US1564731A - Method and apparatus for separating ore particles - Google Patents

Description

Dec. 8 1925. 1,5 6'4,73I

J. WEATHERBY;

' METHOD AND APPARATUS FOR SEPARATI IiG ORE PARTICJJES Fil ed July 21. 1922 4 Sheets-Sheet '1 i Elma wow Q 1 s5 f 5 Dec. 8,1925- J. 'WEATHERBY- METHODAND APPARATUS FOR SEPARATING' ORE PARTICLES Filed July 21-,

1 922 4 Sheec s-Sheet 2 ,J. WEATHERBY METHOD AND APPARATUS FOR SEYARATING 03E PARTICLES Filed July '21, 1922 4 SheetS -Sheet' s J, W'EATHERBY Dec. 3"

METHOD AND APPARATUS FOR'SEPARATING ORE PARTICLES Filed July 21, 1922 4 Sheets-Sheet 4 JOSEPH EATHERBY, OF NEW CUMBERLAND, PENNSYLVANIA, ASSIGNOR, BY DIREGT AND IIIESHE ASSIGNMENTS, T WEATHERBY ORE, SEPARATOR CGMPANY, OF HILADEL?HIA, PENNSYLVANIA, A CDRYORATION 0F DELA'WARE.

laIETHQD AND A'PIEAEATUS FOR SEIQARATING ORE PARTIICLEE.

Application filed July 21, 1922. Serial No. 576,622.,

To all whom may concern:

lie it known that l, Josnrn ii' m'rnnsnr, a citizen of thc United States, residing at :len' (Run crland, in the county of Cranberland flllkl atc of Pennsylvania, have in vcntc l certain new and useful improvei'nents in iiiethods and Apparatus for Separating Ore Particles; and I do hereby dcclarc n": :hwllowing to be a full, clear, and mar-tr! i 'fiion oi lhc same, reference being had to the accompanying drawings,

"forming part oi this 51' ccification.

lily invention relates to an improved method of scparnting ore particles from thcii .1 pie, and one ore from anot icr, de their susceptibility to alternatmagnetic flux and their porcrrneable qualities.

a ration ore particles from their l of one particular ore from an- I the use of niulli-phase alternating filllfil); in the type of magnetic separator shown in drawings attached and described in the foil; ng specification.

l have and that by passing an alternal- 1m: ic flu): tl'irough most inineralsand metals, a countcrclcctro-nioliive force is set up within such minerals and metals rc- ;'J' il out uc.wiingly (iJJPGIlCli-Bllt on ohmic resistan c what .i Will. tcrin responsive] lfreqi icnc and MT) a power factor of the minor; at certain frequencies.

lror insi n :u :1 piece of iron is attracted current magnetic pole and l frequ ncy;whi a cd away fr the -a-lcctrornotivc force 7 d in accordance with i Elcctromagnetically in duced Curr nts always have such a direction lhat'the action. of the nmgnetic fields set up them 1:. .os to stop the motion which produces them, A further form of IJQDZ S law is that jill lndllcfil'l current is always in such a dirtcl'" change in ll Why copycaare repelled x plaining meld, While invention more partic larly relalcs,

of their magnetic pcrmeabililiy,

that its field opposes any ,lU metals iron due to its magnetic permeability is at tractcd.

I have further found that all magnetic -pcrmcabls suhstanccs such as would be attractcd by a hand magnet, respond to an aliQl'DlIilllfZ current magnet with a varying degree of speed dependent on their reluctance and the frequency used i. e., if three or more magnetic substances be mixed to- ;gcther, such as ore particles from different localities, iron filings, etc all will jump and strongly adhere to a hand magnet and they all appear to be equally attracted, but if these same particles are subjected to an alternating magnetic field, they will not all respond alike to the magnetic attraction for while one respond quickly to a certain particle will best respond. Particles of a high magnetic permeability respond to an alternating field much more fecbly than those of low permeability, and this must be borne in mind, to avoid confusion between magnetic permeable ores and nonmagnetic metallic substances in the following specification. 1

Sonie magnetic ore particles will respond freely to cycles and fecbly to cycles alternating current field While a piece of copper or aluininunror other nonmagnetic metal which is of minus permeability will be repelled violently, seemingly dependent upon their ohmic resistance or capacity and not upon their niagnetioqualities.

A magnetic ore particle having. an alternating current magnetic fiuxi passing through it"will respond with a counterflux either in 1 e with the current that energizes it, or iagging behindthc current at that ore particle. The ore particle will be Filfiuenced by several quick or sluggish dependent upon the fremoney that energizes it and ii its responsive frequency is lower than the frequency that energizes it then it will lag to the alternating magnetic attraction.

If an ore particles res onsive frequency is faster than that of anot er ore particle it can be separated from such other ore particle by the fact of it responding to' magnetic attraction away from the reluctant particle. If one ore particle has magnetic permeability and another one has minus magnetic permeability but is metallic, then the one particle is attracted and the other one is repelled, and both can be separated from a gangue material which is neutral to electrical or magnetic action.

I have now described the actiizu' minerals and metals influenced by an tiielllating magnetic flux, and will now describe them and their action when they are in alternating currents spaced apart, but acting as a whole, and known to the art as multi-phase alternating; currents.

Reference will be made to the attached drawings which describe the positions of currents and magnetism at various instances, together with mechanical devices to take advantage of the phenomena for the useful purpose of separating minerals one from the other as will hereinafter be clearly described.

Three phase alternating current is used to describe this case as it is most convenient for this purpose, but it is to be understood that any multi phase current answers equally well when suitable electrical connections and arrangements are provided.

Figure l is a sine Wave diagram of three phase alternating current.

Fig. 2 is a diagram combining the three phases to form one magnetizing current.

Fig. 3 shows the diamond shaped overlapping coils of the field magnets where one side of the coil is in the top of one slot of the field magnet, and the other side of the coil in the bottom of a further slot to form north and south poles, and also showing the electrical connections suitable for three phase a1ternatingcurrent.

Fig. d shows a section of an armature with its single pole wound coils and elem trical connectiona Fig. 5 is a cross section through the core and coils of Fig. 3 with one side of each coil in the bottom of one slot and the other side in the top of a following slot, also showing instantaneous values of the magnetic field.

6 is a side elevation of. the septa Fig. 7 is a central vertical elevation 01 RAG alternating current magnetic feed hopper. Fig. 8 is a i'ra mentary view oii the feed hopper looking down at the magnets that wearer ,A multi-phase current is a rotating or a progressing current, that is, one current follows another spaced a definite distance apart, as for instance as shown 111 Fig. 1

which illustrates a sine wave three phase alternating current where each of the three alternating currents, a, b and a differ in phase by one third of a cycle or 120 electrical degrees. lBy reversing the direction of the current. in the coils of one phase, .7) for example, from the direction or that in the other two phases these three currents are combined to form one magnetizing current and a rotating magnetic field such as that shown in curve (Z of Fig. 2 will result.

10 is a field magnet built of thin sheets of iron bolted together and arranged with teeth and slots as shown, and A, B and {l are properly connected coils placed on the teeth or in the slots as shown in Figs. 3 and l, the electrical connections to the coils being so arranged that the first coil A is nected to a phase lead, the second coil B is connected to I; phase lead and the third coil C to 0 phase lead forming a rotating or progressing magnetic field. Permeable ore particles are attracted to the poles or teeth and are caused to progress with the rotati field to a discharge by no other mechanical means than the rapidly moving magnetic field, while minus permeable metallic particles are repelled from the advancing field.

This can best be described by referring to Fig. 5 which shows a cross section cut through the core and coils of field magnet, Fig. 3, with one side of each coil in bottom of slots 11,12 and 13, an'dlnarlred A, B, and C, and their other sides in the top oi? slots l4, l5 and 16, and marked A, B, and. C, respectively. By means of Fig 2 and Fig. 5 taken together it is possible to build up small pictures the magnetic held from instant to instant and show how it moves in the core and air gap.

These small pictures, of which one is shown in Fig. 5, can very well he mom pared to the individual small pictures or". a moving picture him as they appear Wh A re film is at rest, and the rotating magnetic [ielcl as it really exists could be compared to the same film when in motion and thrown on the screen.

A current is ics ier;

ire

' ferent positions.

iceavsx +0.5 since they are half their maximum value and are also above the reference line XX.. Similarly, the titre represented by the vertical line 2 winch is called position 2 in 2 the values oi? a and h are +0666 and the 0 curve at zero. The value 0.866 is obtained because the current curves ai'call What known as sine curves and the reference points or positions 1, 2, 3,

etc. are taken of a complete cycle apart. A complete cycle is 360 el: t icul degrees similar to the degrees of a circle, and hence the reference positions l, 2, 3, etc, are of 36!) degrees or 30 degrees apart.

From a table of natural sines, it will be found that the sine of 30:O.5, sine of :O.8*36, sine of :1, sine of 0.866, sine of :(L5, sine of Continuing from 180 toBSO the same values recur with (1 except that they have a minus sign since they are measured below the horizontal reference line. It these values which are used in plotting thepictures in Fig. 5 and the values for the dif- Starting from any arbitrary point as at a: Fig, 5, position 1, the line moves in direction and. amoun according to the value of the current in slotli. Slot 11 contains the coil and the value of the current is +0.5 is shown. by the vertical line position one, in Diagram 2 since thedirection of the plus up, the line is drawn upward. from a; to e and cf is drawn horizontally representmg by its height aboverc the current in'slot 11, and the magnetic field at that point. From 7' the line goes up to 9 making fg twice as long as de because the B coil is in slot 12 and the value of the current in'B coil is +1, or twice that in A, and the line h is drawn horizontally, representing by its height above as the current in slot 11 plus slot 12 and therefore the magnetic field at that point. From h the line goes up to 2' because the G coil is in slot 13 and the current in the (E coil as shown at that instant is +0.5. The line if is drawn horizontally-representing its height above 02 the combined mirrcnts in. slots .11 plus slot 12 plus; slot l3 and therefore the magnetic field at that point.

From j the line drops down to because the A conductor in slot 14 and the A conductor is the other side of the A coil and hence the current in. it is in. the opposite direction of that of the A side. If the current in the A side was considered +0.5, the current in the A side must be +0.5 and, hence the curve drops down for a minus value from j to k. Similarly it drops twice as far from Z to equals +1 and I therefore the other side of ll (501i or B must equal -l. -l ollowing the curve in this manner to n and 0, it completes one cycle of one north and south pole. The

m since B- l. by the vertical arrow not have such sharp curves but would be" smoothed out into practically a sine curve such as the current in Fig. 2, but lor the purpose of illustrating the rotating licld the curves are to he considered square shouldered as shown.

Seven positions of the three areshown in Fig. 5 and it will be. noted that the center of the north and corresponding south poles have traveled three slots to the I left which in this case means 189 electrical degrees. 7 lt Will now be seen that it a magnetic permeable substance be introduced into the, rotating magnetic field,

influence of this the substance will be attracted to the'teeth or poles and will then advance or with, and in the direction olvthe progrcs:

ing or rotating magnetic field at a speed dependent on the frequency of the electr c current energizing the magnetic field.

f a non-magnetic, stance, such as copper, silver, zinc, etc. be

electric currents will be induced into them by the action of the alternating magneticflux, and according to Lenzs la Since the magnet is a fixed ho ly but the currents Within are moving the magnetic acted upon are free to move. pelled away from the teeth ing magnetic field at a speed dependent on the frequency of the magnetic current.

Types of separators suitable substances from a gangue material, from another by the ternatmg currents-f wlllunow be described,

I S v 1 l with a i'urthcr description of the ores and 7 connection :with

method of treatment -,in such separators.

Reference will now be had On the inner sides of the frame 20 are bra ckets ill on which rests to Fi a brackets. Suspended rigidly blocked gto it by U-bo'lts 23 and comprising. a part of it, is a field ma securely to form aud radiation of heat and are more clearly shown in Figs. 7 and dercd as that part abovel l. The center of the tor of the south pole, pointing down... In

phase current progressy but a metallic sub-, ,1 aluminum 9. introduced into the influence of this alternating rotating magnetic field,

to the scpara-H tion of magnetic or non-magnetic metallic or one use oi? multiphase ali l shaft 22 'which gis free to turn on I from the shaft but y is a frame work 2% vl Vith n the frumcfwork, -lie net 25 which is composed 01 many sheet are s urred apart to l ture and the field magnet.

8. The units are all bolted .to ether to form a single field magnet. The old magnet 25.ha-s many teeth that form poles 27 and slots 28 to acconnnodate the windings or coils. For the sake of clearness the windings are not shown in Fig.- (3, but are shown in Figs. 3, 4 and Adjustably spaced below field magnet 25 and resting in the frame 20 on adjusting bolts 29 is an armature 30. The armature is a duplicate in construction of field magnet 25 with the exception as to length, it being shorter to permit the free discharge of ore concentrates. Across the base 31 of armature 30 and securely bolted to it is an angle bar32. Holes are bored in angle 32 to accommodate the adjusting bolt 33 to slip through up to its head. At its other end 34 bolt 33 is threaded and passes through frame work 2% and is so arranged that by turning adjusting nut 36 the armature will slip forward or backward in the frame parallel with field magnet 25 permitting the proper adjustment with magnetic relation between the teeth or poles of the arma- By turning adjusting bolts 29 the armature 50 1nay be adjusted closer to or farther from field magnet 25, thus changing. the air gap between them.

Adjustably hung below the field magnet 25 and supported from the frame 24: by adjusting hanger bolts 37 is a board l0 composed of a non magnetic andnon-metallic substance such as glass, wood or any suitable insulating composition. This board has two functions, one to keep the ore concentrate a proper distance from the pole teeth in the. air gap, and second to provide a surface on the under side of which the ore concentrate follows the rotating magnetic field to a point of concentrate discharge.

Attached to the lower end of board to is a wedge shaped section all or the board can be bent or shaped at its lower end to conform. When the ore concentrate arrives at this section in its progression with the rotating magnetic field, it is forced to move farther away from the pole teeth and as the current at this section is weakened, the ore will freely drop away from the field to its discharge, being guided by the adjustableplatfonm 42.

Directly above armature 30 and adjustably hung from the frame' 24 by adjustable hanger bolts 3'7 is an ore feed distributing board 45. The functions of this board are to receive the ore to be treated or separated at its top, supporting the gangue material as it slides by gravity to its bottom discharge and supporting the ore at its proper distance between the field and armature in the air gap. This board' can be independently adjusted toward or further away from the armature or field. The armature can also be independently adjusted toward or further away from the feed board by adjusting bolts 29. Fastened to the upper part of magnet frame 2i is an adjusting bolt 46 having an eye 4:? at one end through which a bolt 48 passesthat holds it to frame 24 in such a. way that it is free to turn, while the other end is threaded, and has a nut 49 and washer 50 This bolt passes through a hole in the projection 51 on frame 20 and is arranged so that by screwing the nut in one direction or the other the magnet frame 24 together with its enclosed members can be tilted on an angle to permit the free flow of ore by gravity down and over the feed board 45.

-M'ounted within the frame 20 at its top is an alternating current magnetic hopper 50 best shown. in Figs. 7, 8 and 9. The hopper is so arranged that it will discharge its granular ore feed to the top of feed board 40. The hopper is actuated in such a way to prevent fine ores or granular materials from packing or arching, and permits an accurate and granular feed to, pass under its gates even under severe conditlons such as moisture in the feeding materials that tend to agglomerate and stick the feed materials in lumps, balls, etc. The ore or other feed material rests on the angular base 52 of the hopper box as shown- On each side and projecting from the lower part of the hopper are angle bars 53 which are reinforcement for the sides and support the bottom and the following mechanism.'

In the bottom of the hopper is an iron plate 55 which acts as a lining and in turn projects over a vibrating spring 1 steel diaphragm 56. This dia hragm rests on and is fastened to corner. locks 57 in such a way that it is free to vibrate, and the blocks in turn are rigidly fastened to the inner legs of angles 58. Adjustable but securely hung from angle bars 53 by threaded stud bolts 58 is an alternating cur rent magnet ($0 composed of laminated iron punchings forming poles for the coils which energizes it. The coils can have either single phase or multi-phase alternating current to energize them, but as it is always possible to use single phase from a multiphase circuit, single phase is preferred. The alternating current magnet is directly under the diaphragm and is adjustable to or away from it by the nuts 59 on the stud bolts 58. switched on the windings or coils the diaphragm is attracted to the magnet and released from it by the action of the alternating current changing from positive to negatlve and violently vibrates it according hen the alternating current is to the frequency'of the current that enerf gizcs the magnet. When the magnet (30 is. adjusted toward. or away from the l kir- .rial, thus preventing diaphragm 56 the vibrations are stronger opper. On thcpart inside, the orcor other feedrests upon the diaphragm while'the outside section guides the feed to the dis charge. The action is as follows: The hopper is filled with the granular ore or other material to, be fed which rests partly on the bottom plate and the diaphragm 56. The gate 62 is raised to permit a sufii cient'feed to pass under, between it and the diaphragm 56 and sidewalls. The current is switched on and the diaphragm violently' vibrates.

This vibration not only passes through the material resting 'on the diaphragin but also to the surrounding matepacking and arching, and at the gate itself.- The material no matter how finely ground will be violently agitated and will pass under the gate whether in a thin granular ribbon or in a thick stream. Afterpassing'thc gatethe discharge is still kept in granular shape and in motion by the outward extending portion of the diaphragm 56.

' The field magnet alone may be used as a separator, and may be placed above or below an ore feed board, or by proper electrical connections the armature andfield'can be considered as one certain poles in the field, fer-instance, every other one, will be field poles for like adjacent poles in the armatureand the follow mg poles be armature poles to like field f poles in the armature. That is, the susceptible ore particles following the rotating field will first jump up to a field magnet tooth or pole and then down to the next armature tooth or pole, which is changed to a field tooth or pole, and then up, and so on to a discharge as would be the case in Fig. 6 if single pole coils were 'used as shown in section in Fig. 4, the first tooth" in the field magnet having an A coil, the

second toothih the armature having. a B coil, the third tooth inthe field having a C coil. the fourth tooth in the armature havingan A coil, etc, all the coils being properly connected together in proper phase re- .lation while the coils on the teeth between can have their coils short circuited, thus forming armature teeth or poles for either section. The object of the armature is merely to intensify or concentrate the magnetic field to improve the power factor and further to increase the distance in which ore is susceptible to the field influence.

, that can be used substances as they and arranged so that alternates back and forth across the air the armature The field magnet 25 has coils and is connected as shown in section Fig. 3, while the armature 30 has single pole coils and is are connected three" can be used on either armature or field to meet different conditions in' the ore to be separated, as each type'has peculiar features advantageously in various ways.

In the following description I describe the diamond overlapping coil on the field";

and the single pole COIlOll the armature, this being the preferable construction. Now

consider that ath'ree phase alternating cur-' rent has been switched on the field magnet and 'currentiis flowing in all the'coils A, B and C, etc. An adjustable resistance or an coils of the-field'magnet to taper their imagnetic impedance is used on the lastfew strength in such a way that each following tooth or pole is weaker in magnetic strength 9 is done to perthan the one before it. This mit magnetic susceptible ore particles to be released and sary in the i to drop away from the rotatQ 111g o1- rogressing field. This is not' neces caseof non-magnetic metallic are repelled by'and away from the rotatingfield, while the magnetic i substances are attracted to and advancefwith the rotating field.

No provisions have as the connection of the terminal wires leading rom the armature poles of the. armature have their terminals short-'cir-' cuited or closed. Current is now flowing in all the teeth OIf'pOleS' are energized witha rotatln magnetic field all the field coils and D for diagrams Fig. 5.

as was-described Magnetic fiux is now flowing through the field. magnet out the tips of the poles or teeth and across the teeth through the armature, back through the teeth and. air gap to the field poles on teeth again. This sets up a strong magnetic" field in the armature teeth by induction" of the field,

which rotates in step with that magnetism that energizes alternating,

it. The current is therefore the magnetic flux p at a speed equal to the frequency and the poles or'teet reverse their polarity chang.

ing from north to south and back to north again very rapidly, as for instance in 60,

yet been made for with the exception that the coils on the last three teeth or air gap to the armature 10f both the field magnet and cycle current they would change polarity 7200 times per minute.

When the coils on the armature are open eircuited no current flows through them. The armature iron is magnetized by the field flux flowing through it. Magnetic permeable particles have a tendency to bridge between the armature poles and the field poles, even though they are spinning in step with the frequency.

When the armature coils are closed circuited as shown inthe last three coils of Fig. 4., current flows in them causing a counterfiux to be set up in the armature which opposes the field flux that energizes it, thus causing the permeable ore particles to be repelled. in the direction of the field poles as they travel with'the rotating field.

Since non-magnetic metallic substances are repelled away from the magnetic field in any case, it makes little difference whether the armature coils are open or closed tor non-magnetic metallic substances. By 1ntermittently opening and closing the arma ture coils permeable ore particles are caused to jumpup and down violently during their progression, as well as to spin thus free ng themselves from the gangue material which tends to adhere to them.

It will now be considered that all the armature coils are closed circuited and thatv the field magnets are tilted to such an angle that ore will freely flow down the feeder board in the air gap between the field and armature, to a discharge.

It is to be noted that there are nomoving parts on this type of separator and that all ore moves by gravity alone or is forced to travel with or againstgravity by the rotating magnetic field.

The gate of the hopper is now opened and a granular stream of ore permitted to flow to the feeder board 45. v The gangue material which is non-metallic and is not affected by the alternating current flux, flows down the feeder board to its discharge at the bottom.

The permeable magnetic particles on em tering the field even though they are as fine as dust, have natural polarity and will start to spin rapidly when the alternating flux passes through them trying to present their Cir l poles in proper relation to the lines of force, I thus freeing themselves from gangue material, and one from the other. They are also repelled from the armature poles and in the direction of the field poles and they are influenced to" travel with the rotating magnetic field. They travel down on the I under side of spacer board 40 at great speed.

much faster than'the gangue that is flowing by gravity on the feeder board 4.5. l/Vhen they reach the bottom of the spacer board it) they are forced away from it by the wearer to the magnetic material traveling with the.

rotating field. In such a case-itis arranged that the armature coils be intermittently opened and closed, which causes the ore particles to violently jump up and down between armature and field as Well as spin while they are traveling to their discharge with the rotating field currents, as the armature is first attractive when the coils are opened and then repellant when the coils are closed.

What I claim is:

1. The art of electrically separating magnetically permeable particles from gangue which consists in passing a mixture of particles and gangue between a progressive guillti-phase magnetic field and an induced 2. The art of electrically separating magnetically permeable particles from gangue which consists in passing a mixture of particles and gangue between two progressive multi-phase fields.

3. The art of electrically separating magnetically permeable particles from gangue which consists in passing a mixture ofparticles and gangue between two progressive multi-phase fields,-the current in one of said fields being induced by-the current in the otherfield.

4:. The art of separating magnetic particles from gangue which consists in passing the mixture of particles and gangue across a multi-phase progressive field which moves with the path. of the mixture, in increasing the frequency of said field until maximum movement of the particles is secured, and in continuing the current in the field at said maximum responsive frequency.

5..The art of separating non-magnetic metallic substances from magnetic substances and from gangue which consists in passing the mixture over a relatively thin inclined non-magnetic surface under which is-placed an electromagnet excited by a multi-phase alternating current so that the rotating or progressive field moves with the passage of the mixture down said inclined surface.

6. The art of separating magnetic ore particles from gangue which consists in passing a mixture of gangue and particles between a multi-pole electromagnet and an armature, said magnet having a multi-phase progressive magnetic field moving parallel particles and gang'ue through the margin only of a progressive field moving in the a direction of material flow.

9. The art of electrically separating magnetically permeable particles from gangue which consists in passing the mixture of particles and gangue through the curved portions only of the lines of force of a progressive field moving in the direction of material-flow. v

10. The art of electrically separating magnetically permeable particles from gangue which consists in passing the mixture of particles and gangue between two progressive fields moving in the direction of the flow of the material while restraining said mixture from crossing the straight and nearly straight portions of the lines of force of each oi said fields;

11. The art of electrically separating magnetically permeable particles from gangue which consists in passing the mixture of particles and gangue between two insulating surfaces, each spaced from a progressive field whereby the mixture is constrained to move in the region of thecurved lines of force of each field.

12. The art of electrically separating magnetically permeable particles from gangue which consists in passing the mixture of particles and gangue along. a nonmetallic surface spacedfrom a progressive field whereby the mixture is caused to move in the margin only of said field.

13. In a separator, an electro-magnetcore having parallel teeth, windings for said teeth, multi-phase alternating current for energizing said, coils to produce a moving magnetic field, and a non-magnetic plate below the toothed pole faces and providing a guiding surface for the material being separated.

14. The device of claim 13, characterized by the plate being adjustable toward andaway from the magnet.

15. The device of claim 13v in combination with an armature for the magnet. I

JOSEPH WEATHERBY.

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