US1024539A - Magnetic ore-separator. - Google Patents

Description

J. WEATHBRBY. MAGNETIC ORE SEPARATOR. 7 APPLICATION FILED AUG. 25, 1911.

1,024,539, I Patented Apr. 30, 1912.

Y awe/micro CuLUMBIA PLANOGRAPH CQ..WASHINGTON. D. c.

UNITED STATES PATENT OFFICE.

JOSEPH WEATHERBY, OF NEW CUMBERLAND, PENNSYLVANIA, ASSIGN OR TO- ANDREW J. DULL, OF HARRISBURG, PENNSYLVANIA.

MAGNETIC ORE-SEPARATOR To all whom it may concern:

Be it known that I, JOSEPH WEATHERBY, a citizen of the United States, residing at New Cumberland, in the count-y of Cumberland, State of Pennsylvania, have invented a certain new and useful Improvement in Magnetic Ore-Separators; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the figures and letters of reference marked thereon.

My invention is an improved magnetic ore separator adapted to the separation of ores of a very low magnetic permeability, the separation of which requires a concentrated magnetic field of an extremely dense character.

Permeable particles are attracted in a concentrated field to the densest area of the poles, as for illustration: If permeable ore particles are placed between two poles of a magnet of equal facial area the various ore particles will be attracted equally to the nearest pole face. If one of the pole faces be chamfered off so as to expose a very small comparative area to its opposed pole, the lines of force will converge to the smaller area where they will be very dense, and all permeable particles will be attracted to the smaller area.

In my invention an extremely concentrated field is formed by an arrangement of two annular pole pieces having frusto-conical faces and narrow annular tips and a centrally located substantially stationary conical armature. The centrally disposed armature at its top and bottom gradually curves away from the pole faces, thus allowing its nearest areas to be located close to the wedgelike pole tips to form a very dense and concentrated field of the lines of force converging from the great armature area to the narrow pole tips.

One of the objects of the invention is to improve the machine of my prior application No. 582,334, filed September 16, 1910, and provide a compact machine having no parts liable to become disarranged or broken, and capable of operating upon and separat- Specification of Letters Patent.

Application filed August 25, 1911.

Patented Apr. 30, 1912. Serial No. 645,958.

ing materials of a very widely different magnetic susceptibility, thus adapting the machine for use in the separation either of magnetite or of practically any of the low grades of ores which do not exist naturally in what would ordinarily be considered a magnetic condition.

The invention contemplates the separation of materials by passing the same through concentrated magnetic fields wherein the lines of magnetic influence pass through the ore particles and converge toward the pole tips and providing means whereby the more susceptible material is advanced and removed from the magnetic influence while the less susceptible materials travel by gravity alone through the successive fields of magnetic influence.

In the practical embodiment of the apparatus for carrying the present invention into practice and adopted for illustrative purposes herein, the magnetic field is produced between annular pole pieces having frusto-conical faces and a centrally located armature; a conical screen rotates at sufficient speed to cause the more susceptible materials to be advanced toward the discharge by centrifugal force, and an internal substantially conical stationary armature which also acts as a guide constitutes the means whereby the materials of less susceptibility are guided to travel by gravity alone down through the annular fields.

The drawing is an elevation with one half in section of a magnetic separator embodying the present improvements.

WVhile any desired form of supporting and adjusting mechanism might be employed, a novel and compact arrangement is shown in the accompanying drawing; that is to say, in a suitable base A there is mounted a series of vertical posts or standards A which, at their upper ends are rigidly connected with lugs b projecting from the outer face of field magnet ring B. The magnetizing coils C are located within cham her 0 opening into the body of the field magnet from the inner conical face.

While the pole pieces may be of different formations, it is preferable that the upper pole piece B be made integral with the field magnet B while the tip 13 of the lower pole piece is separate and in the form of a ring adapted to seat in the under side of the field magnet B after the coils C are properly positioned.

The pole piece B is rigidly held in intimate contact with the body of the field magnet by screws 72*. The inner faces of the pole pieces are of frusto-conical form and are preferably substantially in alinement with each other, their proximate edges forming annular tips of greatly reduced area. Thus constructed, the body of the field magnet, uprights and bases constitute a rigid structure upon which the other parts of the apparatus may be conveniently mounted for proper adjustment and operation.

The arms or legs of the magnet being annular and concentric, one is of greater diameter but longer than the other and in order that the magnetic conductive capacity of the arms or legs may be equal the thickness of the inner arm or leg on radial lines is considerably greater than that of the outer arm or leg, the total cross sectional area of both being however substantially the same.

The hopper E is mounted on the upper ends of the uprights E secured in the upper face of the field magnet B and has a clownwardly projecting centrally disposed discharge spout E on the outside of which is located a feed adjusting sleeve F which is adjusttible vertically by screw thread f. In the base of adjusting sleeve F is a rigidly supported feed pipe f. The regulation and adjustment of adjusting sleeve and pipe will hereinafter be more fully explained.

Suitably mounted and centrally located within the cylindrical central opening of the field magnet B and rigidly held in position at its upper end by supporting ring D and machine screws (Z and (Z is an annular bearing housing D which is in turn machined to support annular ball bearings G and G. Rigidly mounted at the lower end of bearing housing D is a conical shaped oil drip pan H which when full of oil can be pumped out through oil pipe H.

Accurately mounted in the center and supported by the annular ball races of ball bearings G and G is a rotary screen having a long tubelike neck I at its upper end and a hollow coneshaped lower portion I which rotates in close proximity to the frusto-conical faces of the pole pieces. It is rotated through the medium of a belt applied to the double flanged pulley J, rigidly secured to it by threading the outer portion of the neck and the inner flange of the pulley J at J.

It will be noted that the lower belt flange of pulley extends over the top of bearing forced out of alinement when the pulley J is tightly screwed down with its lower flanged portion in contact with the top edge of annular ball bearing G. On the outside and at the junction of the neck I and conical portion of rotary screen I is a shoulder i which is arranged to accurately seat the ball bearing G to take the up thrust while the ball bearing G rigidly held between the lower pulley flange and shoulder ring 2" takes the down thrust.

The radial alinement is taken care of by both ball bearings. Forced over the shoulder 2' is a ring 2' to guide the oil into oil drip pan H. The screen I is of non-magnetic material imperforate and adapted to operate centrifugally in feeding the more susceptible material through and away from the magnetic fields in proximity to the pole pieces.

To prevent the scattering of the magnetic lines of force where they pass from the pole tips of the frusto-conical poles through the rotary screen I to the armature K and also to form a path of least magnetic resistance two lines of headless screws 2' and 2' are provided. The screws extend through the rotary screen, are of magnetic material and spaced close together to prevent the lines of magnetic force spreading to any great extent until they are on the acting side of the rotary screen.

Arranged centrally of the rotating screen I and directly under the feed pipe f is a substantially conical cap or guide 70 over the conical face of which the material from the hopper is caused to travel by gravity into a magnetic field of gradually increasing density. The conical guide is preferably always of non-magnetic material and also acts in conjunction with feed pipe f also of non-magnetic substance, as a feed adjusting gate the adjustment of which will be hereinafter explained. Inasmuch as this guide together with the armature rigidly connected therewith is of some importance, it will be described with particularity, the fact being borne in mind, how ever, that one of the essential features resides in a conical guide having means whereby the material traveling down over the surface may be retarded in its movement so as to check its momentum and preferably means whereby such material will momentarily leave the guide surface as in falling onto a step or shoulder and where the stronger magnetic particles can be more freely acted upon by the magnetic energy and readily disentangle themselves from the lesser magnetic particles and the non-magnetic gangue. Another essential feature resides in the shape of the armature K in its relation to the frusto-conical pole pieces B and B The main body of the conical armature is exactly parallel with the frusto conical faces of the poles to points at right angles with the pole tips, at which points the armature at its top and bottom gradually slopes away, thus causing the ore particles in their downward flow by gravity over the surface of the guide 70 and the armature K to enter a field of gradually increasing density to the point of maximum density thence flow ing in a constantly thinning layer to and over the neutral point on the armature surface, thence through a dense concentrated field of opposite sign, and thence the particles of a less susceptible character, such as gangue, fall by gravity through a field of constantly decreasing strength to the dis charge. The particles having permeability are attracted to the pole tip but are intercepted by the rotary screen I which re volves at such speed as to overcome the magnetic attraction by centrifugal force and discharge permeable particles over a partition M which will be hereinafter described.

At the base of conical guide 70 and the top portion of armature K the step or shoulder indicated by the letter 70 is formed, such of the lesser permeable particles of ore that were not attracted to the upper pole B in their rapid movement by gravity over the face of the conical guide 70 together with the gangue particles, will come to a momentary reston the shoulder formed by the armature K. This point of rest is opposite to the frusto-conical pole tip B and directly within the upper concentrated field the weaker permeable particles on their further movement by gravity will be influenced by the converging lines of force which pass through them from the armature to the pole tip to jump to the dense pole tip but are intercepted by the rapidly revolving screen. Such weak permeable particles that are held back by the weight of gangue material rest ing on them at the top concentrated field will fiow by gravity in a constantly thinning layer to the lower concentrated pole where partly by the reversal of magnetism within themselves and the abrupt action of the dense field of the lower pole B they are easily influenced to cross the air .gap with the converging lines of force until they are intercepted by the rapidly revolving screen. It will be particularly noted that the rest point is very essential for weak or very slightly permeable particles. Should they enter the concentrated field with momentum, their velocity would be such that they would rush to and through the concentrated field regardless of its strength without being perceptibly affected.

The armature K is rigidly supported by a vertically adjustable spider O. The supporting member If is preferably of nonmagnetic material. Between the lower edge of the rotary screen and the outer lower edge of the armature there is erected an annular partition M and outside of said partition, and surrounding the field magnet ring B is an inclosing ring 'or casing N. The rings N and M constitute the upper edges of receptacles for tailings and concentrates respectively, and said rings, together with the central armature, are preferably directly supported upon a vertically adjustable spider 0 whereby they may be adjusted in unison so as to vary both the width of the passageway through which the materials travel between the pole pieces and the central armature and guide and the position of the edge of the partition on opposite sides of which the tailings and concentrate falls. Arranged on the spider O are a number of annular slots k in which various diameter annular partitions M can be placed.

Depending below the spider O and forming continuations of the rings M and N are inverted cones or funnel shaped receivers M and N respectively terminating in chutes M and N through which the tailings and concentrates are discharged. The spider O is conveniently guided on the uprights A and supported by sleeves O which latter are, in turn, supported on a second spider O the latter being upon a centrally located hand wheel nut 0 adjustable vertically on a central screw 0* projecting upwardly from the base A. When the hand Wheel nut O is turned to the right or left, the spider frame support-ing annular partitions M and N together with conical armature K are adjusted closer or farther away from the poles, thus causing a greater or lesser air gap between the poles and armature. This adjustment is necessary for ores of a higher or lower permeability, as for instance, a strong magnetic ore on entering a magnetic field will be charged by induction and form into a mass resembling fur on an angry cats back, entangling with its gangue. It will be obvious that an ore of this character will require a greater air gap, so that in a long jump to the poles it will have a reasonable chance to disentangle from its gangue. Ore of a low permeability does not bunch in clusters and owing to its weak attractability requires the armature to be in close proximity to the pole pieces. When the armature K is adjusted vertically, the guide cone is which forms a feed gate in conjunction with feed pipe f is thrown out of normal adjustment. To replace the adjustment so that the ore will flow properly by gravity down and over the guide cone, the adjustment sleeve F supporting the feed pipe f is adjusted vertically by means of a screw thread f until the proper feed is found.

To secure the proper convergence of the lines of force and an extremely dense unbroken annular field through which all the material must pass requires careful and accurate formation of the parts and while as shown both the superficial and sectional areas of the armature in proximity to each pole of the magnet is greater than the said pole, the convergence of the lines of force outwardly or toward the pole tips is assisted by making the poles of material having a very high magnetic conductive capacity while the armature is of material having less conductive capacity per equal area with the result that the lines of force concentrate at the poles and scatter on and in the armature, but care is to be taken that the total conductive capacity of the armature is practically as great as that of the poles to prevent leakage and cause practically all of the line of force in the circuit to cross the air gap through which the materials pass.

Vhile the mechanical construction and arrangement of the parts such as the bearings, feed spout etc., may be varied the arrangement shown is advantageous in many respects. For instance, by removing the screws connecting the ring or sleeve D and supporting ring D, the conical screen and its bearings are free to be removed downwardly and may be so removed when the magnet is lifted away from its supports or the armature removed from beneath the magnet. The screen and its bearings are removed as a unit and the bearings may be adjusted or cleaned without changing the adjustment.

hat I claim is 1. A magnetic separator embodying a field magnet having continuous annular pole pieces of opposite sign, forming a downwardly diverging or conical chamber having a feed opening at the apex, an imperforate conical screen journaled to rotate within the chamber in proximity to the faces of the pole pieces and an armature having a conical face arranged within the screen in proximity to the faces of the pole pieces, said conical face at both top and bottom merging into curved faces extending gradually away from the pole pieces in a vertical plane, the arrangement being such as to distribute the lines of magnetic force on the armature and cause them to converge toward the pole pieces.

2. A magnetic separator embodying an annular field magnet having continuous annular pole pieces of opposite sign with continuous annular tips in different horizontal planes whereby a downwardly diverging or conical chamber is formed, a conical screen journaled to rotate in said chamber in proximity to the pole tips and having a feed opening at the apex, a circular armature adjustable to fixed positions in said chamber, said armature having a conical face parallel with the screen said face merging at both top and bottom into curved faces extending gradually away from the screen and pole tips in a vertical plane and a conical guide of non-magnetic material located centrally above the armature.

3. A magnetic separator embodying an annular field magnet having continuous annular pole pieces of opposite sign with their tips in different horizontal planes and defining a downwardly diverging chamber, the outer pole piece being of less thickness than the inner pole piece whereby the magnetic conductive capacity of the two pole pieces is equalized, a conical imperforate screen journaled to rotate within the field magnet and a circular armature within the screen and having a conical. face in proximity to the faces of the pole pieces.

4. A magnetic separator embodying an annular field magnet having continuous annular concentric pole pieces of opposite sign with their tips in different horizontal planes, a conical screen mounted to rotate within the pole pieces and in proximity to the tips thereof and a conical armature located within the screen and having a maximum diameter greater than the diameter of the inner portion of the outer pole piece, the top and bottom of the armature being above and below the tips of the inner and outer pole pieces respectively, whereby the lines of magnetic force may distribute themselves vertically on the peripheral portion of the armature.

5. In a magnetic separator the combination with a field magnet having annular concentric pole pieces of opposite sign, the outer pole piece having a tip formed by a removable ring and said pole pieces having conical faces in alinement with each, other, an imperforate conical screen journaled to rotate within the pole pieces in proximity to said conical faces and an armature within the screen, said armature having a conical face extending parallel with the faces of the pole pieces and rounded faces at top and bottom into which the conical face merges without the formation of proj ections by which the lines of force would be caused to converge toward the armature.

6. In a magnetic separator the combination with an annular field magnet having annular concentric pole pieces of opposite tate in proximity to the pole tips and inserts sign with their tips in diflerent horizontal of magnetic material extending through the 10 planles to florm a conical chamlzler handb a screen in proximity to the pole tips.

fixe conica armature Within sai 0 am er but spaced from said tips whereby a conical JOSEPH WEATHERBY' passage is formed between the magnet and Witnesses:

armature, of an imperforate conical screen SAMUEL F. PETERS,

of non-magnetic material journaled to ro- V. V. WEATHIIRBY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner 01' latents Washington, D. G.

Images