US1951108A - Centrifugal amalgamator - Google Patents

Description

March 13, 1934. w. J. REILLY 1,951,108

CENTRIFUGAL AMALGAMATOR Filed July 12, 1950 3 Sheets-Sheet 2 March 13, 1934.

W. J. REILLY CENTRIFUGAL AMALGAMATOR Filed July 12 1950 glaflq rm 2 U 55%? 5 Sheets-Sheet 3 awe/whom Patented Mar. 13, 1934 UNETEEE STATES PATENT QFFICE 1,951,108 CENTRIFUGAL AMALGAMATOR William J. Reilly, Denver, 0010. Application July 12, 1930, Serial No. 467,531 3 Claims. (01. 209--199) This invention relates to improvements in cenparticles will be moved outwardly by the centrif trifugal amalgamators of the type employed for ugal force and come in contact with the mercury the recovery of metals from ore and is designed surface and since there is a great afiinity between more particularly for use in recovering the regal mercury and the precious metals, the latter will 5 or precious metals, platinum, gold and silver, but be absorbed by the mercury and combine with it 60 which may also be used for separating any metals to form an amalgam. It is evident that unless that will amalgamate with mercury from nonsome means is provided for producing a circulametallic materials and from metals that will not tion or fiow of mercury when the machine is in amalgamate with mercury. operation, the action will very soon slow down It is well understood that since gold, silver and because after the mercury has absorbed a quantity 65 platinum have a high specific gravity, they will of metal, it is not so efiective as clean mercury settle to the bottom if they are present in a and I have therefore provided means for producliquid pulp which has been agitated and which is ing a circulation of the mercury for the purpose of then allowed to stand for some time and be submaintaining the operation of the device at maxijected to the action of gravity. Where the gold, mum efficiency at all times. 70 silver and platinum particles are very small, the Having thus briefly described the invention the differential action due to gravity alone, is not sufsame will now be described in detail, and for this ficiently greater in reference to one of these mepurpose, reference will be had to the accompanytallic particles than in reference to a particle ing drawings in which the preferred embodiment of silica or any other nonmetallic pulp material, of the invention has been illustrated, and in and separation in this manner has theretofore not which: proved successful. Fig. 1 is a side elevation of my improved amal- It is well known that if materials are introduced gamating device, portions thereof being shown in into a centrifugal machine and rotated at a very section;

high velocity about a central axis, the force known Fig. 2 is a transverse section taken on line 2-2, 80

as centrifugal force is set up which is many times Fig, 1; greater than the force of gravity and advantage Fig. 3 is a section showing a slightly modified has therefore been taken of this knowledge to form of construction of the bowl; effect separation of materials having different Fig. 4 is a view similar to that shown in Fig. 1,

densities such as cream and milk, which is a well but showing another embodiment of the inven- 8 known example, and for the separation of metals tion;

from nonmetallic particles held in suspension in Fig, 5 is a diametrical section through a slightly a liquid. modified form of bowl;

This invention, briefly described, consists of a Fig. 6 is a Section of portion of t 1 bowl which is Open at the top and which is of Fig. 5 showing the same to a larger scale; mounted for rotation about a vertical axis. Fig. 7 is a Section through the upper portion Means is Provided for rotating the bowl at a Very of a bowl of a slightly different construction; high velocity and for introducing pulp into the and 40 gigg g f i gggi i figi g gfi i g ggfi fi Fig. 8 is a section taken on line 8-8, Fig. '7. when the latter is rotated at a high speed, the' In the drawmgs referenie numeral 1 mercury will move outwardly towards the walls of base member from Whlch two or more Veltical supports 2 extend upwardly. The upper the bowl and will move upwardly, due to the fact ted at a high velocity, its ends of the supports are connected by means that when a liquid is rota of a transverse bar 3, and another s1m11ar bar 100 upper surface will assume the shape of a para- I boloid of revolution. The characteristic of the 4 extends between the Supports a Short distance parabola will vary with the speed and if t i above the top of the base. Where two vertical high, the inclination of the sides to the axis of pp are used, the transverse ba s 3 and 4 the parabola will be very small, with the result may be straight, but in actual practice at least that if asufiicient quantity of mercuryis employed, three vertical supporting members are used and V the entire inner surface of the bowl can be covered the transverse supports indicated in the drawwith mercury when the bowl is rotated. If pulp ings by reference numerals 3 and 4 are then is introduced into the bowl near the bottom theremade with three radial arms spaced one hundred of, and caused to rotate with the bowl, the pulp and twenty degrees apart Since th invention will flow outwardly and upwardly and the heavier is not concerned with a specific shape or con- 1 10 struction of the support, the latter has been shown more or less diagrammatically.

Mounted for rotation in the frame above described, is a bowl comprising a cylindrical or substantially cylindrical portion 5, whose lower end has an outwardly extending flange 6 that is secured to the flange 7 at the upper edge of the concave bottom part 8. The upper end of the member 5 is curved inwardly and downwardly as indicated by reference numeral 9. Secured to the lower surface of member 8 is a shaft 10 that is held to member 8 by means of a flange connector 11, or in any other suit able way. The lower end of shaft 10 has a thrust bearing 12 and where it passes through the horizontal member 4 it is provided with a ballbearing 13. A belt pulley 14 is secured to shaft 10 between the two bearings just described. Secured to the upper surface of flange 9 is a spider having a number of arms 15 that are downwardly and outwardly inclined in the manner shown in Fig. 1. The upper ends of arms 15 terminate in a cylindrical tubular portion 16 that forms a journal and which is rotatabiy mounted in the bearing 17 in member 3. When power is supplied to the pulley 14 by means of a belt the bowl can be rotated at any speed in a manner quite apparent from the drawings.

Secured to the bottom 8 and extending upwardly in a pipe 18, whose axis coincides with the ax1s of rotation, and which is provided near its bottom with openings 19. Extending outwardly from pipe 18 are blades or fins 20. A pipe 21 is .secured to the upper transverse frame member '3 by means of a bracket 22 and extends to a point within the pipe 18 as shown in Fig. 1. The upper end of pipe 21 is connected with a hopper 23 that is adapted to contain liquid pulp ,and a valve 24 is provided between the hopper 40 outer surface of the bowl.

23 and pipe 21 for the purpose of regulating the flow of pulp. Surrounding the upper end of the bowl is a plate 25 that extends downwardly a short distance and is spaced from the A launder 26 sur rounds the upper end of the bowl and has an upwardly extending flange or side 27 that pro- J'ects into the space between the member 25 and the outer surface of the bowl, and which is inclined and terminates in a launder 28 that conveys the pulp to a dump. A pipe 29 provided with a valve 30 is secured to the bottom of the bowl and can be used for draining the mercury.

Let us now assume that the bowl contains a quantity of mercury and that it is rotated at a high speed. Since the mercury is contained in the bowl, it will naturally rotate with the bowl and after it has attained a certain speed of rotation, the action of the centrifugal force and gravity will arrange the mercury in such a way that the inner surface thereof will follow the dotted line 31 which is a parabola. By properly proportioning the amount of mercury to the size and the speed of the bowl, it is possible to make the mercury cover the entire irfner surface of the bowl and to ascend until it comes in contact with the under surface of the inwardly and downwardly inclined flange 9. Since it is the object of my invention to produce a circulation of the mercury, I have provided means for removing mercury from the top and returning it to the bottom of the bowl. This means consists of two or more arms 31 that are secured to the pipe 21 and which extend upwardly along the under surface of flange 9 as indicated by reference numeral 32 and have their ends termihating adjacent the inner surface of the bowl. Since the arms 31 are stationary, they will remove mercury from the sides of the bowl and stop its rotation, thereby permitting it to return in the manner indicated by the arrow. In Fig. 3, I have shown how the bowl can be provided with a groove 33 near its upper end so that the mercury will accumulate to a greater depth at this place, and this will facilitate the operation of the arms 32.

In Fig. 7, among other things, I have shown a slightly modified form of means which consists of arms 31d that are tubular, and which terminate at their outer ends in blades 32a that extend into the groove 33. The inner ends of arms 3111 are provided with openings on their under surfaces and with spouts 34 that direct the mercury into the pipe 18. When the arrangement shown in Figs. land 3 is employed, the mercury that is removed from the side of the bowl will very quickly be made to rotate with the pulp and it sometimes happens that it will not reach the bottom of the bowl, whereas, if it is returned to the pipe 18, it will invariably reach the bottom of the bowl so as to produce a circulation of all the mercury whenever the machine is in operation.

Referring now more particularly to Figs. '7 and 8, it will be seen that the inner surface of the bowl has been provided with vertical grooves 35 through which the mercury flows upwardly. One advantage of these vertical grooves is that they prevent the mercury from lagging behind the bowl and in this way the mercury is forced to rotate at the same speed as the bowl, whereas, if the inner surface of the bowl is smooth, there is a slip between the mercury and the bowl and the former never attains the speed of the bowl which is objectionable in devices of this type because the mercury is required to flow upwardly along the steep walls and should therefore have the greatest rotary speed possible under the circumstances.

In Figs. 5 and e, I have indicated another modification that differs from the one shown in Fig. l in this, that the inner surface of the bowl is provided with depressed areas 36 into which the mercury gathers when the bowl is rotated. Any excess mercury accumulates in the groove 3'7 at the top of the bowl. In the modification shown in Fig. 6, the mercury does not circulate when the machine is operating, but the heavier portions of the mercury or that part of it that contains the amalgam, becomes heavier, and moves outwardly and assumes the position indicated by reference numeral 38, and this leaves the inner surface of the mercury quite clean and free from amalgam.

In Fig. 4 I have shown another modification in which mechanical means comprising a pump 39 is used for returning the mercury to the bowl so as to effect a positive circulation of the mercury at all times. In the embodiment shown in Fig.4, the flange 9 of the bowl is dispensed with and the upper end of the bowl is provided with a downwardly extending flange 25a and a mercury launder 40 that has one side 41 projecting upwardly in the space between theflange 25a and the outer surface of the bowl. A ring 42 extends downwardly into the bowl and terminates a short distance below the top thereof, and the upper edge of this ring is connected with an annular plate 43 whose outer edge is secured to the upper end of the cylindrical ring 44. The outer surface of ring 42 is spaced a short distance from the inner surface of the bowl so as to provide an annular space through which the mercury may pass on its way to the launder 40. When the machine is operating the ring 42 serves to separate the pulp from the mercury and the wings 45 function to stop the rotation of the pulpas it flows outwardly in the direction of the arrows 46. The pulp is directed into the launder 47 by the walls 48 and 49, and finally passes through the conduit 50 to a dump. When the machine is operating the pump 39 functions to remove mercury from the launder 40 and to force it through the pipe 51 into the pipe 21 from which it passes into the interior of pipe 18 and out through the holes 19 and thence upwardly along the wall of the bowl. With the machine just described, a large quantity of mercury can be utilized and the machine can therefore be operated for a long time as it will take much longer to make the mercury so rich with metal that it will not circulate than when the smaller amount of mercury is used as in the other embodiments. With the construction shown in Fig. 4, it is also possible to effect continuous operation because the loaded mercury can be withdrawn through the pipe 52 and fresh mercury introduced and in this way the loaded mercury can be removed from the machine without stopping it.

The vanes 20 rotate with the bowl and naturally tend to impart to the pulp the same speed of rotation as that of the bowl, but since the edges of these vanes do not extend to the inner surface of the bowl, there is a considerable slip between the bowl and the pulp and the latter therefore travels upwardly in a helical path, which is advantageous for this reason that it gives the centrifugal force a longer time to operate for the purpose of effecting a separation of the metal values from the nonmetalliferous particles of the clip.

It will be seen from the above description and from the drawings that in my improved machine, the mercury is constantly circulating and moving upwardly along the sides of the bowl and in this manner clean mercury is always provided for coming in contact with the metal in the pulp and therefore a highly efficient separation is maintained at all times.

Having described the invention what I claim as new is:

1. In a centrifugal amalgamator, in combination, a frame, a bowl secured to the frame and mounted for rotation about a substantially vertical axis, the bowl being open at the top, a ring carried by the frame and located within the open top and spaced a short distance from the inner surface thereof, a quantity of mercury in the bowl, means for rotating the bowl at a high speed whereby the mercury will be thrown outwardly and pass upwardly along the wall of the bowl and whereby a portion of the mercury will flow out between the bowl and the ring, means for delivering pulp to the center of the bowl near the bottom, and means for returning the mercury to the bowl after it has passed through the space between the bowl and the ring.

2. In a centrifugal amalgamator, in combination, a frame, a bowl secured to the frame and mounted for rotation about a substantially vertical axis, the bowl being open at the top, a ring carried by the frame and located within the open top and spaced a short distance from the inner surface thereof, a quantity of mercury in the bowl, means for rotating the bowl at a high speed whereby the mercury will be thrown outwardly and pass upwardly along the wall of the bowl and whereby a portion of the mercury will flow out between the bowl and the ring, means for delivering pulp to the bowl near the bottom, means for returning the mercury to the bowl after it has passed through the space between the bowl and the ring and inwardly extending flanges on the ring for retarding the rotation of the pulp.

3. In a centrifugal amalgamator, in combination, a frame, a shaft attached to the frame and mounted for rotation about a vertical axis, a bowl secured to the upper end of the shaft, said bowl having a bottom and substantially cylindrical side, a pipe secured to the bottom and extending upwardly to a point near the top of the bowl, the pipe having openings at its lower end, a plurality of vanes secured to the pipe and extending radially to a point adjacent the inside of the bowl, a trough carried by the frame and surrounding the upper end of the bowl, a flange carried by the bowl and extending downwardly into the trough, an annular channel shaped ring carried by the frame and enclosing the upper end of the bowl, the inside wall of the channel lying within the bowl and spaced a short distance from it and the outer wall extending into the trough whereby a passageway is formed for the passage of mercury from the bowl to the trough, means for rotating the bowl, means for delivering pulp to the inside of the pipe carried by the bowl and means for transferring mercury from the trough to the inside of the pipe.

WILLIAM J. REILLY.

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