fig. 7 is a detail end elevation, showing the outlet door, Fig. 8 is a detail end elevation of the inlet end,

Fig. 9 is a section on the line 9-9 Fig. 8,

Fig. 10 is an enlarged detail section on the line 99 .Fig. 8, and I Fig. 11 is an enlarged detail section on the line 1111 Fig. 9.

The apparatus generally tated three converters designated generally B and C.

. The first converter comprises a cylinder 10 consists of having rings 11 resting on rolls 12 and 129 on pillars 13, and 14. The cylinder is positioned on an incline, and the upper set of rings 11 and rolls 129 forms an endthrust bearing to upport the cylinder against end movement. This cylinder is constructed of boiler iron'and may be about 125 feet long It is lined for about one-third of its length from its lower end with fire brick or other suitable material, while the unlined part has aseriesof inwardly projecting shelves or lifters extending therealong. The upper end of the cylinder projects into a stationary hopper spaced from 12 to 14 inches apart so as to allow everything under 14 inches to pass into-the hop-per 17. This hopper is provided with two hinged valve plates 20 and 21 placed in series to prevent the gases in the converter from entering the hopper. The casing 16 is connected with a stack 22 through a fan 23 driven by a motor 24. This fan will cause a draft from the lower to the upper end of the cylinder and up the stack 22. The lower end of the cylinder projects into a casing 25 which is provided with roll so as to be movable longitudinallv of the cylinder along a track 26, to allow for expansion and contraction of the cylinder. A pulverized coal burner 27 receives the coal from a bin 28 and an air blast from a fan or pump 29, and this coal is blown in a pulverized condition into the lower end of the cylinder 10. i The cylinder is provided with a toothed ring 30 meshing with a pinion 31 driven by a suitable motor.

The ore is discharged from the cylinder 10 on shaking or reciprocating grids 35, which in this particular casedischarge everything below 2-;- inches into a chute 36, while the oversize discharges into a crusher 37, which may be of the gyratory. type, and

which crusher reduces the material to 2%} inches. The chute 36 from the reciprocating grids, and the chute 38 from the crusher discharge into an elevator 39, which elevates the material and discharges it into a sizing screen or trommel 40. This trommel sizes the material iii-this particular instance to three sizes. The fine material passes by a chute 41 to a tailings bin 42, the second sized material passes by a chute 43 to a belt conveyer 44, discharging into the ore bin 45, and the oversize or coarse material passes onto a picking belt 46 where it is handpicked and the picked ore discharged onto the conveyer 44 and hence taken to the ore bin 45. The hopper 47 for the tailings bin 42 extends upwardly underneath the belt 46 golas to receive the flint etc. picked from the The material from the bin is taken to the second converter B which is shown in detail and enlarged in Fig. 4. This second converter is of substantially the same con struction as the first converter A and is operated in substantially the same manner. It consists in this particular instance of an in clined cylinder 50 about 125 feet long and 8 feet in diameter. it is however lined for a little over three fourths of its length from its lower end with fire brick or the like, while the unlined part is provided with inwardly projecting shelves extending therealong. This cylinder is supported by rings 51 on rolls 52 and 520 on pillars 53 and 54. The center set of rings 51 and rolls 520 in this case also form a thrust bearing. The upper end of the cylinder extends into a casing 56 which is connected to an exhaust fan 57 discharging into a dust collector 58 and from there into ;a stack 69. This dust collector may be of any suitable form and may be provided with inclined shelves 59 placed in staggered relation so as to separate the dust from the air before it is discharged into the stack. An outlet 60 is provided for this dust collector. A conveyer 61 conveys theore from the bin 45 to the casing 56 and thence to the cylinder 50. The lower end of the cylinder projects into a casing 62 provided with rolls and adjustable lengthwise of the cylinder along a track 63. A pulverized coal burner 64 receives coal from a bin 65. and air from a blower or pump 66, and this burner blows the pulverized coal into the lower end of the cylinder. The cylinder is provided with a toothed ring 67 meshing with a pinion 68 driven by a suitable motor.

The material as it leaves the second converter is taken by an elevator 70 to a sizingtrommel 71 which in this case sizes the ore to two sizes. The oversize is taken by a conveyer 72 and discharged onto a picking belt 73 where the flint etc. are hand-picked,

third converter C which will now be described. Referring more particularly to Figs. 5 to 11 inclusive, which show the third converter in detail, 77 designates a cylinder of boiler iron provided with rings 78 resting on rolls 79 on pillars 80, and having a center thrust ring 81 coiiperating with thrust rolls 82. This cylinder is provided with a toothed ring 83 meshing with a pinion 84 driven by a suitable motor. cylinder for about one-half'of its length from its upper end is of a comparatively large diameter, while the lower end is reduced as shown at 85 so as to form a comparatively long outlet of small diameter. Thus in a practical case, the cylinder-is 60 The feet long, has a large diameter of 6% feet mas er hopper 76 discharges through double valve casings 91 and 92, and a chute 93 extending through the plate 86, into the cylinder 77. The valve casings 91 and 92 are provided with valves 94 and 95 respectively, sus pended by links 98 from levers 97 pivoted on the hopper casings. These levers are pivoted in the valve casings by sleeves 99 making close fits with bearing lugs 100 of the valge casings so as to make these joints air ti t. w ights 101. Links 102 are pivoted at their lower ends to the arms 97 and are provided at their upper ends with elongated slots engaging cranks 103 on a shaft v10 1, which is driven from any suitable source of power. A pipe 105projects into the cylinder and extends just through the bottom wall of the chute 93. This pipe 105 delivers crude oil under a pressure of about inch from a tank 106.

The lower end of the cylinder 77 is closed by a door 107 pivoted at its upper end to the frame 108 and held closed by strong springs 109. The door 107 has a cut out portion 110' in which is pivoted a small door 111 closed by weaker springs 112. Both doors bear against the end of the cylinder so as to form an airtight joint, but the lower door 111is opened by the material passing out of the cylinder, the opening being however only sufiicient to permit the ore to pass out.

- The function of the double door is that df a safety device, for if an explosion takes place both doors will blow open and therefore furnish a large outlet for the exploded gases and thereby prevent damage to the converter.

A conveyer 115 takes the material fromthe third converter to a sizing trommel 118 which sizes the material to a series of sizes so that it can be conveniently operated upon by magnetic separators. The material on the conveyer 115 is passed underneath sprays 11 1 of cold water to quench the same. The material from the sizing trommel is conveyed to magnetic separators indicated at 117. These magnetic separators separate the ore from the gangue, the ore be: ing conveyed to a suitable ore bin such as 74: and the tailings discarded.

The coal is stored in a bin 120 from whence it is conveyed to a drier 121. From the drier the coal is taken by conveyors 122 and 123 to bins 28 and respectively. In the diagrams, 124 designates the power house and 125 and 126 designate tracks.

The operation will now be described, and in this operation we will take as a practical case, for the material operated upon,rlimo- 1 nite or brown hematite containing a large percentage of clay as a gangue, containing also siliceous gangue such asstone, quartz, gravel and sand, and containingboth free and combined moisture.

The ore as mined is dumped on the grids The levers 97 are provided with 150 lbs. per square 18 which, as described above, pass everyincline being such that it takes about 45' minutes for the material to pass therethrough. The flame temperature at the lower end of the converter is maintained at about 2200 F., while the stack temperature, or thetemperature at the upper end of the converter, is maintained at about the boiling point of water. draft of about one-half ounce. A low pressure current of air is thus passed through the'drum, the air entering both with the pulverized coal and through the outlet passage in the casing 25. The material in passing through the first converter is subjected/to a drying heat, and the operation performed in this first converter is therefore a drying operation, whereby the material is freed of substantially all of its free moisture. During its passage through the converter the ore and gangue, including the heavy boulders, which are as large as 1 1 inches, are lifted and tumbled around, and during this The exhaust fan creates atumbling operation the heavy boulders will break up to some extent and break and disintegrate the oreand gangue, so that a crushing operation is performed in this converter.

Simultaneously the mass of ore and gangue is subjected to a gradually increasing temperature, as the temperature increases from the upper to the lower end of the converter,

and this ore and gangue will therefore begradually dried out. This combined drying and tumbling operation will also renderthe ore friable, and will in addition separate, 2'. 6., shake loose some of the clay and other gangue, including the larger stone, mixed with the clay. It will be noted however that while a draft of air is passed through the 0 cylinder of this first converter, the blast is not a strong blast, for its function is merely a drying function; its functionis not primarily to ca ea any of the gangue, al-

though some ofthe. clay which has become ore lumps, will be dried, loosened, and

broken and ground, so that it, together with the sand may be separated from the rest by a trommel, as hereinafter described.

The ore and gangue as discharged from the first converter is passed over the shaking grids 35 which pass everything below 2 inches into the elevator 39, while the over- P lumps and expose this gangue; As the ore is thus tumbled around and subjected to the size is sent to the crusher 37 and crushed down to 2%; inches, and discharged into the elevator 39. This elevator takes the ore and gangue to the sizing trommel l0 which sizes the material in three sizes as follows: onesixteenth inch and below, one-sixteenth inch to three-fourths inch, and three-fourths inch and over. Tt is found that the one-sixteenth and below consists mostly of sand and clay and is very lean in ore. This size is therefore discharged directly into the tailings bin e2. The one-sixteenth to three-fourths is discharged directly into the ore bin 45 by means of the conveyer belt 44:. The threefourths and over is discharged onto a picking belt 46 where the flint etc. are handpicked, the picked ore passing into the ore bin. The purpose of the sizing between the second and third sizes is to facilitate the hand picking, as it is found that most of the rock, flint and other siliceous material freed from the ore Wil be found in this size. This sizing of the ore therefore, first, discards the fines, consisting mostly of sand and clay and containing very little ore, and second, throws only the larger sizes on the picking belt where the flint etc. may be readily hand-picked and discarded.

The material is taken from the ore bin 45 to the second converter B. This second converter is driven at such a speed, and the incline is such, that the material will pass through this converter in about 45 minutes. The flame temperature maintained at the lower end of this converter is about 3200 F, while the temperature at the upper end is from 400 to 500 F. The exhaust fan in this case creates a strong blast through the converter cylinder of about 1%; ounces. which blast will lift particles of sand onesixteenth of an inch in diameter. As the material passes through the converter it is tumbled around, and at the same time subjected to the hot strong blast passing through the converter. The temperature in this case also increases from the upper to the lower end of the converter cylinder, tout;

this temperature-is very much higher than I in the first converter. As the ore passes along the converter cylinder it will be'subjected to a calcining heat which not only drives off any free moisture which may be present, but also drives oil the combined moisture. The high temperature causes the ore and any associated siliceous gangue to expand unequally and thus break open the heat, the gangue will be loosened by the heat and shaken loose by the tumbling action,

and dried out so as to become very brittle, and this gangue is powdered by the tumbling action of the lumps against one another. This gangue so loosened and powdered will be picked up by the strong blast essence passing through the converter and carried along with it, while the ore willcontinue downwardly toward the discharge end. The

gangue will not only be shaken loose from the ore leaves the converter it williiot only be entirely freed from its clay gangue, but also from all of its free and combi'ned moisture, so that the ore will be in a dry and porous condition, brought about by the cleaning out of the gangue and the expulsion of the combined moisture. Furthermore the cracking of the ore lumpsand the tumbling-Will free. the siliceous gangue from the ore, so that while this siliceousgangue may not all be separated from the oreby the air blast, it will be loosened therefrom to enable it to be separated in the subsequent operation hereinafter to be described. The ore as it leaves the second converter is at a cherry red heat, or at about 1300 F.

The ore as discharged from the second converter is sized in a sizing trommel to two sizes, an under'size of one-half inch and less, and an oversize of one-half inch and over. This sizing takes place for two reasons. First, it is found that the oversize does not contain very much siliceous gangue, and can there for'ebe conveniently and economically hand-picked, second, it is found that the subsequent magnetizing process and the subsequent magnetic separation can be performed more effectively if performed on an undersi'ze of one-half inch and less, although we have found that the magnetizing and magnetic separation can be performed on pieces whichv will pass through a one inch mesh. The oversize is cooled down by.

always closed while the other is open. En-

trance of air, during the feeding of the ore 'is'therefore prevented. A gaseous hydrocarbon atmosphere is maintained loy feeding in crude oil under 150 lbs. pressure, and this oil is fed in directly under the ore bed as it slidesdown the chute into the converter cylinder, so as to mix directly with the hot ore. This construction will also cause the ore sliding down over the end of the pipe to keep the outlet clean and free. The oil forced into the converter cylinder will volatilize and form a dense and concentrated hlydrocarbon atmosphere in the cylinder. The upper end of the cylinder is of large diameter so as to furnish a large volume for the hydro-carbon gases to act on the material. The lower end of the cylinder, or rather the lower half, is reduced in diameter so as to form a small outlet, thereby preventing entrance of air. The swinging doors at the lower end of the converter cylinder will also keep out the air, and the large door is normally held closed while the lower or small door only opens to let out the material. The material as it is discharged from the second converter B is at about 1300 F., and

as discharged into the third converter C is at 1000 F. or over. The material is therefore maintained in the third converter at about 1000 F. and over 900 F., as it has been found that the temperature in this converter must be over 900 F. in order that the desired action may take place. The material is kept in the third converter C for 30 minutes or over. It has been found when treated as described, the ore as it leaves the converter is magnetic, i. 6., it is attracted by a magnet. The material as it leaves the converter is taken by a conveyer to a sizing trommel 116, and while being conveyed is subjected to the action of jets of water to cool the same. The material is sized to meet the varying requirements of magnetic separation and is then separated magnetically. The material can be separated at as high a temperature as the magnetic separators will take it, but it will be found that it can 'be separated cold.

It is obvious that various changes may be made in the details of construction without departing from the spirit of this invention, and it is therefore to be understood-that this invention is not to be limited to the specificconstruction shown and described.

The process is fully described and claimed in our eopending application, Serial Number 810,530, filed of even date herewith, while the magnetizing process per se is fully described and claimed in an application of Robert W. Erwin, Serial Number 810,532,

I filed of even date herewith.

Having thus described the invention what is claimed is:

1. An apparatus for clearing ore of its gangue, comprising a converter receiving the ore and its gangueandhaving means for heating the material to preliminarily render the gangue separable from the ore, a crusher receiving the material from the converter to preliminarily separate the gangue from the ore, a screen receiving'the material from the crusher to preliminarily remove the gangue from the ore, a second converter receiving the oversize material from the screen and having means for heating the material, means cooperating with said second converter to tumble the ore therein and complete the separation of the gangue from' preliminarily render the gangue separable from the ore, a screen. receiving the material from the converter to preliminarily remove the gangue from the ore, a second converter receiving the oversize material from the screen and having means forheating the material, means cooperating with said second converter to tumble the ore therein and complete the separation of the gangue from the ore, and means for subjecting the ore and gangue in said second converter to a strong blast to remove the gangue from the ore.

3. An apparatus for clearing ore of its gangue, comprising a. converter receiving the ore and its gangue and having means for heating the material and for subjecting the same to a blast, a crusher receiving the material from the crusher, a screen receiving the material from the crusher, and a second converter receiving the oversize material from the screen and having means for heating and tumbling the material and for subjecting the same to a blast to remove the gangue from the ore.

In testimony whereof we have hereunto.

aflixed. our signatures in the presence of these Witnesses.

EDWARD F. GOLTRA.

THOMAS S. MAFFITT.

JESSE D. DANA. Witnesses:

, W. A. STINE,

P. O. MAFFI'I'I.

. ROBERT W. ERWIN. Witnesses:

HARRY ORR,

FRANK CAMPBELL.

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