US2017740A

US2017740A - Slime table

Info

Publication number: US2017740A
Application number: US537070A
Authority: US
Inventors: Charles B Ulrich
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-05-13
Filing date: 1931-05-13
Publication date: 1935-10-15
Anticipated expiration: 1952-10-15

Description

Oct. 15, 1935. B, RICH 2,017,740

SLIME TABLE iled May'lS, 195i 3 Sheets-Sheet 1 INI-"ENTOR. CHARLES [5- (/1; 18/674 ATTORNEY.

Oct. 15, 1935. a LR|H 2,017,740

SLIME TABLE Fi led May 15, 1951 s Sheets-Sheet 2 k I //v VENTO/Q I #104 01,421.55 5. (/LE/CH ATTORNEY Oct. 15, 1935. c u c 2,017,740

SLIME TABLE Filed May 13, 1931 5 Sheets-Sheet 3 //v VEN TOE. C'HA BLES 5. 01.12 /CH M /J5 @wa 4rroelvex Patented Oct. 15, 1935 UNITED STATES PATENT OFFICE 2,017,740 SLIME TABLE Charles B. Ulrich, Jamestown, N. Y.

Application May 13, 1931, Serial No. 537,070

26 Claims.

My invention relates to an improved construction of slime table for collecting precious metal in finely sub-divided condition, occurring, for example, in ore concentrates, in connection with milling ore containing such precious metals, for example gold, silver and the platinum family.

In the past, it has been usual, particularly in connection with placer mining, to first efiect a rough separation of the metals from the bulk of the crushed ore, after which the fine particles of the precious metals, carried by the mass of the refuse and the water employed in the operations, have been permitted to settle and separate from the mass of the refuse, after which the fine particles of the precious metals have been brought into contact with mercury to recover them by amalgamation with the mercury. I find that with the use of slime tables and devices for bringing the fine particles of precious metals into contact with the mercury as heretofore employed, particularly where the particles of the precious metals are in very finely sub-divided condition, the recovery has been inefiic ent due to the difiiculty the mercury into contact with all of the metallic particles. By my present invention, I provide a construction of slimetable which not only brings the finely divided particles into contact with the mercury employed in the amalgamation, but in additionimy construction provides for moving the rnercury and the metallic particles and material" treated upon each other, with the efiect that the metallic particles and the mercury are thoroughly mixed, bringing practically all of the metallic particles into contact with the mercury, sothat the amalgamation is highly emcient.

This applies of course, only to metals that will amalgamate with mercury. As below described, I provide for collecting the finely divided par-,

ticles of other metals, in another manner.

My invention will best be understood by reference to the accompanying drawings showing a preferred embodiment thereof, in which 45 Fig. lillustrates one form of my slime table in vertical, central, sectional view,

Fig. 2 is a horizontal sectional view to amenlarged scale, of the parts shown in Fig. 1, taken along the line 2-2,

Fig. 3 is a horizontal sectional view of the parts shown in Fig. 1, to an enlarged scale taken along the line 33,

Fig. 4 is a sectional view to an enlarged scale, of the parts shown in Fig. 1, taken along the line 64,

of efiecting thorough amalgamation, by bringing Fig. 5 is a horizontal, sectional view to an enlarged scale, of the parts shown in Fig. 1, taken along the line 55,

Fig. 6 is a plan view to an enlarged scale, of

a part of the table shown in Fig. 1, taken along 5 the line 6-6,

Fig. 7 is a sectional view to a further enlarged scale, of a part of the construction shown in Fig. 6, taken along the line 1-1,

Fig. 8 is a sectional view of a part of the construction shown in Fig. 6 to a further enlarged scale, taken along the line 88,

Fig. 9 shows in plan view, a modified arrangement of slime table and. filtering bed,

Fig. 10 is a sectional view of the parts shown in Fig. 9 to an enlarged scale, taken along the line 10-40,

Fig. 11 is a sectional view of the parts shown in Fig. 9 to an enlarged scale, takenalong the line ll--|l, and

Fig. '12 is a sectional view of a part of the structure shown in Fig. 11 to a further enlarged scale, taken along the line l2-l2.

Similar numerals refer to similar parts throughout the several views.

As shown in Fig. 1, my slime table consists of a conical base lllof any suitable supporting ma--- terial, for example sheet metal, pressed wood, or

l4 and extend downwardly therefrom to engage and be supported by one member iii of a .ballbearing, the other member I! of which receives 7 a stationary support as indicated, from piers l8 extending upwardly from the foundation I9 of the device. As a result, the table may rotate about its vertical axis as permitted by other parts of the mechanism described below.

The sections ll of the table, are covered by a relatively fine mesh screen 20, which prevents particles larger than a desired size, engaging the 45 mercury carried by the sections I l.

The table is provided with a central opening 22 surrounding the upper ends of brackets 23 extending upwardly from the piers l8, l8, to support a ring 24 in stationary position, co-axial with the vertical axis of the table. A pipe 25 is mounted in vertical position, or substantially so, and extends through the ring 24, said pipe having an enlarged upper end as shown at 26, to act as an overflow for material supplied to the pipe 25.

portion of the table.

The enlarged portion 26 ofthe pipe 25, is surrounded by an annular shield 21 secured to the upper portion of the pipe by studs 28 as indicated, so that a clearance space is provided between the rim of the enlarged portion 26 and the inner surface of the shield 21. The lower end of the shield 21 is flared inwardly as indicated at 21a, so that any liquid material flowing over the edge of the portion 26 into the shield 21, will drip along a line indicated at 29 towards the upper The pipe 25 has extending into it, a first hose 38 which may be used to supply the slime to be treated by the device, to the pipe 25. The hose 30 is preferably armored to protect it from mechanical injury and withstand the pressures required to pump the liquid material through the hose. A second hose 3| similar to the hose 30, also extends into the pipe 25, to supply water to the pipe as may be required to float the finer particles of the slime, including the finely subdivided metals, over the rim of the portion 26 of the pipe 25.

The pipe 25 is supported from the ring 24, as more clearly shown in Fig. 2. As shown in this figure, the pipe 25 has rigidly secured to it, a ring 32 having

studs

33, 33 extending oppositely therefrom, which have bearing supports in an intermediate ring 34. The ring 34 is provided with

studs

35, 35 extending oppositely from it, midway between the

studs

33, 33, and into bearing engagement with the ring 24. In this manner, the weight of the pipe 25 and its contents, is carried by the ring 24 in a manner preventing rotation of the ring and pipe, andyet'permitting the axis of the pipe to have a wobbling motion imparted to it. The pipe 25 has secured to it above the ring 32, a hood 36 which prevents any of the liquid material delivered from the rim 26, dropping into or against the parts carried by the ring 24.-

Below the ring 24, the pipe 25 is provided with a lower end port-ion 31 of conical form, the lower end of which extends through a horizontally disposed gear 38 supported by downwardly extending

arms

39, 39 from a stud shaft 40 supported in vertical position for turning movement in a pedestal 4| carried by the foundation 9.

As more clearly shown in Fig. 3, the gear 38 is provided with a web 42 having a radial slot 43 theret-hrough. The web 42 has mounted upon it, by means of a pivot rod or screw 44, a plate 45 provided with a slot 46 extending angularly across the slot 43. The plate 45 is also provided with a second slot 41, which is in the form of an arc about the pivot screw or rod 44. A clamping screw 48 extends through the slot 41 into threaded engagement with the web 42, so that the plate 45 may be clamped in any desired position of adjustment. The slots 43 and 44 are of the same width and this width is substantially the outer diameter of the pipe portion 31 where it extends through ,the gear 38. The axis of rotation of the gear 38 is substantially co-axial with the vertical axis of 110 table l8, and in this manner the pipe portion 31 may be caused to describe a circle of desired diameter, depending upon the adjustment of the plate 45 on the web 42, when the gear 8 is rotated, without imparting rotation about its own axi to the pipe 25.

The wobbling motion imparted to the pipe 25 by rotation of the gear 38, serves to spill the overflow from the pipe 25, over the rim 26 successively at different points around the rim, to

the end that the liquid material dropping from the shield 21, is uniformly distributed around the upper portion of the table.

The gear 38 meshes with a pinion 49 carried by a vertical shaft 58, to the lower end of which 5 is secured a first bevel gear 5| meshing with a second bevel gear 52 rigidly secured to a driving shaft 53 which may be operated from any suitable source of power not shown. The upperend of the shaft carries a crank 54 engaging one 10 end of a connecting rod 55, the other end of which engages a stud 56 rigidly secured to a bracket 51 carried by the angle bar I3 of the table. The relation of the crank 54 to the stud 56 is more clearly shown in Fig. 5. As a result of this con- 15 struction, when the shaft 50 is rotated to wobble the pipe 25, the table In is oscillated by the crank 54, and as a result of the gear 38 being much larger than the pinion 49, the table is oscillated at amore rapid rate than the pipe 25 is wobbled. 20

The lower tapered portion 31 of the pipe 25, is provided with a valve casing 58 provided with a valve member pivotally supported at 59, from which an arm 60 extends outwardly to engage a stud 6| carried by the gear 38, the stud 6| 25 being preferably located on the gear 38 in line with the outer end of the slot 43, as indicated in Fig, 3, and the arm 60 preferably extending from the pipe portion 31, in the same direction. As a result, as more clearly shown in Fig. 4, 30 when the gear 38 rotates in the direction indicated by the arrow, the arm 68 is engaged by the stud 6| and moved on its pivotal support 59, thus opening the valve disk 58a momentarily, and allowing the heavy material collected in the lower 35 portion of the pipe 25, to discharge from the lower end of said pipe, for subsequent treatment, as may be desired. A spring 62 is provided between the arm 60 and a second arm 63 extending from the valve casing 58, to close the valve 40 58a when the stud 6| passes beyond the end of the arm 60. The arm 60 and the stud 6| may be proportioned in any desired manner, to con trol the period of opening of the valve member 58a for each engagement of the arm 68 by the 45 stud 6|.

The covering material [I of the table l0, preferably consists of segmental sections, as shown in Fig, 6, which are preferably made of relatively soft rubber. To facilitate handling these sec- 5 tions, it is desirable that they be not of too great extent, and I find it convenient to make these segments of substantially forty-five degrees each, although any other desired number of sections may be employed if preferred. The outer edge of the table I0 is provided with an upwardly extending flange |0a retaining the segments of the covering material II in place with their edges tightly pressed against each other as indicated at Ila and lb. The segments of the covering material II have annular grooves 64 in their upper surfaces, said grooves being co-axial with the axis of the table l0, and there being as many of these grooves as can be conveniently arranged in the covering material according to the 65 size of the table II). The grooves 64 are preferably formed as shown in Fig. '7, the lower or outer wall 64a of each groove being inclined upwardly and towards the axis of the table In, while the inner or upper wall 641; of each of these grooves is curved so as to widen the groove somewhat outwardly and upwardly, and engage the upper surface of the covering material tangentially. Each of the segments of the cover ing material II is provided with a plurality of partition walls 55 extending radially of the table, and between adjacent partition walls, each groove contains mercury as indicated at 66. As shown in Fig. 8, each partition wall 65 is preferably formed of thin sheet metal folded upon itself, so that its upper edges may be bent outwardly away from each other as shown at 65a, to constitute outwardly deflecting walls for directing the mercury back into the grooves 64, in the event the oscillation of the table I is vigorous enough to throw the mercury upwardly on the partition walls 65. 4

While it is not intended that pieces of solid material of large size will be delivered to the table from the shield 21, I find it desirable to prevent the coarser solid matter delivered from the shield 21, from reaching the screen 20 andinterfering with the treatmentiby the table of the finer slimes. This I accomplish by mounting a conical shield 16, preferably ofv sheet metal, above the screen 20, on posts 11 carried by the lower portion of the base l0, which shield 16 is of larger inner diameter than the screen 20, and carries a relatively coarse mesh screen extending over the inner part of the screen 20 and in the path of the drip from the shield 21. The lower edge of the shield 16, preferably extends sufficiently beyond the moving parts of the machine, to deliver the relatively coarse solid material from the machine, for collection or disposition in any desired manner, not shown.

As a result of the construction described, the liquid material delivered from the rim 26 and flange 21a, is distributed around the upper and inner portion of the table 10, carrying with it in finely sub-divided form the precious metals to be recovered; the liquid mixture-first engages the screen 15 which removes the relatively coarse solid material; the remaining slime then engages the screen 20 which removes the smaller solid matter which is too coarse to be treated by the table, and the fine slime flows down the upper surface of the material I I, and from one to another of the grooves 64, until the remaining slime reaches the lower edge of the table. As-the slime fiows slowly down over the surface of the table, it comes successively into engagement with the several portions of mercury 66, and the oscillation of the table serves to agitate the slime and to thoroughly bring its metallic particles into contact with the mercury, which permits much more thorough amalgamation of the precious metals with the mercury, than if the oscillation did not occur. It will be observed that the fine particles er the metals will tend to remain in the grooves 64, on account of being heavier than the remaining slime, and as a result, if the particles of metal are not engaged by the mercury at first, the mercury is repeatedly moved over them by the oscillation of the table, so that sub stantially all 0' the precious metals in the slime susceptible of amalgamation, are collected by the mercury and amalgamated with it. I

ter the mercury has picked up all of the precious metals it can hold efi'ectivel'y, the operation of the table is stopped, the mercury is collected and removed from the table, and distilled to recover the .values carried by it. To facilitate cleaning up the table and collecting the mercury, the partitions 65 are made sliding fits in corresponding grooves in the covering material I I, and the partitions are provid'ed with holes 651) through them which, when the partitions are moved somewhat towards the axis of the table I, register with the grooves 64, so that the mercury in any groove may flow from the several segments to a single point in the groove and be readily collected from the groove. Each of the partitions 65 is preferably provided with one or more holes 65c through its upper portion, for engagement with a suitable tool for sliding the partition either to register the holes 65b with the grooves 64, or to cover the holes 65b and restrict the mercury action in any groove, to the space between two 1 adjacent partitions 65. I find that for efiective operation, the angle of oscillation of the table by the crank 54, should preferably be substantially the same as the angle between successive or adjacent partitions 65, to the end that the mercury 1 in any groove between adjacent partitions may be caused to travel from end to end of that particular partof the groove 64, for each complete movement of the table Ill in a direction to produce the movement just referred to of the mer- 2 cury.

The lower edge of the table ID has secured thereto a metal trough 61 having a perforated bottom as indicated at 61a, said trough being nearly filled with sponge rubber or other finely subdivided filtering material as indicated at 68. The piers l8 carry brackets 69 extending around the outer edge of the trough 6'! and over the same, to support rollers 10 in engagement with the upper surface of the filtering material 68, as a result of which oscillation of the table [0, rolls the filtering material 68 under the rollers I0 so as to press the water contained in the filtering material through it and retain in the filtering material any fine particlesof solid material which may find their way into the trough 6] from the lower edge of the table I 0. As many rollers 10 maybe employed as desired. In this manner the trough 61 collects the remaining solid material in the slime which is not susceptible of amalgamation, 4 for example rare metals'of the platinum family when they are present in the slime, and the water flowing over the'edge of the trough 61 and through its perforated bottom 61a, may be conveniently,

collectedin a stationary trough 1| supported by brackets 69, from which trough the liquid may be discharged in any desired manner.

The arms 39 of the gear 38 preferably support a pan 12 around the lower end of the conical portion 31 of the pipe 25, to receive the material discharged from said pipe by the opening of the valve member 58a, this pan being provided with an outlet pipe 13 discharging into a fixed trough -14 carried by the pedestal 4|, said trough l4 discharging its contents in any convenient manner.

In Fig, 9 I illustrate a modified form of my slime table and filter bed construction, in which I show a reciprocable slime table I I4 of rectangular form, having its entire surface arranged for treatment of the slime, and a separate reciprec'able filter bed 60 I20 for reeeivingtheremain ng slime from the table"! l4. 'The slime to be treated by the table is fed to'it by a trough I H from .undercurrents derived from a sluiceway or sluiceways in placer mining, from settling tanks, or from any other source of slime containing metal particles susceptible of recovery by the treatments of the present invention. After the slime has been treated by the table, it is discharged from the lower'end thereof to a trough H8 which is widened at its discharge end as shown at I I Ba, the widened portion being provided with partitions H9 to distribute the slime over a much greater width than that of the table 4. The discharge end of the trough H8 delivers the slime to the upper portion of a relatively wide filter bed I20. The liquid, and whatever remaining material is carried thereby, after being acted upon by the filter bed I20, is delivered to a discharge trough I2I to be carried to any desired point. The parts described are supported on a base I22. The slime table H4 is provided with lugs I23 pivotally connected with connecting rods I24 engaged by cranks I25 carried by a shaft I26 mounted in bearings I21 supported by the base I22. The shaft I26 carries a gear I28 by which the shaft may be rotated from any suitable source of power and at any desired rate of operation. The filter bed I20 is provided with lugs I29 pivotally connected with connecting rods I30 engaging cranks I3I carried by a shaft I32 mounted in bearings I33 carried by the base. I22. The shaft I32 has mounted thereon a gear I34 by which the shaft may be rotated at any desired speed from any suitable source of power not shown.

The entire upper surface of the slime table II4 is provided with a covering H5 'similar to the covering II above described. The covering II 5 is provided with grooves extending laterally thereof, similar to the grooves 64 above described, excepting that they are straight instead of annular. The grooves in the covering II5 are crossed by partition walls I I6 of the construction described above for the partition walls 65,-extending longitudinally of the table H4 and sub-dividing the grooves in the covering II5 into short sections, each of which contains mercury, as and for the purposes above described in connection with the grooves 65.

The slime table I I4 is supported by rods I35 extending upwardly therefrom in pairs, each pair of rods, as more clearly shown in Fig. 10, extending through the ends of a yoke I36 resting at its mid portion upon a ball or roller bearing I31 carried by a shaft I38 at a substantial distance above the slime table I I4 and extending longitudinally of the slime table. The shaft I38 is supported by frames I39 spanning the table H4 and carried by the base I22. The upper ends of the rods I35 are preferably provided with nuts I35a for securing desired adjustments of the yoke I36 relatively to the slime table II4. With this construction, when the shaft I26 is rotated, the slime table H4 is oscillated on the bearings I31, and since these hearings are a substantial distance above the slime table and the throw of the cranks I25 is preferably small, the amount of power required to oscillate the table is relatively small since the speed of oscillation is never great, ranging preferably from to oscillations per minute. The proportions of the parts should be such, relatively to the rate of oscillation, that the rate of oscillation imparted to the table by rotation of the shaft I26, will be different from the natural rate of oscillation of the table II4 about the axis of the shaft I38, acting as a pendulum, to the end that the oscillation of the table may produce movement of the mercury in the grooves of the covering II5 of the table, this movement of the mercury being preferably from end to end of the parts of the grooves in any case, in which the mercury is confined by the partitions H6, for each oscillation of the table H4. The filter bed I20 is preferably supported by rods I40 for oscillation relatively to supporting frames MI in the manner just described for supporting the slime table II4.

As shown in Fig. 11, the filter bed I20 has a bottom consisting of a screen I42 supported by an edge flange I20a extending inwardly from the framework of the filter bed. The screen I 42 supports a layer, of filtering material I20d of for example, sponge rubber or other material adapted to engage and remove fine metallic particles from the slime, which filtering material is preferably 5 held in place by a top screen I53, preferably provided with longitudinal ribs I54 holding it in flat condition. The filter bed I 20 has hinged to its longitudinal upper edges at I200, inturned flanges I20b to prevent the slime flowing over the edges 10 of the filter bed when the latter is reciprocated,

- which flanges are provided with horizontally exis desired to remove the screens and the filter- 20 ing material from the filter bed.

The framework of the filter bed has secured thereto and extending below the filter bed, a pan I43 having imperforate side, end and bottom walls so that the pan may at all times be nearly 25 or quite full of water during the operation of the filter bed. The bottom wall oi' the pan I43 is shaped to form three parallel troughs I43a M31), and H30 extending longitudinally of the filter bed and separated by upwardly extending 30 ridges I43d and I436. The mid portion of the screen I42 is supported from the ridges M311 and I43a by a member I44 of triangular cross section engaging the screen I42 at its apex and resting at its lower edges on the ridges M311 and I436, 35 webs I44a preferably joining the side walls of the member I 44 at intervals to reinforce and strengthen it. As more clearly shown in Fig. 12, each of the side walls of the member I44 is preferably shaped so that it consists of a plurality 40 of shallow troughs I 44b extending from the apex of said member to its lower edge, these troughs having slots I44c formed between them to permit the free flow of water through the member I44.

The rods I40 preferably extend around the 45 bottom of the pan I43 in the form of a web section as indicated at I40a, to fit and support the several troughs of the pan and thereby carry the pan and its contents for oscillation with the filter bed by the connecting rods I30. 50

The trough I440 has located therein, an imperforate tube I45 of soft rubber, connected by a flexible pipe or tube I46 with one end of a cylinder I 41. The cylinder I41 contains a piston I48 secured to one end of a piston rod I49, the other 55 end of which is pivotally connected with one end of a connecting rod I50, the other end of which engages a crank I5I carried by a shaft I52. The fluid medium contained in the rubber tube I45 and the corresponding end of the cylinder I41, is 60 preferably air or gas, although liquid, for example water, may be used if preferred. Rotation of the shaft I52, produces corresponding movement of the piston I48, which in turn moves the fiuid in the cylinder alternately into and from the 5 tube I45, producing corresponding inflation and deflation thereof, at a rate determined by the rate of rotation of the shaft I52. Each inflation of the tube I45, indicated at I45a, displaces a corresponding amount of water from the trough 7 I43a and through the slots I440 and correspondingly acts upon the filter material I20d to raise and loosen the small particles of solid material held by said filter material. In this manner, the material caught by the filter bed may be agitated 7 i ticular embodiment above described, it will be.

.When the filter bed has been operated for a sufiicient length of time to collect an appreciable quantity of solid material in the troughs MM and l43b, the filter material I2Ild may be removed from the filter bed, the screen I42 may then be removed, and access may be had to the troughs H36: and M3!) for cleaning purposes. At the same time, the member I44 may be removed and the trough I43c may be cleaned, if suflicient of the solid material has entered the trough I43c to warrant it.

While I have shown my invention in the parunderstood that I do not limit myself to this exact construction as I may employ. equivalents known to the art at the time of the filing of this application without departing from the scope of the appended claims.

What I claim is:

1. In a slime table construction, the combi-' nation of a base supported in inclined position for alternate movement in opposite directions, a layer of covering material on said base inactive relatively to mercury, said covering material having first grooves therein extending in the direction of movement of said base, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing said first grooves respectively into a plurality of short portions each, mercury in each of said groove portions, and means for znoving said base alternately in opposite direcions.

2. In a slime table construction, the combination of a base supported in inclined position for alternate movement in opposite directions, a layer of covering material on said base inactive relatively to mercury, said covering material having first grooves therein extending in the direction of movement of said base, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing said first grooves respectively into a plurality of short portions each, mercury in each of said groove portions, and means for moving said base alternately in opposite directions, each of said first grooves having a lower wall inclined upwardly and towards the upper edge of the base and an upper wall curved away from said lower wall to merge tangentially with the upper surface of said covering material.

3. In a slime table construction, the combination of a base supported in inclined position for alternate movement in opposite directions, a layer of covering material on said base inactive relatively to mercury, said covering material having first grooves therein extending in the direction of movement of said base, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing said first grooves respectively into a plurality of short portions each, mercury in each of said groove portions, and means for moving said base alternately in opposite directions, said partitions being. a sliding fit in said second grooves and having openings registering with said first grooves for one position of said partitions, said partition openings being covered by said covering material for another position of said partitions.

4. In a slime table construction, the combination of a base supported in inclined position for alternate movement in opposite directions, a layer of covering material on said base inactive relatively to mercury, said covering material having first grooves therein extending in the direction of movement of said base, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing said first grooves respectively into a plurality of short portions each, mercury in each of said groove portions, and means for moving said base alternately in opposite directions, said partitions being. a sliding fit in said second grooves and having openings registering with said first grooves for one position of said partitions, said partition openings being covered by said covering material for another position of said partitions, said partitions having holes therethrough for receiving a partition 25 moving tool.

5. In a slime table construction, the combination of a base supported in inclined position for alternate movement in opposite directions, a

' layer of covering material on said base inactive relatively to mercury, said coveringmaterial having first groovestherein extending in the direction of movement of said base, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing said first grooves respectively into a plurality of short portions each, mercury in each of said groove portions, and means for moving said base alternately in opposite directions, said partitions having ontheir upper edges curved flanges extending over the adjacent portions of said first grooves.

6. In a slime table construction, the combina-- tion of a base supported in inclined position for alternate movement in opposite directions, a layer of covering material on said base inactive relatively to mercury, said covering material having first grooves therein extending in the direction of movement of said base, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing said first grooves respectively into a plurality of short portions each, mercury in each of said groove portions, and means for moving said base alternately in opposite directions, said second grooves being deeper into a plurality of short portions each, mercury in each of said groove portions, means for moving said base alternately in opposite directions, pairs of rods extending upwardly from said base, a yoke engaging the upper ends of each pair of said rods and extending laterally of said base, an anti-friction bearing supporting each of said yokes, a shaft extending longitudinally of and above said base supporting said bearings, and frames supporting said shaft.

8. In a slime table construction, the combination of a base supported in inclined position for alternate movement in opposite directions,'a layer of covering material on said base inactive relatively to mercury, said covering material having first grooves therein extending in the direction of movement of said base, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing said first grooves respectively into a' plurality'of short portions each, mercury in each of said groove portions, means for moving said base alternately in opposite directions, pairs ,of rods extending upwardly from said base, a yoke engaging the upper ends of each pair of said rods and extending laterally of said base, an antifriction bearing supporting each of. said yokes, a shaft extending longitudinally of and above said base supporting said bearings, and frames supporting said shaft, said moving means comprising a rotary shaft, cranks carried by said shaft, and connecting rods connecting said cranks and said base.

9. In a slime table construction, the combination of a base, covering material on said base adapted to carry mercury for amalgamation treatment of slime flowing over said covering material, a second base, filtering material carried by said second base for receiving treated slime from said covering material, means for moving said bases alternately in opposite directions, each of said bases being rectangular and said second base being wider than said first named base, a trough for receiving slime from said covering material and delivering it on said filtering material and increasing in width towards said filtering material, and partitions in said trough diverging towards said filtering material to distribute the slime laterally over said filtering material.

10. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, and partitions in said second grooves dividing each of said circular grooves into a pluralityof relatively short portions.

11. In a slime table construction, the combination of a conical base supported for oscillatoiy movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, and partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions. each of said circular grooves having a lower wall inclined upwardly and towards the upper edge of the base and an upper wall curved away from said lower wall to merge tangentially with the upper surface of saidcovering material.

12. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, and partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, said partitions being a sliding fit in said second grooves and having openings registering with said circular grooves for one tion of a conical base supported for oscillatory 5 movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, and partitions in said second grooves 10 dividing each of said circular grooves into a plurality of relatively short portions, said partitions being a sliding fit in said second grooves and having openings registering with said circular grooves for one position of said partitions, said partition 15 openings being covered by said covering material for another position of said partitions, said partitions having holes therethrough for receiving a partition moving tool.

14. In a slime table construction, the combinago tion of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, 25 and partitions in said second grooves dividing each of said circular grooves-into a plurality of relatively short portions, said partitions having on their upper edges curved flanges extending over the adjacent portions of said circular grooves. 30

15. In a slime table construction, the combinaation of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second 35 grooves therein extending across said first grooves, and partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, said second grooves being deeper than said circular grooves. 40

16. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on said-base having circular grooves for holding mercury, said covering material having second 45 grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, a fine-mesh screen above said covering material, and means for de- 50 livering slimes upon the upper portion of said screen.

17. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on 55 said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circular grooves into a plurality 60 of relatively short portions, a fine-mesh screen above said covering material, a coarser-mesh screen above said fine-mesh screen, means for delivering slimes upon the upper portion of said coarser-mesh screen, and a filter bed carried by grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circulargrooves into a plurality of relatively short portions, afine-mesh screen above said covering material, a coarser-mesh screen above said fine-mesh screen, means for delivering slimes upon the upper portion of said coarser-mesh screen, a filter. bed carr ed by'the lower portion of said base below the path of flow of material on said coarser-mesh screen and receiving material discharged from the lower portion of said fine-mesh screen and from the lower portion of said covering material, said coarsermesh screen extending from over the upper portion of said base part way towards the lower portion of said base, and an'imperforate shield extending from the lower edge of said coarser-mesh screen and continuing the path of flow of material from the latter over and outside of said filter bed.

19. In a slime table construction, the combination of a conical base supported'for oscillatory movement about its ax s, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, said covering material being in sections-permitting ready handling, and a flange extending upwardly from the lower portion of said base holding said covering sections in place.

20. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, a screen above said coveringtmaterial, said base, said covering material and said screen having central clearance openings, a pipe extending vertically through said openings, a universal joint supporting said pipe restraining said pipe from rotary movement about its axis and permitting a wobbling movement of said pipe, devices closing the lower end of said pipe, means for supplying slimes 'to said pipe, said pipe having an enlarged rim at its upper end for directing overflow from said pipe upon said screen, and mechanism for oscillating said base and for wobbling said pipe at a slower rate than the rate of oscillation of said base.

21. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, a screen above said covering material, said base, said covering material and said screen having central clearance openings, a pipe extending vertically through said openings, a universal joint supporting said pipe restraining said pipe from rotary movement about its axis and permitting a wobbling movement of said pipe, devices closing the lower end of said pipe, means for supplying slimes to said pipe, said pim having an enlarged rim at its upper end for directing overflow from said pipe upon said screen, mechanism for oscillating said portion of said pipe to move it.

base and for wobbling said pipe at a slower rate than the rate of oscillation of said base, and a 22. In a slime table construction, the com- 5 bination of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first 10 grooves, partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, a screen above said covering material, said base, said covering in erial and said screen having central clearance 15 openings, a pipe extending verticallythrough said openings, a universal joint supporting said pipe restraining said pipe from rotary movement about its axis and permitting a wobbling movement of said pipe, devices closing the lower end of said pipe, means for supplying slimes to said pipe, said pipe having an enlarged rim at its upper end for directing overflow from said pipe upon said screen, mechanism for oscillating said base and for wobbling said pipe at a slower rate 25 than the rate of oscillation of said base, said slme supplying means comprising a flexible tube inserted in the upper end of said pipe, and a second flexible tube extending into the upper end of said pipe for supplying water thereto. 30 23. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding grooves therein extending across said first grooves, partitions. in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, a screen above said covering material, said base, said covering ma- 40 terial and said screen having central clearance openings, a pipe extending vertically through said openings, a universal joint supporting said pipe restraining said pipe from rotary movement about its' axis and permitting a wobbling move- 45 ment of said pipe, devices closing the lower end of said pipe, means for supplying slimes to said pipe, said pipe having an enlarged rim at its upper end for directing overflow from said pipe upon said screen, a first gear for wobbling said 50 pipe, a smaller gear meshing with said first gear, and devices connected with said smaller gear for oscillating said base, said first gear having an eccentric opening through it receiving the lower 55 24. In a slime table -construction, the combination of a conical base supported for oscillatory movement about. its axis, covering material on said base having circular grooves for holding mercury, said covering material having second 60 grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, a screen above said covering material, said base, said covering ma- 05 pipe, a smaller gear meshing with said first gear, devices connected with said smaller gear for oscillating said base, said first gear having a slot extending radially through it, a plate pivotally mounted on said gear and having a slot extending obliquely across said gear slot, and devices for holding said plate in desired position on said first gear, said slots being of substantially the same width and receiving the lower portion of said pipe.

25. In a slime table construction, the combination of a conical base supported for oscillatory movement about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves dividing each of said circular grooves into a plurality of relatively short portions, a screen above said covering material, said base, said covering material and said screen having central clearance openings, a pipe extending vertically through said openings, a universal joint supporting said pipe restraining said pipe from rotary movement about its axis and permitting a wobbling movement of said pipe, devices closing the lower end of said pipe, means for supplying slimes to said pipe, said pipe having an enlarged rim at its upperend for directing overflow from said pipe upon said screen, mechanism for oscillating said base and for wobbling said pipe at a slower rate than the rate of oscillation of said base, and 9.

shield carried by said pipe above and around said universal joint protecting the latter from said slimes.

26. In a slime table construction, the combination of a conical base supported for oscillatory movement. about its axis, covering material on said base having circular grooves for holding mercury, said covering material having second grooves therein extending across said first grooves, partitions in said second grooves divid- 10 ing each of said circular grooves into a plurality of relatively short portions, a screen above said covering material, said base, said covering material and said screen having central clearance openings, a pipe extending vertically through said openings, a universal joint supporting said pipe restraining said pipe from rotary movement about its axis and permitting a wobbling movement of said pipe, devices closingthe lower end of said pipe, means for supplying slimes to said pipe, said pipe having an enlarged rim at its upper end for directing overflow from said pipe upon said screen, mechanism for oscillating said base and for wobbling said pipe at a slower rate than the rate of oscillation of said base, said closing devices comprising a valve having a projecting arm and means tending to hold said valve in closed position, and a member engaging said valve arm during movement of said pipe to periodically open said valve.

CHARLES B. ULRICH.