US641148A - Method of magnetically separating ores. - Google Patents

Description

N0. 64|,|48. Patented Ian. 9, I900.

c. u. PAYNE. METHOD'OF MAGNETICALLY SEPARATING GEES.

(Application filed Aug. 15, 1899.)

(No Model.)

WITNESSES: INVENTOR Patented Jan. 9, I900. G. PAYNE. METHUB 0F MAGNETIBALLY SEPARATENG ORES.

(Application filed Aug. 15, 1899.)

(No Model.)

2 Sheets-Sheet 2.

WITNESSES:

m: NORRIS PEYEHS ed, PMcTo-mnu. vusumamu. D, c,

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CLARENCE Q. PAYNE, OF NEW YORK, N. Y.

METHOD OF MAGNETICALLY SEPARATING ORESL SPECIFICATION forming part of Letters Patent No. 641,148, dated January 9, 1900.

Original application filed January 20, 1897, Serial No. 619,881. Divided and this application filed August 15, 1899. Serial No. 727,286. (No specimens.)

To all whom, it may concern:

Be it known that I, CLARENCE Q. PAYNE, a citizen of the United States,residingin the borough of Manhattan, city, county, and State of New York,have invented certain new and usefulImprovements in Methods of Magnetically Separating Ores, of which the following is a full and true description.

Similar letters of reference indicate like parts in the several views of the drawings.

My invention relates to improvements in methods of separating substances-of all degrees of magnetic susceptibility from one another or from non-magnetic substances with which they may be mixed.

It consists, broadly, in acting upon the mixture containing such substances by means of undulations or cyclic variations of magnetic potential while within a magnetic field and in determiniug'the motions of the attracted particles therein and during their subsequent conveyance out of the field in directions which assist in producing a more thorough and complete separating action than would otherwise be possible.

In an application for United States Letters Patent filed January 20, 1897, 'Serial No. 619,881, and of which this application is a division, I have described and claimed certain improvements of means for controlling the positions or directions of the lines of force within a magnetic field by edge or line dispersions of the flux density therein, whereby I secure vast differences of magnetic potential within the field and am thus able to attract and separate substances of all degrees of magnetic susceptibility from mixtures containing them. In the present invention, while utilizing the effects produced in a magnetic field by the means above described, I combine them with other improvements for controlling the direction of motion of the ore particles while undergoing separation within the field in accordance with the method and for the purpose described hereinafter.

The invention will be best understood by reference to the accompanying two sheets of drawings, forming part of the specification, in which-- Figure 1 is a diagrammatic section through the magnetic field in which the separation takes place. Figs. 2 and 3 show various constructions of the surface of the separatingcarrier to control the positions or directions of the lines of force Within'the field. Figs. 4 and 5 show in sectional views an electromagnet and an armature so arranged that two fields on one magnetic circuit are formed between them, in each of which the method of separation may be applied. Figs. 6 and 7 show a similar application in the case of an electromagnet and an armature so connected that a single field is formed between them upon two magnetic circuits.

The method of separation which forms the subject of my present invention may be conceivedof without reference to a particular design of electromagnet or embodied in a particular type of ore-separatin g apparatus. In the drawings 3' ust referred to I have therefore chosen, merely for the purpose of illustrating my invention, two different designs of electromagnets, in the fields of which the sepa-- ration of substances contemplated by my invention may be effected. Other designs of electromagnets will readily suggest themselves to those familiarwith the design of electrical machinery, although in any case the magnetic field is preferably formed between opposing magnetic surfaces. I have also omitted from the drawings those details rated into the magnetic field and for col1ecting and discharging the products after separation.

Referring now to Fig. 4, we have here a section through the magnetic field formed between au electromagnct M R and an armaturebarA. The electromagnet maybe either of the horseshoe or two-pole type, as shown in Fig. 5, or of the one-pole type, as shown in Fig. 7. In both cases the electromagnet M R is rigidly supported within the separating carrier or cylinder S by means of shaft extensions at each end, which are held in suitableclampbearings -as indicated, for example, in Fig. 6-in order to secure the proper rotary ad.just ment of the position of the magnet-pole R.

The iron armature bar or cylinder A is supported parallel with the axis of the cylindrical carrier S and at a short distance away from its pole orpoles, as shown in Figs. 5 and 7. The armature-bar A is also rigidly supported within the feed-cylinder T and is held by shaft extensions at each end in suitable bearings, as shown in Fig. 7, which permit a certain amount of adjustment of the distance between the surfaces of the feed-cylinder T and the separating-cylinder S. The two cylinders are respectively mounted upon drumheads J J and J J, and are each made to revolve through the field or fields formed between the electromagnet and armature by any convenient means of power transmission. (Not shown in the drawings.)

The electromagnets are provided with coils of insulated copper wire placed upon the core or cores R, and these are charged with an electric current from a dynamo-electric machine, the strength of which may be varied to suit the various requirements of ore separation.

In Fig. 5 the construction of the electromagnet is such that two magnetic fields are formed on one and the same circuit of the magnetic flux in the air-gaps between the opposing surfaces of the electromagnet-cores and the armature.

Since the lines of force are not reversed at any pointin the same field, each field is of the so-called unipolar type.

In Fig.7 by means of the outside yoke con-- nections B B, joining the electromagnet and the armature, a single unipolar magnetic field is formed upon two circuits of the magnetic flux, as shown by the broken lines, within the air-gap between the opposing surfaces of the electromagnet-core and the armature.

The separating carrier or cylinder S, which revolves about the electromagnet, maybe constructed in various ways to accomplish the object of the present invention; but, as shown in the illustrations, it consists, essentially, of an iron portion S, whose outer surface is serrated or ridged, so as to secure a series of wedge-shaped teeth or serrations thereon. Pyramidal shaped teeth may also be employed, as shown in Fig. 3, in certain cases; but in general and in order to secure as many positions of attachment as possible for the ore particles to the separating-carrier it will be sufficient to employ a series of parallel wedge-shaped teeth or serrations placed along rectilinear elements of the cylinder, as shown in Figs. 1 and 2. wedges may be varied; but since their terminations may be brought to sharp edges these may be considered linesthat is, they have length without breadth.

In order to describe more clearly the principle involved in my invention, it is desirable to consider the condition of the mag netic field first when the separatingcarrier is at rest and then when it is in motion. the first case we have, as shown in Fig. 1, a magnetic field established in an air-gap be- The shape and size of these tween opposing magnetic surfaces, consisting, respectively, of the magnet-pole R and armature A. This air-gap is filled with lines of force, which would occupy approximately parallel positions therein, from the fact that the total magnetic flux passes through the air-gap, if they were not otherwise intercepted or diverted. The presence of the iron wedges of the separating-carrier on one side of the field, however, causes a great change in the relative positions or directions of the lines of force. By the inductive magnetization of these wedges and by their shape the lines of force are intercepted and made to converge toward the terminations of each of the wedges. They are then rapidly diverged or dispersed across the remaining air-gap from the terminations toward the armature-surface, as indicated by the broken lines in Fig. I. In this way are obtained what may be called edge or line dispersions of the flux density within the field. A very great accumulation of the lines of force at the wedge terminations is thus produced, since an edge or line cannot, as is well known, be saturated. The

rapid dispersion of the lines of force thence toward the smooth surface A on the other side of the field produces greatdifferences of magnetic density per unit of length in the direction of their dispersion. This difference of density at the limits of these divergencies viz., at the wedge terminations and at the armature-surfacebeing incommensurate is theoretically infinite. By this control over the positions of the lines of force within the field and by variations in the strength of the magnetomotive force the widest possible range of magnetic effect in acting upon the magnetic particles to be separated can be obtained.

For the reason that the magnetic particles are caused to move while within the field when undergoing separation it may be more convenient to define the field in terms of potential rather than of magnetic force or densitythat is to say, in terms of its potential energy or power to do work.

Since magnetic force is the rate of change of magnetic potential per unit of length, the greater the difference of magnetic potential between two points in a field the greater is the work done in moving a particle, for example, from one point to the other, work being the mathematical product of a force and a distance.

By the means already described, whereby I obtain the maximum differences of flux density within a magnetic field by line dispersions thereof, I secure also, with reference to the effect upon the ore particles, the greatest differences of magnetic potential within the field, and I am thus able to impress the greatest possible amount of work upon the magnetic ore particles in moving them away from the less or non magnetic particles with which they may be mixed.

It will be evident that while the magnetic potential thus varies greatly at nearly every point within the field (shown in Fig. 1) there are certain lines which occupy curved and approximately concentric positions about the wedge terminations, along each of which lines the magnetic potential is constant. The exextension of these equipotential lines lengthwise through the field produces equipotential surfaces.

Having thus described the condition of the magnetic field when the separatingcarrier is at rest, it is now desirable to consider the ef fect of its motion through the field.

By moving the carrier in the direction of the arrow, Fig. 1, the lines of force which are held approximately stationary at their ends where they join the magnetic surfaces R and A are made to bend rapidly back and forth at right angles to their lengths as they are alternately extended and retracted by the inductive action of the iron wedges moving through the field on one side thereof. This vibrating or oscillating motion of the lines of force is greatest immediately at the wedge terminations. The -effect of this oscillating motion of the lines of force so produced is to cause a forward motion of the various equipotential surfaces lengthwise throughout the field. In other words, undulations of magnetic potential are produced within the field in the same way that waves are produced on the surface of water by a vertical disturbance at any point. A fixed point within the field is thus acted on by undulations or cyclic variations of magnetic potential as the successive wedges upon the separating-carrier pass it.

The ore particles to be separated are introduced into the field upon the feed carrier or cylinder T on that side thereof which is opposed to the wedge terminations and are carried through the field at a somewhat lower speed than that of the separating-carrier in order to insure a thorough separating action. The feed-cylinder may be made either of magnetic or non-magnetic material, depending upon the nature of the material to be separated.

It is an importantstep in the method of separation which is the subject of the present invention that the magnetic particles which are thus carried into the field with the less or non magnetic particles upon one side thereof are attracted and moved to the other side of the field while passing through it.

I have found that the interference of par ticles with one another in a magnetic field while undergoing separation is a frequent cause of inefficient separation. This interference is more marked where the magnetic particles after being attracted are held in a relatively stationary position while the nonmagnetic particles are caused to move away from themas, for example, by gravity. By the present method of separation, on the other hand, whereby line dispersions of the flux density are employed in the magnetic field to produce great differences of magnetic potential therein, the ore to be separated is acted on intermittently and successively by undulations of magnetic potential which cause the attracted particles, even when they are of very low magnetic permeability, to be lifted outof and away from the mixture in which they are contained when fed into the field, thus securing a much more complete and efficient separating action than would otherwise be possible. The two groups of particles being thus separated are then conveyed through the remainder of the field alonglines which diverge within the same or parallel vertical planes until they are discharged at the end of the field by gravity on opposite sides of a convenient division-plate. This method of separation also permits the discharging-line of the attracted particles to be of the same length as the feed-line of the original ore mixture. A much more thorough separating action is thus secured than in passing the ore through a field Where the vertical planes of the feed and discharge particles .are not parallel, because new feed and separating surfaces of the same widths are thus constantly opposed to each other as the ore passes through the field.

In the separation of feebly-maguetic material the separating-cylinder S is preferably rotated in the opposite direction to that of the feed-cylinder T, as shown in Figs. 1 and 4, for the reason that the attracted ore particles are thus conveyed only a short distance in effecting their separation from the less or non magnetic particles. In the separation of strongly-magnetic material,on the other hand, the separating-cylinder S may be rotated in the same direction as the feed-cylinder T by varying the angular position which the two cylinders make with a horizontal line. While thus employing the same method of separaration in both cases, the strongly-magnetic material in the latter case is made to travel a greater distance by conveying it over the top of the separating-cylinder and discharging it on the other side.

In the drawings illustrating applications of my present invention I have shown cylinders to be employed as the separating and feed carriers. These will generally be found convenient on account of their mechanical simplicity in accomplishing the work required. It is, however, also possible to use belts for the separating and feed carriers when properly constructed for the purpose. In the same way, although for the sake of simplicity an electromagnet has been shown on one side of the air-gap and an armature on the other in the various illustrations, yet an electromagnet might obviously be placed on each side of the air-gap as well, the field thus formed being likewise between opposing magnetic surfaces. Other positions for the field-coils of the electromagnets might also be chosen instead of on the cores or poles R, as will readily be sug gested to those familiar with the design of electrical machinery.

Having described the various steps involved in the above method of magnetically separating ores, I claim as my invention 1. The method of separating substances of all degrees of magnetic susceptibility from one another,or from non-magnetic substances with Which they may be mixed, which consists in introducing the mixture into a magnetic field of undulating magnetic potential, formed in the air-gap of a magnetic circuit; attracting to one side of said field the more magnetic particles thereby separating them from the less-magnetic or non-magnetic particles; conveying both groups of particles along vertically-diverging lines out of the field, and discharging them in different paths of movement at the end thereof.

2. The method of separating substances of all degrees of magnetic susceptibility from one another or from non-magnetic substances with which they may be mixed, which consists in inductively intercepting the lines of force on one side of a field formed between opposing magnetic surfaces in the air-gap of a magnetic circuit; producing line dispersions of the flux density and wide differences of magnetic potential within said field; generating cyclic variations, or undulations, of the magnetic potential therein; introducing the mixture to be separated into said field; attractin g to one side thereof the more magnetic particles, thereby separating them from the less-magnetic or non-magnetic particles; conveying both groups of particles along vertically-diverginglines out of the field, and discharging them in different paths of movement at the end thereof.

CLARENCE Q. PAYNE.

Vitnesses:

JAMEs J. Cosenovn, 1 WM. H. BERRIGAN, Jr.

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