US994871A - Method of magnetically separating ores. - Google Patents

Description

C. Q. PAYNE. METHOD 0F MAGNETIGALLY SEPARATING DRES.

APPLIOATION FILED MIL15, 1911.

Patented June-13, 1911.

2 SHEETS-SHEET 1.

G. Q; PAYNE. l METHOD OF MAGNETIOALLY SEPARATING CRES.

APPLICATION FILED MAR. l5, 1911.

Patented June 13,1911.

2 SHEETS-SHEET 2.

WIT/VESSEL? CLARENCE a. rerun, or nnss' nona, n. a.

' METHOD OF MGNETICALLY SEFRATING RE.

sensei.

Specification of Letters Patent. ltdaftqgiftgqll Juin@ 13, Ilfl.

Application led March 115, 1911. Serial No.J 514,53?.`

To all whom it may concern.;

Beit known that I, CLARENCE Q. PAYNE, a citizen of the United States of America, and'residing in the borough of Manhattan, city, county, and State of New York; have invented certain new and useful ImprovementsA in Methods of Magnetically Separating Ores, of which the following is a full and true description.

My invent-ion relates to improvements in methods ot'separating substances ot' all degrecs of magnetic susceptibility from one another or from non-magnetic substances with which they may be mixed.

It consists essentially 1n a method of overl coming mechanical interference or entanglement of the various particles ot' an ore mixture with each other while in a magnetic field, and whereby uniform conditions are provided for the attachment of the attracted particles.

I have found that mechanical entanglement is due to two principal causes, lirst, tol

the presence of particles diiering greatly in size in an orc mixture, whereby the large particles when acted upon by magnetic attraction, Wedge and hold the similar particles not so acted upon and prevent their tree motion; and, secondly, to the unequal action. of' magnetic attraction, especially upon the smaller particles when they are afforded areal rather than lineal positions of attachment upon the separating surface.

I have succeeded in overcoming mechanical entanglement in a method oi magneticallyv separating ores by dividing the'ore mixture to be separated into groups by sizingit so that the particles in each group willbe as nearly uniform in size as possible, and-then treating each group independently upon a separating surface so formed that the particles acted upon by magnetic attraction are permitted lineal or independentpositions instead of areal or massed positions of attachment, and will be tree to respend to the forces of gravity and magnetic attraction to which they are subjected. i

In my accompanying application, Serial No. 614,585., filed March 15,1911, vI have described and claimed a general method et separating ores which includes both a magnatio andan electrostatic method. I have also claimed .in the said application the specii'ic method Jet separation described there-- in as the electrostatic method. Vllhe claims of this application are limited to the modi- Patent No, 791,494, dated June 6th, 1905, .as Well as in several other` patents granted to me, tosc control the positions of the lines l of force in a magnetic field as to secure what may be'called a unipolar field, z'. e., one in which the lines of force all pass in the same direction and do not reverse at any point. This I accomplish by causing the separation to takeplace in an air-gap of amagnctic circuit, between two opposing pole pieces. In this waya large amount of mechanical interference or entanglement of the particles undergoing separation is prevented, as compared with the use of a bipolar Heldin which loops or bridges of attracted particles are permitted to span the space between the adjacent poles, and thus surround and inclose a considcrable'amount' of non-magnetic material. ligt-withstanding the use of the unipolar field, a considerab e amount of mechanical entanglement has heretofore still persisted. Ihis mechanical entanglement it is the purpose of my invention to overcome, and at the same time to exert as uniform an effect as possible upon the attracted cparticles while they are undergoing separation.

In the drawing accompanying and form ing a part oit this specification, Figures 1, 2, 3 and -i are detail views illustrating the principle ot my invention, and show upon an enlarged scale sections 4of disks VWhose thickness bears a certain ratio or size relation to the diameter of the particles which they are illustrate more clearly what is sought to be accomplished hy my invention, I have shown in Fig. V1 in section upon a much enlarged scale a series ot disks it. fi ot soft iron or steel having smooth edge Jaces. These disks are alternately interleaved with a series of magnetized, while the particles D D do notv so respond and are `hence free to be removed byV other forces, it is evident that in the positions in which the particles D D are placed,vthey are held or blocked by the irregular shape of the attracted particles C C,

and their separation from the latter is thusprevented'. This interference or mechanical entanglement of a certain percentage of one set of particles D D by another set C C, hasthe obvious disadvantage that the entangled. particlesD D are caused to pursue the same path of movement as the particles-C C when they are nally/ released and discharged from their separating cylinder at the end of the field, instead of a diverse path of movement, 'thiis causing a defective or ineticient separation. It is evident that if the smaller particles D D are removed from the larger ones C C by screening them out before the ore mixture is fed upon the separating cylinder A B their mechanical entanglement would be prevented. lt is also evident that since the more highly charged edges of the disk faces largely determine the position of the attracted particles, the thickness of the disks should not be disproportionatelygreat as compared with the diameter of the particles to be separated. For illustration if in Fig. 1 only particles of the size C C be treated upon the disks A B whose thickness bears to the diameter of the particles C C approximately the ratio 2 :1, there will then be little or no 'mechanical entanglement between particles of such vrelative size while they are undergoing separation, and an efficient separation can then be made.

, The videal conditions for sized particles may be assumed to be realized when the thickness ofthe disks is just equal to the diameter ofthe particles to 'be separated'. Each attracted particle then almost instantly finds a point of attachment when fed upon the cylinder made up of such disks, and the free distribution of the attracted particles upon the separating surface is thus aided.-

Such a size relation, however, is not feasible in practical work, and l havefound that a ratio of the thickness of the disks to the diameter of the -particles of 3 :1, 4:1, or even somewhat greater, will give practical and eii'icient results, especially when the re mixture is properly fed. upon the separating cylinder. l

ln Fig. 2 is illustrated the eect of the disproportionate size relation between the thickness of a magnetized disk, and the diameter of -the sized particles Ato he separated. -Here the attracted particles C tend toI form column-like attachments especially toward theedge of the disks where magnetic density is greatest, and considerable mechan- 'icalientanglement ef the non-attracted particles D is thus caused among them.` yFhis can be largely prevented `by using thinner disks for the small particles, as shown in Fig. 3 by A2 A2 and B2 B2, and by properly feeding the ore4 mixture upon the separating cylinder.

-ln Fig. 4 is illustrated an appropriate size relation in the case of still smaller ore particles C3 C3. l have found that-the best results are obtained when thin disks are used for the separation of particles of small size,l

medium thick disks for medium size particles, and thick disks for coarser particles,

in other words an approximately similar size relation should existv between the thickness of the disks and the average diameter of the particles of each group treated upon` them respectively. The exactiiumber of the group divisions into which an ore mixture should be subdivided, also the` number of separating cylinders employed, andthe pre-l l cise ratio of the thickness of the disks of each cylinderto theaverage diameter of the particles of each group division will vary with the different -ore mixtures, but it is evident that the sizing and disk variations may be carried to as great a degree of refinement as the value of a given ore and the resultingA gainin eiiiciency will warrant.

In Fig. 5 l have shown a complete separating cylinder such as may be employed in carrying out my present invention. Here the separating surface consists of two series of disks mounted upon a shaft E, and held in place by means of compression flanges F F. One series A? A4 is made of iron or soft steel, and the other -series B4 B4 of a nonmagnetic material, such as liber, etc. The disks have smooth edge faces and those of one series, are alternately interleaved with those vof the other as shown in Fig. 5. ln place of the interleaved noninagnetic disks Bt it is also possible to employ mag' netizable disks A4 alone, and to construct them with alternately projecting edges as shown in Figj or else to give .their edges toothed outlines as shown in Fig. 7. The latter construction, especially when the disks are so assembled that the teeth arestaggered or are out of alinement permits, in such cases where it is found desirable,asomewhat more intense localization of the magnetic attracting force than in the case of the interleaved disks with smooth edges. rlhe latter, on the other hand, aord somewhat more uniform conditions under which the attracting force acts upon the magnetic particles of an ore mixture while being conveyed through the magnetic Afield. y i

lt is obvious that the specific arrangements of disks shown in Figs. 5, 6 and'7 may be modified by those skilled in the art in practicing my invention without departing elo from' the scope of my claims. It is essential, however, that the disks be so arranged as to. secure magnetically exposed disk edges along the surface of the separating cylinder, in order that the attracted particles may be afforded as far as possible lineal positions of attachment while undergoing separation.

In Fig. 8 `l have shown 1n sectional view a'magnetic separator adapted for use in carrying out Amy invention. `Here W represents the'coil of an electromagnet which, when energized by an electric current, establishes a magnetic eld betwen the pole ieces M N. The edges of the magnetizable disks which Wholly or partly make up the armature-cylinder A lthen become charged with local condensations of magnetic'lines of force when it is revolved through the field formed between ,the *p ole pieces M N. Those particles oftheore mixture fed upon the cylinder A from 4'a "convenient hopper H and guide plates G,.`Which'.are susceptible to magneticl attraction are held to the charged edges' ofthe disks while they are being conveyed through 'the magnetic field, and are discharged from the cylinder at the end of the field ina different path of movement from those particles of the ore mixture which are not 4acted on by magnetic attraction, thus aflecting a separation between them.

in carrying out my improved invention each ore mixture is first divided into sev eral groups, preferably by screening it, so thatthe average diameter of the particles in `each `group differs respectively among then'iselves'.v rThese groups arethen treated upon l.several separators of the type which I have shown in Fig. 8 and which dider among themselves in the thickness of the .disksfwhich arcrespectively used in the separating cylinders. The group containing the lco'arsest ore particles is then separatedupon the cylinders containing the thickest disks,

while the group containing the finest ore particles is treated upon the cylinder containing the thinnest disks. rlhe greater the number of the groups into which an ore mix- Y `ture is divided, and the more closely the thickness of the disks approximates to the size of the ore particles in each group the more perfectly can the mechanical entanglement of one set4 of particles with another set, during separation, be overcome, and the more perfect will the separation then become, While practical considerations based upon the value 'of a given ore and the expense involved in its treatment will necesmodify the ideal conditions already in connection with overcoming mechanical entanglement, it is evident that there must be at least two groups of particles into which an ore mixture must be divided, and that at least two separating cylinders must be employed having disks of diierent thicknesses in order to apply my method of separating to ore mixtures in accomplishing the purpose of my invention.

I am aware that the sizing of ore mixtures as a preliminary step to their treatment by various methodsof separation is not uncommonly practiced, but it will be seen that the main feature of my invention consists in providing unobstructed positions of attachment for those particles in an ore mixture which are acted on by magnetic attraction, and as a further aid in thus overcoming mechanical entanglement, I have found that a preliminary sizing of the ore particles is of assistance.

VIclaim as my invention:

1. The method of magnetic ore separation which consists in dividing an ore mixture into a plurality of groups which differ respectively in the average diameter of their particles, and subjecting each of said groups independently to the inagnetized edges of disks arranged in series, which disks vary in` thickness with the average diameter of the particles acted on. v 2'. The method of magnetic ore separation which'consists in dividing ore into a plurality of groups differing respectively in the average diameter of'their particles, and subjecting each of said groups independently to the separating action of a series of mag# netic charges spaced proportionately to the average diameter of the particles of the group treated, substantially as described.

3. The method of .separating substances of all degrees of magnetic permeability from one another, or from non-magnetic substanceswithf which they may be mixed, which consists in dividing such an ore mixture into a plurality of groups which differ respectively in the average diameter of their particles; feeding each group separately upon one of a plurality of' cylinders each of which is provided with a series of magnetic and non-magnetic disks placed alter-V :mer

nately which (lider in their thickness, each series with respect to the others, acting upon each group by means of magnetic attrac-4 tion as well as gravity and centrifugal force, and discharging two or more sets of separated particles from each cylinder along diverging paths of movement.

CLARENCE Q. PAYNE. l/Vitnesses WALTER S. Jones,

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