US1071975A - Ore-concentrator. - Google Patents

Description

UNITED STATES PATENT OFFICE.

JOSEPH WEATHERBY, OF NEW CUMBERLAND, PENNSYLVANIA, ASSIGNOR. BY MESNE ASSIGNMENTS, TO ELECTRIC ORE SEPARATOR COMPANY, OF NEW CUMBERLAND, PENNSYLVANIA, A CORPORATION OF DELAWARE.

ORE-CONCENTRATOR.

Application filed January 4, 1913.

To (11/ 101mm 2'? may concern.

lle it known that T, Josnrrr \VnATImnnv, of New Cumberland, in the county of Cumberland and State of Pennsylvania, have invented certain new and useful Improvements in Ore(,onccntrators; 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 part of this specification, and to the figures and letters of reference marked thereon.

My invention relates to ore concentration, being particularly, though not excluslvcly, adapted to pulsating or shaking tables to enable them to effectually separate ore mixtures having such slight difference in specific gravity as precludes separation by the ordinary operation.

The embodiment of the present invention illustrated contemplates an improved means whereby the ore pas es through highly concentrated fields into direct contact with magnetic terminals, during its progress over a pulsating table. the arrangement being such that some of the particles depending upon their degree of susceptibility are supported in such a way that the action of gravity is apparently wholly or partly overcome and the sus eptible ore is caused to flow with the water to the di charge, while the lesser susceptible ore particles are mechanically deflected and permitted to progress to another part of the table.

I do not limit my invention to any particular form of table, and the accompany ing drawings show only some of the many forms of apparatus which may be utilized.

In the drawings,-Figure 1 is a top plan view of a shaking table of a well known make, showing one embodiment of the invention with the magnet ox'er the table. Fig. 2 is a top plan view of a shaking table showing an arrangement of magnetic terminals in the table deck. Fig. 3 is a sectional elevation showing the arrangement of the magnet above the table, the concentrating magnetic terminals in the table deck and the magnet or armature under the table. Fig. l is a detail section on an enlarged scale of a portion of the table with magnet poles and magnetic circuit terminals showing concentrating areas on their surface and grooves Specification of Letters Patent.

Patented Sept. 2,1913.

Serial No. 740,210.

to progress the lesser susceptible ore particles. Fig. 5 is another form of Fig. 4 showing a highly concentrated field. Fig. 6 is an enlarged view of magnetic terminals showing insulating blocks in their surface to prevent progression of susceptible ore particles along their surface. Fig. 7 is an enlarged sectional View of magnetic terminals showing susceptible ore supported along the terminal edges.

Like letters of reference refer to like parts in the several figures of the drawings.

The apparatus shown in the drawings, with the exception of the n'iagnetic equipment, is of a well known type of longitudinally difi'erential reciprocating table or concentrating surface A disposed in a horizontal position in a line parallel to its motion and adjustably inclined transversely with the pulp feeding device a and a clear water box a for supplying a proper amount of dressing ater to the table.

The concentration and delivery of the ore is effected by the action of gravity influenced by the flow of dressing water which stratifies the particles according to their relative specific gravity. The differential reciprocating lilfiVolllPllt of the table is produced by the usual mechanism B termed a head motion.

The surface of the table, termed the deck, is partly riffled and partly unrifilcd. The motion necessary to be imparted to the deck of a concentrating table of the type shown in the drawings consists of moving it substantially longitudinally of the rifiie cleats upon its surface and toward the concentrates discharge end from a position of comparative rest with a gradually accelerated speed to the end of the stroke. reversing the direction quickly with a. maximum speed during the return to the position of comparative rest at the beginning of the for ward stroke. This has the desired effect of agitating and inducing the stratification of the settling material which is caught in the channels between the riflle cleat a and advancing the same at each forward stroke of the mechanism toward the riflie tips with a step-by-step progression.

The cross flowing wash water 10001115 plishes the final cleaning and removal of the light gangue as the material approaches and passes the raffle tips, and the heavier concentrates, in the order of their specific gravities, pass out u on the cleared ore plane, and are carrie forward thereupon to the concentrates discharge end of the deck and into the concentrates box, while the tailings are discharged to the waste. Should there be but a slight difference only in the specific gravity of the material to be separated, the method as above described is not effective. There are many ore bodies of the latter character which heretofore could not be separated. The separation of such an ore will be later described in accordance with my invention.

Suitably mounted above the deck of the pulsatin table is a owerful ma net C with the win ings c an the pole p eces 0 and c". The lower faces of the magnetic pole pieces are smooth, as in Fig. 4, or with projections 0 as in Fig. 5. The pole pieces are suitably spaced from the deck disposed in a horizontal plane, preferably parallel but may be diagonal with the motion and suitable to the table with which they are employed. Directly under and parallel with the pole pieces are magnetic riflies D, Figs. 2 and 3, which are suitably mounted and rigidly supported in the table deck. The magnetic rifl'le plates D, as they will be hereinafter termed, form'a part of the magnetic circuit but pulsate as a art of the table deck. They are composed o a magnetic substance, such as iron or steel, and are preferably built up of strips of metal as shown in Fig. 4 and Fig. 5 forming alternate parallel ribs and grooves.

The edges of the ribs (1 form highly concentrating areas in the magnetic field caused by the converging lines of force, and will be hereinafter described as magnetic terminals. The ma etic terminals in the drawing Fig. 4 are uilt up of several thin sheets forming in turn several other little terminals and grooves d, the purpose of which will be later described. The grooves 03 between the magnetic terminals permit the lesser susceptible mineral to drop in them and form guiding paths for progressing some of the mineral to another part of the deck. The tops of the magnetic terminals are preferably arranged in the plane of the deck surface.

Suitably mounted under the table is a powerful magnet E with its magnetizing coils e and pole pieces e and e properly spaced from, but parallel with the riflie plates D. The magnet E is in proper relation with the magnet C above the table, and the magnetic rifile platesD, and completes the magnetic circuit. Current can be turned on either magnet C or F) either magnet using the other as an armature, or current-can be turned on both at the same time forming a stillmore powerfulmagnetic field between 'them. By regulating the current flowing in each magnet, a nicety of adjustment can be obtained to equalize and regulate the attraction of riffle plates D.

It is known that all substances can, to a varying de ree, be acted upon by magnetism. It is true that many of them are less permeable than air. The substances less permeable than'air will be termed dia-magnetlc. These substances when subjected to a powerful magnetic field seem to be repelled. Some substances, such as magnetite, iron and steel are strongly acted upon by a magnet. Other substances are only slightly acted upon by magnetism, and then, only in a powerful concentrated magnetic field and during or after being brought into contact With a magnetic terminal. Such substances are called para magnetic. Para magnetic substances tend to follow the converging lines of force in a concentrated magnetic field and as shown in Fig. 3 and Fig. 4 when the current is turned on the magnet the convergence of the lines of force is downward to the edges of the magnetic terminals thus tending to cause the para-magnetic ore particles to move toward the magnetic terminals or to be held thereby after having been brought into contact therewith. The para-magnetic particles will build up in ribs along both edges of the magnetic terminals, as shown in Fig. 7 d while the center of the top surface of the magnetic terminals have little or no attraction to the ore. This action is considered ideal on some kinds of ore, but it can readily be seen that the attraction area is limited to the exposed edges. In Fig. 4 the magnetic terminals are built up of many strips of metal forming in turn many little magnetic terminals 03 or concentrating edges and practically allow the Whole surface to be utilized as an attracting area.

The converging lines of force from the edges of the magnetic terminals to the pole pieces form fields of magnetic density constituting magnetic bridges ,across the grooves d as shown by dotted lines in Fig. 4 and Fig. 5. These bridges are the medium in which the susceptible ore particles ride from magnetic terminal to terminal in their progression to discharge, while the lesser susceptible material falls into the grooves. The magnetic loops or bridges being above the bottom of the grooves, not only form barriers to prevent the susceptible ore particles falling in the grooves, but also exert an upward attraction to the susceptible ore particles that might be forced in the grooves y the weight of an over feed or by eddy currents of wash water. It will thus be seen that the effective weight of a susceptible ore particle is constantly changing as the attraction to it is first down to the magnetic terminal edge, then the heavy flow of dresslng water against it forces it off the terminal, then it rides across the groove with the dressing water to the next terminal on the bridge formed by the converging magnetic lines of force. If it is forced in the groove by the weight of the ore feed, it is moved upward in its progression to the edge of the next terminal and so 'on to its discharge across the riflle plates D.

It is an advantage with certain ores of a low magnetic susceptibility to flatten out the magnetic loops or bridges of the converging magnetic lines of force. To accomplish this (reference being had to drawing Fig. 5) the bottom faces of the pole pieces a" and c of magnet C are preferably machined with projections or teeth c, and the projections c are arranged directly over the centers of the grooves d The magnetic lines of force from the edges of the magnetic terminals are thus more concentrated toward the point of the projecting teeth over the centers of the grooves.

Some of the particles of ore, particularly the finer and more susceptible particles, have a tendency to adhere to the magnetic terminal edges and by the peculiar motion of the table deck will progress along the terminal edges to the end of the ritlle plates and may again mix with the lesser permeable particles that progressed in the grooves. To-prevent this undesirable action (reference being had to drawing Fig. 6) small blocks of a din-magnetic substance (1 are inserted in the magnetic terminals as shown. The blocks (1'' are preferably spaced only a few inches apart. \Vith this construction particles of ore progressing along the edges of the magnetic terminal advance over the dia-magnctic block whcre attraction cem-cs or is reduced to a point where the particles are released and carried on by the dressing water. Certain ores of a greater magnetic susceptibility will adhere to the magnetic terminals and refuse to be either advanced by the peculiar motion of the table or be washed away by the dressing water, and to overcome this, an alternating current of a low frequency or an intermittent direct currcnt may be used for energizing the magnet. ln the intervals of time when the current i 72/17 the magnetic ore will not be acted upon by the magnet and will be carried on by the dressing water.

Particles which are magnetic in the popular sense, 2'. 0., that will jump across an air gap to a magnetic terminal, even in a highly concentrated magnetic field, would adhere so strongly to the terminals that the operation of the particular form of apparatus illustrated would be blocked or the deck destroyed and to guard against any such porsibility, provision should be made for removing all magnetic material before it reaches the magnetic rifhes. In the present apparatus a preliminary magnetic pole or guard pole is arranged in advance of the magnetic riffles so as to catch and retain all magnetic particles. Conveniently the guard pole or poles are in the form of lateral extensions of the poles c 0 As shown in Figs. 1 and 3 an angle iron lV is adjustably mounted on the pole piece and to its horizontal flange a second angle iron \V is adj ustably connected with one flange or edge projecting down in proximity to the table or to a position where the ore may pass freely beneath it. In practice it is found that if the edge be well above the surface of the ore and water, all magnetic particles will be drawn up to it and held until removed by hand or otherwise. The guard pole is arranged at the ends of the main poles as at WV so as to give complete protection and it will be understood that it is not essential that the guard poles he energized from the main magnet but may have independent energizing coils.

The action of the table on a certain ore mixture which has never heretofore to my knowledge been successfully separated on a pulsating table is as follows: An ore mixture whose separate mineral contents vary less than one in specific gravity, such for example as an orc containing a mixture of pyrite, zinc blende, and serpentine rock, has not to my knowledge been successfully separated on a pulsating table, There is but little difference between the specific gravities of these minerals, and in the succession named the pyrite is the heavier, the z nc blendc next in weight and the serpentine rock the lighter, and normally. the three minerals will only partly stratify on the table a large proportion remaining in a greatly mixed ccndition. Should the zinc blende be removed, there would be a difference in specific gravity of more than one between the pyrite and serpentine rock. and these two minerals would separate in the ordinary way.

Referring to the drawing Fig. 1 and Fig. 2. the space between the dotted lines and riflle tips marked is the ore feed on the surface of the table deck, Z dcnot s zinc blende and a small quantity of pyrite and rock flowing over table deck between the rillle plates 1). Z" denotes zinc blende concentrate flowing over table deck to its discharge, and P and I represent stratas of pyrite and rock flowing to their discharge at the end of the table.

In active operation, with the current turned on the magnet, dressing water valve opened, and ore feed started, the ore will flow down the table in a thin layer 0 partly stratify ng until it reaches and flowsrunder magnet pole 0 The current strength is now regulated in the magnetic coil by a rheostatso that the zinc blende only is affected, but

terminals. The zinc blende will build up on the edge of the first magnetic terminal to a height where the flow of the wash water against it will overcome the attraction and cause it to ride over the groove on the magnetic bridge to the next terminal, and so on to space marked Z on table between the poles. The pyrite and rock flowing down over the table and not being afiected by the magnetism will fall into and fill to a greater or less degree each successive groove. A careful regulation of the ore feed to prevent more ore than the grooves can accommodate is essential. Should a greater flow of ore than the grooves in the first rifile plate can accommodate occur, the surplus ore will overflow and travel with the zinc concentrate in layer Z to the next riiile plate, where the surplus pyrite and rock will be caught in the grooves with a like action to the above. The pyrite and rock that is now in the grooves is effectually trapped, and the peculiar motion of the table progresses it in the channels or grooves to the end of the rifiie plates where it is again discharged on the table deck. Since the zinc, which having been effectually removed, allows a difference of more than one between the pyrite and rock, the discharged pyrite and rock will stratify on the discharge end of the table deck in strata marked P and R and are separated by the ordinary method.

Where there are only two minerals present in the ore, to be separated, the magnetic strength is regulated toafi'ect only one of the minerals and the process is similar to the above.

In ores-that will stratify on a table in its normal operation, a greater economy will result by the use of my invention from the fact that the minerals can be kept apart and the particles cannot intermingle where the present strata join each other and a cleaner separation will result.

The magnetic rifile tips or edges, it will be noted, lie substantially in the plane in which the material affected thereby travels over the table, while the less susceptible material drops away from the'same into the channels. In other words, the susceptible material will normally travel directly into contact with the magnetic tips or edges and will be charged by direct contact without which ore particles of low susceptibility cannot be sufficiently influenced to effect cessful separation, as they seem to be incapable of. being otherwlse charged sulficiently to cause them to travel in the magnetic field in the direction in which the lines of force converge. 7

It wi l" be understood that one or more magnets or magnetic fields with its riflie plates can be used on a single table and it is generally, desirable to usemore than one, especially where several mlnerals are to be separated from an ore mixture as each magnet or magnet field can be adjusted to a feet a diflerent mineral content.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. In an ore concentrator, the combination with a table, of means for feeding-materials to be separated to said table, means for agitating said table to pass said materials gradually along the table to effect Stratification and separation thereof, and means for creating a ma etic field in the path of the moving material and with the lines of force convergin to lines lying in a plane coin- .cident wit the path of the body ofmaterial traveling over t e table.

2. In an ore concentrator, the combination with a table, of means for feeding materials to be separated to said table, means for agiitating said table to pass said materials along the table to efl'ect Stratification and separation thereof, and means for creatin a magnetic field having parallel lines o concentration to which the lines of force converge located intermediate the top and bottom levels of the material flowing over the table in proximity to said lines of concentration.

3. In an ore concentrator embodying a shaking table movable in substantially its own plane said table being provided with rifiles of magnetic material and channels intermediate the rifiles, and means for creating a magnetic field with the lines of force in the ore paths converging to the edges of. the riflies.

4. An ore concentrator embodying a, shaking table movable in substantially its own plane, said table being provided with riiiies having longitudinally extending edges of magnetic material with channels between said rifiies, and means for creating a magnetic field with the lines of force in the ore path converging to the edges of the riflies.

5. An ore concentrator embodying a shaking table -movable in substantially its own plane, said table being provided with a rifiled surface, a portion only of the rifiies having longitudinally extending edges of magnetic material, and means for creating a magnetic field with the lines of force in the ore paths converging to the rifile edges of magnetic material.

6. An ore concentrator embodying a shak- 'ing table on which Stratification is effected, said table beiit'fi; provided with rifiles of mag netic material exposed directly to the contact of the material passing over the table with channels between said rifiles, with means for effecting the feed of material both longitudinally and transversely of the ,rifile's x ed es of the riflles. I An ore concentrator embodying. a shak-' their edges projecting into the path of the material moving over the table, and means for creating a magnetic field in the ore path with the lines of force converging to the 'riflies.

9. An ore concentrator embodying a shaking table'on which stratification is effected, riftles formed of a plurality of strips of magnetic material mounted in the table and spaced apart to form channels, and means for creating a magnetic field in the ore path with the lines of force converging to the upper edges of the ritlie's.

10. An ore concentrator, embodying a shaking table on which stratification is effected, riflles each formed of a plurality of strips with their edges projecting into the path of material over the table, and means for creating a magnetic field in the ore path with the lines of force converging to the edges of the strips.

11. An ore concentrator, embodying a shaking table having incorporated therein rifiles formed of laminated magnetic material with the edges of the laminations in the ore path, and means for creating a magnetic field with the lines of force converging to the said edges of the riflies.

12. An ore concentrator embodying a shaking table provided with riflles of magnetic material each formed of thin strips, the edges of alternate strips being located field in the ore path with the lines of force converging to the edges of the riflles.

14. An ore concentrator embodying a shaking table provided with riflles of magnetic material with thin edges in the ore path, said edges having inserts of non-magnetic material, whereby the edges are made magnetically discontinuous, and means for magnetically energizing the rifiies.

15. An ore concentrator embodying a table on which Stratification is efiected, means for creating an intense magnetic field with the lines of force converging to lines of concentration coincident with the plane of movement of the material over the table and means for removing the magnetic constituents of the material before the material reaches said intense magnetic field.

16. An ore concentrator embodying a table on which Stratification is effected, riflies of magnetic material forming a part of the table, means for magnetically energizing said ritlles, and a magnetic pole forming a magnetic guard to prevent access of-magnetic' material to said ritlies.

17. An ore concentrator embodying a shaking table on which Stratification is effected, riffles of magnetic material incorporated in the table, a fixed magnet for energizing the riflies, and a fixed guard magnet located above the path ofthe material for removing magnetic constituents before the same reach the rifiies.

JOSEPH WEATHERBY.

Witnesses:

THOMAS DURANT, ALEXANDER S. STEwAR'r.

Images