US2356463A - Magnetic separator - Google Patents

Description

Aug. 22, 1944.

R. ,1. LINNEY MAGNETIC SEPARATOR Filed Nov. 14,1942

- 3 Sheets-Sheet l 7 INVENTOR. P035787 J." z/AWA'Y A I'm/Pm; rs

Aug. 22, 1944. R. J. LINNEY MAGNETIC SEPARATOR Filed Nov. 14, 1942 3 Sheets-Sheet 3 iii A ra/P/vsys Patented Aug. 22, 1944 MAGNETIC SEPARATOR Robert J. Linney, Port Henry, n'. Y. 7 Application November 14, 1942',"Serial No. 465,550

' 13 Claims. (Cl. 209-225) This invention relates to material separating apparatus and more particularly to an improved form of magnetic separator for concentrating iron ore or other magnetic materials.

Iron ore, as mined,c ommonly contains substantial quantities of impurities and waste matter. To separate such materials magnetic separators have been devised and use in which an endless belt is moved through a magnetic field and a mixture of ore and impurities discharged against the belt which passes through a tank of water whereby certain waste matter and impurities are removed.

The present invention relates to improvements in magnetic separators of the belt type, and it is among the objects of my invention to provide a magnetic seperator which will give an increased output as compared to prior devices and which will deliver a high grade of concentrates with an extremely low iron loss in the tailings.

Other objects of my invention include: the provision of means for causing all of the cleaning water to flow in one direction counter to the movement of the magnetic material; the pro- Figure 7 is a cross-sectional view taken on line '|-'lofFlg.6;

Figure 8 is a fragmentary sectional view taken on line 8-8 of Fig. 7; and, r

' Figure '9 isan enlarged view showing the relative positions of the magnets and thetransverse spray pipes of Fig. -1. I

In certain 1 previous wet magnetic separators with which I amfamiliar the belt is submerged 10in a bath of water. 'With this type of equipment the 'level' of water in the bath must be maintained at the proper point at all times. This requires constant attention, Further, in the submerged type of wet separator, substantial quantities of the floating waste and soluble materials,

such as phosphorous colloid, are carried over into the concentrate. with 'my apparatus, however, any such material is instantly washed away by clean water, and the concentrate are delivered substantially entirely free fromsuch impurities.

As is best-seen in Figure 1, my improved separator' includes an endless belt I," supported on' I a suitable sheavesor pulleys 2 and-3.. Mounted on the shaft 4 0f the pulley! is a" drive pulley 5 envision of -a separator in whichthe belt is never gaged by the "driving belt 6 which-may extend submerged and which therefore eliminates the necessity of providing a water-tight box for enclosing the electro-magnets which create the magnetic field; the provision of a separator in which the material being handled is subjected to a series of separate washings with clean water; and the provision of'a magnetic separator in which the delivered concentrates are substantially free from soluble impurities.

The above andother objects of my invention will appear from the following description of one embodiment thereof, reference being had to the accompanying drawings in which:

Figure l is a somewhat diagrammatic vertical,

longitudinal, sectional view through a magnetic 40 separator embodying my'invention.

Figure2 is a fragmentary enlarged view, generally similar to Figure 1, but showing only the feed inlet and parts adjacent thereto.

Figure 3.i a transverse cross-sectional view taken substantially 'on line 3-3 of Figure 1.

Fi ure 4 is a transverse cross-sectional view taken approximately on line 4-4 of Figure 1.

Figure 5 is a side-elevational view of a mag- 30 I which also'supports the tailings hopper 8. Supporting members-9.10 and carry the generally inclined collecting apparatus which in- V 'cludes concentrates hopper l2 andspaced hoppers. I3 and I4 for tails or middlings, The shaft 4 and pulleys 3, and 5 are mounted on theupper part of the supporting structure. Trough forming side walls l5 and I6 (Figure 3) are disposed on either side 'oithe lower reach-of thebelt l and are connected to'the launder plates 28, 29

and 30 as later'described.

Transverse beams I! extend across between the upper portion" of the supporting framework for the separator and carry a housing structure I 8 on the bottom of which are mounted a plurality of electro-magnets l9. Spaced belt; engaging bars 20, preferably made of wood, are secured to the bottom of the magnet housing 18 and are arranged to engage the lower reach of.

netic separator embodying the present invention 50, at the lower part of the'concentrator, is conand including structural features additional to those shown in Figs. 1 to 4;

Figure 6 is an enlarged fragmentary end-elevational view of a part of the feeding mechanism of Fig. 5;

In like mannerthe upper group of magnets is connected through conductors 24 and switch 25 to a supply .line 26 and a variable resistance 21 is employed to modify the magnetic effect as desired.

Below the bottom surface of the belt I is a trough consisting of a seriesof inclined launder plates 23, 23 and 30 composed of non-magnetic material. These plates are spaced closely adja cent to the bottom side of the belt I and are preferably mounted for adjustment toward and away from the belt in any suitable manner (not shown). The lower end of the top launder plate 23 i bent slightly downwardly at 28 to provide an outlet 28" for water and non-magnetic materials. In like manner the lower end of the center launder plate 23 is curved downwardly at 23 providing an outlet 29" between it and the upper end of thebottom launder plate 30. The

launder plates are connected at their side edges to the lower edges of the inclined trough side members 4 5 and l i.

The discharge from thelower end of the launis provided with an outletpipe 3| for removing the tailings to a suitable place ofdlsposal. In like manner the opening 285' discharges into the hopper I3 having an outletpipe 32 and the open ing 29f.;discharges into the hopper H which has anoutlet pipe 33. r a

. Material to be treated, consisting of a mixture of magnetic and non-magnetic materials and water, is fed through a supply pipe 34 into the feed hopper 35. As seen in Figure 3 this feed hopper 35 extends across the full width of the belt l and feeds the material up against the under-side of the belt. A transversely extend- The magnetic field from the magnets It causes any magnetic material in the mixture to be drawn up against the under-side of the belt which moves, upwardly from left to right in ,Figure 1 and carries with it the magnetic material.

der plate30 is into the tailings hopper 8 which into the hopper l3 will be either tailings or middlings, depending upon the sizeof material being treated by the separator. The water from the spray jets 33 and 40 flows downwardly by gravity in a direction opposite to the movement of the belt I and the magnetic material which is adhered to the belt. As the belt moves upwardly beyond the upper magnet IS the magnetic influence on the material ceases and the mag.- netic concentrates drop into the hopper I! which is provided with an outlet pipe 4]. A spray pipe 42, extending across the width of the belt and provided with a plurality of spray nozzles in a manner similar to pipes 36, 31, etc., is disposed adjacent the pulley 3 and washes any adhering concentrate material from the belt.

By inclining the belt I throughout its entire length, disposing a series of launder plates adjacent the bottom inclined surface of the belt, and

directing a series of spaced clean water sprays against the material on the belt a plurality of separate cleaning operations are effected upon the material whichis fed through the supply pipe 34. All possibility of contaminated water being discharged with the concentrates is eliminated due to the fact that the fi'owpf washing water is all downwardly counter to the movement of thebelt and material being handled. It will be understood that all parts of the hoppers, sprays, pipes, etc., which come within the magneticfleld of the magnets is are preferably made ofnon-magnetic material such as brass or bronze. The major part of the water which is used in V separating the material is discharged into the Clean water fed through the pipe 38 flushes a substantial part of the non-magnetic waste materials down overthe'launder plate 30 into the.

tailings hopper 8 and the belt, due to its upwardmovement, carriesthe magnetic material, together with foreign'material which; has not been eliminated, upwardly over the next launder. plate 23. Spray pipes 31 and 38, similar to the pipe '36 and similarly provided; with a series of spray outlets, are mounted in the launder plate 28 with their outlets substantially flush with this downward movement the cleanwater from the sprays 3| and 38 washes additional nonmagnetic material from the belt. This material is discharged through the opening 29" into the hopper H, and some may alsovpass on down over the launder plate 30 into the hopper 8. It will be understood that, if any magnetic material is washed fromthe belt itwill be again picked up against the'belt by the action of the magnetic field before it can drop into the tailings hopper.

Thelaunder plate 28 is also supplied with spray pipes- 39 and 40 and these function in the same manner as those previously described. The maiterial discharge through the slot opening 25'.

tailings and this results in a high quality concentrate output. As any magnetic particles which may be washed oif from the belt, after having once been adhered thereto, will flow downwardly with the water in the spacebetween the launder plates and the belt inclose proximity to the belt a large percentage of such particles will again be picked up by the belt and the ,the lower and upper portions of the belt will be regulated to give the most efficient separating results and'the speed of the belt will be correlated with the feed through the supply pipe 34 and the water discharge through the cleaning jets.

' The apparatus of Fig. 5 is quite similar to the apparatus of Figs. 1 to 4. The belt I passes around idler pulley 2 and drive pulley 3, the latdlings hoppers l3 and Il may be disposed between hoppers l and i2 and'below passages 29a.

'thru which material may be discharged from the trough. If desired, these hoppers l3'and H may discharge into a catch pan l5a'or the hop- 7 per may be omitted or the two hoppers combined into one large hopper;

When a two-part separation is desired, namely, concentrates and combinedtailings and middlings, the material 'passingthru the openings 29a may be collected in hopper I. When a threepart separation is desired, the middlings passing thru openings 29a are collected in hoppers I3 and l4 or a hopper substituted for those hoppers.

Beneath the lower reach of the beltis disposed a trough A composed of non-magnetic material shown in Figs. 1 to 3 is disposed closely adjacent V to the upper surfaceof the lower reach of the belt I and encloses a plurality of magnets l9a so that liquid in the troughmay not have free access to the magnets.

Pipes 34a serve to convey a mixture of water and material to be separated to opposite ends of feed box 35a which is disposed under thelower reach oi the belt I and some little distance from the lower or tailings discharge end of the trough A. This feed box, as is better shown in Figs"? and 8, is generally rectangular in' cross-section and is open at the top for its full width and for a length which is somewhat less than the width of the belt I. Within the feed box 35a are disposed two opposed feed-distributing; nozzles 40. and a feed diluting pipe 4| having outlets in its upper surface. Y

It will be understood that whena mixture of water and ore, consisting of magnetic and non-' magnetic materials, is delivered thru pipes 340 into opposite endsof the feed box 35a, the mixture will fill the feed box and flow-thru the open upper end thereof into th trough A where the water will be free to flow downwardly in the trough, carrying with it non-magnetic materials,

and the magnetic particles may be attracted to and carried upwardly in the trough bythe belt. In order that the mixture in the feed box may be distributed properly into the; trough, valves (not shown) are employed to regulate the flow of water thru nozzles 40. When the flow of liquid thru the opposed nozzles 40 is equal, the solids will be prevented from settling to the bottom of the box and also the mixture will feed up into the trough and into contact/with the belt more or less equally thruout the full length of the top opening of the feed box. When more liquid is admitted thru one nozzle 40 than thru the other, settling out of solids will be prevented andralso a greater amount of mixture may be fed against one'part of the belt than against another part. In this manner the mixture will be kept quite uniform and th amount of mixture that is fed from the feed box against different parts of the belt may be regulated as desired.

location of the .feed box has been found to be responsible, at least in part, .for a considerable reductionin the percentage of magnetic particles which previously were collected in the tailings hopper. I

In Fig. 9 is shown a modificationof the spray apparatus of Figs. 1 to 3. The header pipe 42 which extendsvalong one side of trough A- opens into pipes 43 which extend from header pipe 42 across the trough A and have openings in their top surface to discharge water upwardly in .the

trough against the lower surface of the belt.

These pipes 43 correspond to pipes 31, 38, 39 and 40 of Fig. 1', but are purposely positioned beneath the centers of superimposed magnets l9a. In other words, water discharged from pipes 43 will impinge against the belt in line with the central portions of the ends of the super-imposed magnets.

One purpose of this location of these parts is to release non-magnetic material which may have been entrapped by magnetic material and thereby carried alongby the belts; Since th transverse rows of magnetsare alternately of opp site polarity, the weakest points in the magnetic fields are on transverse lines passing thru the cen- 'ters of the ends of the transverse rows of .mag-

non-magnetic pieces. 35.

nets. When water is sprayed toward these points of lowest magnetic force, it tends to disturb solid particles held against the belt by the magnets. When a plurality of pieces of magnetic material are attracted to the belt by a part of the strong magnetic field, those pieces may carry with them When water is sprayed against that collection of magnetic and nonmagnetic pieces in the weaker parts of the magnetic .field, the piecesof material may beshifted about on the belt or may even be dislodged there- -i'rom. In this manner the non-magnetic pieces are permitted to escape from a position where they were entrapped by the magnetic-particles and may thus be washed .down along the trough by the stream of water flowing therein while the magnetic pieces ar ag ain attracted to and carried along by the belt. As-a result of positioning the spray pipes 43, as has just been described, the

, amount of non-magnetic material which is carried into the concentrates hopper is considerably The liquid discharged thru pipe 4| serves to agi- V up by the belt before the particles can escape f from the lower end of the trough. This relative ried'into the concentrates hopper is considerably reduced. v

Another advantage of the'present invention is that the amount of phosphorous which is carreduced over prior practice. This advantage is traceable to the fact that substantially all the water discharged into the trough escapes into the tailings or middlings hoppers and very little 9! it is discharged into the concentrates hopper and suchof that water as does reach the concentrates hopper is clear and clean because of the repeated washings to which the ore has been subjected in the lower parts of the trough; and to the further fact that there is very little dirt or soluble material left on thebelt when it reaches the topmost pipe43. I

'This application is a continuation-in-part of my copending application Ser. No. 365,659, filed on or-aboutNovember14, 1940.

Although I have described theillustrated embodiment of my invention in considerable detail, it will be understood by those skilled in the art that the drawings are somewhat schematic and that numerous variations and modifications can "be made without departing from the spirit of my invention. I do not, therefore, wish to be limited to the particular apparatus shown and described but claim as my invention all forms thereof coming within the scope of the appended claims.

What is claimed is:

1. A magnetic separator comprisingan inclined trough having a bottom provided with an opening therethru between the ends thereof, a hopper disposed below said trough to receive material passing through the opening," an endless belt having an inclined lower reach movable upwardly adjacent to the bottom of said trough, electromagnets disposed along and adjacent to the top surface of said reach of said belt, means to discharge liquid against the lower'surface of said reach of the beltat elevations above said opening, and means to deliver materials into the trough near the lower end thereof.

lower reach inclined upwardly, and for driving said belt whereby said inclined portion moves upwardly, a plurality of launder plates below said inclined portion of said belt and spaced therefrom, a plurality of outlet openings between said plates and spaced along the length of said belt, a plurality of spaced water supply means for discharging water into the space between said plate and belt and against the-lower surface of said belt, electro-magnetic means above said inclined portion of said belt for attracting magnetic material to said belt, means disposed between the ends of the lowermost launder plate for discharging material to be separated into the space between said plate and belt, hoppers below said plates positioned to receive and segregate the discharge from said spaced discharge openings, and a concentrates hopper below the upper end of the uppermost plate and extending beyond the upper end of said electro-magnetic means.

3. A magnetic separator comprising an inclined trough having a bottom provided with openings therethru at different elevations, hoppers disposed below said trough to receive material passing therethrough, an endless belt having an inclined lower reach movable upwardly adjacent to the bottom of said trough, electromagnets disposed along and adjacent to thetop surface of said reach of said belt, means to discharge liquid against the lower surface of said reach of the belt at elevations above said openings, and means to deliver materials into the trough near the lower end thereof.

4. 'A magnetic separator comprising an inclined trough having a bottom providedwith openings therethru at different elevations, hoppers beneath said openings to receive material discharged therethru, other hoppers beneath the upper and lower ends of said bottom to'receive material passing thereover, an endless belt having an inclined lower reach movable upwardly in and adjacent to the bottom of said trough, electromagnets disposed along and adjacent to the top surface of said reach of said belt, means to discharge liquid against the lower surface of said clined reach movable upwardly in and adjacent.

to the bottom of said trough, electromagnets disposed along and adjacent to the top surface of said reach of said belt, means to discharge liquid thru said trough bottom against the lower surface of said reach of the 'belt at elevations above each of said openings, and means to deliver materials into the trough thru the lower part of said bottom.

6. A magnetic separator comprising an inclined trough having a bottom formed by a plurality of plates spaced apart to provide openings therebetween at different elevations, hoppers beneath said openings to receive material discharged therethru, other hoppers beneath the upper and lower ends of said bottom to receive material passing thereover, an endless belt having an inclined lower reach movable upwardly in and adjacent to the bottom of said trough, electromagnets disposed along and adjacent to the top surface of said reach of said belt, means to discharge liquid against the lower surface of said reach of the belt near the upper end of each plate, and means to deliver materials to be separated into the trough near the lower end thereof.

7. A magneticseparator comprising an endless belt having an inclined lower reach, means to drive said reach of the belt upwardly, a plurality of electromagnets adjacent to the upper surface of said reach of the belt, a plurality of inclined launder platesdisposed adjacent and substantially parallel to the lower surface of said reach, said plates being spaced apart from each other to provde openings at their lower ends for the discharge of materials therethru, hoppers beneath said openings to receive materials discharged therethru, a hopper beneath the lower end of the lowermost plate to receive material discharged over said end of said plate, a hopper below theupper end of the uppermost plate to receive material I ing liquid into the space between each of said plates and the opposed surface of said belt.

8. A magnetic-separator comprising an endless belt having an inclined lower reach movable upwardly, a plurality of electromagnets disposed along and adjacent to the top surface of said reach of said belt, an inclined, open-ended, nonmagnetic trough disposed below said reach of the belt and in the magnetic field ofsaidmagnets, said trough bottom having an opening therethru between its ends, means for feeding an aqueous mixture of magnetic and non-magnetic materials to be separated into said trough near its lower end, and means for discharging liquid into said trough and against the belt at elevations above said opening and opposite the centers of said magnets.

9. A magnetic separator comprising an endless belt having an inclined lower reach movable upwardly, a plurality of electromagnets disposed along and adjacent to the top surface of said reach of said belt, an inclined, open-ended, nonmagnetic trough disposed below said reach of the belt and in the magnetic field ofsaid magnets, said trough bottom having an opening therethru between its ends, means for feeding an aqueous mixture of magnetic and non-magnetic materials to be separated into said trough near its lower end, said feeding means including a feed box positioned below, extending across, and opening at its top into said trough, said box having of said aqueous mixture, and means in said box for controlling the distribution of said mixture into said trough,. and means for discharging liquid into said trough and against the belt and at elevations above said opening.

10. A magnetic separator comprising an endless belt having an inclined lower reach movable upwardly, a plurality of electromagnets disposed along and adjacent to'the top surface of said reach of said belt, an inclined, open-ended, nonmagnetic trough disposed below said reach of the belt and in the magnetic field of said magnets, said trough bottom having an opening therethru between its ends, means for feeding an aqueous mixture of magnetic and non-magnetic materials to be separated into said trough near its lower end, said feeding means including a feed box positioned below, extending across, and opening at its top into said trough, said box having openings at its opposite ends for entry thereinto of said aqueous mixture, and means in said box for controlling the distribution of said mixtureinto said trough, and means for discharging liquid into said trough and against the belt and at elevations above said opening and opposite the centers of said magnets.

11. In a magnetic separator having a movable member for propelling magnetic particles, a plurality of magnets on one side of said member, and confining means on the other side of said member'within the magnetic field of said magnets, said member and confining means defining a space for an aqueous mixture of magnetic and jacent to its bottom for discharging liquid under.

pressure lengthwise of the box to control the distribution of solid particles in the aqueous mixture passing thru the top of said feed box.

- 12. In a magnetic separator having a movable member for propelling magnetic particles, a plu- 'rality of magnets on one side of said member and for feeding an aqueous mixture of magnetic and non-magnetic materials into said space, said feeding means comprising a feed box positioned below said member and opening at the top into said space across a major part of the width of said member, conduits opening into opposite ends of said box for delivering an aqueous mixture of metallic and non-metallic particles into the box, and means extending lengthwise of the box near its bottom for discharging liquid under pressure upwardly in a plurality of-streams to agitate and dilute the aqueous mixture and to promote the feeding of the mixture thru the top of said feed box.

13. In a magnetic separator having a movable member for propelling magnetic particles, a plurality of magnets on one side of said member and confining means on the other side of said member within the magnetic field of said magnets, said member and confining means defining a space'for an aqueous mixture of magnetic and non-magnetic particles to be separated, means for feeding an aqueous mixture of magnetic and non-magnetic materials" into said space, said feeding means comprising a feed box positioned 1 below and extending across said member and opening at,its top into said space across a major part of the'width of said member, conduits opening into opposite ends of said box for delivering an'aqueous mixture of metallic and non-metallic particles into the box, means near each end of said box and adjacent to its bottom for discharging liquid under pressure lengthwise of the

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