US1526997A

US1526997A - Flotation of ores

Info

Publication number: US1526997A
Application number: US434071A
Authority: US
Inventors: Edwin B Malmros
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-12-30
Filing date: 1920-12-30
Publication date: 1925-02-17
Anticipated expiration: 1942-02-17

Description

F b, 1 7, I925.

E. MALMROS FLOTATION OLE ORES Filed Dec. 30, 1920 liill llh'ftl ii 13. MMLMZRGS, 0F L'ZWNIERUUK, TLWELWV noun.

TWIMTATIU'H UL? Application flied Ttlccemhcr 30. 1920. Eleriai No. 4234971.

To all via/tom it may concern iEle it known that l, i lowm' B. Mluuuuos, a sui' icot of the King of Eviction, residing iLVl'llJIOOli, in the county of Nassiuu tato of New York, have invented certain new anti useful Improvements in the l lota tion of (Mes; antl I do hereby declare the foilowiup: to ho a ifuli, clean anti exact (18-- oci'intion oi the iut'hhtion, such as; will onteruiniuotl hy the percentage of metalliieroua mutton therein as oom'pai'eclWith the amount oi ganggue matter? therein ancl it is, of course, desirable to attain as high a grade oitcoucenti" to as is; consistent with satisfactory practice in othei' respect-s, such, for ouauiplo as the percentage of recovery of the metalliieroua material. Where a com oitlet'ahle amount oi gaugue material is CF11"- riccl up into the floating mass oi mineraliafllen gas huhhleu, the oracle oi the resulting" concentrate is very likely to he long anti this is especially true in the oneumatic flotation process. 'l ho present invention aims partiouiaily to improve or Yaioo the oracle of a flotation coucontiute and. in the impro ecl t}T )tr?HlI-HS oi the invention, this aim is accomplished by causing; the floating mass oft" ii1iiiei?al-'.l:ic'len gas bubbles to move over the miclacc of a relatively quiescent liquid rue-- tiium into which "particles of gaug'ue cli'op i'uouo the floating mass aucl are retunnco'to tho hotly of ore pulp undergoing the iiota tiou treatment" Who present iuveutiou is; mote uarticw lai'ly applicable to the iueumatic i'lotatio-u procesog iiiuce in utoeosa a vow oouuhlctahle al'uount of gauguo ia oai'rieol into the floating *oaaa of gait liuhhlea (on louhhle coiuiuu) aloug with the-nictailifetous mattei, ao

that the guaole of the ioiaaultinn; couceutiato is to a large extent cletcin'iinetl lay the selective action talziu place iii mass; Oi column of goo loulohlce, as a which thit mass U1" column of huohieo is piogiosaivcly richer in mine 'al particles from theholtom to the top thereof. in the improved appu ratus of the present invention, tho mas;v or column of, gas bubbles resulting; from the pneumatic flotation process is cauacrl to move over the surface of a relatively quicscent liquid medium which is in cou'imunicw tion with the main hody of one pulp uuclen going; the flotation treatment During: the movement of the most 01 column of {fill huhbles over this quiescent liquifl iucdilu'n. a solective cleaning. action tfll iOS place as' a re sult of which a wry considerable quantity of gangiue particles drop from the mast; 01 column oi? gas bubbles iiiito the liquid cliuin ancl are returned to the main body oi ore pulp. in this iiuani'ier, a very nriatciiial enrichment in mineral matter takes placo in the mass or column of goo huhhles, as a consequence of which a higher giracie oi couceiutlatc ohtainetl.

The principle of operation and novel ie: JCHTOS of the apparatus of the invention Will he hotter uulctstoorl from the following ticscription talteu in conjunction with the ac companyiug thawing, illustrating; a pneumatic flotation cell einhoclyiug; the invention. in this; cluawii i2:

is a transverse tatiou cell;

2 is a longitudinal section of tho ilotation cell autl 3 is av plan View oi the iiot-atiou coll.

Referring now partioulai iy to the iaocoinpanying thawing, the apparatus thehciu illustrated is; a flotation c ot the PHGQHM iic t vpe. As Te pr'eaentetl in the imiting the cell has a suhstuntialiv ilat bottom h anal upwai'clly and outwarcily inclined. sic'io Waiis 6, at the upper end of which one ptovioiedi the longitudinal concentrate iauntiei'a l. The bottom 5 out tho celi may loo suhstaur tially horizontal or, iiiflesii'odl, the hottoii'i may have a slight downward inclination from the teed encl towat'clu "1o tailingo thischarge enol.

Appropriatc means are piwwicletl for introclucing into the cell a suitable gaeoous flotation agent, such as an. iiuch means may take various iorims and in the con struction illustrated in the accompanying: drawing a plurality of gas or air compattments time aseociatcd with tho hottoirn 5 of the cell. lrliach air compartment 8 io pro viclcxl with a iooroua medium 9, such canwas, through which ail 0E tithe" appropriate Section of the iioillilgas, may be introduced in a finely disseminated state into the ore pulp. Each compartment 8 is connected by a valved pipe 10 with the air or gas main'11. By this arrangement the supply of all or other gaseous flotation agent to each compartment 8 may be independently controlled.

Two vertical bafiles or partitions 12 are longitudinally mounted within the flotation cell. The battles 12 'are arranged substantially above the longitudinal or side walls of the compartments 8 whereby the upwardly rising stream or current of gas bubbles passing through the porous media 9 is contined between the baffles 12, and a relatively quiescent zone is provided in the spaces between the bullies l2 and the side walls 6. .lhe tops of the bullies 12 are slightly below the normaloperating liquid level off the ore pulp, while the bottoms of the baliles are spaced from the bottom ot' the cell to provide an appropriate communication between the relatively quiescent zones (between the battles and the side walls of the apparatus) and the active aeration zone (between the battles .12).

' In operating the apparatus illustrated in the drawing, in accordance with the principles of the present invention, the ore pulp is fed into the apparatus at the end of the cell between the inclined teed ballle '13 and the adjacent end wall of the cell. The tailings are dischargedfrom the cell through the tailings discharge outlet 14. The rate of the tailings discharge is controlled in the usual manner by a float ball 15 and coopcrating mechanism so as to maintain the liquid level of the ore pulp in the apparatus at thedesired height. Air, or other appropriate gas, in introduced through the porous media 9 in a finely disseminated state into the body of ore pulp between the baflles 12 and produces a supernatant or floating mass or column of immoral-laden gas bubbles *in.

the well understood manner. As a result of'the arrangement of the bailles 12, substantially no gas bubbles find their way into the longitudinal space between the batlles 12 and the side walls 6, and accordingly the liquid in these longitudinal spaces is in a relatively quiescent state. The floating mass j or column of mineral-laden gas bubbles moves outwardly in either direction and. passes over the surface ,of the relatively quiescent liquid in the longitudinal spaces between the bellies 12 and the inclined side walls 6. During the passage of the mass or column of gas bubbles across these relatively quiescent zones, gangue particles drop from the mass of air bubbles into the liquid in the uiescelit zones and are returned be neath t e bottoms of the baflies 12 into the active flotation zone of the apparatus. In this manner, a selective cleaning of the mass or column. of mineral laden gas bubbles takes place over the aforementioned quiescent zones and a richer or higher rade concentrate flows into the launder than in pneumatic flotation apparatus of the here toi'ore customary types.

The apparatus of the invention p )ssesscs many features of superiority ovtr the heretotore'customary types of pneumatic fiotalion cells. In the first place, as a result of the enrichment oi the concentrate, it is pos sible to produce in one cell or apparatus a concentrate of satisfactory grade, thus eliminating the retreatment or" concentrates and the use of rougher and cleaner cells now generally practiced. Moreover, the invention permits the use of a larger volume of air (or other appropriate gas) per square foot of air-mat without blowing over and carrying into the final concentrate an objrctionable percentage of ganguc. Consequently, a higher air pressure can be employed in ellecting the flotation operation and on this account a fiat (or substantially flat) bottom cell can be employed without danger of blinding the porous medium. Moreover, the cross currents produced in the ore pulp by the arrangement of the longitudinal ballles have a tendency to clean the top surface of the porous medium. and. finally, the circulation around the battles provides for a retreatment of particles once fioated'and returned to the active flotation zone through the agency of the relatively quiescent zones.

From the foregoin description, it will be seen that in the impi ved apparatus of the invention the flotation concentration involves the following three (3) steps, (1) the formation of a column or mass of mineralladen (both metalliferous and gangue) gas bubbles, (2) a cleaning of this column or mass of gas bubbles while passing over a relatively quiescent liquid medium, in course of which a relatively considerable pro portion of the gangue particles and a relatively much smaller percentage of the metalliferous particles (carried upwardly into the mass of gas bubbles by the flotation treatment) are permitted to drop into the liquid medium, and (3) the return of the mineral matter (both gangue and metalliferous),

' mac o-r a gas bubbles into the liquid medium. Accordmgly, a much higher or richer grade of concentrate is Withdrawn from the a "paratus vthan can be obtained; in the a sence of: the selective cleaning step of the invention, and to this extent, the flotation operation as a whole is materially improveci. ll claim 1. An apparatus lorthc concentration of ores by flotation comprising an elongated chamber, means at one end of the chamber for feeding ore pulp thereto, means for maintaining a lon itutlinal flow of ore pulp through the chamber, a longitudinal] froth ores by flotation comprising an elongated chamber, means at one end of the chamber 9?; apparatus for the concentration of for feeding ore pulp thereto, means for maintaining a longitudinal flow of Olt pulp through the chamber, means for generating mineral laden gas bubbles over a longitudb nal area including a portion only transverselv of thesurface area, a froth overflow eaten ing along the length of the chamber, a longitudinal launder adjacent to the chamber, means for moving the column of mineral-laden gas bubbles immediately upon formation in a substantially lateral direction towards the launder to subject the column of gas bubbles .to a selective cleaning action by passage laterally over the remaining'longitudinal surface of the ore pulp thereby permitting certain portionsv of the ore to return to the longitudinally flowing ore pulp and to be carried further along into the chamber "for retreatlnent, said chamher having: outwardly inclined side walls to facilitate the return of said certain portions of the to the longitudinally flowing ore in testimony whereof I allix my signatnre.

EDWIN B. MALMROS.