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WO1993025313A1 - Concentration de mineraux - Google Patents

Concentration de mineraux Download PDF

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Publication number
WO1993025313A1
WO1993025313A1 PCT/US1992/004822 US9204822W WO9325313A1 WO 1993025313 A1 WO1993025313 A1 WO 1993025313A1 US 9204822 W US9204822 W US 9204822W WO 9325313 A1 WO9325313 A1 WO 9325313A1
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WIPO (PCT)
Prior art keywords
column
pulp
flotation
recycle
flotation column
Prior art date
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Ceased
Application number
PCT/US1992/004822
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English (en)
Inventor
Clinton A. Hollingsworth
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Individual
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Individual
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Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CA002138145A priority Critical patent/CA2138145C/fr
Priority to AU22261/92A priority patent/AU676459B2/en
Priority to PCT/US1992/004822 priority patent/WO1993025313A1/fr
Publication of WO1993025313A1 publication Critical patent/WO1993025313A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION 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
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/24—Pneumatic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION 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
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/02—Froth-flotation processes
    • B03D1/028—Control and monitoring of flotation processes; computer models therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION 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
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/1412—Flotation machines with baffles, e.g. at the wall for redirecting settling solids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION 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
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/1443—Feed or discharge mechanisms for flotation tanks
    • B03D1/1475—Flotation tanks having means for discharging the pulp, e.g. as a bleed stream
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION 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
    • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
    • B03D1/00—Flotation
    • B03D1/14—Flotation machines
    • B03D1/1493—Flotation machines with means for establishing a specified flow pattern

Definitions

  • the present invention relates to a process and apparatus for beneficiation of minerals through froth flotation and more particularly to improvements for increasing the efficiency of column type flotation operations wherein impurities are separated from minerals and other floatable materials.
  • froth flotation involves conditioning an aqueous slurry or pulp of the mixture of mineral and gangue particles with one or more flotation reagents which will promote flotation of either the mineral or the gangue constituents of the pulp when the pulp is aerated.
  • the conditioned pulp is aerated by introducing into the pulp a plurality of minute air bubbles which tend to become attached either to the mineral particles or to the gangue 313
  • aqueous pulp ordinarily is aerated by means of a mechanical impeller-type agitator and aerator which extends into the body of pulp and which disperses minute bubbles of air throughout the body of pulp by vigorous mechanical agitation of the pulp.
  • the feed mixture of particulate material is normally introduced into one end of a bank of flotation machines, and the agitated pulp travels or progresses in an essentially horizontal direction to the pulp discharge at the opposite end of the bank of machines.
  • the agitated pulp of course, becomes increasingly depleted in floatable mineral values as the pulp progresses from the feed end to the discharge end of the bank of machines.
  • a bank of four to six mechanical cells are normally used for this purpose.
  • Flotation machines which employ vigorous agitation of the pulp to effect aeration thereof posses serious disadvantages when employed in connection with pulps that contain difficult to float particles which, because of the vigorous agitation, may not become attached to a sufficient number of air bubbles to float the particles or which may be dislodged from the froth column lying on top of the agitated body of pulp.
  • vigorous mechanical agitation of the pulp tends to produce slimes which in many cases adversely affect the efficiency of flotation otherwise obtainable.
  • aerating air has been introduced directly into a relatively quiescent body of aqueous pulp by means of air diffusers or aerators which are immersed in or are in direct contact with the pulp.
  • Such flotation apparatus are commonly referred to as pneumatic flotation machines and as with mechanical cells, the flow is essentially horizontal but sometimes they have some slope.
  • pneumatic flotation machines have been found to be efficient when used with ores that do not require vigorous agitation in order to prevent too rapid settling out of the solid particulate matter in the aqueous pulp. They are particularly useful when the pulp being treated tends to form harmful slimes when subjected to vigorous agitation.
  • the air diffusers or aerators of conventional pneumatic flotation machines ordinarily comprise a porous material (for example, heavy canvas, sintered metal powder structures, and the like) through which minute air bubbles are directly introduced into the aqueous pulp.
  • a porous material for example, heavy canvas, sintered metal powder structures, and the like
  • conventional pneumatic flotation machines are subject to a very troublesome problem caused by the tendency of the air diffusers immersed in or in contact with the pulp to become covered with a tenacious coating composed of oily flotation reagents and fine particles of minerals and gangue which clogs the minute openings frustrating air flow.
  • recycle in this context refers to either the drop of particles from the froth zone to the flotation zone or to the running off of a product from one column followed by a recycle through a second separation device.
  • Pp. 103-106, 132 and 134 The authors do not even suggest, but rather teach away from the concept of recycle within the flotation zone of an individual flotation column.
  • acst mineral bsneficiatia ⁇ o ra ions it is custr- ⁇ a y tr have what is known as rougher and cleaner circuits of flotation devices.
  • the rougher circuit a tailings product and a rougher concentrate product are produced.
  • the rougher concentrate is then sent to one or more cleaner circuits where it is cleaned to produce a high grade final concentrate that is suitable to be marketed and a middlings product that is recycled back to the head of the circuit.
  • the underflow tailings product is sent to a scavenger circuit to recover additional mineral values.
  • the circuits involved can either be columns, mechanical cells or air cells and in some cases combinations of several devices.
  • the present invention has many advantages over conventional columns and mechanical cells, the most important of which is high recovery and high grade in a single column, thus, in many operations this completely eliminates the need for both rougher and cleaner circuits, greatly reducing both capital and operating costs.
  • This invention provides a new column flotation process and apparatus for separating mixtures of relatively floatable and relatively non-floatable particles permitting sharper separation of floatables from non-floatables than possible in previous columns or mechanical flotation cells.
  • Flotation conditions in the process and apparatus of this invention are so controlled that for many minerals a final concentrate and a final tailings are both produced in a single column, contrasted with prior art attempts to avoid non-linear flow in the column this invention involves a plurality of controlled rec ⁇ le chambers intentionally introduced into the column where the fluids are recycled to continually mix air with pulp while coursing through the column. This is the opposite of what is strived for in prior art flotation columns as presented in the prior art.
  • Recycle zones are positioned on the periphery of the main passage or flotation zone within chambers located in series along the column. A portion of the slurry is drawn into a recycle zone where it passes downwardly to return to a flotation zone or the main passage through the column to again be swept upwardly through the column.
  • Disengaging chambers between the recycle chambers to slow the movement of the pulp.
  • Disengaging chambers accentuate the dropout of non-floatable materials so that such materials can be sent to a lower stage in the column.
  • Disengaging baffles may be set at the recycle zone exits where recycle streams re-enter the column to further separate non-floatables from floatables.
  • Another embodiment is the use of disengaging baffles at the exit of the recycle chambers. Baffles further separate non-floatables from floatables. These baffles can be in the form of vertical or horizontal bars or a perforated plate.
  • Another embodiment involves the use of shields to improve air distribution over the aerators and to protect the aerators from reagents and materials that could plug them.
  • Fig. 1 is a schematic elevational view of the laboratory pilot plant flotation column to test the process of this invention.
  • Fig. 2 is a schematic cross-section view of the column of Fig. 1 along lines 2-2.
  • Fig. 3 is a schematic cross-section view of the column of Fig. 1 along lines 3-3.
  • Fig. 4 is a schematic elevational view of a preferred embodiment of the invention described herein.
  • Fig. 5 is a schematic elevational view of another embodiment of the invention described herein incorporating a conventional flotation column section.
  • Fig. 6 is a schematic elevational view showing another embodiment of the invention described herein.
  • Fig. 7 is a schematic elevational view of another embodiment of the invention described herein.
  • Figure 8 is a schematic elevational view of a recycle chamber utilizing baffles.
  • FIG. 9 is a schematic elevational view of yet another embodiment of the invention. Detailed Description of the Drawings
  • the present invention generally includes a flotation column 10, a feed line 20, an aerator 30, an overflow basin 40, and an underflow section 50.
  • the flotation column 10 of this invention includes a plurality of recycle or recirculation chambers 60 oriented adjacent to, and in fluid communication with conventional column sections 70 (a conventional flotation column does not include any recycle chambers 60 and thus does not encourage the mixing of pulp and air) attached in sequence to provide a longitudinal passageway 71 along the length of the column 10.
  • the pulp which contains a mixture of mineral particles and gangue particles is introduced to the flotation column 10 through feeder line 20.
  • Feeder line 20 may simply be a tube or any other suitable line for the convenyance of pulp.
  • the lower end of feeder line 20 includes an orifice 22 through which the pulp is introduced into the flotation column 10.
  • the lower end of the feeder line 20 may be located at various depths within the flotation column 10 to vary the grade and recovery of the flotation column 10. Feed is normally introduced at a depth approximately midway into the flotation column 10 to produce a good grade and good recovery. However if emphasis is placed upon a high grade, the lower end of the feed line 20 can be placed below the midway point for the introduction of feed. If emphasis is placed on a high recovery rate, the lower end of the feed line 20 can be located at a depth above the midway point for the introduction of feed. Feed can also be introduced through the sides of the flotation column 10.
  • Aeration of the column 10 is not limited to any particular type of aerator 30.
  • aeration can be achieved via a constriction compartment 39 (Figs. 4 and 7), air diffusers or spargers 36, a mechanical aerator 37, etc. depending upon the industrial application. If a mechanical aerator 37 is used, it is sometimes desirable/ to have a perforated plate above it to reduce turbulence. Fine bubbles can also be generated outside of the column 10 and then fed to the column 10.
  • a gas other than air may be used for aeration. For example, nitrogen may be used for some sulfide ores if they are subject to oxidation.
  • eductors 31 to aspirate air into a constriction compartment 39 (Figs. 4 and 7) using water as the driving force as shown in Fig. 4 and described in U.S. Patent Nos. 4,431,531 and 3,371,779 which are incorporated herein for all purposes.
  • Aspirated air/water from, for example, an eductor 31 can also be introduced into one or more perforated air distribution tubes 36 in lieu of a constriction compartment 39.
  • aerator 30 is located at the lower end of flotation column 10. H wever, additional levels and forms of aeration may be located within the flotation column 10.
  • Eductor 31 as shown includes a running water line 32 which sucks in air forming a venturi 33. Air introduced through air line 34 is normally atmospheric air.
  • the aspirated mixture is then run through line 36a to a pipe 36 disposed within the lower end of flotation column 10.
  • Pipe 36 contains multiple holes (not shown) , normally ranging in size from l/8th inch to 5/16ths inch in diameter, arranged around the portion of the pipe disposed within the flotation column 10 to enhance the uniformity of distribution of the aspirated mixture introduced into the flotation column 10.
  • V-shaped shield 35 is attached to flotation column 10 over pipe" 36 to deflect the aspirated mixture and to protect pipe 36 from reagents and materials that could plug them. Such deflection further enhances the uniformity of distribution of the aspirated mixture.
  • V-shaped shield 35 is optional (for example, it is not used in column 200 shown in Fig. 5) and may be constructed in other shapes.
  • the eductor method and apparatus for aerating the flotation column 10 is particularly desirable if the percent solids of the feed into the column 10 are fifty percent or higher because water used not only aspirates air into the column 10 thus eliminating the need for a compressor, but water provides needed dilution and keeps the pulp fluidized. On the other hand, if the percent solids is less than 50%, compressed air can be used as the driving force to aspirate a small amount of water into the system.
  • the eductor method generates small bubbles, it is customary to add a surfactant (frother) to the water to create even finer bubbles as taught in U.S. Patent No. 3,371,779 to Hollingsworth et al.
  • porous diffuser Another type of aerator 30 which may be used and installed like pipe 36 when there is not an aspirated mixture running into the column is a porous diffuser (not shown) for generating fine bubbles.
  • porous diffusers include the ordinary garden soil soaker material found at any hardware store, porous metal, ceramic, plastic, perforated rubber tubing, etc.
  • the upper end of flotation column 10 preferably includes a flared section 12 as is well known in the art to slow the ascent of the pulp near the upper end in a froth or cleaner zone 14 of the flotation column 10 allowing better separation of non-floatable particles.
  • An overflow basin 40 is attached around the upper end of flotation column 10 to catch the overflow of froth emerging from flotation column 10 created by the rise of a float fraction containing floatable particles.
  • the overflow froth located in overflow basin 40 is drained through outlet 42 for handling in ways well known in the art.
  • the lower end of flotation column 10 includes an underflow section 50.
  • Underflow section 50 is preferably tapered to the outlet 52 to encourage the descent of the non-float fraction containing unfloated particles toward outlet 52.
  • the underflow is drained from underflow section 50 through outlet 52.
  • Flotation column 10 generally includes recycle chambers 60, partitions 62 and conventional column sections 70.
  • Fig. 1 illustrates the invention depicting schematically the test unit for this invention. Four stages of recycle 60a, 60b, 60c and 60d are shown, but almost any number can be used as determined by the separation required. Normally four to ten recycle chambers are used depending on the application. It is an advantage to the practice that each recycle chamber 60 may be made by modular construction and removed or added by simply disconnecting a fastener such as bolts, for example.
  • partitions 62a and 62b are attached to two opposing walls 63 and 64 of recycle chambers 60.
  • Feed line 20 is preferably centrally located within flotation column 10.
  • the regions on the periphery or external to the partitions 62a and 62b are referred to as recycle zones 61a.
  • the .region internal to the partitions 62 (the region between partitions 62a and 62b) and the region within conventional column sections 70, is referred to as the flotation or collection zone 71.
  • the height of partitions 62 is less than the height of recycle chamber 60 and such partitions are positioned intermediate the upper and lower ends of recycle chamber 60. This intermediate positioning defines an entry or opening 61b above partitions 62a and 62b and below the upper end of recycle chamber 60 and also defines a similar opehing or exit 61c below partitions 62a and 62b and above the lower end of recycle chamber 60. Entry 61b and exit 61c are areas of transition between flotation zone 71 and recycle zone 61a.
  • the width of both recycle zones 61a within a recycle chamber 60 is preferably ten to fifty percent of the flotation zone 71.
  • Fig. 4 illustrates a preferred embodiment 100 of the invention which is similar to flotation column 10 except for the differences discussed below.
  • a constriction compartment 39 as described in U.S. Patent No. 4,431,531 and incorporated herein for all purposes is located at the lower end of flotation column 10.
  • Eductor 31 introduces water and aerated air through orifices 39a formed in a top plate 39b of constriction compartment 39 in the form of a plurality of streams of uniformly aerated water.
  • constriction compartment 39 is not an air diffuser and that the orifices 39a formed therein are not intended to control air bubble size or promote air diffusion, the stream of water flowing through each orifice 39a already being aerated with a multitude of minute, uniformly dispersed air bubbles.
  • the orifices 39a formed in the top plate 39b are distributed in a relatively widely spaced geometric pattern across the entire area of the top plate 39b in order to insure uniform distribution of the aerated water and, thereby, to insure uniform aeration of the aqueous pulp in the flotation column 100.
  • a typical top plate 39b is formed with orifices about 5/16th inch in diameter spaced apart on two or three inch centers, as contrasted with the multitude of minute, bubble-forming pores with which a diffuser of conventional design is formed.
  • bypass conduits 39c are distributed in a relatively widely spaced geometric pattern across the entire constriction compartment 39 and are attached to orifices (which are relatively large compared to orifices 39a) formed in top plate 39b and bottom plate 39d.
  • Underflow section 50 is preferably tapered or conical to collect the underflow from the multiple bypass conduits 39c, however individual pipes (not shown) with valves could also be used to collect the underflow. As shown in Fig. 7, the non-float fraction can also be discharged through one hole or bypass conduit 39c through an air distributing constriction compartment.
  • a feed distributor 24 as described in U.S. Patent Nos. 4,287,054 and 4,431,531 and incorporated herein for all purposes may be attached to the lower end of feeder line 20. As pulp flows out the lower end of feeder line 20 it will fill up feed distributor 24 and then overflow into the interior region of flotation column 100.
  • the cone section 26 is a constriction compartment including a perforated plate 28 to which water and air are added via eductor line 31a. Water and air pass through the perforated top plate 28 thus fluidizing and aerating the incoming pulp. If desired, water alone can be used for fluidizing the pulp.
  • the feed distributor 24 would be round but if the flotation column is constructed with a square or rectangular cross-sectional configuration, the feed distributor 24 is preferably designed as a narrow rectangular trough running between walls 63 and 64.
  • Lower ends 67 of walls 65 and 66 are preferably inclined to create a more uniform flow within the recycle chamber 60 and to prevent the build up of pulp due to the force of gravity within a 45* corner.
  • Disengaging chambers 80 are preferably positioned in series above or in a downstream floatable fraction position from each recycle chamber 60. Disengaging chambers 80 are structured to have a larger cross-sectional area than the cross-sectional area of recycle chamber 60.
  • Each disengaging chamber 80 preferably includes front walls and back walls (not shown) which are parallel to each other similar to walls 63 and 64 of flotation column 10 shown in Fig. 2 and include side walls such as tapered edges 82 and 84 on opposite sides.
  • the front and back walls and tapered edges 82 and 84 of disengaging chamber 80 define a disengaging zone 81. Tapered edges 82 and 84 enhance mixing or non-vertical flow while discouraging build-up in corners within the disengaging zone 81. Because of the increase in the cross-sectional area, the movement of pulp through a disengaging zone 81 is slowed thus allowing non- floatable materials to drop out so that such materials can be sent to a lower stage or chamber within the flotation column 100.
  • the size of the flotation zone 71 is preferably five feet by five feet with an eighteen feet six inch flotation depth.
  • the overall depth including the froth zone 14 and underflow section 50 is preferably twenty-two feet.
  • FIG. 5 the lower end of another embodiment of a flotation column 200 is shown.
  • the lower end of the flotation column 200 is constructed with an extended conventional flotation column section 270.
  • Extended conventional column sections 270 could also be placed at the upper end 'or at various intermediate positions of a recycle flotation column.
  • the flotation zone 71 serves to connect recycle chambers 60 in series.
  • the vertical and horizontal distance between recycle zones 61a will of course vary according to the characteristics of the materials being tested in order to take advantage of the optimum characteristics of the apparatus of this invention.
  • the number and placement of disengaging zones 81 and their spacing from the recycle chambers 60 will vary as well.
  • a column 10 may have eight recycle chambers 60 and only four disengaging zones 81.
  • a mechanical aerator 37 (shown schematically) connected by air line 38 is represented. Mechanical aerators 37 are generally not preferred although conditions may exist in which they can be beneficial.
  • a flotation column 300 constructed without conventional flotation column sections 70 depicts the flow of the fluid through the flotation zone 71 and recycle zones 61a.
  • Aeration pipes 36 or alternatively porous diffusers (not shown) which are connected through flotation column 300 may be placed at a variety of levels within the flotation column 300. These pipes 36 are preferably located proximate the lower end of the recycle chambers 60 within the flotation zone 71. More than one pipe 36 can be placed at any level within the flotation column 300 to increase the initial uniformity of aeration within the flotation column 300. For example, four pipes are shown at each of two different levels in Fig. 7. For large commercial columns it would not be unusual to use twenty or more pipes at each level. Shields 35 are optional and if used are positioned over the pipes 36.. The lower ends of shields 35 should not extend below the level of the top of pipes 36.
  • water is introduced at forty to sixty pounds per square inch into a three inch running water line 32 and then introduced into a four inch eductor 31.
  • the aspirated mixture is run through a four inch pipe into a distributor box 90.
  • a one and one half inch pipe 31a runs from distributor box 90 to feed distributor 24.
  • Four separate two inch pipes 91 run from distributor box 90 to constriction compartment 39.
  • Other embodiments utilizing an eductor 31 can be designed by one skilled in the art.
  • Recycle rates can be controlled by varying air, by varying the width of recycle zone 61a, or preferably it is controlled by the size of openings 61b and 61c to and from the recycle zones 61a.
  • Restriction plates 68 are a preferred embodiment to be used for such control. Restriction plates 68 are attached to opposing walls 63 and 64 and positioned to partially restrict the entries 61b to the recycle zones 61a. As shown, these restriction plates ' 68 are preferably horizontally disposed and abut partitions 62 although they may be positioned in other manners which would restrict the flow through the recycle zones 61a. Since restriction plates 68 restrict the flow through recycle zones 61a, they impede or slow down the recycle rate of a recycle chamber 60. Hence, different sized restriction plates 68 can be designed to control the recycle rate within any recycle chamber 60.
  • Fig. 8 shows another optional feature which may be added within a recycle chamber 60.
  • Baffles 97 can be added to cover the exits of the recycle zones 61a to dislodge gangue that is attached to the mineral.
  • the baffle 97 is preferably constructed of a perforated plate 98.
  • baffle 97 could also be constructed from a series of parallel, vertically or horizontally, disposed bars (not shown) .
  • Frother type reagents which are used in conventional columns are also used in the recycle flotation column for forming fine bubbles.
  • Some examples of reagents which can be used in the recycle flotation column are as follows: F-507 which is a mixed polyglycol; alcohols, such as methyl amyl alcohol, methyl isobutyl alcohol, etc., generally C s to C M ; mixed alcohols, generally C, to C 1(S (generally the composition is such that several other oxygenated compounds makeup the mixture; often referred to as distillation bottoms) ; polyglycol ethers (common examples are polypropylene gly ⁇ ol, methyl ether, 250 to 400 molecular weight). All of the reagents have varying degrees of effectiveness. Some reagents may be more cost effective, some will provide better metallurgical results, i.e. concentrate grade and percent recovery (yield) .
  • a column seven feet high and about four x four inches with one inch wide recycle zones 61a on opposite sides has been utilized as a test unit. It was used in the following examples, offered for the purposes of illustration and not limitation. These examples show the marked advantages of using a series of internal recycle zones in the beneficiation of ores.
  • Fig. 1 illustrates this test unit or original lab pilot plant. Four stages of recycle are shown. An eductor 31 is used at the lower end to generate fine bubbles for flotation. A constriction compartment (not shown) similar to the constriction compartment 39 shown in Fig. 4 has also be used. An air diffuser (not shown) has been installed near the lower end and another (not shown) about one-third the way down. This allows testing of the eductor alone, air diffusers alone or a combination of the two aeration systems.
  • Fig. 9 illustrates a further modified form of the invention and wherein additional benefits are achieved. The same is similar in most respects to the form of Fig. 1, but wherein the column sections 70 of Fig. 1 are eliminated and replaced by radially inwardly extending divider plates 150 between the recycle chambers 60a, 60b, 60c, 60d, and 60e.
  • the divider plates 150 be of lesser radially inwardly extending length than the lateral width of the recycle chambers 60, thereby permitting the non-float gangue to pass downwardly with less bucking against the upward flow of air and float passing to the top discharge as the gangue passes to the underflow discharge. Nonetheless it will be seen that as with the other embodiments the descending gangue will be serially reintroduced at least in part into the upflowing column to facilitate the processing thereof.
  • air distribution is important in column flotation, the present invention makes air distribution less critical.
  • air may be introduced just at or near the bottom of the column, or at two or more depths depending upon the overall height and width of the column.
  • air introduction is disclosed in my patent 2,758,714, for example.
  • the specific aeration means is not shown in Fig. 9, but may be any of the presently used forms as earlier set forth as simple air diffusers, eductor ⁇ to aspirate the air into a constriction compartment or into perforated or porous tubes.
  • Diverse other and sophisticated systems have been developed by the U.SA, Bureau of Mines and other investigators. While in the preferred form of Fig. 9 the plates 150 are shortened as shown, the same may be about the same length as the width of the chambers 60 with workable results.
  • Plant was used ⁇ as the flotation feed (mostly 14 x 100 mesh) and was conditioned at high solids (about 70%) for 90 seconds using fuel oil, fatty acid (such as fatty acid sold under the mark "P ⁇ M ⁇ K" by
  • BPL-(bone phosphate of lime or essentially tricalcium phosphate) 32.19
  • EXAMPLE 2 Using both coarse and fine phosphate flotation feeds that were difficult to obtain a good grade product, a comparison was made between a conventional laboratory column and the laboratory recycle column (see Fig. 1) .
  • the feed material comprised essentially mixtures of phosphate rock and silica particles. Feeds were conditioned at about 70% solids using a fatty acid, fuel oil and ammonium hydroxide. The particle size of the coarse feed was mostly between 14 mesh and 65 mesh (Tyler Standard) and the fine feed was mostly between 35 mesh and 200 mesh.
  • Feed was -100 mesh material. F-507 was used as the reagent or collector and lime was used as modifier (raise pH) .
  • EXAMPLE 4 A Spodumene rougher flotation concentrate from a plant in North Carolina was used as the feed for the test. The spodumene rougher flotation concentrate presently undergoes two stages of cleaner flotation in the plant for upgrading. The plant data obtained from two stages in series of cleaner flotation is compared to one stage of cleaning in the test recycle column:
  • Tailings (mostly sand) from a spodumene flotation plant in North Carolina was used as the feed for the test.
  • the tailings feed was conditioned at high solids with reagents and was subjected to flotation to remove iron and residual spodumene to produce a high grade sand product.
  • a comparison was made between the plant flotation column and the recycle test column:
  • the invention described above can be constructed with a square, rectangular or circular cross- section implementing the recycle chamber and disengaging chamber concepts described.
  • the same recycle and disengaging principles as shown and disclosed in the rectangular column represented in the drawings with modified construction can be applied to square and circular recycle columns.
  • Partitions 62, and hence recycle zones 61a could be staggered within the flotation column.
  • partitions 62 could also be located on all four sides creating four recycle zones 61a per recycle chamber 60. It is not essential that partitions 62 be vertically aligned with the walls of conventional column sections 70. Attachments or connections made to construct the invention are preferably made by welding although fasteners, adhesives or other known methods of attachment can be used.

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Abstract

L'invention se rapporte à des processus et des appareils comprenant une colonne de flottation (10) destinée à la séparation d'une pulpe en fractions flottante et non flottante. La colonne de flottation (10) est pourvue d'une série d'au moins deux chambres de recyclage (60) verticalement espacées, ainsi que d'une conduite d'alimentation (20) située au niveau de l'extrémité supérieure de la colonne (10). La fraction non flottante qui descend dans la colonne (10) est réintroduite à plusieurs reprises dans les chambres de recyclage et continuellement mélangée avec la pulpe tout en traversant la colonne (10).
PCT/US1992/004822 1992-06-15 1992-06-15 Concentration de mineraux Ceased WO1993025313A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CA002138145A CA2138145C (fr) 1992-06-15 1992-06-15 Concentrateur de minerais
AU22261/92A AU676459B2 (en) 1992-06-15 1992-06-15 Concentration of minerals
PCT/US1992/004822 WO1993025313A1 (fr) 1992-06-15 1992-06-15 Concentration de mineraux

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CA002138145A CA2138145C (fr) 1992-06-15 1992-06-15 Concentrateur de minerais
PCT/US1992/004822 WO1993025313A1 (fr) 1992-06-15 1992-06-15 Concentration de mineraux

Publications (1)

Publication Number Publication Date
WO1993025313A1 true WO1993025313A1 (fr) 1993-12-23

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1992/004822 Ceased WO1993025313A1 (fr) 1992-06-15 1992-06-15 Concentration de mineraux

Country Status (2)

Country Link
CA (1) CA2138145C (fr)
WO (1) WO1993025313A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7510083B2 (en) 2004-06-28 2009-03-31 The Mosaic Company Column flotation cell for enhanced recovery of minerals such as phosphates by froth flotation
WO2014188232A1 (fr) 2013-05-23 2014-11-27 Dpsms Tecnologia E Inovação Em Mineração Ltda Système automatique de colonnes de flottation par mousse avec buses d'injection d'aérateurs et procédé
EP3281704A1 (fr) * 2016-08-12 2018-02-14 Danish Technology Center-dantech ApS Système de flottation destiné à séparer les particules d'un liquide

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1457077A (en) * 1919-08-21 1923-05-29 Thomas A Janney Flotation machine
US1886979A (en) * 1931-01-26 1932-11-08 Jr Joseph P Ruth Flotation method
US2758714A (en) * 1954-08-25 1956-08-14 Smith Douglas Company Inc Concentration of minerals
US3298519A (en) * 1963-10-23 1967-01-17 Borden Co Concentration of minerals

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1457077A (en) * 1919-08-21 1923-05-29 Thomas A Janney Flotation machine
US1886979A (en) * 1931-01-26 1932-11-08 Jr Joseph P Ruth Flotation method
US2758714A (en) * 1954-08-25 1956-08-14 Smith Douglas Company Inc Concentration of minerals
US3298519A (en) * 1963-10-23 1967-01-17 Borden Co Concentration of minerals

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7510083B2 (en) 2004-06-28 2009-03-31 The Mosaic Company Column flotation cell for enhanced recovery of minerals such as phosphates by froth flotation
US8231008B2 (en) 2004-06-28 2012-07-31 Mos Holdings Inc. Column flotation cell for enhanced recovery of minerals such as phosphates by froth flotation
WO2014188232A1 (fr) 2013-05-23 2014-11-27 Dpsms Tecnologia E Inovação Em Mineração Ltda Système automatique de colonnes de flottation par mousse avec buses d'injection d'aérateurs et procédé
EP3281704A1 (fr) * 2016-08-12 2018-02-14 Danish Technology Center-dantech ApS Système de flottation destiné à séparer les particules d'un liquide

Also Published As

Publication number Publication date
CA2138145A1 (fr) 1993-12-23
CA2138145C (fr) 1999-02-23

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