US1387075A - Ore-concentrator - Google Patents

Ore-concentrator Download PDF

Info

Publication number
US1387075A
US1387075A US322112A US32211219A US1387075A US 1387075 A US1387075 A US 1387075A US 322112 A US322112 A US 322112A US 32211219 A US32211219 A US 32211219A US 1387075 A US1387075 A US 1387075A
Authority
US
United States
Prior art keywords
pan
trough
concentrates
discharge
ore
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
US322112A
Inventor
Charles C Rueger
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 US322112A priority Critical patent/US1387075A/en
Application granted granted Critical
Publication of US1387075A publication Critical patent/US1387075A/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
    • B03B5/68Washing granular, powdered or lumpy materials; Wet separating by water impulse
    • B03B5/70Washing granular, powdered or lumpy materials; Wet separating by water impulse on tables or strakes
    • B03B5/72Washing granular, powdered or lumpy materials; Wet separating by water impulse on tables or strakes which are movable
    • B03B5/74Revolving tables

Definitions

  • My invention relates to that class of concentrating apparatus which is used for the treatment of ore material commonly designated in the art as sand. It is of the type of concentrators known as bateas or pans, and embodies some features common to mechanisms of that type, but difiers from the known forms in several important features and particulars.
  • Figure 1 is a top plan view of the apparatus, with certain parts omitted for the purpose of clearness.
  • Fig. 2 is a vertical partly sectional view taken through the center of the pan.
  • Figs. 2 and 2 are enlarged views of details.
  • Fig. 3 is an enlarged detail sectional view of the peripheral trough and one of the out lets for the heavier concentrates.
  • Fig. 3 is a section taken on line a?; of Fig. 3.
  • Figs. 4 and 4 illustrate radial vertical sections of modified forms of pans.
  • Figs. 5 and 5 show detail views from two sides of the cam mechanism for imparting oscillations to the pan.
  • Figs. 6 and 6 show a detail side view and a detail partly sectional view at rlght' angles to the other, of the recoil mechanism for returning the pan to normal position and imparting impacts to it.
  • Fig. 7 illustrates a modified. mechanism for feeding ore pulp into the separating
  • the most essential part of my apparatus is a shallow pan,preferably made of cast iron or of pressed sheet steel, circular in form, as shown in to view Fig. 1; its form in vertical and radia cross section along line heavy black line inFig. 2, also modifications of form in Figs. 4: and 4
  • the pan being circular, all similar sections through its center present practically identical forms.
  • the deepest part of i the pan is along acircular valley or line 0 about half way between the rims or ridges A and D, and that the pan bottom rises in regular gentle slopes E and F from C to A and D.
  • Rim or ridge D is ata higher level than rim or ridge A and'slope F is steeper than slope E. This may be the preferable arrangement of the slopes but I am aware that other pitches may be employed Without departing from the invention.
  • a circular trough Gr Surrounding the peripheral rim D is" a circular trough Gr divided into two compartments by means of a central annular rib G In this rib are located several outlet tubes H v and H passing out through the bottom of the trough G.
  • One of the outlet tubes is illustrated in Fig. 3.
  • the pan is attached at its center to a funnel shaped casting B having a tubular outlet B, which outlet is pivotally mounted in the tubular socket standard and base plate I.
  • This socket base plate is fastened adjustably to another base plate J, which latter is firmly attached to foundation timbers K.
  • An outlet tube L extends from the plate J and the tubular outlet B to the tailings trough M.
  • the peripheral rim D of the pan is set absolutely level by means of adjusting screws J, provided in the base plate I, before this plate is bolted permanently to its foundation plate J.
  • the pan thus supported and pivoted at its center, isgiven a horizontal vibratory or vanning' movement by a mechanism located at one side near the peripheral trough G.
  • the vibration must be
  • the cam has two camfaces a, a, Fig. 5 alternately engaging with a tappet c, projecting vertically from the bottomof the trough G.
  • Thistappet c has an arm Z secured-to the pan by screws 6.
  • Thethrust of thecam is horizontal, as shown by the arrow in Fig. 5
  • thedevice which I have' contrived forthis purpose It consists of ajlfeed launde'r Q containmg at its outlet a screen Q (shown diagrammatieall'y) for arresting fibrous andother undesirable matter; 'v
  • the launder discharges through the screen into the rotatable hopper 'R, from which a number of'pipes B, provided'wvith suitablefnozzles, distribute the "orepu'lp' into the'pan.
  • ajlfeed launde'r Q containmg at its outlet a screen Q (shown diagrammatieall'y) for arresting fibrous andother undesirable matter; 'v
  • the launder discharges through the screen into the rotatable hopper 'R, from which a number of'pipes B, provided'wvith suitablefnozzles, distribute the "orepu'lp' into the'pan.
  • the hopper R is adjiista hlysupported by means of a bolt R ;'wh ich passes through a sleeve R and is provided witha nut R By turning the nut R the hopper and its "attachment may be raised or lowered. vTo insure regular and uniform distribution of the ore pulp around the Whole circumference oi the pan,
  • thehop per R a'nd its distributing pipes are rotated by means of a cord drive from cam shaft'pulleyis, igsl 1' and 2.
  • a cone Y Fig. 7 attached to the hopper R and rotating ,with it, can be used as the distrib ute'r of the ore pulp
  • the ore pi il'p' p'as'sesirom the hopper B into the cupped apex of the cone Y, thence it fio wsover' the top edge of the cone and spreads evenly over its surface, discharging into the pan at the periphery or base of the cone in althin sheet, the aim always being to combine. uniform distribution of the feed with a minimum disturbance of the ore pulp in the pan.
  • the nozzle of the distributing pipes, ortheperiph'eral edge of the cone is'subme g d slightly the pulp occu 'aying the pan; whichefi'ectsa rotary drag to the pan pulpfand gives the tailings a spiral path to the central discharge instead of the,
  • the discharge tube H communicates with the outside bypassing through the bottom of trough G.
  • Half of the top of the tube is cut off slanting toward compartment G, the remaining top is covered by a suitably formed L-shaped apron of sheet metal U fastened to the top of the rib G with screws.
  • This apron is so made, as shown in Fig. 3, that it shuts off the passage to the top of the tube H on all sides except around the lower edge of the apron.
  • the actual discharge of the concentrates is regulated by caps V screwed onto the outlet of the tube H, said caps being perforated to suit the requirements. If desired, however, some other discharge regulating device may be used.
  • the lighter concentrates flowing into the trough compartment G" are discharged through a similar device provided at outlet tubes H, (Fig. 1) the parts above described being suitably arranged therefor.
  • the concentrates are delivered by the tubes into receptacles W (Fig. 2), or drop into launders which carry them to conveniently placed storage tanks.
  • Fig. 4 shows a pan in which the valley 0 is flat, while Fig. 4c shows the valley C as forming a segment of a curve extend ing from A to D.
  • An apparatus for concentrating ore sand comprising a circular pan having a circular central rim for the discharge of tailings or waste, and a circular peripheral rim for the discharge of concentrates, the lowest or deepest part of said pan being located along a circular channel intermediate and concentric to the said discharge rims, the pan bottom rising from said lowest level by concentric slopes to said central and peripheral discharge rims, means for oscillating said pan, and a pulp feeder for said pan.
  • a concentrating pan of the kind described in claim 1 pivoted on a tubular central axis serving as a tailings conduit, said axis resting rotatably in a socket having a. base plate attached to it, leveling screws in said base plate by which the discharge rims of the pan can be set level, and other screws by which said base plate can be connected with a foundation plate and fastened to foundation timbers.
  • a concentrating pan of the kind defined in claim 1 having a peripheral trough to receive the concentrates discharging over the peripheral. rim, said trough being divided into two concentric compartments and having automatic discharge devices from said compartments to the outside of the pan.
  • a concentrating apparatus of the kind defined in claim 1- in which the mechanism imparting an oscillating movement to said pan includes elements for producing differential oscillations, to impart upward travel to the concentrates from the lower level of the pan toward the peripheral rim.
  • a concentrating apparatus comprising a horizontally oscillating circular pan having an annular central rim for the discharge of tailings or waste and a circular peripheral rim for the discharge of concentrates, the lowest or deepest part of the pan being located along a circular channel intermedi ate and concentric to the said discharge rims, the pan bottom rising from said channel by concentric slopes to said central and peripheral discharge rims, means for oscillating the pan, means for imparting a shock to the pan at the end of each oscillation, a
  • peripheral trough arranged at the circumference of the perlpheral rim and adapted tov receive the concentrates passing over said rim, means for automatically discharging concentrates from said trough, and a feed launder discharging into a revolving hopper, distributing means depending from the hopper and adapted to deliver pulp at or below the level of the pulp occupying the pan.

Description

C. C. RUEGEB. ORE CONCENTRATOR. APPLICATION FILED SEPT-,6, 191s.
Patented Aug. 9, 1921.
2 SHEETSSHEET 2 fly. J.
INV
BY w will ATTORNEYJ UNITED STATES CHARLES C. RUEGER, 0F BEN'ICIA, CALIFORNIA.
ORE-CONGENTRATOR.
Specification of Letters Patent.
Application filed September 6, 1919. Serial No. 322,112.
e, A, A, e, of ri 1 being shown by the To all whom/it may concern:
Be it known that 1, CHARLES C. RUEGER, a citizen of the United States, residing at Benicia, in the county of Solano and State of California, have invented certain new and useful Improvements in Ore-Concentrators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.
My invention relates to that class of concentrating apparatus which is used for the treatment of ore material commonly designated in the art as sand. It is of the type of concentrators known as bateas or pans, and embodies some features common to mechanisms of that type, but difiers from the known forms in several important features and particulars.
The invention consists in the novel features hereinafter described in detail in connection with the accompanying drawings, and more particularly pointed out in the appended claims.
Referring to the drawings Figure 1 is a top plan view of the apparatus, with certain parts omitted for the purpose of clearness.
Fig. 2 is a vertical partly sectional view taken through the center of the pan.
Figs. 2 and 2 are enlarged views of details.
Fig. 3 is an enlarged detail sectional view of the peripheral trough and one of the out lets for the heavier concentrates.
Fig. 3 is a section taken on line a?; of Fig. 3.
Figs. 4 and 4 illustrate radial vertical sections of modified forms of pans.
Figs. 5 and 5 show detail views from two sides of the cam mechanism for imparting oscillations to the pan.
' Figs. 6 and 6 show a detail side view and a detail partly sectional view at rlght' angles to the other, of the recoil mechanism for returning the pan to normal position and imparting impacts to it.
Fig. 7 illustrates a modified. mechanism for feeding ore pulp into the separating The most essential part of my apparatus is a shallow pan,preferably made of cast iron or of pressed sheet steel, circular in form, as shown in to view Fig. 1; its form in vertical and radia cross section along line heavy black line inFig. 2, also modifications of form in Figs. 4: and 4 The pan being circular, all similar sections through its center present practically identical forms.
Patented Aug. 9, 1921.
It will be noticed that the deepest part of i the pan is along acircular valley or line 0 about half way between the rims or ridges A and D, and that the pan bottom rises in regular gentle slopes E and F from C to A and D. Rim or ridge D is ata higher level than rim or ridge A and'slope F is steeper than slope E. This may be the preferable arrangement of the slopes but I am aware that other pitches may be employed Without departing from the invention.
Surrounding the peripheral rim D is" a circular trough Gr divided into two compartments by means of a central annular rib G In this rib are located several outlet tubes H v and H passing out through the bottom of the trough G. One of the outlet tubes is illustrated in Fig. 3. The pan is attached at its center to a funnel shaped casting B having a tubular outlet B, which outlet is pivotally mounted in the tubular socket standard and base plate I. ,This socket base plate is fastened adjustably to another base plate J, which latter is firmly attached to foundation timbers K. An outlet tube L extends from the plate J and the tubular outlet B to the tailings trough M.
The peripheral rim D of the pan is set absolutely level by means of adjusting screws J, provided in the base plate I, before this plate is bolted permanently to its foundation plate J. The pan, thus supported and pivoted at its center, isgiven a horizontal vibratory or vanning' movement by a mechanism located at one side near the peripheral trough G. The vibration must be The cam has two camfaces a, a, Fig. 5 alternately engaging with a tappet c, projecting vertically from the bottomof the trough G. Thistappet c has an arm Z secured-to the pan by screws 6. Thethrust of thecam is horizontal, as shown by the arrow in Fig. 5
and tangential to the pan circle. The recoil :by means of the'screw bolt) 1.
There must "also be provided means for feeding the ore pulp un formly to the concen rat ng pan. F 1g. 2 shows in elevation,
and partlyhsectional, thedevice which I have' contrived forthis purpose. It consists of ajlfeed launde'r Q containmg at its outlet a screen Q (shown diagrammatieall'y) for arresting fibrous andother undesirable matter; 'v The launder discharges through the screen into the rotatable hopper 'R, from which a number of'pipes B, provided'wvith suitablefnozzles, distribute the "orepu'lp' into the'pan. As best shown in Figs. '2; Q 'and 2 the nozzle .R of the pipes R are flattened to present a rectan- 'gular cross section, whichnozzles discharge infspreading jets onto horizontal spreader plates R that deliver the feed material in {thin sheets 'at the surface only and tangenltially' to the pan contents. The hopper R is adjiista hlysupported by means of a bolt R ;'wh ich passes through a sleeve R and is provided witha nut R By turning the nut R the hopper and its "attachment may be raised or lowered. vTo insure regular and uniform distribution of the ore pulp around the Whole circumference oi the pan,
thehop per R a'nd its distributing pipes are rotated by means of a cord drive from cam shaft'pulleyis, igsl 1' and 2. Instead oi the pipes a cone Y Fig. 7 attached to the hopper R and rotating ,with it, can be used as the distrib ute'r of the ore pulp The ore pi il'p' p'as'sesirom the hopper B into the cupped apex of the cone Y, thence it fio wsover' the top edge of the cone and spreads evenly over its surface, discharging into the pan at the periphery or base of the cone in althin sheet, the aim always being to combine. uniform distribution of the feed with a minimum disturbance of the ore pulp in the pan. Vith the latter end in view, the nozzle of the distributing pipes, ortheperiph'eral edge of the cone, is'subme g d slightly the pulp occu 'aying the pan; whichefi'ectsa rotary drag to the pan pulpfand gives the tailings a spiral path to the central discharge instead of the,
shorter radial one to the'ridge A, and con seqlll i ly increased opportunity for separae ti o i ofthevaluable mineral is provided.
I Havingdescribed the'iconstruction, I will now desri be ,theaction or operation of the pan. "The ore'pulp having filled the pan men are carried by the flower Water aided by the vanning motion of the pan. The level of the discharge rim 1s variable by means which can be raised or lowered to regulate the centripetal fiow of the water and tailings into the discharge funnel, from which they p'alss 'downthrough the pipe B and L into the waste launder M, and are carried by the latter to further treatment or to the waste dump. Any valuableminerals sepa rating from thetailings on their way to the overflow151m"); settle on theslope E and gravitateback toward the lowest level 0 of thepan.
When the heavier mineral particles (concentratesfhave settled on the pan bottom. they come under the influence of centrifugal force induced by the oscillating motion of the pan, and tend to mov'e'radially up the slope F. "At the same time the differential motion of thepa-n, fespeciallyif ending in percussion, will move the concentrates tan gontially. resultanttravel of the particles will bediago i'ally'up the slope F along lines dependent on many factors which need not be considered here, but end ing in any case by discharge over the peripheral edge Dintothctrough G. Tofurtangled interior matter, clear water run into trough G from the perforated supply pipe Tin suchcuiantity that a eurrcnt of water toward th center of the pan is produced which ejiiects cleaningas it meets the new of concentrates passing outward over r m D.
" The concentrates having arrived in trough G' are subjected to the maximum motion Of the pan which again stratifies them accordingto their specific gravitypthe heaviest accumulating in the inside compart t GJ the lighter flowing over the divid ing rib G into the outside compartment G or" trough i An enlarged illustration of trough G is given 3 to facilitate adescription of the further course of the concentrates. As already stated, the heavier concentrates settle into the inner compartment G, whence the percussive action ofthe pan, especially,
will transport them along-the trough to the in Figs. 3 and 3 The discharge tube H communicates with the outside bypassing through the bottom of trough G. Half of the top of the tube is cut off slanting toward compartment G, the remaining top is covered by a suitably formed L-shaped apron of sheet metal U fastened to the top of the rib G with screws. This apron is so made, as shown in Fig. 3, that it shuts off the passage to the top of the tube H on all sides except around the lower edge of the apron. Thus the concentrates are compelled to travel the course indicated by the dotted arrow from D to the outlet of the tube H. The actual discharge of the concentrates is regulated by caps V screwed onto the outlet of the tube H, said caps being perforated to suit the requirements. If desired, however, some other discharge regulating device may be used.
The lighter concentrates flowing into the trough compartment G" are discharged through a similar device provided at outlet tubes H, (Fig. 1) the parts above described being suitably arranged therefor. The concentrates are delivered by the tubes into receptacles W (Fig. 2), or drop into launders which carry them to conveniently placed storage tanks.
Fig. 4, shows a pan in which the valley 0 is flat, while Fig. 4c shows the valley C as forming a segment of a curve extend ing from A to D.
It is obvious that various modifications can be made in the herein described apparatus, and in the construction, combination and arrangement of parts, which can be used without departing from the spirit of my invention.
hat I claim and desire to secure by Letters Patent is 1. An apparatus for concentrating ore sand, comprising a circular pan having a circular central rim for the discharge of tailings or waste, and a circular peripheral rim for the discharge of concentrates, the lowest or deepest part of said pan being located along a circular channel intermediate and concentric to the said discharge rims, the pan bottom rising from said lowest level by concentric slopes to said central and peripheral discharge rims, means for oscillating said pan, and a pulp feeder for said pan.
2. A concentrating pan of the kind described in claim 1, pivoted on a tubular central axis serving as a tailings conduit, said axis resting rotatably in a socket having a. base plate attached to it, leveling screws in said base plate by which the discharge rims of the pan can be set level, and other screws by which said base plate can be connected with a foundation plate and fastened to foundation timbers.
3. A concentrating pan of the kind defined in claim 1, having a peripheral trough to receive the concentrates discharging over the peripheral. rim, said trough being divided into two concentric compartments and having automatic discharge devices from said compartments to the outside of the pan.
A. A concentrating apparatus of the kind defined in claim 1-, in which the mechanism imparting an oscillating movement to said pan includes elements for producing differential oscillations, to impart upward travel to the concentrates from the lower level of the pan toward the peripheral rim.
5. A concentrating apparatus of the kind defined in claim 1, in which the mechanism for imparting oscillating movement to said pan is combined with means for imparting shocks to the pan at the end of each oscillationto impart upward travel to the concentrates from the lower level of the pan toward the peripheral rim.
6. A concentrating apparatus of the kind defined in claim 1, in which the mechanism imparting oscillating movement to the pan includes elements for producing differential oscillations, to cause upward travel of the concentrates from the lower level of the pan toward the peripheral rim, and means for imparting shocks to the pan at the end of each oscillation, to accelerate this upward travel.
7. A concentrating apparatus comprising a horizontally oscillating circular pan having an annular central rim for the discharge of tailings or waste and a circular peripheral rim for the discharge of concentrates, the lowest or deepest part of the pan being located along a circular channel intermedi ate and concentric to the said discharge rims, the pan bottom rising from said channel by concentric slopes to said central and peripheral discharge rims, means for oscillating the pan, means for imparting a shock to the pan at the end of each oscillation, a
peripheral trough arranged at the circumference of the perlpheral rim and adapted tov receive the concentrates passing over said rim, means for automatically discharging concentrates from said trough, and a feed launder discharging into a revolving hopper, distributing means depending from the hopper and adapted to deliver pulp at or below the level of the pulp occupying the pan.
8. The combination with a circular ore separating or concentrating pan having a peripheral trough provided with an annular vertical partition, of a plurality of discharge tubes extending vertically through said partition and through the bottom of the trough, for automatically discharging con-, centrates from said trough, the receiving upper ends of said tubes being. partly covered by L-shaped aprons and partly open on the sides, the horizontal portions of said aprons resting on and being fastened to the upper edge of said annular partition, the approximately vertical portions of said aprons extending downwardly along side of the tubes and closing against the annular partition, the lower edges of the vertical portions of the aprons being below the receiving upper ends of the tubes, so that the concentrates will have to pass to the receiving end of the tubes through an opening looat-ed at a lower level, and means for regulating the discharge at the lower ends of the tubes.
In testimony whereof I aflix my signature.
CHARLES C. RUEGER.
US322112A 1919-09-06 1919-09-06 Ore-concentrator Expired - Lifetime US1387075A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US322112A US1387075A (en) 1919-09-06 1919-09-06 Ore-concentrator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US322112A US1387075A (en) 1919-09-06 1919-09-06 Ore-concentrator

Publications (1)

Publication Number Publication Date
US1387075A true US1387075A (en) 1921-08-09

Family

ID=23253469

Family Applications (1)

Application Number Title Priority Date Filing Date
US322112A Expired - Lifetime US1387075A (en) 1919-09-06 1919-09-06 Ore-concentrator

Country Status (1)

Country Link
US (1) US1387075A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2822090A (en) * 1957-03-15 1958-02-04 Arthur A Johnston Concentrator for minerals
US5057211A (en) * 1988-12-19 1991-10-15 Baummer George P Benefication apparatus and process for land and seabed mining
WO1991016135A1 (en) * 1990-04-26 1991-10-31 Cosmos Systems, Inc. Particle concentrator and method of operation

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2822090A (en) * 1957-03-15 1958-02-04 Arthur A Johnston Concentrator for minerals
US5057211A (en) * 1988-12-19 1991-10-15 Baummer George P Benefication apparatus and process for land and seabed mining
WO1991016135A1 (en) * 1990-04-26 1991-10-31 Cosmos Systems, Inc. Particle concentrator and method of operation
US5160035A (en) * 1990-04-26 1992-11-03 Cosmos Systems, Inc. Particle concentrator and method of operation

Similar Documents

Publication Publication Date Title
US2322415A (en) Sand dewatering wheel
US2064554A (en) Separator
US1825157A (en) Method and apparatus for hydraulically separating materials
US1517509A (en) Apparatus for classifying granular material
US3123551A (en) Method and apparatus for separating
US1283846A (en) Centrifugal separator.
US1387075A (en) Ore-concentrator
US1456563A (en) Ore classifier
US1996547A (en) Separator and method
US1990129A (en) Apparatus for separating materials of different specific gravities
US3349904A (en) Method of separating ore particles
US1478761A (en) Gold-washing machine
US1888131A (en) Gyroseparator
US1306270A (en) Ore-separating machine
US1374645A (en) Tailing-separator
US1881875A (en) Bowl classifier
US552995A (en) Ooncentbator
US1494704A (en) Apparatus for separating floating and other impurities in suspension from liquids
US1841462A (en) Separator
US973363A (en) Separator and classifier.
US1314335A (en) Ore-concentrator
US2607484A (en) Method and apparatus for separating granular material
US2323557A (en) Concentrator
US946759A (en) Combined ore feeder, sampler, classifier, and separator.
US3367499A (en) Shaking-funnel device for the gravity concentration of solid particles