US1208880A - Magnetic separator. - Google Patents

Description

P. WRIGHT & G. LAND. MAGNETIC SEPARATOR. APPLICATION-FILED "my 26, 1913.

Patented Dec. 19, 1916.

2 SHEETS-SHEET I.

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draw 7 P. WRIGHT & G. LAND.

MAGNETIC SEPARATOR. APPLICATION FILED MAY 26. 1913.

Patented Dec. 19, 1916.

2 SHEETSSHEET 2- f 6 d a a 64 a I 1% a Q q b w 4 Q. 5 e M Z w a 1? PARVIN WRIGHT AND GORDON LAND, OF SEATTLE, WASHINGTON; SAID LAND ASSIGNOR TO SAID WRIGHT. I

MAGNETIC SEPABATOR.

Specification of Letters Iatent. at t 19, 191

Application filed May 26, 1918. Serial No. 769,895.

To all whom it may concern:

Be it known that we, PARVIN WRIGHT and Gonnon LAND, citizens of the United States, residing at Seattle, in thecounty of King and State of Washington, have invented a new and useful Magnetic Separator, of which the following is a specification.-

This invention relates to apparatus for "separating magnetic material from sand,

gravel, etc., and the main object of the invention is to provide a magnetic separator which will be capable of operating with wet material.

A further object of the invention is to prevent. non-magnetic material from being picked up along with the magnetic material in the separating operation.

Another object of the invention is to pro vide for effective remov-l of the magnetic material from the collecting means.

Other objects of the invention will appear hereinafter.

The accompanying drawings illustrate embodiments of our invention, and refer-- ring thereto:

Figure 1 is a longitudinal section of the apparatus, showing the magnetic collecting means in elevation. Fig. 2 is a longitudinal section, showing the magnetic collecting means in section. Fig. 3 is a plan view of the machine with portions broken away. Fig. 4 is a plan view partly in section of the magnetic devices for producing the magnetic field in the collecting means. Fig. 5

, is a section showin a modified form of the magnetic drum. ig. 6 is a longitudinal section of another form of the apparatus.

The apparatus is mounted on a frame 1 and comprises a table or plate 2 adapted to receive the material from a suitable fiume or chute 3, a magnetic collecting means 4 adapted to pick up the magnetic material from said table, a discharge fiume 5 for said magnetic material, and a discharge table or flume 6 for the'non-magnetic material. The machine is shown as adapted for use in separating magnetic material from gold bearing sands and the discharge fiume 6 is shown as a rifile table, being provided with rifiies 7, this table discharging at its lower end onto suitable means indicated at 8 for performing further operations upon the material for separating gold therefrom.

The receiving table 2 is preferably formed as a shaking table, said table 2 being inclined downward from the feed end to the discharge end thereof, and bein mounted on resilient plates or boards 9 ed at their lower ends to the frame 1, and at their upper ends to the table so as to permit longitudinal reciprocation of the table. Such reciprocation of the table is effected by cams or tappets 10 on a shaft 11, said cams or tappets engaging with a bearing plate 12 in rigid connection with the table 2. The shaft 11 is driven by any suitable means, for example, by a pulley 1 L thereon. At the upper end of the table a screen 15 is preferably provided, said screen being bent down wardly to form a foraminous trough which is retained in position between inclined downwardly convergent boards 16 and 17,

the boards 16 forming the upper end wall for the table 2, and the boards 17 extending across between the side walls 18 of the table 2, leaving a space or opening 19 below said board 17 for'passage of the screened material. The board 1-7 extends obliquely across the table 2 so that the trough formed by screen 15 has sufiicient downward inclination toward one end to cause the sand accumulated on said screen to gradually work toward one end of the trough and an opening 20 is provided at that end through which such material is discharged. Near the lower end of the table 2 is provided a screen or forami Said cylinder may be of any suitable construction adapted to' present magnetic poles of suflicient intensity. The construction which we have found suitable for this pur pose is shown in the drawing and consists of a series of magnetic elements arranged on a shaft 22; journaled in bearings 23 on the frame 1; each of said magneticelements tending from said cores longitudinally with respect to the shaft 22. The pole-pieces 24 of adjacent magnetic elements, extend in onposite directions; and the cores of said elements are in staggered relation, so that the pole-pieces of adjacent elements overlap. Said cores are-provided with windings 26 connected to an ener 'zing circuit, in such manner that the ad acent pole-pieces are magnetized oppositely. A casing is provided for the magnetic cylinder, consisting of a cylinder 28 of copper or other nonmagnetic material, surrounding the series of magnetic elements, and heads 29 of nonmagnetic material, brazed or otherwise secured to said cylinder 28; a hole 30 being left in one of said heads, through which suitable insulating material, such as pitch, is run into the cylinder, to completely fill the same and form, when said material is solidified, a solid, waterproof body. The wires 31 connected to the windings for the magnetic elements, are carried through a longitudinal bore 33 in the shaft 22, and are connected to collector rings 34 on said shaft. Brushes 35 contact with said collector rings, and are connected by wires 36 to an electric generator 37 driven by any suitable means. Shaft 22 for the magnetic device is driven by any suitable means, for example, by belt and pulley connection 63, 64 and 65 from shaft 11 aforesaid. Any other suitable construction of the magnetic device may be used, for example, as shown in Fig. 5. The same may consist of cylindrical armature body 38 of iron having longitudinal slots 38 for receiving the magnetizing windings 39, which are wound on said body so as to develop magnetic poles at the surface of said body, the said body and coils being inclosed in a cylindrical casing 28. The cylinder s0constructed is mounted to rotate in the machine in the manner above described.

An endless, flexible conveyer member, consisting, for example, of an endless canvas belt 40, extends around the cylinder 28, and around a roller 41 mounted-in bearings 42 on a fiume 5, which is pivotally supported on a pipe 45, extending transversely through the delivery or discharge flume 6, the mounting being such that the said fiume 5 acts as a thrust member and the belt 40 acts as a tensible member whereby the belt is tensioned bythe wei ht of the flume 6, the roller 41 and the belt itself. The bear-.

ings 42 are preferably adjustable to regulate the tension of the belt and the distance between the lower run of the belt 40 and the fiume 5, said bearings bein for example, formed in the upper ends 0 levers 50, pivoted at 51, on the sides of the flume 5 and adjusted by set screws 52 screwing through said pipe being connected to any suitable source of water supply, under definite head, and having perforations 58 through which water is discharged into a box 49 at the upper end of the fiume 5, the upper edge of said box serving as a spillwa over which any surplus water will flow ectly .to the fiume 6, the rest of the water flowing over the lower edge ofsaid box and down al'on the flume 5. The fiume 5 dis charges at 1ts lower end into a chute 60 for conveying the magneticmaterial to any desired place.

The operation is as follows: The sand or gravel which has been screened in asuitable manner so as to remove the coarse gravel and bowlders, is delivered together with water by the fiume 3 to the screen 15 which allows only the sand to pass under the table 2, all the coarser materials passing through the outlet 20, the sand passing through the screen including not only the ordinary silica sand and other non-ma etic sand, but also including any black san that may be present in the deposit which is being worked, this black sand consisting generally of magnetite, but also comprising in some cases chromite, monazite and other magnetic materials. Any finely divided gold the table. The shaking motion ofthe table in conjunction with the action of the water passing along with the material also tends to stratify the material to some extent, the black sand and the gold,platin'um, etc., if any be present, accumulatin in a lower layer and the lighter materia s tending to pass'along the top of the bed of material on the table 2. The black sand therefore tends to as beneath the screen 21, said screen 21 d eing spaced above the table 2 a suflicient distance to permit of substantially all of the black sand passing beneath the same. Thecylinder 4 being set in rotation and the magnetic, devices therein being energized by curre tjirom the generator 37,. a strong magnetic-field or a series of magnetic fields is produced' idirectly above the screen 21, causing the particles of magnetic material below the screen to be drawn up through the meshes of the screen, such meshes insuring that the particles will be picked up individually and not in the form of chains or bunches. For this reason only the'magnetic particles are drawn up to the cylinder 4 and said cylinder doesnot pick up any nonmagnetic particles entangled with such magnetic particles. The particles so picked up accumulate against the canvas belt 40, being held against said belt by the magnetic attraction due to the fields between the pole-pieces for the magnetic devices in this cylinder. In the movement of the belt, the portions of the belt carrying the magnetizedparticles eventually pass away from the cylinder on entering the upper straight run of the belt and are thereby removed from the magnetic fields produced by the cylinder. These particles are carried down by the belt and over the lower roller which is partly immersed in water flowing downwardlyin the flume 5 from the supply pipe 45. The current of water passing down the flume from this supply pipe tends to sweep ofl any particles of magnetic material that may adhere to the belt and to carry the same down the flume 5, such magnetic material being discharged through the discharge flume chute 60.

The invention has especial adaptability to the separation of magnetic material from gold bearing sands so as to facilitate the subsequent treatment of the sand in the separation of gold therefrom, and in such connection we prefer to use the .form of riflies shown in Figs. 1 and 2, said riflles consistingof angle bars having their .upper faces extending obliquely upward and forward with reference to the riflie floor, this construction causing the water and sand as they pass over the riflie to be given an eddying motion which tends to keep the rifile spaces cleared and prevents clogging thereof.

In cases where the magnetic material comprises several diflerent constituents, such for example, as magnetite, chromite, and monazite, we prefer to provide for separation of such different constituents from one another, and in that case the construction shown in Fig. 6 may be adopted, the same comprising a series of shaking tables 2, 2", 2", each provided with a screen 21, said tables being preferably connected together and mounted to reciprocate in unison, and the last table discharging onto a rifi'le table 7. At the lower end of each of the tables 2 is provided a magnetic collecting device 4, 4", 4; having a belt 40 and a washing flume 5 is pro.- vided for clearing the belt of each magnetic device. The respective magnetic collecting drums are connected to branch circuits 61 of an energizing circuit 62, said branch circuits including rheostats 63 to enable the current through the respective magnetic devices 4 4", 4, to be regulated independently. By such regulation or by making the magnetic devices of different resistance, the magnetic device 4 is made to present stronger magnetic action than the device 4, and the device 4 is made to present stronger magnetic action than the device 4. The operation of this form of the invention is as follows: The material supplied to the first shaking table 2 is brought under the first wmagnetic collecting device 4* and is there subjected to magnetic field sufficientto' pick.

up the more readily magnetizable constituents, for example, the magnetite which is thereby removed from the body of sand and discharged through the first discharge means 60. The remaining material passes beneath the second magnetic separating device 4 whereby it is subjected to a stronger magnetic field, causing another constituent, for example, the chromite, to be picked up and separated, this operation being repeated, subjecting the material'at each operation to a stronger field so as toseparate the different constituents. g

WVhat we claim is: I

1. In a magnetic separator, a material receiving table, a cylinder mounted to rotate adjacent said stable and provided with magnetic devices for producin magnetic poles at the periphery of said cy inder, means for supplying material and water to said table, means for conveying away the discharge from said table, a flume mounted over said discharge means, a roller journaled on said flume, and a belt passing around said cylinder and said roller to convey the magnetic material from said cylinder to said flume, said flume being pivotally mounted so that its weight is sustained by said belt and tensions the belt.

2. In a magnetic separator, a material receiving table, a cylinder mounted to rotate adjacent said table and provided with mag netic devices forproducing magnetic poles at the periphery of said cylinder, means for supplying material and water to said table, means for conveying away the discharge from said table, a flume mounted-over said discharge means, a roller journaled on said flume, a belt passing around said cylinder and said roller to convey the magnetic material .from said cylinder to said flume, said flume being pivotally mounted so that its weight is sustained by said belt and tensions the belt, and means for adjusting the ends of said roller relatively to said cylinder.

3. In a magnetic separator, a material re ceiving table, a cylinder mounted to rotate adjacent said table and provided with magnetic devices for producing magnetic poles at the periphery of said cylinder, means for supplying material and Water to said table, means for conveying away the discharge from said table, a flume mounted over said discharge means, a roller journaled on said flume, a belt passing around said cylinder and said roller to convey the magnetic material from said cylinder to said flume, said fiume being pivotallymounted so that its set ourflhands at Seattle, Wash.,-on this 21st weight is sustained by said belt and tensions day of May, 1913. v i the belt, and a water supply pipe on which PARVIN WRIGHT. said fiume is 'pivotally mounted, provided GORDON LAND. 5 with openings ,for discharging water into In presence ofsaid fiume. J. B. MAGHANS,

In testimony whereof, we have hereunto JONATHAN Gmro m.

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