US1491870A - Pulsating jig - Google Patents

Pulsating jig Download PDF

Info

Publication number
US1491870A
US1491870A US417783A US41778320A US1491870A US 1491870 A US1491870 A US 1491870A US 417783 A US417783 A US 417783A US 41778320 A US41778320 A US 41778320A US 1491870 A US1491870 A US 1491870A
Authority
US
United States
Prior art keywords
screen
jig
tank
water
valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US417783A
Inventor
Martin J Lide
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US417783A priority Critical patent/US1491870A/en
Application granted granted Critical
Publication of US1491870A publication Critical patent/US1491870A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B03SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03BSEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
    • B03B5/00Washing granular, powdered or lumpy materials; Wet separating
    • B03B5/02Washing granular, powdered or lumpy materials; Wet separating using shaken, pulsated or stirred beds as the principal means of separation
    • B03B5/10Washing granular, powdered or lumpy materials; Wet separating using shaken, pulsated or stirred beds as the principal means of separation on jigs
    • B03B5/24Constructional details of jigs, e.g. pulse control devices

Definitions

  • My invention relatesgto a jig-f0r ;the sepa ration of minerals of different specificgrav ities which relles upon impulses ofwater-to effect the, separation and stratification of the particles, undertreatment.
  • One distinctive feature of my invention is the utilization of-jan elongated g rotaryor; oscillatory valve substantially co-extens ye' with the screen andlthus adapted to-deliver the water impulse with'substantial uniformity for the length orwidth of the screen, according to its arrangement lengthwise or transversely of the screen.
  • a furthellfeaiurtigf my invention is; the arrangement and synchronousj operation of; such elongated. inlet Valves when disposed ".011 opposite sides of the: jig,1so as to further increase the uniformity of the'elfect of;-the impulses transversely as of the screen.
  • a further feature of my invention is that it lends itself peculiarly to jigs of the type employing traveling screens.
  • the screen issubmerged in the tank with the impulse alvesdisposed between the upper and lower-flights of the screen, and, according to the relative position of-the feed gate, the I discharge chute for the-lighter material and apparatus will function as a concurrent or counter-current jig.
  • Figs. 1 and 2 illustrate in plan and-verticalj cross section; aj ig; with afixed screen and; side impulse valves.-;
  • FIGs. 3 and 4. are similar views of a jig haying a single impulse valve across: the upper I; end ;of the jig; tank;
  • Figs; 5 and 6 are I similar-viewsofawjig with: a; moving; screen; arranged for concurrent flow operation, While Figs 7 and 8- show a jigwith amoving screen arranged for countencurrent. flow pe t1 n;-,
  • Fig. 91 is;a transverse central cross sectional' view taken -through Fig. 6 01- 8.
  • Similarjreference numerals refer to simi- As illustrated in Figs. 1 and .2, I showajig ta-nkjlmounted onsuitable supports 2 and flanked on each side by an" elevated water tank 3 provided near its bottom with a port 4 substantially co-extensive with the length of the jig screen 5'and of the jig tank 1 and normally closed by an elongated rotating or oscillating butter-fly valve 6.
  • a tepifeed gate 10 delivers the coal or-.- mineral to be treated; under control of- -afeeder 11; andat the discharge endpfthe-screen I provide a bottom outlet 12, delivering into a trough 13 containing an endless conveyorl t and an adjustable gate 15, operated by handles 16, which controls the overflow of the lighter particles to the discharge chute -17.
  • ⁇ Vater can be drained from the jig tank through a pipe 18 under control of" a valve 19.
  • the water in tanks 3 is in this art, the separation or Stratification,
  • the efliciency of the jig is due to the uniform distribution of the impulse throughout the cross sectional area of the jig and to the simplicity of the operating mechanism which is confined t0 thetwo rotating valves with the resultthat the apparatus has negligible maintenance cost and requires a minimum power for operation.
  • a single water tank 20 is provided at the upper end of the jig tank in place of the side tanks 3 and the water impulses are delivered into the upper end of the jig tank 5 by working in a flaring conduit 22 which extends from side to side across the jig tank and has its flaring ends projecting into both the water tank and jig tank.
  • the water tank is closed overhead by a sloping bottom 23 which delivers material to be treated to the feed gate 10, which in turn delivers it to a chute 24: which causes it to fall upon the upper end of the screen bed.
  • Figs. 5 and 6 I show a jig arranged for concurrent flow of water and mineral utilizing a traveling screen.
  • the jig tank the butter-fly valve 21' the right 25 is elongated and in its ends has mounted sprocket wheels 26 which support and operate an endless chain screen 27 which is disposed substantially horizontal.
  • These 1 sprockets are driven by any suitable driving mechanism and cause the upper flight of the belt to travel continually and slowly towards the chute l7 and trough 13, in the latter of which theendless conveyor 14: works.
  • the jig is flanked on each side by elevated water tanks 28, these tanks having elongated bottom ports in which are disposed conduits 29 in which butterfly valves 30 work,
  • Fig. 9 which discharge into the jig tank between the upper and lower flights of the screen.
  • the material is fed to the screen by the feed gate'lO under control of the feed er 11 and as'the impulses of water enter and pass upwardly through the screenbelt the material is separated and it is caused to move toward the discharge end of-the jiig both by the motion of the screen and by the concurrent fiow of the water.
  • This arrangement gives a very greatly increased output without materially complicating the mechanlsm.
  • FIGs. 7 and 8 I show a jig similar tothat described in Figs. 5 and 6, except that this design is changed for countercurrent operation, that is to say, for the outflow of water counter to the direction of movement of the hea ie pVaIiicIes on the screen.
  • the'jig'tank 25 is flanked with the water tanks 28 from which the water impulses are admitted to the jig tank under control of valves 30 through conduits 29.
  • the sprockets 26 serve to drive thev endlessdisposed at the left hand end of the tank while the feed gate 10, the overflow chute 17 r and gate 15 are arranged at the other end of the'tank, the chute 17 having a downturned lip 32 which extends down close to the upper level of the traveling screen and serves to and sprocket 26.
  • the operation in this arrangement is that'the screen, as it moves, tends to carr particles towards the left and counter to the current of Water flowing with the lighter particles towards the chute 17 at the right.
  • a jigging mechanism comprising a jig tank, a screen therein, a water tank alongside the screen, there being an elongated nar row inlet port connecting the tanks below the screen and substantially co-extensive with the adjacent marginal edge of the screen, a valve to control the admission of the water supply to the tank by pulsations through said port, said valve being co-extensive with the port, and separate juxtaposed outlets to conduct ofi' the particles of diiierent specific gravity after separation on the screen.
  • a jigging mechanism comprising a jig tank, a screen therein a water tank alongside the screen having a narrow elongated substantially rectangular port connecting the tanks below the screen and substantially co-extensive with the adjacent side of the screen, a relatively narrow elongated ro- .tatable valve extending the full length 01":
  • a jigging mechanismbom prising a tank, a screen therein, a water tank alongside the screen and substantially co-extensive in length with the adjacent side of the jig tank, there being a port substantially co-extensive in length with the jig screen which connects said tanks below the screen, which port has its vertical width reduced to the minimum dimension permissible to conduct the volume of water required for a pulsation under a given head in the water tank, a valve substantially co-extensive in length with said port, and means to admit the water supply to the jig tank by intermittently opening said valve to admit impulses of water below the screen, and means to conduct away from the same end of the jig tank separated material on the screen.
  • a jig comprising a jig tank, a screen, a pair of water tanks disposed on opposite sides of the screen tank and having ports entering the jig tank below the screen and extending substantially for the length of the screen, valves substantially co-extensive'with said ports to admit pulsationsof water to the jig tank, and means to conduct off the particles of different specific gravity after separation on the jig screen.
  • a jig comprising a jig tank, a moving endless screen submerged in the water in the tank, a water tank adjacent to the jigtank having a port entering the jig tank lengthwise of and between the upper and lower flights of the screen, means to move the screen, valve means to admit impulses of water to the jig tank, and means to conduct off the particles of different specific gravity as separated by the jig.
  • a jigging mechanism in which a pair of water tanks are provided on opposite sides of the jig, and opposite valves are operated to admit impulses of water from opposite sides of and substantially co-eXtensive with the screen.
  • Water tanks 1 85 ing a submerged endless screen and means to move it continuously, a water tank alongside the jig tank and having a narrow elongated port for admitting water to the jig tank be-- tween upper and lower flights of the screen, said port being in length substantially'coextensive with the eiiective separating portion of the upper flight of the screen, and means to admit impulses of water through said port into the jig tank, substantially as described.
  • a jigging mechanism a jig tank, a screen therein, opposing water inlets extending substantially the length of the screen, and co-ordinated valve means to admit simultaneously opposed pulsations of water which are effective for substantiallythe full length i of the screen.

Landscapes

  • Separation Of Solids By Using Liquids Or Pneumatic Power (AREA)

Description

A ril 29, 1924. I 1,491,870
M. J. LIDE PULSATING JIG Filed Oct. 18 1920 5 Sheets-Sheet 1 INVENTOR [ATTORNEY April 29, 1924. 1,491,870
M. J. LlDE PULSATING JIG Filed Oct... 18;, 1920 5 Sheets-Sheet 3 INVENTQR 1 ATTORNEY April 29 1924.
- 1,491,370- M. J. LIDE PULSATiNG JIG Filed Oct. 18, 1920 5 Sheets-Sheet INVENTOR /\7/7/P7'//Y. J. ,4 IDE ATTORNEY April 29, 1924. 1,491,870
M. J. LIDE PULSATING JIG Filed 061}. 18 1920 5 Sheets-Sheet 5 INVENTOR Nfl/P Tl/Y. ./1 1 /DE ATTORNEY Patented Apr. 29, 1924.
UNITED? STA/res:
MARTIN J; LIDE; OFLBIRMINGHAM, ALABAMA.
PUL SAT ING JIG.
plication filed fict be 1 1 0; e ial; No; 417,783.
I T 0 all whom it may concern-.1
Be; it known that I, MARTIN" J. LIDE, acitizen of the United Statesof America, re-
siding at Birmingham, in the-county of:
Jefferson and State. of-Alabama, have invented certain new .1 and} useful Improve-l ments in'Pulsating J igs,; of which'the-following is a specification.
My invention relatesgto a jig-f0r ;the sepa ration of minerals of different specificgrav ities which relles upon impulses ofwater-to effect the, separation and stratification of the particles, undertreatment. a
One distinctive feature of my invention; is the utilization of-jan elongated g rotaryor; oscillatory valve substantially co-extens ye' with the screen andlthus adapted to-deliver the water impulse with'substantial uniformity for the length orwidth of the screen, according to its arrangement lengthwise or transversely of the screen.
A furthellfeaiurtigf my invention is; the arrangement and synchronousj operation of; such elongated. inlet Valves when disposed ".011 opposite sides of the: jig,1so as to further increase the uniformity of the'elfect of;-the impulses transversely as of the screen. a
into thejig to a minimum. It can be demonstrated that for a given quantity of water being, pumped into the jig, the; powerre;
quired will varyinversely as the. squarev of the valve opening, or directlyas-the difference in elevation between-the surface levels,
in the jigtanksand the watertank supplylar parts throughout the drawings.
ing it. A- condition of minimum; power consumption would therefore require along rectangular valve opening rather than; a square or circular opening. This condition Icmeet bymaking a rectangular valve opening substantially water isfed in impulseskto the jigltankj by-- the elongated rotating valve or I valves;
The vdistinctiw; featuresabov udescr b d ,for' producing the impulses are. applicable;
Wellies lengt wise the length or width of the screen. as previously'stated; a
to various, types ofji'gs and my inventioncontemplates certain; improved results obtained with; a. fixedscreen by the arrangement of theelongated'impulse valves alongsidethe screen, or by the utilization of a single impulse'valve disposed transversely across theupper-end ofthe jig tank and thus directing itsimpulses towards the discharge-,end of the tank.
A further feature of my invention is that it lends itself peculiarly to jigs of the type employing traveling screens. Here the screen issubmerged in the tank with the impulse alvesdisposed between the upper and lower-flights of the screen, and, according to the relative position of-the feed gate, the I discharge chute for the-lighter material and apparatus will function as a concurrent or counter-current jig.
My-invention will bebetter understood in itsvariousembodiments by reference. to the accompanying drawings, in which the direction of rotationofthescreen, the
Figs. 1 and 2 illustrate in plan and-verticalj cross section; aj ig; with afixed screen and; side impulse valves.-;
Figs. 3 and 4. are similar views of a jig haying a single impulse valve across: the upper I; end ;of the jig; tank;
Figs; 5 and 6 are I similar-viewsofawjig with: a; moving; screen; arranged for concurrent flow operation, While Figs 7 and 8- show a jigwith amoving screen arranged for countencurrent. flow pe t1 n;-,
Fig. 91is;a transverse central cross sectional' view taken -through Fig. 6 01- 8.
Similarjreference numerals refer to simi- As illustrated in Figs. 1 and .2, I showajig ta-nkjlmounted onsuitable supports 2 and flanked on each side by an" elevated water tank 3 provided near its bottom with a port 4 substantially co-extensive with the length of the jig screen 5'and of the jig tank 1 and normally closed by an elongated rotating or oscillating butter-fly valve 6.
These ports 4; are preferably rectangular and are disposed in opposition, as indicated in Fig. 9, and-the valves,preferably-rectam gular' aredriven bygears 7 which mesh gears 8 on a common driving shaft 9," A tepifeed gate 10 delivers the coal or-.- mineral to be treated; under control of- -afeeder 11; andat the discharge endpfthe-screen I provide a bottom outlet 12, delivering into a trough 13 containing an endless conveyorl t and an adjustable gate 15, operated by handles 16, which controls the overflow of the lighter particles to the discharge chute -17. \Vater can be drained from the jig tank through a pipe 18 under control of" a valve 19.
In operation, the water in tanks 3 is in this art, the separation or Stratification,
according to their specific gravity, and by virtue of the flow of water over and across the top of the screen in conjunction if necessary with an inclination of the screen the material is caused to move lengthwise thereover, the heavier particles in the lower stratum passing to the trough 13 while the light-' er particles in the upper stratum overflow through chute 17 with'the surplus water, which in general practice will have the foreign matter in suspense therein settled out,
after which it is returned to the tanks 3. The efliciency of the jig is due to the uniform distribution of the impulse throughout the cross sectional area of the jig and to the simplicity of the operating mechanism which is confined t0 thetwo rotating valves with the resultthat the apparatus has negligible maintenance cost and requires a minimum power for operation.
In Figs. 3 and 4, the jig mechanism is the same as described in connection with Figs. 1 and 2, except that a single water tank 20is provided at the upper end of the jig tank in place of the side tanks 3 and the water impulses are delivered into the upper end of the jig tank 5 by working in a flaring conduit 22 which extends from side to side across the jig tank and has its flaring ends projecting into both the water tank and jig tank. The water tank is closed overhead by a sloping bottom 23 which delivers material to be treated to the feed gate 10, which in turn delivers it to a chute 24: which causes it to fall upon the upper end of the screen bed. The operation in this arrangement is similar to that described, eXcept that the water impulses are derived wholly through the single water inlet below the upper end of the screen and as the impulses are discharged with equal force transversely of thetank and in the direction of the overflow, they facilitate the movement of the material on the screen" towards the discharge. v
In Figs. 5 and 6, I show a jig arranged for concurrent flow of water and mineral utilizing a traveling screen. Here the jig tank the butter-fly valve 21' the right 25 is elongated and in its ends has mounted sprocket wheels 26 which support and operate an endless chain screen 27 which is disposed substantially horizontal. These 1 sprockets are driven by any suitable driving mechanism and cause the upper flight of the belt to travel continually and slowly towards the chute l7 and trough 13, in the latter of which theendless conveyor 14: works. The jig is flanked on each side by elevated water tanks 28, these tanks having elongated bottom ports in which are disposed conduits 29 in which butterfly valves 30 work,
see Fig. 9, which discharge into the jig tank between the upper and lower flights of the screen. The material is fed to the screen by the feed gate'lO under control of the feed er 11 and as'the impulses of water enter and pass upwardly through the screenbelt the material is separated and it is caused to move toward the discharge end of-the jiig both by the motion of the screen and by the concurrent fiow of the water. This arrangement gives a very greatly increased output without materially complicating the mechanlsm.
In Figs. 7 and 8, I show a jig similar tothat described in Figs. 5 and 6, except that this design is changed for countercurrent operation, that is to say, for the outflow of water counter to the direction of movement of the hea ie pVaIiicIes on the screen. Here the'jig'tank 25 is flanked with the water tanks 28 from which the water impulses are admitted to the jig tank under control of valves 30 through conduits 29.
The sprockets 26 serve to drive thev endlessdisposed at the left hand end of the tank while the feed gate 10, the overflow chute 17 r and gate 15 are arranged at the other end of the'tank, the chute 17 having a downturned lip 32 which extends down close to the upper level of the traveling screen and serves to and sprocket 26. The operation in this arrangement is that'the screen, as it moves, tends to carr particles towards the left and counter to the current of Water flowing with the lighter particles towards the chute 17 at the right. In jigs of this character, where a 'large'vol- 'ume of water is supplied, with the impulses uniformly distributed, and relatively free of eddies and whirls, a most rapid and effective separation willtake place and it will be found that the heavier particles are most eifectivel washed as they pass with the'belt to the le t.
My invention contemplates various other.
modifications in the design and arrangement of the screens, water tanks and inlet valves according to the difl'erent classes of material to be treated and the particular results prevent any matter passing over with it the heavier sought, and it may therefore be widely varied within the scope of the appended claims.
Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is I 1. A jigging mechanism comprising a jig tank, a screen therein, a water tank alongside the screen, there being an elongated nar row inlet port connecting the tanks below the screen and substantially co-extensive with the adjacent marginal edge of the screen, a valve to control the admission of the water supply to the tank by pulsations through said port, said valve being co-extensive with the port, and separate juxtaposed outlets to conduct ofi' the particles of diiierent specific gravity after separation on the screen.
2. A jigging mechanism comprising a jig tank, a screen therein a water tank alongside the screen having a narrow elongated substantially rectangular port connecting the tanks below the screen and substantially co-extensive with the adjacent side of the screen, a relatively narrow elongated ro- .tatable valve extending the full length 01":
said port, means to operate said valve to admit pulsations of water through said port into the jig tank, and means at one end of the jig tank to conduct off the particles of different specific gravity after separation on the screen.---
3. A jigging mechanismbomprising a tank, a screen therein, a water tank alongside the screen and substantially co-extensive in length with the adjacent side of the jig tank, there being a port substantially co-extensive in length with the jig screen which connects said tanks below the screen, which port has its vertical width reduced to the minimum dimension permissible to conduct the volume of water required for a pulsation under a given head in the water tank, a valve substantially co-extensive in length with said port, and means to admit the water supply to the jig tank by intermittently opening said valve to admit impulses of water below the screen, and means to conduct away from the same end of the jig tank separated material on the screen.
4. A jig comprising a jig tank, a screen, a pair of water tanks disposed on opposite sides of the screen tank and having ports entering the jig tank below the screen and extending substantially for the length of the screen, valves substantially co-extensive'with said ports to admit pulsationsof water to the jig tank, and means to conduct off the particles of different specific gravity after separation on the jig screen.
5. A jig in accordance with claim 4, in which the opposing valves are of the rotatable type and their operating means are co-ordinated and timed to admit simultaneous opposing impulses of water along the opposite sides of the jig tank.
6. A jig comprising a jig tank, a moving endless screen submerged in the water in the tank, a water tank adjacent to the jigtank having a port entering the jig tank lengthwise of and between the upper and lower flights of the screen, means to move the screen, valve means to admit impulses of water to the jig tank, and means to conduct off the particles of different specific gravity as separated by the jig. I
7. A jigging mechanism according to claim 6, in which a pair of water tanks are provided on opposite sides of the jig, and opposite valves are operated to admit impulses of water from opposite sides of and substantially co-eXtensive with the screen.
8. In a jigging mechanism in accordance with claim 7, the provision of Water tanks 1 85 ing a submerged endless screen and means to move it continuously, a water tank alongside the jig tank and having a narrow elongated port for admitting water to the jig tank be-- tween upper and lower flights of the screen, said port being in length substantially'coextensive with the eiiective separating portion of the upper flight of the screen, and means to admit impulses of water through said port into the jig tank, substantially as described.
10. In a jigging mechanism, a jig tank, a screen therein, opposing water inlets extending substantially the length of the screen, and co-ordinated valve means to admit simultaneously opposed pulsations of water which are effective for substantiallythe full length i of the screen.
In testimony whereof I aifix my signature.
MARTIN J LIDE. Witness:
W. L. ADAMsoiw.
9. In a jigging mechanism, a tank hav
US417783A 1920-10-18 1920-10-18 Pulsating jig Expired - Lifetime US1491870A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US417783A US1491870A (en) 1920-10-18 1920-10-18 Pulsating jig

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US417783A US1491870A (en) 1920-10-18 1920-10-18 Pulsating jig

Publications (1)

Publication Number Publication Date
US1491870A true US1491870A (en) 1924-04-29

Family

ID=23655365

Family Applications (1)

Application Number Title Priority Date Filing Date
US417783A Expired - Lifetime US1491870A (en) 1920-10-18 1920-10-18 Pulsating jig

Country Status (1)

Country Link
US (1) US1491870A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2480140A1 (en) * 1980-04-15 1981-10-16 Fives Cail Babcock Air closure for storage hopper - has double acting ram which acts on rack displacing butterfly air admission valve
US4772384A (en) * 1985-06-07 1988-09-20 Klaus Schonert Jigging method and apparatus for gravity separation in the fine and finest particle size ranges

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2480140A1 (en) * 1980-04-15 1981-10-16 Fives Cail Babcock Air closure for storage hopper - has double acting ram which acts on rack displacing butterfly air admission valve
US4772384A (en) * 1985-06-07 1988-09-20 Klaus Schonert Jigging method and apparatus for gravity separation in the fine and finest particle size ranges

Similar Documents

Publication Publication Date Title
US984866A (en) Aero ore-concentrator and placer-machine.
US1950861A (en) Method and apparatus for feeding and separating dry coal from refuse
US1491870A (en) Pulsating jig
GB959849A (en) Improvements in vibrator apparatus for the surface treatment of workpieces
WO2020186591A1 (en) Pulsating-type heavy medium shallow slot separating device and method
US2609098A (en) Method of and apparatus for continuously cleaning and separating minerals of different settling rates
US763019A (en) Ore sizer and concentrator.
US615968A (en) Apparatus for treating ores
AU637263B2 (en) Method and apparatus for separating particulate solids
US1792179A (en) Coal-cleaning apparatus
US955329A (en) Reciprocating multiple-compartment concentrator.
US1207452A (en) Tabular ore washer or concentrator.
US1939121A (en) Coal cleaner
US269563A (en) Ore concentrator and amalgamator
USRE17272E (en) Pulsating jig
US1494480A (en) Concentrator
US2305568A (en) Ore concentrator
US921089A (en) Ore-concentrator.
US747265A (en) Dry ore-concentrator.
US1346818A (en) Flotation ore-separator
US560552A (en) Ore-concentrator
US1140764A (en) Concentrator.
GB212598A (en) Improvements in and relating to concentrators for ores or other materials
US1369899A (en) Ore-concentrator
US3486620A (en) Dry ore-concentrating table