Untitled record

Application filed August 29, 1888. Serial No. 284,083, (No model.)

To all whom it may concern:

Be.it known that I, William Bainbridge, a citizen of the United States, residing at Omaha, in the county of Douglas and State of 5 Nebraska, have invented certain new and useful Improvements in Apparatus for Treating Ore; and I do hereby declare the following to be a full, clear, and exact description of the invention, suqh as will enable others io skilled in the art to which it appertains to make and use the same.

My invention relates to an apparatus adapted to be worked in the presence of water to collect the particles of gold or other min15 era! from sand or gravel containing the same, it being particularly intended for treating lowgrade ores containing but little mineral, from which it is adapted to collect the flour or float scale as well as the grain gold.

It consists of an apparatus to be hereinafter described, whereby such low-grade ores or sand and gravel may be advantageously and profitably washed and the precious metals concentrated and saved therefrom.

In the drawings, Figure 1 is a central longitudinal section. Fig. 2 is a transverse section looking toward the tail end of the cylinder, part of one of the cylinder-heads beingbroken away and the position of water-ele30 vator being indicated in dotted lines. Fig. 3 is a transverse section, enlarged, of a portion of the cylinder. Fig. 4 is a horizontal section, enlarged, of a portion of the head end of the cylinder. Fig. 5 is a front end view, en35 larged, of the cylinder, parts being broken away,

The material to be treated is fed into the casing A' inclosing the apparatus through a hopper A, which discharges upon an incline 40 or chute a, by which it is directed into a cylindrical rotating screen Β, mounted upon a central shaft D. This cylinder-screen is composed of the heads 2 3, supported from the . shaft D by spiders 4, and connected with each 45 other by longitudinal bars or stay-rods 5,. extending lengthwise of the cylinder-screen.

Each cylinder-head supports interiorly two concentric rings F F', formed, preferably, of metal and grooved upon their inner faces to 50 receive, respectively, the ends of the bars, which together make up the screening-sur-1 faces of the cylinder-screen, represented, respectively, by C and E. The inner surface C is in the nature of a grate formed of longitudinal bars c, preferably of metal square in 55 cross-section, and placed edge to edge, so as to leave narrow spaces between them, through which the screened material may pass to the outer screening-surface E,which is composed of slats or bars e, preferably of glass, sup- 60 ported by the rings F, and also by intermediate rings 6, carried by the longitudinalbars 5, if found necessary. The glass slats βoverlap each other, as best seen in Fig. 3, and are arranged so that the spaces between- them are 65 less than the spaces between the bars c. The interior of the cylinder-screen is divided into several compartments, preferably four, by longitudinal partitions N, extending from head to head and from the shaft to the 70 outer screening-surface E. Each partition has. secured to one end of its faces inclined strips or flights 0, which serve to feed through the machine such material as fails to pass through the surface C, the final strip O' at the 75 tail end of the machine being scoop-shaped to facilitate the discharge of the material through the central opening of the head 2. Such fine material as passes outward through the outer screening-surface E and which con- 80 tains the scale or flour gold or other mineral being collected falls upon the inclined wingboards 7, by which it is directed to a shoe G, mounted in an inclined position upon rollers or equivalent supports II below the cylinder. 85 This riffle is composed of a series of Z-shaped plates g, mounted in a frame so as to slightly overlap each other and leave open spaces between and under the sections or plates g. The angles or knees of the Z-shaped plates retain 90 any grain gold which may find its way to the riffle. The float gold and fine lighter debris floats off into a hopper X, by which it is conveyed to a reservoir or settling-receptacle L, while , the pyrites, black sand, and the like 95 heavier materials pass to the discharge end of the riffle and are conveyed away by a conveyer K.

To facilitate the separation of the various kinds of material delivered upon the shoe, 100 the latter is given a vibratory and preferablyknocking or thumping motion. This I prefer

413,013 to impart by means of an inclined bearing strip or cam I, carried by the cylinder-screen and engaging with a projection i upon the riffle, which is thereby slid upon its supports toward the head of the machine. As soon as this cam disengages the projection i the riffle is returned by gravity, assisted by a weight J, until it is .arrested with a jar by striking against the partition 8, situated opposite its io discharge end. These jarring and reciprocating movements advance the materials upon . the riffle and cause them to separate, as above set forth. The lighter portions of the sediment collected in the tank or reservoir L are 15 withdrawn through a siphon 9, which leaves the heavier portions containing the gold or other mineral in the bottom of the tank, which, when sufficient has collected, is cleaned and the material removed treated in any suitable manner to collect the fine gold or other mineral contained therein.

The cylinder-screen B is provided at its head end with a series of curved elevatorblades M, of scoop shape, secured to the outer 25 face of the head 3 and arranged to elevate the water from the tank and discharge it through the opening 1 into the cylinder through the central opening in the head 3, thus creating a constant circulation of water 30 through the cylinder from the interior outward so -long as it is rotated, such circulation carrying with it the fine particles of the mineral through the screening - surfaces C and E.

X' is a screen or filter consisting, preferably, of some porous or fibrous material mounted between perforated plates or wire-cloth and situated between the partitions h and x, below the elevator-blades M. This screen operates to prevent the passage of any float material which may be in suspension in the water while allowing the latter to flow readily through the same. A portion 12 of the gratesurface C, bounding each division formed bj^r the partitions N, is hinged at 10, so that as the cylinder-screen revolves it automatically vibrates between the positions shown in full and dotted lines in Fig. 3, thus periodically opening communication between the interior 50 of the cylinder-screen and the space between the gratings C and E, so that all material which has passed through the grate-surface C, but is too coarse to pass through the sur- face E, is returned through the opening made 55 by the grate-surface 12, assuming the dottedline position, into the interior of the cylinder-screen, to be passed out along with the other waste material at the tail end thereof. Each division of the cylinder-screen is pro60 vided with a trap P, arranged adjacent to one of the partitions N and opening into the space between the screening-surfaces C and E. ' Into these traps the particles of gold which are too large to pass between the glass strips forming the surface E collect, and from which they may be removed at proper intervals through openings Q in the outer screen E, which openings are covered by slides R.

Opposite the discharge - opening through the tail and head 2 of the cylinder-screen is 70 mounted a conveyer-belt S, running over a concave or centrally-grooved pulley s, mounted on the shaft 15, and receiving such material as is discharged from the cylinder B and delivering it out of the machine. 75

T are stirrer arms or blades arranged within the hopper or feeding-chute a and mounted upon the shaft D, by which they are rotated to stir and feed into the cylinder the material from the hopper A. 80

The cylinder-screen may be driven from any suitable motor, and the shaft 15, carrying the pulley s, may be belted to the shaft I) of the cylinder by a belt 13, passing over pulleys 14 and V, carried by the said shafts, respectively. 85

The conveypr K is driven from the shaft D by a belt 16, passing over pulleys U U', carried, respectively, by the said shaft and the shaft of one of the turning wheels of the conveyer, and serves to raise the material passing 90 from the shoe and to deposit it on the grooved wheel S', from which it drops on the conveyerbelt S, above referred to.

I will now describe the operation of the apparatus: The tank being sufficiently filled 95 with water, the cylinder-screen is rotated and the material fed slowly into the machine from the hopper A. As it passes along the cylinderscreen it is thoroughly agitated by the rotation thereof and the action of the screening- too surfaces C and E. The finest material, including the float and very small particles of gold, passes through the two screens C andE, being aided in such passage by the water which is being constantly poured into the 105 cylinder by the elevator-blades M, and is directed by the wing-boards 7 to the riffle G. The agitation of the.riffle, as hereinbefore described, serves to furtherseparate the matter fed thereto, the finest portion (including the ito float gold) being carried off, and finally collecting in the reservoir L, the small particles or granules of gold being caught by the knees of the riffle-plates g, while the practically worthless matter is fed over the tail end of 115 the riffle and is delivered to any suitable receptacle or place by the conveyer K. The larger particles of gold which, having passed between the bars of the grave C, yet fail to pass between the bars or slats of the screen E, 120 are collected in the pockets P, whence from time to time they are removed together with such other material as may have collected therein. After the material between the screening-surfaces has been sufficiently sub- 125 jected to their action, it comes opposite to the pivoted portion 12 of the inner grate or screensurface, whereby such portion as has failed to pass through the screen E or to collect in the pockets P, and which is usually worthless 130

413,013 matter, is returned into the interior of the cylinder, to be passed therefrom and out of the machine by the conveyer S.