CA1052737A - Metal separating process and apparatus - Google Patents

Abstract

ABSTRACT
Heavy metals such as gold, silver platinum, copper, etc., in the free state, are separated from their ore by applying water and the ore in finely divided form to at least three rotating, inclined, spiral grooved discs driven from a common shaft. The grooves are closely spaced and with declining pitch from periphery to an annulus at the center of the disc. The free metal tends to sink to the bottom of the grooves and the lighter ore is washed away as the metal moves along the spiral grooves to the annulus.
The free metal and any remaining ore is fed from the annulus to the succeeding disc and the process is repeated.

Description

-` 105~,73i~ - 2 -1 OA,~. ~llND 0~ INVlNTION

; This invention relates to a process and apparatus 4 ~or separating heavy me-tals such as gold7 silver, platinuM, 5 copper, lead~ etc., in their free sta-t~?7 from their 6 surrounding ore, In some instances, the me-tal is present 7 in mine tailings which heretofore had little9 if any, - 8 commercial value because of the large recovery costs, and 9 hence were abandoned.

11 In other instances, the metal is present in a 12 natural occurring ore body9 but not of suf~icient si~e to 13 permit economic recovery by conventional processes.

:- 15 Various types of apparatus have in the past been employed ~ 16 to recover precious metals such as gold from tailings, raw ore, - 17 etc.~ using water washing techniques. One -type of apparatus 18 employed an inclined grooved wheel separator to which was 19 fed a supply of ore which was -then water washed. Gold 20 particles sank to the bottom of the grooves and the rotation i 21 of the wheel caused the gold to be moved to a central orifice ; 22 where it was recoveredJ
,' 23 24 The basic problems with employing a single wheel or a ~- 25 plurality of wheels involved the use of feed augers 26 fo:r every wheel and the necessity for maintaining a uniform 27 feed to each wheel. Once the beneficiated ore was removed 28 from a wheel, i-t tended to dry ou-t in a non-uniform fashion;
29 this made it difficult to feed it uni~ormly to a succeeding 30 wheel even with a mechanical device such as -m auger.
:............ 31 ~ 32 ~urthermore~ more grooved-wheel separators produced a !. 3~ spectrum of ore grades each of which required separate treatmen-t.
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1 Consequently~ many bodies of ore tailings still

2 exist which contain gold bu-t which could not be ~ur-ther

3 economically refined with the available apparatus, It is, therefore~ an objec-t of -this invention 6 -to provide a process and apparatus therefor which is 7 adapted to separate hea~y metals including preVious 8 metals from their associated ore such as tailings) raw 9 ore~ sluice box cleanings, sand bodies such as found in 10 rivers, in waste from sand plan-ts, etc, ., 11 12 Other objects of this invention will become 13 apparent from the description and single drawing to 14 follow which show~ a cross-sec-tion view of the apparatus 15 of this in~ention in side elevation.

17 According to the invention~ the process and 18 apparatus therefor provides a plurality of inclined 19 grooved wheels, each having an outer rim -to retain ore 20 ma-terial on the wheel surface, ~he grooves are tightly 21 packed with a minimum of flat sur~ace be-tween each groove 22 so that the free flow of dressing water is not a significan-t 23 factor in the process. The grooves are spiralled inwardly 24 with a declining pitch andte~nina-te in a central annulus 25 which leads to a downwardly inclined feed funnel, 27 A succeeding wheel is fed directly ~rom the 28 funnel, with at least -three wheels and as many as six 29 wheels being employed. ~he number o:f wheels employed ; 30 depe~d on such factors as the concentration of metal in 31 the ore~ the mesh size of the ore 9 wheel speed, wheel ~2 size and groove spacing, the amount of wa-ter etnployed, ~ 3 _ ,~, , ;' , .. ~. ' , . . .
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.. 1 -the cohesiveness of -the or~ itself9 et~ A wa-ter feed ; 2 system is provided -to produce a ~lurry by applying water .. 3 thereto, the heavy gol.d particles se-ttle to the bottom

4 of the grooves and are ro-ta-ted to~ard -the center orifice . 5 of the wheel along with some ore, The concentrate is 6 then fed as a slurry to the f1mnel and downwardly by 7 gravity feed along the funnel to -the succeeding wheel : 8 where the process is repeated, Af-ter successive .. 9 treatments with at least three wheels and as many as : 10 six wheels, if necessary, a highly concentra-ted gold 11 ore is produced.
.. 12 ~ 13 (rhe process is not only con-tinuous 9 ra-ther :; 14 than being a batch operationl but also can be continuously .` 15 controlled by regulating: a~ the weight and volume of .. : 16 initial feed to the first wheel; b) the amoun-t of water .. ; 17 applied; c) the inclination7 and d) the speed of each succeeding . 18 wheel. This permits the production not only of a 19 concentrated ore but also results in a high recovery . 20 which in many cases varies from about 95% 99%. Furthermore, . 21 the e~fect of feeding a slurry of beneficiated ore .~ 22 through the centrally located feed funnel -to-tally 23 elimina-tes the requirements of feed augers while , 24 permitting the controlled flow of slurry from wheel .. :., 25 to wheel.
.. ~ 26 ~. 27 In FIG~ 1, a plurality of adjustably inclined ; 28 grooved wheels 10~ 11 and 12 are ,shown mounted by brackets ; 29 13~ 14 and 15 on vertical support frames 16~ 17 and 18 ~' 30 which are ,secured at thei.r bases by a hori~on-tal support =~
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.`r,JI 1 frame 199 Thc upper surface of each wheeel bears a plurality 2 of grooves 20 which spiral frorrl the periphery of -the wheel 3 to a central annulus 21. rach wheel has an outer retairl1ng rim 22 and an inwardly inclined lip 23. This arrangemen-t of rim and lip permits the optimum retention of ore on each ~- 6 wheel The underside of each wheel provides a plurality of 7 spoked supports 24, A plurality of hubs 25 is provided to permi-t ~ 8 mounting on a drive shaft. Adjustable wa-ter spray bars 9 - 9 only one bar 26 being showrn is provided for applying 10 water to slurry the ore af-ter i-t contacts each wheel. An 11 adjustable speed motor 27 drives a horizontal rotating ; 12 shaft 28 connecting to belt drives 29 (only one being 13 shown) in each of the brackets 133 14 and 15D Connecting 14 shafts 32, 33 and 34 connect belt drives 29 to drive gears 15 ~5, 36 and 37 mounted in the hubs 25. When the adjustable 16 motor 27 is actuated, the grooved wheels 10, 11 and 12 ,~ 17 will be rotated. Collector funnels 40 and 41 are provided 18 on the wheels 10 and 11 to transfer the gold and some of 19 the ore as a slurry -to succeeding wheels 11 and 12. A
20 collector funnel 42 transfers the final concentrate to a 21 concentrate collector 4~. Funnels 443 45 and 46 collect 22 the separated ore, tailings, e-tcO, following treatment on 23 each wheel where they may be treated further if necessary `~ 24 or discharged through a connecting pipe 47 to a tail pile~
25 A nugge-t screen 48 may be employed, if desired, to collect 26 large size gold par-ticles, `~ 28 The collector wheels 10, 11 and 12 may be 29 constructed of an injection-mvlded plastic such as a ~2

- 5 -' ' 5i~737 ~ 6 1 filled nylon~ polyester, polyurethane9 polypropylene, e-tc.
2 The grooves 20 in each wheel are pre~eYclbly V-shaped 9 and have a declining pi-tch Prom the periphery to the central 4 annulus 21. The upper edge o~ each ridge is sharply 5 angled to maintain the dressing water in -the grooves and

6 minimiæe water overflow For a 43 inch diameter wheel,

7 a preferred length of spiral would be about 88 inches

8 with a spiral wind of abou-t 1--~ turns. A to-tal number o~ about 30 grooves are suitable ~or the ~irs-t two wheels 10 10 and 11, while -the wheel 12 employs 14 grooves per 11 wheel. The groove depth in the first two separator 12 wheels 109 11 decreases from abou-t 350 mils at the rim 13 to about 280 mils at the annulus. For the third separa-tor 14 wheel 12 and succeeding wheels~ the groove depth decreases 15 fromabout ~00 mils at the periphery to about 240 mils at 16 the annulus. Typical annulus diameters for the three 17 wheels are 7 inches, 5 inches and 1.5 inches for the 18 wheels 10, 11 and 12 respectively. The wheels 109 11 19 and 12 are adjustably inclined -to the horizontal wi-th a 20 decreasing angle; typical inclination angles ~or a 43 inch 21 wheel are about 120-150, 120-1407 and 100-125 for 22 wheels 107 11 and 12 respectively. X~ addi-tional wheels 23 are employecl, typical inclinations are 100- 125.

When employing a 24 inch diame-ter wheel, a 26 preferred spiral wind is about 2 revolu-tions from periphery 27 to center; a total number of about 15 grooves are suitable.
28 The groove depth in the first two wheels 10~ 11 decreases 29 from abou-t 350 mils at the rim -to about 280 mils at the ~2 ~, .. . . .
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- l ~annulus. For the third separator wheel 12, and succeeding wheels, 2 the groove depth decreases from about 300 mils at the periphery 3 Ito about 240 mils at the annu~ The 24 inch diameter wheels 4 lemploy the same gro~ve depths as the corre~ponding 43 inch wheels.

: 6 In operation7 heavy metal tailings or ore are - 7 applied to the rota-ting (10-30 RPM) whe l 10 at the down-. wardly moving side~ and below the cen-ter annulus 21. The

- 9 ore may be applied manually, but it is preferable to employ an auger9 belt or bucket feed (not shown) -to maintain a ll uniform supply to the first separa-tor wheel 10. Simultaneously, .. 12 water from spray bar 26 is applied to the ore to :~ 13 form a slurry~ H~avy metal is washed to the bo-ttom of -the : 14 grooves 20 and is rotated along the grooves to the annulus 21.
Lighter coarse ore is washed to the periphery of the 16 wheel and over the lip 22 where it is collected and .~ 17 discharged by troughs 44, 45u ~ slurry of fine ore and . 18 heavy metal is passed through the first funnel 40 and : l9 then passes downwardly to the separator wheel 11 for further separa-tion. Addi-tional spray bars are employed -~ 21 for the wheels 11 and 12. Further -treatment of the ore -; 23 on the wheels 11 and 12 effec-ts a metal recovery of abou-t .~ 23 95%-g9% efficiency.
. 24 . 25 In another embodiment of this inven-tion, raw .-~. 26 ores9 tailingsg etc., are fed to a flrs-t separator wheel 27 and a secon.d separator wheel on a common mount, and having ~,t'' 28 the same in.clination as the first wheel~ is fed the over-~ 29 flow from -the first wheelJ ~he beneficiated ore from the first separa-tor wheel bypasses -the second wheel and is 31 fed through the funnels at the annulus directly -to th~

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10'~ ~37 ., third whe~l. Consequently3 the second wheel ~unc-tions 2 solely to recovcr any gold lost in the overflow at -the 3 first wheel separation stage, :5mploying a -~ H~P~ adjustable drive7 the .: 6 apparatus of this lnvention can process 1.5~2 tons of .. : 7 ore per hour and this perrni-ts the working of tailings 8 which previously had been considered impossible.
, 9 ;- 12 ; 13 . 15 .~ 16 .i. 18 ~` 19 ~ 21 ,`i 23 ; 24 ` 25 .. 26 ~: 29 "
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Claims (10)

CLAIMS:
1. Claim 1. An apparatus for separating metal, from ore which comprises:
   a.) a plurality of commonly driven, serially mounted, upwardly inclined, rotatable wheels;
   b.) each wheel bearing a plurality of spiral grooves directed from a peripheral lip to a central annulus of the wheel;
   c.) each wheel providing a funnel around the annulus adapted to forward a slurry of separated metal and ore to a succeeding wheel.
2. Claim 2. An apparatus for separating metals in the free state from ore which comprises:
   a.) a plurality of at least three downwardly inclined, serially mounted 7 rotatable, flat pan-shaped separating wheels including a common shaft means for driving said wheels, each wheel providing:
   i. a peripheral retaining lip, ii. a central annulus, and iii. a plurality of spiral grooves disposed on the upper surface of each wheel and directed upwardly and inwardly to the annulus, each of said wheels being concntrically rotatable about its central annulus;
   b.) means to form a water slurry with the ore on each wheel; and, c.) a funnel positioned around the annulus of each wheel for forwarding beneficiated ore along the spiral grooves from the central annulus downwardly to the succeeding wheel.
3. Claim 3. The apparatus of Claim 2 in which each wheel in succession bears an angle of inclination to the horizontal of about 120° - 150°, 120° - 140°, and 100° - 125° thereafter.
4. Claim 4. The apparatus of Claim 2 in which the said wheels are constructed of an injection molded plastic material.
   
   CLAIMS:
5. Claim 5. A process of separating metals in the free state from ore which comprises the steps of:
   a.) applying the ore containing the metal successively to a plurality of downwardly inclined, rotatable, flat pan-shaped separating wheels, said wheels being driven by a common shaft and providing:
   i. a peripheral retaining lip, ii. a central annulus, and iii. a plurality of grooves disposed on the upper surface of each wheel and directed from the wheel periphery to the annulus, each of said wheels being concentrically rotatable about its central annulus;
   b.) forming a water slurry with the ore on each wheel;
   c.) washing lighter waste ore out of the grooves and downwardly over the outer retaining lip;
   d.) forwarding the slurry of beneficiated ore inwardly and upwardly along the spiral grooves to the central annulus and downwardly through a funnel positioned around the annulus;
   e.) applying the slurry to the next succeeding wheel; and, f.) repeating the process until at least three wheel separations have been effected.
6. Claim 6. The process of Claim 5 in which each wheel in succession bears an angle of inclination to the horizontal of about 120°-150°, 120°-140°, and 100 125°.
7. Claim 7. The process of Claim 5 in which the separating wheels are adjustably inclined.
   
   CLAIMS:
8. Claim 8. The process of Claim 5 in which the first two separating wheels are commonly mounted, overflow from the first separator wheel is fed directly to the second wheel and beneficiated ore is fed directly through the funnels to the third wheel.
9. Claim 9. The process of Claim 5 in which the metal is selected from the class consisting of: gold, silver, platinum, copper and lead.
10. Claim 10. The process of Claim 5 in which the said wheels are constructed of a molded plastic material.