Патент USA US2573524код для вставки
Oct. 30, 1951 w. A. WASLEY ET AL FLOTATION APPARATUS Filed Oct. 4, 1947 2,573,520 Patented Oct. 30, 1951 12,513,520 UNITED STATES PATENT OFFICE 2,573,520 FLOTATION APPARATUS William Arthur Wesley, Cananea, Mexico, and John Clement Maclntosh, Bisbee, Aria, assign V ors to The Cananea Consolidated Copper Com pany, S. A., a Mexican corporation Application October 4, 1947, Serial No. 778,006 I 2 Claims. (Cl. 209-169) 1 2 This invention relates to ?otation apparatus, The chamber is divided by a series of transverse and is particularly concerned with the provision , partitions 5 into a plurality of individual cells of improvements in ?otation machines having q-‘(only two cells are shown in the drawing, but chamber submerged?ir pumps. The especially principal machines feature of of the -. 6 ‘ordinarily contain ?vethe or six ceus)_ 1 will be long enough to Fagergren type. present invention is the provision, in such ap A feed box 6 is provided at one end of the The end wall ‘I of the chamber which separates the feed box 6 from paratus, of baflies of improved design which are .5, trough'?like chamber I. arranged so as not to impede, the-?ow of an ore 5‘ pulp through the machine, but which minimize ' the chamber itself is formed with an opening 8 rotary motion of the pulp' induced by the air 10 near its bottom, so that an aqueous ore pulp in pump. We have found that the provision of such troduced into the feed box may enter and ?ow lengthwise throughthe chamber. Openings 9 in bailles leads to a decided improyement in the recovery of mineral values in the‘_ ?otation cone . the transverse partitions 5 enable the ore pulp centrate produced in Fagergren Itype ?otationlj,‘ 1‘:‘j’to ?ow lengthwise from the feed box serially machines. A typical ?otation machine of the type'to through the several cells to a tailing discharge box I!) at the opposite, end of the chamber. which the invention relates comprises a long, ;_ trough-like chamber‘ divided by transverse pare . titions into a plurality of cells. The partitions are formed with openings which permit an ore 20 pulp to flow lengthwise from cell to cell through 1 supported on vertical and horizontal frame mem bers I3 and I4. The impeller shafts are rotated in their bearings at fairly high speed by a motor the chamber. l5 connected by V-belts Hi to pulleys l1 keyed An impeller mounted on a ver--. . A vertical impeller shaft H is mounted sub stantially centrally in each cell, in bearings l2 to the upper ends of the shafts. An impeller I8 is mounted at the lower end of is provided in each cell for introducing air into 25 each shaft beneath the normal level of the ore the pulp. The impeller and shaft are usually en pulp in the cell. The impeller comprises fan-like blades l9 set at an angle such as to force air closed by a housing that extends upwardly from downwardly into the ore pulp when the impeller about the impeller to above the zone in which tical shaft for rotation in a substantially hori zontal plane beneath the normal level of the pulp, " the ?otation froth collects. to prevent recircula shaft is rotated in its normal operating direc tion of the froth by the impeller. 30 tion (clockwise, as indicated by the arrow, in the ‘ apparatus shown in the drawings). The im In apparatus of this character, the invention provides the improvement comprising a pair of peller also comprises ‘a squirrel cage of vertical thin vertical bafiies positioned below the normal bars 20 which rotate with the blades IS. The impeller and impeller shaft are surrounded by a pulp level in each cell. The baiiies extend length wise of the trough chamber, parallel to the line 35 cylindrical housing 2|, the upper portion 22 of ‘ of pulp ?ow therethrough; they are arranged on which, above the impeller. is of solid wall con opposite sides of the impeller housing, and ad— struction, and the lower portion of which, imme diately about the impeller, comprises a cage of vantageously are secured thereto. Except for stationary vertical bars 20'. ’ ' these baiiles, none are provided in apparatus ac Inside the solid wall upper portion 22 of the cording to the invention, so that each cell is sub- 40 stantially free of any, obstruction, apart from ‘housing is, a splash cone 23, which terminates in the impeller housing, to the ?ow of pulp there a substantially cylindrical lower portion 24 lo through, but t e baiiles serve to minimize rotary cated about at the normal pulp level. A series ?ow of the p p caused by rotation of, the im of vanes 25 on a. collar 26 extend laterally from peller. \ A preferred embodiment of the invention is shown in the single ?gure of the accompanying drawing, which shows in perspective, parts being the impeller shaft inside the lower cylindrical ' portion 24 of the splash cone, and also at about the normal level of the pulp in the cell. These laterally extending vanes are pitched at an angle to the vertical, thereby forming an air screw broken away, a Fagergren type ?otation ma chine equipped in accordance with the invention. 50 which assists in forcing air downwardly when The ?otation machine comprises a long trough . the impeller shaft is rotated in its normal‘ op like chamber I having a ?at bottom Land side erating direction. The vanes 26 also prevent any walls each having a lower portion 3 which slopes ‘accumulation of ore pulp mud in the splash outwardly and upwardlyfrom the bottom and an cone. The air screw formed by thesej‘vanes'j‘ is upper portion 4 which is substantially vertical. 55 not a part of heretofore known Fagergrenitype 2,573,520 while at the same time the depth of the top edge of the baffles below the normal level of the pulp is made maximum at all points. In consequence, the baiiles have a minimum e?ect in preventing ‘ ?otation machines. They form the subject mat ‘ ter claimed-in our copending patent application ‘ Serial No. 778,436, filed October 7, 1947, and are , more fully described therein. In the operation of apparatus as thus far de ‘ scribed, an ore pulp to which suitable ?otation 1 reagents have been added is introduced into the . feed box 8 and ?ows lengthwise through the ‘ chamber I from cell to cell. “The impeller shafts the froth, as it rises to the surface of the pulp, from ?owing laterally to the side edges of-the cell and over?owing into the collecting launders L. The substantially improved results obtained with Fagergren type ?otation machines equipped . are rotated at a fairly high' speed by the motor 10 in accordance with the invention isshown in the 15, so that the impeller blades l9, assisted by the _ following table. One of -?ve rows of Fagergren type ?otation machines in aconcentrator plant ‘ air screw vanes 25, suck air downwardly about treating sulphidic copper ore was equipped with the impeller shaft through the splash cone 23, baiiles 21 and air screw vanes 25 of’ the character Q and deliver it radially outwardly through the 3 squirrel cage bars 20 and the housing bars 20’ 15 herein described, while the remaining rows were carrying the mineral values of the ore with it _ not so equipped. The second column of the table shows the percentage of copper in the tailings withdrawn from the machines in rows 1 to 4 (the 1 into the body of the pulp. _ The air bubbles form ‘ . a froth in the pulp which rises to the surface and over?ows into collecting launders L arranged rows in which standard Fagergren machines were I alongside the upper edges of the vertical side ‘ members 4. The gangue component of the ore not equipped with baii'les or air screws), and the third column shows the corresponding analysis does not ?oat, but flows with the main body of , the pulp to the tailing discharge box It, through of tailings from row 5 (the row of machines that were equipped with ba?ies and air screws). The ‘ which it is withdrawn. data are given for the twenty-two successive days It is desirable and important that once air has 25 that formed the test period. The difference be tween the amount of copper present in the tail been admitted to the pulp, it be agitated as little ings from machines in rows 1 to 4 and in the . as possible, for otherwise many of the froth bub tailings from the machines in row 5 are given in bles will be broken and the mineral values car the fourth column of the table. ried thereby will sink. The lengthwise ?ow of 1 pulp through the apparatus is su?lciently slow '30 Table I a so as not to produce excessive agitation. The ‘ ‘ rapid rotation of the impeller, however, tends to 3°“ 1' 2' impart a vigorous rotary or swirling motion to the pulp. To a considerable extent this is over 1 come by the cage bars 20' of the impeller housing, 35 Days Row #5 , Difference, aégragedni' Copper Per Cent Copper Per Cent Copper 1st day ..................... _. . 123 . 098 . 030 2nd day.3rd day . . 139 . 117 . 099 .078 . 040 . 039 ‘ but it is not by any means entirely overcome 1 thereby. It is, however, very largely overcome in accordance with the invention by the provision‘ of a pair of substantially vertical thin sheet ‘ j ballles 21. These baffles extend radially out from 40 a in a vertical plane parallel to the ?ow of pulp 1 lengthwise through the apparatus from cell to cell. The bottom edges 28 of the ba?les are par 3 allel and spaced quite closely to the ?oor 2 of 45 the ?otation chamber l. The upper edges 29 of a the baffles slope downwardly from the side 30 adjacent the impeller housing to the side 3| ‘ remote therefrom. Thus the width (vertical height) of the ba?les is greatest near the impeller, 50 1 and progressively less at progressively greater distances outwardly therefrom. The baiiles are sti?ened against lateral de?ection by straps 32 3 and 33, or other suitable stiffening element ‘ weldedtothe baf?e sheets. ' With the ba?les 21 arranged in a vertical plane and parallel to the line of pulp ?ow through I each cell, as shown and described, they impose no appreciable resistance to the ?ow of pulp 5th day-.. 6th day." 7th day___ a the impeller housing 2|, on opposite sides thereof, ‘ 4th day.. .128 . 091 . 125 . 093 . 032 .......... __ Mill Down __________ __ .134 . 090 .037 . 044 8th day. . .117 .080 .037 9th day-10th day-. .118 . 121 . 090 . 090 . 028 .031 llth day _________________ -. .142 . 111 . 031 12th day".-13th day... _ _ . 170 .174 . 144 .147 . 026 . 027 14th day.____ .171 . 152 . 019 15th 16th 17th 18th . . . . . . . . . 020 . 023 . 017 . 022 day..-“ day._._. day“ day 164 176 158 171 144 153 141 149 19th day. 20th day___-. . 183 .192 . 169 . 182 .014 . 010 21st day _____ __ . 135 .123 . 012 __ . 160 . 148 ~ 012 Averages _____________ __ . 148 .122 . 026 22nd day ____ .. It is evident from the foregoing table that the invention enables a substantial improvement to 55 be achieved in the recovery of copper in the con , centrate, as indicated by the markedly and con , sistently less amount of copper present in the tailings from machines equipped in accordance , through the cell, and they cause no de?ection 60 with the invention, as compared with the tail in the direction of pulp ?ow lengthwise through the apparatus which might contribute to breaking I of the ?otation froth bubbles. However, they do , 1 provide substantial resistance to rotary motion 1 of the pulp induced by rotation of the impeller, ‘ thereby minimizing turbulence in the pulp. Rotary motion which the impeller tends to induce in the pulp is greatest near the impeller and ‘ ‘ progressively less as the radial distance there ings from machines not so equipped but operat ing concurrently as the same ore pulp. We claim: 1. In ?otation apparatus comprising a long trough-like chamber divided by transverse parti- . tions into a plurality of cells, said partitions be ing formed with openings adjacent the ?oor of the cells for permitting an ore pulp to ?ow lengthwise directly from cell to cell through the Since the bailles are widest near 70 chamber. an impeller of substantial height ro tating in~each cell for introducing air into the ‘ the impeller and- slope to substantially less width ‘ from increases. pulp therein, said impellers being located sub stantially in the horizontal plane‘of the parti tion openings, and a housing surrounding each ‘ their length in minimizing rotary motion of the ‘ pulp. This uniform baming emciency is achieved 75 impeller, the improvement comprising a pair of in the radial direction outwards from the impeller housing, they are uniformly effective throughout ‘ 2,573,520 thin vertical ba?les positioned below the normal pulp level in each cell and substantially in the horizontal plane of the impeller therein, said ba?les extending lengthwise of the trough a sub stantial distance and parallel to the line of pulp substantially parallel with the floor of the cham ber and the top edges thereof being sloped down wardly from the side thereof adjacent the im ?ow therethrough from cell to cell and being ar near the impeller, and there being substantially ranged on opposite sides of the impeller housing, the height of each ba?le at the housing being equal to the height of the impeller, and pro- ‘ rotary ?ow of the pulp in the cells. the cells. peller housing to the side remote from said hous ing, the height of the ba?les thus being greatest gressively less at progressively greater distances outwardly from the impeller, each cell being substantially equal to the vertical dimension of the impeller, each cell being substantially free 10 substantially free of any obstruction apart from the impeller housing to the ?ow of pulp length of any obstruction apart from the impeller hous wise therethrough, but said bai’?es serving to sub ing to the flow of pulp lengthwise therethrough, stantially preclude rotary ?ow of the pulp in but said baiiles serving to substantially preclude _ ' WILLIAM ARTHUR WASLEY. JOHN CLEMENT MACINTOSH. 2. In ?otation apparatus comprising a long 15 trough-like chamber divided by transverse parti tions into a plurality of cells, said partitions be REFERENCES CITED ing formed with openings adjacent the ?oor of the, cells , for permitting _-an,;..ore.- pulp to . ?ow- '1 lengthwise directly ' from cell ‘to'cell through the The following references are ofgrecord ?le of this patent: chamber, an impeller of substantial height ro stantially'in the horizontal pla'ne'of the parti- - Q tion openings, and a housing surrounding each 25 impeller, the improvement comprising a. pairof thin vertical ba?les mountedv on opposite sides of each impeller'housing below the normal level of the pulp and substantially in the horizontal plane of the impeller,- said bailies also‘being posi 30 tioned in a vertical plane parallel to the line 01 ?ow of the pulp from cell to cell and extending a substantial distance lengthwise of the cell, the bottom edges of said bames being close to and ’ ' UNITED STATES tating ineach celliforlintroducing air into the pulp therein, said impellers being located ‘sub " Number . Name > " . ~5 2,073,148 1,984,366 Fahrenwald Gayford _____ ___‘___'_"_‘ __ __-Mar.;,9,,1'931 pea-‘i8, 1934 _' 2,304,270 Mead _________ ..~ _ Dec 8,1942 > OTHER REFERENCES; Handbook of Mineral Dressing, Tagg'f" section 12, pages ~66, 67, and 68.‘ v _ ' “The Laboratory Fagergren Flotation chine,” American Cyanamid Company, teller Plaza, New York, N.‘ Y. ' " I e, , ;" "