Nov'. 5,1946. R. E. cRocKETT 2,410,601 MAGNETIC sEPARAToR Filed Nov. l2, 1940 . nu wun Y 5 Sheets-Sheet l Nov. 5, 1946. R'. E. cRocKET'r -2,410,601 MAGNETIC SEPARATOR Filed NOV. l2, 1940 mm. 3 Sheets-Sheet 2 R. E. CROCKETT ì 2,410,601 MAGNETIC SEPARATOR Filed Nov. l2, 1940' 3 Sheets-Sheet 3 Patented Nov. 5, 1946 2,410,601. MAGNETIC SEPARATOR Robert E. Crockett, rompton Lakes, N. J., as signor to Dings Magnetic Separator Co., Mil waukee, Wis., a corporation of Wisconsin Application November 12, 1940, Serial No. 365,183 17 Claims. (Cl. 209-225) My present invention relates in general to im provements in the art of separating mixed solids h_aving different characteristics, and relates more specifically to various improvements'in the con struction and operation of magnetic separators ofthe type shown and described in my prior Patents No. 2,003,430, granted June 4, 1935, and No. 2,090,112, granted August 17, 1937. An object of the present invention is to provide 2 To provide improved mechanism for effecting final separation of the ingredients from each other and from the advancing conveyor, and for expressing excess moisture from the finally sepa rated product.v » To provide other improvements in magnetic separator structures, whereby the cost of con struction and operation thereof is reduced to a minimum, while the efliciency Vis enhanced to a a new and useful magnetic separator, which is 10 maximum. simple in construction, fiexible in adaptation, and highly efficient in operation. Some of the more specific objects of my present invention are as follows: To provide various improvements in the con These and other objects and advantages of the*l invention will be apparent from the following detailed description. A clear conception of the several features con 15 stituting my present improvements,'and of the struction of magnetic separators of the general construction and operation of magnetic separa type shown in my prior patents above referred tors embodying the same, may be had by referring to, whereby the operation of such machines and to the drawings accompanying and forming a the adaptability thereof to effectively meet var part of this specification wherein like reference ious conditions, are vastly improved. 20 characters designate the same or similar parts To provide an improved separator of the class in the various views. wherein magnets coacting with one side of a trav Fig. 1 is a part sectional side elevation of one elling conveyor such as an endless belt, effect of the improved magnetic separators, showing separation of magnetic from non-magnetic mixed a longitudinal vertical section through the feed particles brought in proximity to the opposite 25 and separating zones; , face of _the advancing conveyor, and which is Fig. 2 is a part sectional end view of the sepa compact and durable in construction and auto rator of Fig. 1, the section through the lower matic in operation. structure having been taken along the line 2_2; To provide improvements in the construction Fig. 3 is an enlarged fragmentary section and operation of the magnet assemblages for 30 through the pole-piece of one of the magnets in magnetic separators having magnets of consider the pick-up tails and concentrates section of the able bulk and which are normally exposed to machine; moist and gritty surroundings, whereby such Fig. 4 is a similarly enlarged fragmentary sec magnets may be readily assembled and handled, tion through the pole-piece of a magnet in the and are thoroughly protected against damage 35 middlings section of the machine; A from moisture and grit. Fig. 5 is a somewhat enlarged longitudinal sec To provide improved means for safeguarding tion through a special feed tray or chute for and for'prolonging the usefulness of the material initially introducing the mixed materials to the transporting conveyor or belt of a magnetic sep arator or similar assemblage. ‘ To provide improved instrumentalities for feed ing mixed materials to the advancing conveyor of a magnetic separator or the like, and for in suring most effective separation and removal of the products from the zone of separation. To provide improved control means for regu lating the supply of material to be treated to, and the discharge of treated product from, the separating zone of a magnetic separator or simi lar assemblage. To provide improved means for controlling-the delivery of liquid to a magnetic separator of the ` type wherein separation is effected in the pres ence of liquid, and for most elîectively subjecting the material to the hydraulic action. machine; . Fig. 6 is a transverse section through the tray of Fig. 5, taken along the line 6_6; Fig. '7 is an enlarged transverse section through a fragment of the magnet and conveyor belt, showing one of the vertically and laterally ad justable baffles; Fig. 8 is a side view of the assemblage of Fig. '7, showing the baffle in section; Fig. 9 is an enlarged fragmentary part sectional side view of the liquid control and injecting mech 50 anism associated with the separating zone of the machine; Fig. 10 is a transverse section through the as semblage of Fig. 9, taken along the line Ill-l0; Fig. 11 is a diagrammatic part sectional side elevation of a modified hydraulic magnetic sepa 2,410,601 4 rator, the section having been taken longitudi nally through the lower portion of the assem binge; Fig. 12 is a transverse section through the ma chine of Fig. l1, taken along the line I2--I2; and Fig. 13 is a fragmentary top view of one side of a modified type of feed tray somewhat similar to that of Figs. 5 and 6. While the various improved features constitut be suspended from the main frame 32 of the machine, by means of eye-bolts 33 and removable cross-beams 34 in such manner that the lower catenary stretch of the belt 20 willv travel closely adjacent to the pole-pieces I6, l1 but will not actually touch the same due to the injection of flushing and lubricating liquid between the belt and pole-pieces. The conveyor belt 20 may be of any desired width and formed of durable rub ing my present invention have been shown and 10 ber impregnated fabric, and the opposite longi tudinal edges of the lower belt stretch may be described herein as being especially applicable to caused to coact with rubber sealing strips 35 se hydraulic magnetic separators for magnetic ore cured to the lower edges of the side plates 29 as and of the type shown in my prior patents, it is shown in Figs. 2 and 7. Lubricating and flushing not my desire or intent to thereby unnecessarily restrict the scope of the invention or the utility 15 liquid, preferably clean water, may be admitted to the area between the lower belt stretch and and possible application of the improved struc the surface I9 and «between the strips 35, by means tures- to other types of separators. _ of a pipe 36 having orifices therein, as indicated Referring to Figs. 1 to l0 inclusive of the draw in Fig. 1, and this liquid after being drawn under ings, the improved magnetic separator shown therein, comprises in general an elongated arcu 20 the magnet face between it and the belt, eventu ally flows outwardly between the belt 20 and ate bank of material agitating magnets I5'hav strips 35 and prevents gritty particles from reach ing lower pole-pieces I6, I1 the bottom faces of ing the surface I9.. The belt idler pulley 2| is which cooperate with spacers I8' to provide an mounted upon a shaft 31 near the lower feed end approximately catenary shaped curved lower sur face I9; an endless non-magnetic conveyor or 25 of the frame 32; and the driving pulley 22 which beitv 20 supported by pulleys 2 I, 22, and having coacts with the higher discharge end of the belt its lower stretch movable along and in close prox imity to the magret surface I9: an adjustable chute or tray 23 for feeding a. mixture of mag 20, is mounted upon a driving shaft 38 which may be adjustable by means of adjusting bolts 39 as shown in Fig. 1, and may be rotated from any netic and non-magnetic particles to the lower 30 desirable source. Since the lower stretch of the belt 20 is constantly passing through liquid and face of the belt 20 and into the magnetic field of may be moist and slippery when approaching the the magnets I5; means including spray pipes 24,pulley 22, this driving pulley 22 is preferably 25 for subjecting the material within the sepa formed with a plurality of parallel slats 46 on its rating zone to a needle spray washing and jetting surface, forming intervening grooves along which action, the latter to break up mass magnetism; and means for effecting final separation and liquid may escape. With this construction, liquid grading of the treated product. adhering to the inner face of the belt 20 will be pressed into the intervening grooves by contact The magnets I5 which may be of any desired of the belt with the slats 40, and this removal of width, are of relatively well known structure, and alternate magnets of the series preferably are of 40 liquid will enhance the traction and will prevent slippage. like polarity, while the intermediate magnets are Supported upon the main frame 32 beneath the of opposite polarity, in order to provide successive magnetic fields having reversed polarity which` belt and magnet assemblages, is a series of hop will agitato the magnetic particles passing there pers 4I, 42, 43, 44, of which the hopper 4I is a through, to the maximum extent. As shown in 45 tailings collector, the hopper 42 is a middlings receptacle, the hopper 43 is a dewatering cham Figs. 1 and 3, the magnets I5 at the feed and discharge ends of the separating zone, are pro ber, and the hopper 44 is a concentrate discharge chute. These hoppers may be adjustably sus vided with relatively narrow pole-pieces I9 and are of greatest intensity since the magnet cores pended from the frame 42 by means of jack 26 are rather heavy; whereas the magnets I5 at 50 screws 45, and the tailings hopper 4I has a feed the middlings section of the separating zone, are spout 46 at one end within which an independent provided with wider pole-pieces I1 and are of feed tray 23 is adiustably confined, and is pro lesser intensity because the cores 21 are relatively vided with liquid overflow compartments 41 at light, as shown in Figs. l and 4. All of the mag its opposite sides, see Figs. 1 and 2. The hop nets I5 are preferably housed directly within a 55 pers 4I, 42 are normally filled with liquid 48 to liquid-tight casing 28 formed of sheet metal such the levels indicated in Fig. 1, and excess liquid will flow over dams 49 disposed between the hop as copper or stainless steel, and the cores 26, 21 and their energizing coils are preferably sealed per 4I and the compartments 41; and each of within the casing 28 and are immersed in oil or these liquid ñlled hoppers may be divided into the like. The enclosing casing 28 is protected at 60 two laterally adjoining sections each of which the bottom by the spacers I8 which may be may be provided with a special material dis charge spigot 50 such as shown in Figs. l and 2. formed of wood or the like, and the opposite sides of the casing 28 are likewise protected by heavy Each spigot 50 may consist of an outer sleeve 5I Wooden or other non-magnetic slabs or plates 29. secured to the bottom of the adjacent hopper 4I, The top of the magnet bank has a. curved backing 65 42; a flexible and elastic tube 52 confined within plate 30 firmly «but detachably secured thereto in the sleeve 5I and protruding from the lower end thereof; and a gate 53 swingably suspended from any suitable manner, and this curved reenforcing the sleeve 5 I and being swingable across the lower plate may be formed of suitable metal and is provided with a central longitudinal stiffening sleeve end to kink or compress the tube 52 near and suspension rib 3I which may be pierced by 70 its lower end and to thereby throttle the dis charge, more or less. In order to completely shut openings to facilitate suspension and handling of off the discharge of material and liquid, the the magnet bank. ' gates 53 may be swung to positions directly be As previously indicated, the lower curved sur face I9 of the magnet assemblage is approxi neath the sleeves 5I, thereby bending the tubes 52 mately a, catenary curve, and the magnets I5 may 75 which may be formed of rubber, to right angle _ ‘ 2,410,601 5 6 position. The overiiow compartments 41 may be provided with lower liquid discharge passages 54, and the dewaterlng hopper 43 may likewise be provided with a liquid discharge pipe 55. 25 also have pin holes 1| therein, and are as sociated with a common plate 15 which is also adjustably suspended from the wooden side plates by bolts 13 coacting with slots 14. vLiquid under- 'I'he raw material feed chute or tray 23 for de pressure may be supplied .t0 the pipes 24, 25 through flexible conduits 16 successive ones of which may be located on opposite sides; and the uid 48, may be constructed either as shown in end of each pipe 24,. 25 remote from the inlet Figs. 5 and 6, or as illustrated in Fig. 13; and this thereof, is preferably provided with a valve con tray 23 ls preferably made -swingably adjustable 10 trolled orifice 11 for. indicating the pressure as shown in Fig. 1, by means of adjusting rods within the pipe, and hence the intensity of the 56 coacting with the lower end of the tray. 'I'he jets issuing from the holes 1| thereof. These interior of the tray may be rubber lined, and as needle jets-are directed at approximately right shown in Figs. 5 and 6, the tray is divided by angles to`the face of the belt 28 to ‘break up mass . livering the mixed magnetic and non-magnetic particles to the separating zone beneath the llq partitions 51 into a central valley extending lon gitudinally thereof beneath the belt 28, and two opposite side channels 58 located outwardly be yond the path of the belt. 'I‘he central valley formed by the >partitions 51 may either be free 15 magnetism, thus permitting most- effective re lease of entrained waste materials, and the plates 12, 15 serve to 'prevent magnetic particles which may be dislodged by the jets, from falling out of the magnetic ñeld or zone of separation. “The from obstructions as in Fig. 1, or it may be prof 20 open spaces between successive spray baflles 12 vided with one or more ñow retarding riilies 59, allow the- immediate discharge of waste or mid 60, 6| as in Figs. 5 and 6; and liquid may be sup plied to the channels 58 by supply pipes 62 either ` as in Figs. 1 and 2 or as in Figs. 5 and 6. dling material >to the hoppers below. It is desirable to remove at least the greater The portion of the liquid from the concentrates, be -side channels 58 may either' be unobstructed as 25 fore the latter are discharged into the hopper 44, Y shown in Figs. 5 and 6; or they may be spanned by high dams 63 as in-Figs. 1 and 2; or they may be sub-divided into divisions as in Fig. 13, by -means of barriers 64. These several modified types of feed trays may be used advantageously- 30 _under diiferent conditions of operation. The interior of the tailings and middlings hop.V . pers 4|, 42, adjacent to the zone of separation and beneath the liquid 48, is preferably provided and ín order to express this liquid, a roller 18 sus pended from the lower ends 0f side links or arms 19, is provided. This( roller 18 may be formed of soft rubber or the like, and is pressed against the lower face of the belt 20 by means of adjustable springs 80 coacting with the swinging ends of the arms 19 and with the wooden side plates 29. The upper ends of the suspension links 19 are ad justably pivotally confined in slotted plates 8| with a series of baliies 65 having their upper ends 35 also secured to the side plates 29, and the roller _ directed toward the feed end of the machine, and 18 may thus be adjusted forward-1y 4or. rearwardly some or al1 of these baffles 65 are preferably and may be caused to engage the belt 20 with mounted for both vertical and lateral adj'ustment.l more or less pressure due to the adjustability In Figs. 7 and 8 is shown a means for effecting of the springs 80. The liquid expressed'from the such adjustment, and each of the baffles 65 may 40 concentrates advancing with the belt 28, drops be suspended from side arms 66 having slots 61 into the dewatering hopper 43, land in order to therein coacting with studs 68 secured to the 'insure proper delivery of the ñnal concentrates magnet side plates 29„the studs 68 being pro into the hopper 44, an adjustabledividing plate vided with clamping nuts ‘69. With this assem 82 such as shown in Fig. 1 may be employed. This blage, the baffles 65 may obviously be independ 45 dividing- plate 82. is suspended from a> cross-rod ently adjusted toward'or away from the belt 28, 83 which is rotatably adjustabIe in cross-heads or forwardly or rearwardly relative to the feed> 84, and the cross-heads 84 are vertically adjust end of the machine, in order to secure most ef able in slides 85 which are bodily movable along fective separation. In addition to the bail‘les 65 horizontal angle irons 86 at the opposite sides of spanning the separating zone, barriers 18 may 50 the machine. With such an assemblage, the di be provided between thehoppers 4| ,` 42 beyond viding plate 82 may be adjusted horizontally, ver the opposite sides of the belt 28, see Fig. 1, and tically, and angularly in order'to `insure most these barriers should also be made vertically and effective discharge of the final product. The laterally adjustable. plate 82 may be replaced bya somewhat simpler In order to obtain thorough washing of the 55 dividing plate 81 adjustably supported on side particles as they are conveyed along the separat angle bars 88 as shown in Fig. 1l, and the plate ing zone by the belt 2li-and while being agitated 81 may be- used either alone or'in conjunction by the magnets »|5, I have provided improved with a plate 82. The dividing plate 81is pref Àmeans for subjecting the- conveying surface oi'l erably adjustably disposed in a zone starting mid-> the belt to pin sprays of liquid. This'improved 60 way between the last two poles and terminating > spray means comprises a series'of transverse liq just beyond the last pole-piece Vlli as shown in uid supply pipes 24 located between some of the ‘ bañles 65 in the tailings hopper 4| and between others of the baiiies 65 in the front part Vof the Fig. 11. ' The oil ñlled magnet housing 28 may be pro vided with an oil gage 89 near the highest end middlings hopper, and a subsequent group of 65 of the magnet bank and the oil may be positivelyr liquid supply pipes 25 near the concentrate dis- A circulated through the casing 28 for cooling pur charge zone, see Figs. 1, 2, 9 and 10. Each of poses, and in order to remove heavy liquid such the individual liquid supply pipes 24 has a series as Water or moisture from the atmosphere which of pin holes 1| therein,_and is provided with a may accidentally enter the magnet housing 28, ' transverse plate 12 disposed approximately par 70 I provide one or more depressions 90 in the low-l allel to the adjacent belt 20, and these pipes 24 est portion of the casing 28 in which such heavy and their plates 12 are adjustable toward and liquid may accumulate beneath the oil, see Fig. away from the belt 20 by means of bolts 13 coact 10. Pipes 9| the upper ends of which are normal ing with the magnet side plates 29 and with slots ly capped, have their lower ends disposed iny these 14 in the plates 12, see Fig. 9. All oi' the pipes 75 depressions, and upon removal of the closure caps, 2,410,601 siphon tubes 92 may be applied to the upper pipe ends in order to remove the accumulated water. Since the static oil pressure within the casing 28 is much greater than that of the liquid outside, any leakage of oil from within will prevent other liquid from entering the casing and damaging the coils, and such oil leakage may be readily de 8 concentrates are being conveyed over the trough plate l5 they are finally subjected to a thorough washing and desliming action by the jets 25 be fore being subjected to the press roller 18. The roller 18 expresses most of the residual liquid, and the final high intensity magnets also remove some _ of the liquid, so that the final concentrates deliv tected with the gage 89. In order to insure more ered into the hopper 44 over the diverter plate 82, effective lubrication and expulsion of gritty ma are in relatively drycondition. The final high terial from between the belt 20 and seal strips 35, 10 intensity magnets are designed also to carry the I may also provide a series of fresh water supply magnetic material across the dewatering hopper pipes 93 as shown in Figs. 11 and 12. These pipes 43 without loss of mineral. It will therefore be 92 extend through the magnet bank to the slight apparent that the separation of the tailings and space between the surface I9 and belt 20, midway middlings from the concentrates is effected au between the sealing strips 35, and each pipe 93 15 tomatically and continuously, and the concen may be provided with a control valve 94 for regu trates may be effectively dewatered before ñnal lating the quantity of liquid admitted. discharge thereof. While the machine shown in Figs. l and 2 is relatively standard and adapted to meet a broad While the operation of the machine shown in Figs. 11 and 12 is quite similar to that just ex range of separation problems, it may in some 20 plained, this modiñed assemblage is adapted to cases be possible to omit the middlings production retain all material within the zone of magnetic and reduce the size and weight of hoppers, by influence for a longer» period of time. The mix using a simplified thin trough such as shown in ture of liquid and solids delivered to the separat Fig. 1l, which would be particularly applicable to ing zone by the feed tray 23 in this improved line material having the gangue separated as by 25 machine, is compelled to travel along a laterally crushing. In this modified magnetic separator, and entirely enclosed flat conduit 95 and is thor curved troughs 95, 96 are disposed forwardly and oughly subjected to the magnetic influencé which 'rearwardly of the tailings hopper 9T and closely permeates the entire interior of this conduit, until adjacent to the .lower face of the conveyor belt the material reaches the open hopper 91. Here 20. The feed tray 23 is adapted to deliver the 30 the tailings and non-magnetic materials are_remixture of liquid and solids directly into the sep leased and drop into the hopper, whereupon the arating zone at the forward end of the trough 95, concentrates are carried into and along another and the tailings hopper 9'! is in open communica laterally enclosed conduit formed by the trough tion with the confined spaces between the troughs 96. In this latter conduit, the concentrates are 95, 96 and the belt 29 at the rear end of the trough 35 finally thoroughly washed and deslimed by the 95 and the front end of the trough 86. Water jet relatively strong needle jets of fresh liquid de injection pipes'24I 25 may be provided along the livered from the pipes 24, 25, and the final con rear trough 96 for the purpose of thoroughly centrates are thereafter dewatered and dis , washing the concentrates, and dewatering and as previously described. concentrate collecting hoppers 43, 44 are provided 40 charged It will thus be noted that the improved mag at the delivery end of the trough 96. This modi netic separators are adapted to automatically fied assemblage may also be provided with a de and effectively remove magnetic from non-mag watering roller 18, a magnet suspension plate 39, netic materials, and to deliver the concentrates and special feed troughs, such as previously de 45 in relatively dry condition. The improved mag scribed. net structure wherein the magnets are confined During normal operation of the improved mag in oil within a complete enclosure such as the netic separator shown in Figs. 1 and 2, the con housing or casing 29, and are provided with re veyor belt 20 is being constantly driven at an ap movable pole-pieces I6, I1, permits removal and propriate speed in the direction indicated by the arrow in îF’ig. 1, the magnets I 5 are energized, and 50 replacement of these pole-pieces without disturb ing the concealed magnet parts. The curved material and liquid are being delivered in regu backing and suspension plate 3l) for the magnet lated quantities through the feed tray 23 and bank reenforced by the spine or spines 3|, not the various supply pipes. As the material ad only provides strong means for facilitating han vances along the separating zone the magnetic solid particles are drawn upwardly against the 55 dling and convenient suspension of the magnets, but also enables the magnet cores 26, 21' to be lower face of the belt> 20 by the magnets l5, and properly disposed approximately perpendicular to the tailings or non-magnetic particles are quick the lower stretch of the belt 20. While the mag ly removed by the washing and jetting action and nets are quite-effectively cooled by the fresh the bailles 85 which may be set to insure such prompt removal. The opposite polarity of the 60 water admitted to and circulating through the machine, the oil within the enclosing casing 28 successive magnets causes the retained magnetic may also be circulated to enhance the cooling particles which adhere to and advance with the leffect„and Water which may enter the casing 28 belt 20, to be thoroughly agitated, and as this may be readily removed with the aid of the siphon retained material passes over the spray pipes 24 it is subjected to thorough Washing and agitation 65 tubes 9|, 92. The use of the sealing strips 35 coacting with the belt 20, and the admission of by the high intensity needle jets issuing from the fresh liquid to the surface I9 either through an orifices 1I. Other non-magnetic material is thus end pipe 39, or several pipes 93, provides simple removed from the belt 20 by the jets, and the open and eiîective means for cooling the magnets thus spaces between jets and the adjacent baffles 65 quickly direct this other material into the ho-p 70 allowing -the use of higher currents andA conse quently obtain stronger magnetic fields, and for pers 4I, 42. As the belt proceeds over the mid dlings hopper 42, some material containing mag keeping grit away from the belt surfaces. The netic particles may be washed from the magnetic ribbed pulley 22 insures proper driving of the belt separating zone, and these middlings may be 20 and avoids undesirable slippage, and the belt treated for subsequent separation; and when the 75 supporting pulleys 2|, 22 can be readily adjusted ’ 2,410,691 9 , to position the lower belt stretch in snug engage ^ 10 p thereof, a roller resiliently engaging said opposite ' , side -of said conveyor near the discharge end of The improved feed trough 23 is angularly ad the field for expressing moisture from» the con justable to insure most effective deliveryl of the centrates within said field, means for removing , feed to the separating zone, and by utilizing _bar 5 material from said conveyor beyond said roller, riers or riiiies 59, 60, 6|, the feed can be retarded and a diverter plate coacting with said conveyor as it enters the zone of separation and the solid near the delivery end of said field beyond said particles are forced to flow upwardly toward the roller. belt. The provision of the side chutes 58 with 4. In'a separator, an endless conveyor, a series barrier partitions 64 therein for returning spillage 10 of magnets on one side of saidconveyor for cre to the separating zone, prevents loss of magnetic ating a magnetic field along the opposite side particles with the tailings, and the adjustability thereof, a resilient roller swingably suspended of the baffles 65 also enhances the efficiency of from said magnets near the discharge end of the separation by quickly removing the non-magnetic field and resiliently engaging the opposite side of particles from the separating zone. The im 15 said conveyor for expressing moisture from the proved spigots 50 Inot only make it possible to concentrates within said iield, and means for control the discharge of tailings and middlings, swinging said roller toward and away from said but also permit quick closing when the machine conveyor. f is shut down, and prevents complete drainage -5. In a separator, a conveyor belt having a of the hoppers 4|, $2, 20 lower stretch, magnets above said stretchrfor ment with the sealing strips 35. The improved needle spray arrangement com creating a magnetic field therebeneath, and a bined with the adjacent trough plates 12, 15 is feed tray for delivering material into one end of very important since. the strong jets 'of fresh said field beneath said stretch, said tray having liquid effectively spray the material being carried ~a central valley beneath said stretch and opposite along the separating zone by the belt 20, and the- 25 side channels beyond the sides of said conveyor plates prevent dislodged magnetic particles from provided With barriers for catching overflow ma dropping out of the zone of magnetic influence. terial above the magnetic field. ' , The oriñc'es 1l provide simple means- for observ 6. In a separator, a conveyor belt Vhaving a ing the pressure in the several pipes 24, 25 so as lower stretch, magnets above said stretch for to obtain most efficient operation, and the. press 30 creating a magnetic field therebeneath, and a roller 18 and diverter plates 82, 89 enable the feed tray for delivering material into one end of operator to thoroughly dewater the concentrates before ñnal delivery thereof from the machine. These needle sprays and dewatering appliances are readily applicable to other types of separa tors wherein the materials are transported through a washing and separating zone by con-. veyors of other types. These various improve said field beneath said stretch, said tray having a central valley within said field and opposite side channels beyond the sides of the field provided 35 with barriers for catching overflow material es caping above said field. . 7. In a separator, a conveyor belt' having a lower stretch, magnets above said stretch for _cre ating a‘magnetic ñeld therebeneath, a feed tray ments have proven highly satisfactory in actual use, and provide a separator which besides being 40 for delivering material into one end o'f said field simple and compact in construction, is also ñex beneath said stretch, said tray having a central ible in use, and can be installed and operated at valley beneath said stretch and opposite side minimum cost considering the enormous capacity channels beyond the sides of said conveyor pro thereof. The use of oil under high static pressure vided with barriers for catching overflow mate head within the casing 28 not only provides ef rial above the magnetic field, and a dam spanning fective insulation, but is also extremely important as a safety feature, since it positively prevents liquid from entering the casing 28 and thus said valley. , 8. In a separator, a conveyor f belt having a lower stretch, magnets above said stretch for creating a vmagnetic field therebeneath, a feed casing 28. 50 trayfor delivering material into one end of said It should be understood that it is not desired field beneath said stretch, said trayhaving a cen to limit this invention to the exact details of trai valley within said field and opposite side ' construction or to the precise mode of operation, channels beyond the sides of the field provided damaging the coils, in case a leak occurs in the herein shown and described, for various modifi with barriers for catching _ overflow material cations withìn the scope of the claims may occur 55 escaping above said field. and a dam spanning the to persons skilled in the art. I claim: delivery end of said valley. , l. In a separator, a4 conveyor belt. having a . - 9. In amagnetic separator, a pair of spaced pulleys, a carrier belt for running over said pul leys and having a lower reach suspended in lower stretch, a bank of magnets adjoining the top of said stretch, and a feed tray for delivering- 60 loosely sagging position therebetween, means for material beneath said stretch into the magnetic feeding along the under side of said reach a liquid zone, said tray having a central valley and oppo mixture of the magnetic and non-magnetic par site side channels provided with barriers for ticles to be separated, a series o_f magnets on the catching overñow material on opposite sides of upper side of said> reach, said magnets having and above the magnetic field, 5 pole faces forming a series which extends along 2. In a separator, an endless conveyor, a series and is curved in substantial conformity with the of magnets on one side of said conveyor-for cre upper surface of said lower reach, spacer means ating a magnetic field along the opposite side between such pole faces to form therewith _a sur thereof, and a roller resiliently engaging said op face opposed to the upper surface of said reach, posite side of said conveyor near the discharge 70 and a conduit opening into a slight space between end of said field for expressing moisture from the said surfaces at a point spaced from the edges of concentrates within said ñeld. the belt and spaced from the ends of the series 3. In a separator, an endless belt conveyor. a series of magnets on one side of said conveyor for of pole pieces, said conduit being constructed _ and arranged for connection to a source of water creating a magnetic ñeld along the opposite side 75 supply under pressure for injecting water to cause 2,410,601 11 -said slight space to be maintained against the conducting along the under side of said first named areas, a liquid mixture containing mag netic particles and non-magnetic material, a se riesV of magnets on the upper side of said lower magnetic forces on the particles which tend to press said belt stretch against the pole faces. ' 10. In a, magnetic separator, a pair of spaced pulleys, a carrier belt for running over said pul 5 reach, such series extending along and being leys and having 'a lower reach suspended in loose curved in substantial conformity with said areas, for causing said particles to be separated and 1y sagging position therebetween, means for feed ing along the under side of said reach a liquid carried on the belt, while the belt areas with mixture of the magnetic and non-magnetic par such particles thereon travel from an approxi ticles to be separated, a series of magnets on the 10 mately horizontal position, through a region of .upper side of said reach, said magnets having submergence in said liquid, and thence up to said pole faces forming a series which extends along discharge point, means at said region for project* and is curved in substantial conformity with the ing submerged jets of water against the belt for upper surface of said lower reach, spacer means between such pole faces to form therewith a sur dislodging non-magnetic material, means ex tendingalong adjacent the sources of said jets for preventing settling _of magnetic material away Aface opposed to the upper surface of said reach, and a plurality of conduits opening into a slight space between said surfaces at spaced points re spectively, said conduits being constructed and fromv the belt, and means at 'said more inclined areas, subsequent to said region of submergence and in advance of said discharge point for wash arranged for connection to a source of water sup ply under pressure for injecting water to cause said slight space to be maintained against the magnetic forces on the particles which tend to press said belt stretch against the pole faces. ingt remaining non-magnetic material from the bel . 13. In a magnetic separator, a pair of spaced pulleys, one substantially higher than the other, 11. In a magnetic separator, a pair of spaced . pulleys, one substantially higher than the other, a carrier belt for running over said pulleys and having a lower reach suspended in loosely sagging position therebetween, the lower reach areas 'which are nearer the lower pulley sagging in ap proximate tangency to the horizontal while areas a carrier belt for running over said pulleys and having a lower reach suspended in loosely sag ging position therebetween, the lower reach areas which are nearer the lower pulley sagging in ap proximate tangency to the horizontal while areas nearer the higher pulley are inclined more 30 and more upwardly to a discharge point, means for driving the pulleys and belt in a direction for upward travel of said reach, means for feeding and conducting along the under side of said ñrst ward travel of said reach, means for feeding and 35 named areas, a liquid mixture containing mag netic particles and non-magnetic material, a se conducting along the under side of said ñrst ries of magnets on the upper side of said lower named areas, a liquid mixture containing mag reach, such series extending along and being netic particles and non-magnetic material, a se curved in substantial conformity with said areas, ries of magnets on the upper side of said lower nearer the higher pulley are inclined more and more upwardly to a discharge point, means for driving the pulleys and belt in a direction for up reach, such series extending along and being 40 for causing said particles to be separated and carried on the belt, while the belt areas with such curved in substantial conformity with said areas, particles thereon travel from an approximately for causing said particles to be separated and horizontal position, through a region of sub carried on the belt, while the belt areas with such mergence in said liquid, and thence up to said particles thereon travel from an approximately horizontal position, through a region of sub 45 discharge point, and means providing a station ary surface extending up along and in spaced y'mergence in said liquid, and thence up to said relation to said more inclined areas on the belt, discharge point, means at said region for project to form a trough space subject to the effective ing submerged jets of water against the belt for field of said magnets above said region of sub dislodging non-magnetic material, and means mergence, and means for projecting a series of extending along adjacent the sources of said jets forceful sprays of water against the belt in said for preventing settling of magnetic material trough space, to thereby release remaining non away from the belt, means providing a station magnetic material on the belt while said station ary surface extending up along and in spaced ary surface retains any dislodged magnetic par relation to said more inclined areas on the belt, to form a trough space subject to the effective 55 ticles within said field for recapture on the belt, and said remaining material is washed back down field of said magnets above said region of sub the trough space by the spray water. mergence, and means for projecting a series of i4. In a magnetic separator, an endless belt forceful sprays of water against the belt in said having a lower material conveying reach,`means trough space, to thereby release remaining non magnetic material on the belt while said station 60 for advancing said lower reach upwardly at an oblique angle, a series of magnets above and in 'ary surface retains any dislodged magnetic par close proximity -to said advancing reach, means ticles within said field for recapture on the belt, providing a stationary surface extending along and said remaining material is washed back down and in spaced relation to the under side of said the trough space by the spray water. 412. In a magnetic separator, a pair of spaced 65 lower reach to provide a space subject to the effective field of said magnets, means for feeding pulleys, one substantially higher than the other, magnetic particles and non-magnetic material a carrier belt for running over said pulleys and mixed with liquid into a lower region of said having a lower reach suspended in loosely sag space while maintaining said feed receiving ging position therebetween, the lower reach areas which are nearer the lower pulley sagging in ap 70 region constantly submerged in liquid, means for projecting forceful jets of other liquid through proximate tangency to the horizontal while areas the liquid within said region to dislodge non >nearer the higher pulley are inclined more and magnetic material from said lower reach while more upwardly to a -discharge point, means for preventing settling of the magnetic particles, driving the pulleys and belt in a direction for up ward travel of said reach, means for feeding and 75 and means for effecting discharge of the mag 13 2,410,801 `netic particles at a point above said submerged regions. 15. In a magnetic separator, an endless belt having a lower material conveying reach, means for advancing said reach upwardly at an oblique angle, a series of magnets above and in close proximity to said advancing reach, a normally ' ñxed plate having an upper surface extending ~ 14 and along beneath said reach in spaced relation thereto and arranged together with the tailings hopper to maintain a body of liquid submerging a substantial portion of said reach, means ad jacent one end of said reach for feeding into said trough means and thence along the under side of said reach toward said hopper, a mixture of the magnetic and non-magnetic particles to along and in spaced relation to the under side of said lower reach to provide a space subject to 10 be separated, the concentrates discharge being adjacent the end of said reach opposite from the effective ñeld of said magnets, means for said feeding means, a sexies of magnets on the eiîecting variation in the position of said plate upper side of said reach, said magnets having relative to said conveying reach to vary the dis pole faces forming a series which maintains a tance between said surface and said magnets, ñeld along said reach extending from the feeding means for feeding a'mixture of magnetic and non-magnetic materials into a lower region of 15 means to the discharge position, and means be-À tween said hopper and discharge position for said space, means for projecting forceful jets of introducing jets of water into the trough space. liquid across said space to dislodge non-mag 17. In a magnetic separa-tor, a conveyor belt netic material from said lower reach while pre venting settling of the magnetic particles, and 20 having a lower stretch, a series of magnets ex tending along the upper surface of such stretch, means for eiïecting discharge of the magnetic and a feed tray for delivering material along particles from an upper region of said space. beneath said stretch into the ñeld of said mag 16. In a magnetic separator, a pair of spaced nets, said tray having a central valley and oppo pulleys, a carrier belt for running over said pul leys and having a lower reach suspended in loose 25 site side channels provided with barriers for catching overñow of material on opposite sides ly sagging position therebetween, a tailings hop of said central valley and for directing such over per beneath a low _sagging portion of said reach, ñow material into the magnetic ñeld. trough means extending in upwardly inclined directions from each side of said tailings hopper ROBERT E. CROCKE'I'T.