Gasified fluid supply arrangement and flotation cell

Abstract

A gasified fluid supply arrangement (1700), a flotation cell (1000), and a method for treating particles suspended in slurry (1214) is disclosed. The gasified fluid supply arrangement (1700) comprising a manifold (1701), and one or more tube distributors (1703) connected to the manifold (1701). The one or more tube distributors (1703) comprise one or more nozzles (1704). The manifold (1701) is configured to distribute gasified fluid to the one or more tube distributors (1703). The one or more nozzles (1704) are configured to inject the gasified fluid to at least a center area (A1) of the tank (1100).

Description

[0001] GASIFIED FLUID SUPPLY ARRANGEMENT AND FLOTATION CELL

[0002] FIELD OF TECHNOLOGY

[0003] This disclosure concerns mineral processing . In particular, this disclosure concerns separation of minerals from their ores by flotation .

[0004] BACKGROUND

[0005] The energy consumption of comminution processes , especially grinding, typically constitutes a significant part of overall energy consumption in mineral processing . As such, significant effort has been invested in reducing energy consumption of grinding . This may generally be achieved by lowering the degree of liberation of ore , i . e . , by increasing the average si ze of ore particles prior to concentration . Standard mechanical flotation cells are best suited for separation of particles within a si ze range of approximately 20 pm to 150 pm . Consequently, alternative solutions are required to increase the average particle size of ore beyond 150 pm .

[0006] SUMMARY

[0007] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description . This summary is not intended to identify key features or essential features of the claimed subj ect matter, nor is it intended to be used to limit the scope of the claimed subj ect matter . The scope of protection sought for various embodiments of the present disclosure is set out by the independent claims . Example embodiments of the present disclosure provide a flotation cell for treating particles suspended in slurry and for separating the slurry into underflow and overflow. The flotation cell may comprise a gasified fluid supply arrangement configured to distribute gasified fluid, for example aerated water, into a center area of a tank. The main purpose may be to make the main gasification in the center of the process tank.

[0008] According to a first aspect, a gasified fluid supply arrangement comprises a manifold; and one or more tube distributors connected to the manifold, wherein the one or more tube distributors comprise one or more nozzles, wherein the manifold is arranged to distribute gasified fluid to the one or more tube distributors; and the one or more nozzles are configured to inject the gasified fluid to at least a center area of the tank. The gasified fluid supply arrangement is aerated fluid supply arrangement, for example. The one or more gasified fluid generators are aerated fluid generators, for example. The gasified fluid is aerated water, for example. The gasified fluid may comprise gas bubbles and fluid, for example water and air bubbles. The gasified fluid may comprise gas bubbles and slurry for example slurry and air bubbles. The gasified fluid supply arrangement may comprise multiple, such as 12 tube distributors, or such as 120 tube distributors, or such as 300 tube distributors, or such as 720 tube distributors, for example. The manifold may enable the multiple tube distributors to inject the gasified fluid from the center area of the process tank. It may also enable multiple, for example four, or 40, or 100, or 240, gasified fluid generators to inject the gasified fluid to the tube distributors. According to an example embodiment of the first aspect , the gasified fluid supply arrangement may comprise one or more gasified fluid generators connected to the manifold . The mani fold may be arranged to distribute gas if ied fluid from the one or more gasif ied fluid generators to the one or more tube distributors .

[0009] According to an example embodiment of the first aspect , the one or more noz z les may point downwards . When the one or more noz zles are pointing downwards it may prevent clogging of them .

[0010] According to an example embodiment of the first aspect , the one or more tube distributors may extend radially from the manifold . The tube distributors may extend from the center of the tank to a periphery area of the tank . This may allow the tube distributors to feed the gasified fluid mainly from the center area of the tank but also some amounts from a middle area of the tank, and minor amounts from the periphery area of the tank .

[0011] According to an example embodiment of the first aspect , two or more tube distributors may be arranged at equal distance from each other so that a distance between any two adj acent tube distributor is the same . This may allow the tube distributors to feed gasified fluid 360 ° around the tank .

[0012] According to an example embodiment of the first aspect , the two or more tube distributors may be arranged in one or more levels . The two or more tube distributors may be arranged in two levels , for example . Arranging the tube distributors in different levels may improve feeding and distribution of the gasified fluid evenly . According to an example embodiment of the first aspect , height difference between two levels of the tube distributors is less than six times a diameter of the tube distributor . This may allow the gasif ied fluid to be fed to the tank in an optimi zed way to create a thick, for example 500 mm, calm froth layer in a low tank . In the low tank the height H to diameter D ratio H / D of the flotation tank may be lower than 2 . The height is a combined height of a froth zone , mixed zone , and settling zone .

[0013] According to an example embodiment of the first aspect , the manifold may comprise one or more manifold inlets arranged to connect the gasified fluid generators to the manifold; and one or more manifold outlets arranged to connect the tube distributors to the manifold . The manifold outlets and inlets may allow different parts to be attached to the manifold .

[0014] According to an example embodiment of the first aspect , the one or more manifold outlets may be arranged equally spaced circumferentially around the manifold so that a distance between any two adj acent manifold outlets may be the same . This may allow the tube distributors to be attached circumferentially and equally around the manifold, which may allow them to feed aerated fluid and bubbles 360 ° evenly around the tank and especially in the round center area Al of the tank .

[0015] According to an example embodiment of the first aspect , the one or more manifold inlets may be arranged above each other . The one or more mani fold inlets may be arranged vertically above each other . One manifold inlet may be located at a top of the manifold, one manifold inlet may be located at a bottom of the manifold, and none , or one , or more inlets may be arranged at a side of the manifold . This may allow equal distribution of the aerated fluid to the manifold and from there to the tube distributors .

[0016] According to an example embodiment of the first aspect , the gasified fluid supply arrangement may comprise one or more connecting means located between the one or more gasified fluid generators and the manifold, wherein the one or more connecting means may be arranged to connect the one or more gasi fied fluid generators to the manifold . The connecting means is at least one of the fol lowing : a tube , pipe , hose , and / or channel . When the gasified fluid generators are located outside the tank, the connecting means may be arranged inside the tank and may be used to connect the gasif ied fluid generators and the manifold . One or more gasified fluid inlets may connect the one or more gasified fluid generators to the one or more connecting means . The connection means may also help to locate the manifold in the center of the tank .

[0017] According to a second aspect , a flotation cell for treating particles suspended in slurry and for separating the slurry into underflow and overflow is disclosed, wherein the flotation cell comprises a tank for holding a slurry and a froth layer over the slurry; a feeding arrangement configured to feed the slurry; and a gas ified fluid supply arrangement according to any of the first aspects . The manifold may enable the multiple tube distributors to inj ect the gasified fluid from the center area of the process tank . It may also enable multiple , for example four, or 40 , or 100 , or 240 , gasified fluid generators to inj ect the gasified fluid to the tube distributors .

[0018] According to an example embodiment of the second aspect , the one or more noz zles may be configured to inj ect gasified fluid downwards to at least a center area of the tank . The gasified fluid may be concentrated more to the center of the tank but also may be lightly di stributed in the middle and periphery areas of the tank .

[0019] According to an example embodiment of the second aspect , the tank may comprise the center area, the middle area, and the periphery area ; and the two or more noz zles may be arranged in each of the tube distributors so that amount of the noz zles in the center area > amount of the noz zles in the middle area > amount of the noz zles in the periphery area . The center area, the middle area, and the periphery area may be round areas around the center axis . Also , other kind or areas may be formed . The gasified fluid may be concentrated more to the center of the tank but also may be lightly distributed in the middle and periphery areas of the tank . This may be possible by locating the noz zles and gasified fluid flow more to the center area of the tank .

[0020] According to an example embodiment of the second aspect , the one or more noz z les may be arranged to distribute the gasified fluid so that gasified fluid center flow rate in the center area > gasified fluid middle flow rate in the middle area > gasified fluid periphery flow rate in the periphery area . This may allow most of the gasified fluid to be located in the center area from where it may move upwards towards the froth layer . This may help the coarse particles to remain in the froth layer and not to descend down into the tank . This arrangement may lead to increased recovery of al l hydro- phobic particles , and especially larger particles .

[0021] According to an example embodiment of the second aspect , superficial gas velocity inside the tank is taken as volume flow of gas / area of the froth, wherein center superficial gas velocity [ cm / s ] in the center area may be from 2 to 7 ; middle superficial gas velocity in the middle area may be from 1 to 5 ; and periphery superficial gas velocity in the periphery area may be from 0 to 3 . Superficial gas velocity may be greater in the center area wherein more bubbles may be needed to move upwards towards the froth layer . This may help the coarse particles to adhere to the gas bubbles and increase recovery of larger particles .

[0022] According to an example embodiment of the second aspect , the gasified fluid supply arrangement may be arranged below the froth layer . The gasified fluid supply arrangement may be arranged below the froth layer . The gasified fluid supply arrangement may be arranged above the settled underflow particle layer . When the gasif ied fluid supply arrangement is arranged below the froth layer it may allow gasified fluid to move efficiently towards the froth layer slurry allowing more coarse particles to attach to the gas bubbles .

[0023] According to an example embodiment of the second aspect , the manifold may be arranged parallel to a side wall at the center of the tank . Arranging the gasified fluid supply arrangement in the center of the tank may allow the gasi fied fluid to f low out of the noz zles into the center of the tank . According to an example embodiment of the second aspect , the manifold may be arranged vertically in the tank .

[0024] According to an example embodiment of the second aspect , the tube distributors may be arranged perpendicular to a side wal l or hori zontally in the tank . Arranging the tube distributors perpendicular to the side wall or hori zontally in the tank may allow the gasified fluid to be fed out of the noz zles downwards . This may prevent blocking of the noz zles which may be located at the bottom side of the tube distributors .

[0025] According to an example embodiment of the second aspect , the one or more gasif ied fluid generators may be located outside the side wall of the tank . Technical requirements may require locating the one or more gasified fluid generators outside the tank . The one or more gasified fluid generators may be located inside the tank .

[0026] According to an example embodiment of the second aspect , the flotation cell may be a gravity feeding flotation cell . In a gravity feeding system, the slurry may be fed into the flotation tank at the froth layer . In the gravity fed type of flotation cell , gas for producing the gas bubbles for flotation may be added through gasified fluid generator in the main flotation tank . The gas may be added in the main flotation tank wherefrom it raises up to the froth layer and may adhere to fine and / or coarse particles of the slurry .

[0027] According to an example embodiment of the second aspect , the feeding arrangement may be configured to feed slurry onto the froth layer, into the froth layer, into the froth slurry interface , or immediately below the froth layer . Different methods and systems may be used to feed the slurry in the di fferent parts of the froth layer .

[0028] According to an example embodiment of the second aspect , the flotation cell may further comprise one or more froth crowders arranged to direct froth towards a lip . The crowder may be util i zed to direct or guide the upwards-flowing slurry and / or gasified fluid within the flotation tank closer to a froth overflow lip of a froth collection launder, thereby enabling or easing froth formation very close to the froth overflow lip, which may increase the collection of des irable ore particles .

[0029] According to a third aspect , a method for treating particles suspended in slurry and for separating the slurry into underflow and overflow using a flotation cell according to any of the second aspects is disclosed, wherein the method comprises providing a tank for holding a slurry and a froth layer over the slurry; feeding slurry to the tank with a feeding arrangement ; distributing, us ing a mani fold of a gasi fied fluid supply arrangement , gasi fied fluid to one or more tube distributors comprising one or more noz zles ; and inj ecting the gasified fluid to at least a center area of the tank using the one or more noz z les . The manifold may enable the multiple tube distributors to inj ect the gasified fluid from the at least center area of the process tank . It may also enable multiple gasified fluid generators to inj ect the gasified fluid to the tube distributors .

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present disclosure will be better understood from the following detailed description read in light of the accompanying drawings , wherein : FIG . 1 shows schematically an example of a flotation cell with a gasified fluid generator,

[0032] FIG . 2 shows schematically an example of tube distributors seen from below,

[0033] FIG . 3 shows schematically an example of a manifold and connecting means , and

[0034] FIG . 4 shows an example method for treating particles suspended in slurry and for separating the slurry into underflow and overflow using a flotation cell .

[0035] Unless specifically stated to the contrary, any drawing of the aforementioned drawings may be not drawn to scale such that any element in said drawing may be drawn with inaccurate proportions with respect to other elements in said drawing in order to emphasi ze certain structural aspects of the embodiment of said drawing .

[0036] Moreover, corresponding elements in the embodiments of any drawings of the aforementioned drawings may be disproportionate to each other in said drawings in order to emphasi ze certain structural aspects of the embodiments of said drawings .

[0037] DETAILED DESCRIPTION

[0038] Reference will now be made in detai l to example embodiments , examples of which are illustrated in the accompanying drawings . The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present example may be constructed or utili zed . The description sets forth the functions of the example and the sequence of steps for constructing and operating the example . However, the same or equivalent functions and sequences may be accomplished by different examples .

[0039] According to an example embodiment , gasified fluid is distributed from a center of a circular tank . The gasified fluid may be distributed to a tube distributor, so that the gasi fied fluid may be inj ected in the tube distributor close to the center area of the tank . In this way, the gasi fied fluid may be fed to the tank in an optimi zed way, and it may create a thick, for example 500 mm, calm froth layer in a low tank . The gasified fluid, for example aerated water, may be concentrated more to the center of the tank but it also may be lightly distributed in the middle and periphery of the tank .

[0040] The figures are not drawn to proportion, and many of the components of the flotation cell 1000 are omitted for clarity . The enclosed figure 1 illustrates a flotation cell 1000 in some detail . Figures 2 and 3 illustrate in a schematic manner embodiments of a gasified fluid supply arrangement .

[0041] A flotation cell 1000 according to an example embodiment of FIG . 1 is intended for treating mineral ore particles suspended in slurry 1214 and for separating the slurry 1214 into an underflow 1105 and an overflow 1003 , the overflow may comprise a concentrate of a desired mineral .

[0042] By overflow herein is meant the part of the slurry collected into the launder of the f lotation cell and thus leaving the flotation cell . Overflow may comprise froth, froth and s lurry, or in certain cases , only or for the largest part slurry . In some embodiments , overflow may be an accept flow containing the valuable material particles collected from the slurry . In other embodiments , the overflow may be a rej ect flow . This is the case in when the flotation arrangement , plant and / or method is utili zed in reverse flotation .

[0043] By underflow herein is meant the fraction or part of the slurry which is not floated into the surface of the slurry in the flotation process . In some embodiments the underflow may be a rej ect flow leaving a flotation cell via an outlet which typically is arranged in the lower part of the flotation cell . Eventually the underflow from the final flotation cell of a f lotation line or a flotation arrangement may leave the entire arrangement as a tailings flow or final residue of a flotation plant . In some embodiments , the underflow may be an accept flow containing the valuable mineral particles . This is the case in when the flotation cell or flotation line is utili zed in reverse flotation .

[0044] According to an example embodiment , the flotation cell 1000 comprises a tank 1100 for holding a slurry 1001 and a froth layer 1002 over the volume of slurry 1001 , wherein the feeding arrangement is configured to feed slurry 1214 . The flotation cell 1000 may further comprise a gasified fluid supply arrangement

[0045] 1700 comprising a manifold 1701 , one or more gasified fluid generators 1702 connected to the manifold 1701 , and one or more tube distributors 1703 connected to the manifold 1701 , wherein the one or more tube distributors 1703 may comprise one or more noz z les 1704 . The manifold

[0046] 1701 may be configured to distribute gasified fluid from the one or more gasif ied fluid generators 1702 to the one or more tube distributors 1703 , and the one or more noz zles 1704 may be configured to inj ect the gasified fluid to at least a center area Al of the tank 1100 .

[0047] According to an example embodiment , a gasified fluid supply arrangement 1700 comprises a manifold 1701 , and one or more tube distributors 1703 connected to the manifold 1701 . The one or more tube distributors 1703 may comprise one or more noz zles 1704 , wherein the manifold 1701 may be arranged to distribute gasified fluid to the one or more tube distributors 1703 . The one or more noz zles 1704 may be configured to inj ect the gas ified fluid to at least a center area Al of the tank .

[0048] According to an example embodiment , a gasified fluid supply arrangement 1700 comprises one or more gasified fluid generators 1702 connected to the manifold 1701 . The mani fold 1701 may be configured to distribute gas if ied fluid from the one or more gasif ied fluid generators 1702 to the one or more tube distributors 1703 .

[0049] Throughout this specification, "flotation" may refer to separation of a mixture by adhering a substance in said mixture at an interface . The flotation may be concentration method to separate ore from the gangue . In flotation, separation of a mixture may be based on differences in the hydrophobicity of substances in said mixture . Herein, "separation" may refer to the extraction or removal of a substance from a mixture for use or re j ection .

[0050] Further, "froth flotation" may refer to flotation, wherein froth is utili zed for separation . Herein, "froth" may refer to a dispersion, comprising a greater portion by volume of gas ified fluid dispersed as gasified fluid in lesser portion by volume of a flotation liquid . Generally, froth may or may not be stabili zed by solid particles . In froth, gasified fluid may general ly have an average diameter greater than or equal to 1 mm . Additionally or alternatively, an average distance between neighboring gasified fluid in froth not stabili zed by solid particles may general ly be les s than or equal to some tens of micrometers , for example , less than or equal to 50 pm or 30 pm . Naturally, in froth stabilized by solid particles , average distance between neighboring gasified fluid may be increased in proportion to the average si ze and quantity of said solid particles .

[0051] The term "flotation gas" may refer to any gaseous substance suitable for use in flotation . Although in practical applications air is often used as a flotation gas , other types of gaseous substances may also be utili zed, as known to the skilled person .

[0052] On the other hand, " flotation liquid" may refer to any liquid substance or mixture suitable for use in f lotation . Although in practical applications water or aqueous solutions are often used as flotation liquids , other types of liquid substances may also be utili zed, as known to the skilled person .

[0053] Throughout thi s specification, a "cell" may refer to a device suitable for or configured to perform at least one specific process . Naturally, a "flotation cell" may then refer to a cell suitable for or configured to subj ect material to flotation . A cell may generally comprise one or more parts , and each of the one or more parts may be classified as belonging to an arrangement . A flotation cel l meant for treating mineral ore parti cles suspended in slurry by flotation . Thus , valuable metal-containing ore particles may be recovered from ore particles suspended in slurry . By flotation line herein is meant a flotation arrangement where a number of flotation cells may be arranged in fluid connection with each other so that the underflow of each preceding flotation cell may be directed to the following or subsequent flotation cell as infeed until the last flotation cell of the flotation line , from which the underflow may be directed out of the line as tailings or rej ect flow . Slurry may be fed through a feed inlet or slurry feeding arrangement to the first flotation cell of the flotation line for initiating the flotation process . A flotation line may be a part of a larger flotation plant or arrangement containing one or more flotation lines . Therefore , a number of different pre-treatment and posttreatment devices or stages may be in operational connection with the components of the flotation arrangement , as is known to the person skilled in the art .

[0054] The flotation cells in a f lotation l ine may be fluidly connected to each other . The fluid connection may be achieved by different lengths of conduits such as pipes or tubes , which may also comprise pumps or regrinding units , the length of the conduit depending on the overall physical construction of the flotation arrangement . In between the flotation cells of a flotation line, pumps or grinding / regrinding units may also be arranged . Alternatively, the flotation cells may be arranged in direct cell connection with each other . By direct cell connection herein is meant an arrangement , whereby the outer walls of any two subsequent flotation cells are connected to each other to allow an outlet of a first flotation cell to be connected to the inlet of the subsequent flotation cell without any separate conduit . A direct contact may reduce the need for piping between two adj acent flotation cells . Thus , it may reduce the need for components during construction of the flotation line , speeding up the process . Further, it might reduce sanding and simplify maintenance of the flotation line . The fluid connections between flotation cells may comprise various regulation mechanisms .

[0055] By "neighbouring", "adj acent" , or "adj oining" flotation cell herein is meant the flotation cell immediately following or preceding any one flotation cell , either downstream or upstream, or either in a rougher flotation line , in a scavenger flotation line , or the relationship between a flotation cell of a rougher flotation line and a flotation cell of a scavenger flotation line into which the underflow from the flotation cell of the rougher flotation line may be directed .

[0056] By a flotation cell is herein meant a tank or vessel in which a step of a flotation process may be performed . A flotation cell may typically be cylindrical in shape , the shape defined by an outer wall or outer wall s . The flotation cells regularly may have a circular crosssection . The flotation cells may have a polygonal , such as rectangular, square , triangular, hexagonal , or pentagonal , or otherwise radially symmetrical cross-section, as well . The flotation cel ls may have a radially unsymmetrical cross-section, as well . The number of flotation cells may vary according to a specific flotation line and / or operation for treating a specific type and / or grade of ore , as is known to a person skilled in the art .

[0057] The f lotation cel l may be a froth flotation cell , such as a mechanically agitated cell , for example a TankCell , a column flotation cell , a Jameson cell , or a dual flotation cell . In a dual flotation cell , the cell may comprise at least two separate vessels , a first mechanically agitated pressure vessel with a mixer and a gasified fluid input , and a second ves sel with a tailings output and an overflow froth discharge , arranged to receive the agitated slurry from the first vessel . The flotation cell may also be a fluidi zed bed flotation cell ( such as a HydroFloatTM cell ) , wherein air or other gasi fied fluid bubbles which are di spersed by the fluidization system percolate through the hindered-setting zone and attach to the hydrophobic component altering its density and rendering it sufficiently buoyant to float and be recovered . In a fluidi zed bed flotation cell axial mixing may not be needed . The flotation cell may also be an overflow flotation cell operated with constant slurry overflow . In an overflow flotation cell , the slurry is treated by introducing gasified fluid bubbles into the slurry and by creating a continuous upwards flow of slurry in the vertical direction of the first flotation cell . At least part of the valuable metal containing ore particles may be adhered to the gas bubbles and ri se upwards by buoyancy, at least part of the valuable metal containing ore particles may be adhered to the gas bubbles and rise upwards with the continuous upwards flow of slurry, and at least part of the valuable metal containing ore particles may rise upwards with the continuous upwards flow of slurry . The valuable metal containing ore particles may be recovered by conducting the continuous upwards flow of slurry out of the at least one overflow flotation cell as slurry overflow . As the overf low cel l may be operated with virtual ly no froth depth or froth layer, effectively no froth zone may be formed on the surface of the slurry at the top part of the flotation cel l . The froth may be non-con- tinuous over the cell . The outcome of this may be that more valuable mineral containing ore particles may be entrained into the concentrate stream, and the overall recovery of valuable material may be increased .

[0058] All of the flotation cells of a flotation line may be of a single type , that is , rougher flotation cells in the rougher part , scavenger flotation cells in the scavenger part , and scavenger cleaner flotation cells of the scavenger cleaner flotation line may be of one single flotation cell type so that the flotation arrangement comprises only one type of flotation cells as listed above . Alternatively, a number of flotation cells may be of one type while other cells are of one or more type so that the flotation l ine comprises two or more types of flotation cells as listed above .

[0059] Depending on its type , the flotation cell may comprise a mixer for agitating the slurry to keep it in suspension . By a mixer is herein meant any suitable means for agitating slurry within the flotation cell . The mixer may be a mechanical agitator . The mechanical agitator may comprise a rotor-stator with a motor and a drive shaft , the rotor-stator construction arranged at the bottom part of the flotation cell . The cell may have auxiliary agitators arranged higher up in the vertical direction of the cel l , to ensure a sufficiently strong and continuous upwards flow of the slurry .

[0060] An "arrangement" of a cell configured to perform a process may refer to a set of parts of said cell suitable for or configured to perform at least one specific subprocess of said process . As such, a "cell comprising an arrangement" may refer to said cell comprising parts belonging to said arrangement . On the other hand, an arrangement for a cell may refer to a set of parts suitable for or configured to perform at least one specific subprocess . Generally, an arrangement for a cell may or may not form a part of said cell . Any arrangement may comprise any part ( s ) , for example , mechanical , electrical , pneumatic, and / or hydraulic part ( s ) , necessary and / or beneficial for performing its specific subprocess . Herein, a "part" may refer to an element or obj ect , which is or may be assembled with one or more other elements or obj ects to form a device , an arrangement , or a cell .

[0061] One or more gasif ied fluid inlets 1106 may connect the one or more gasified fluid generators 1702 to the one or more connecting means 1705 .

[0062] Further, "slurry" may refer to a dispersion, comprising solid particles suspended in a continuous phase of flotation liquid . Consequently, a "slurry feeding arrangement" may refer to an arrangement of parts of a flotation cell or for said flotation cell suitable for or configured to feed slurry into a tank of said flotation cell . A slurry feeding arrangement may be suitable for or configured to feed slurry to a froth layer situated over a slurry in a tank of a flotation cell . Herein, slurry being "fed to a froth layer" may refer to feeding said slurry onto , and / or into , and / or immediately below, e . g . , at most two times the froth depth, or at most the froth depth, or at most 1 / 2 of the froth depth, or at most 1 / 5 of the froth depth, or at most 1 / 10 of the froth depth below, the surface of said froth layer, and / or into froth slurry interface . Additionally or alternatively, in embodiments , wherein a height of a launder lip defines a height of an upper surface of a froth layer, slurry being fed to said froth layer may refer to feeding said slurry into a tank at said launder lip level and / or at a position at most the froth depth, or at most 1 / 2 of the froth depth, or at most 1 / 5 of the froth depth, or at most 1 / 10 of the froth depth, or at most 1 / 50 of the froth depth below said launder lip level . Throughout this specification, froth flotation, wherein slurry is fed to a froth layer, may be referred to as "froth-interaction flotation" . Naturally, a "froth-interaction flotation cell" may then refer to a cell configured to or suitable for separation of material by froth-interaction flotation .

[0063] Herein, a "tank" may refer to a receptacle suitable for or configured to hold a fluid, for example , a liquid .

[0064] In this disclosure "froth slurry interface" may refer to a layer on top of the s lurry where gas hold-up percentage is between 10 -50 .

[0065] The flotation cell 1000 of the example embodiment of FIG . 1 may be used in so-called "standard flotation" , wherein valuable mineral ( s ) in slurry is collected as overf low and gangue is directed to underflow . In other example embodiments , a flotation cell may be used in any suitable manner, for example , in standard flotation and / or in so-called "reverse flotation" , wherein valuable mineral ( s ) in slurry is directed to underflow and gangue is collected as overflow .

[0066] The flotation cell 1000 of the example embodiment of FIG . 1 may be configured for use in so-called "coarse flotation" , wherein slurry comprising a considerable amount of coarser solid particles is used as feed material for flotation . In other example embodiments , a flotation cell may or may not be configured for use in coarse flotation .

[0067] In the example embodiment of FIG . 1 , the flotation cell 1000 comprises a tank 1100 . In other embodiments , a flotation cell may or may not comprise a tank .

[0068] The tank 1100 of the embodiment of FIG . 1 is configured to hold slurry 1001 and a froth layer 1002 over the slurry 1001 . In other embodiments , a tank may or may not be configured in such manner .

[0069] In the example embodiment of FIG . 1 , the flotation cell 1000 comprises a "gasified fluid supply arrangement" 1700 for supplying gasified fluid, for example aerated water, into the slurry 1001 . Gasified fluid may comprise gas bubbles . The gasified fluid may be aerated fluid . The fluid may be water and / or the gas bubbles may be air bubbles .

[0070] In this disclosure , a "gasified fluid supply arrangement" may refer to an arrangement of parts of a flotation cell suitable for or configured to supply gasified fluid into a tank of said flotation cell . Generally, a gasified fluid supply arrangement may comprise any part ( s ) suitable or necessary for supplying gasified fluid into a tank.

[0071] The gasified fluid supply arrangement may comprise a gasified fluid generator, for example, one or more spargers, e.g., jetting and / or cavitation sparger (s) , and / or one or more static mixers.

[0072] According to an example embodiment, the gasified fluid generator comprises jetting spargers, or cavitation spargers, or Venturi spargers.

[0073] Jetting spargers may be utilized for the direct introduction of microbubbles with a size range of 0,5 to 1,2 mm. Especially if microbubbles are introduced in or near the turbulence zone (mixed zone) , they may have higher probability of colliding with finer particles in the mixed zone, thus improving the transporting of those particles into the froth zone. Cavitation spargers or Venturi spargers may be utilized to introduce water and air or other gasified fluid into the flotation cell. In these embodiments, air / gas or air / gas and water, respectively, will be introduced into the spargers to create gas bubbles, injected into the flotation cell. The gas bubbles may attach to the mineral ore particles and increase the overall recovery of valuable mineral.

[0074] In the example embodiment of FIG. 1, air and water may be used as the gasified fluid 1301. In other embodiments, any suitable gas e.g., air, argon, nitrogen, hydrogen, or mixtures thereof, may be used.

[0075] The gasified fluid supply arrangement 1700 of the embodiment of FIG. 1 is configured to supply gasified fluid 1301 into the slurry 1001 such that the froth layer 1002 is maintained over the slurry 1001. In other embodiments , a gasified fluid supply arrangement may or may not be configured in such manner .

[0076] The gasified fluid supply arrangement 1700 of the example embodiment of FIG . 1 is configured to supply gasified fluid 1301 into the slurry 1001 below the froth layer 1002 . Generally, a gasified fluid supply arrangement being configured in such manner may enable directing gasified fluid bubbles rising in a slurry onto an outer bottom surface of a lower part of a crowder, and / or increase the probability of recollection of valuable material containing particles into a froth layer following drop-off . In other embodiments , a gasified fluid supply arrangement may or may not be configured in such manner .

[0077] The gasified fluid supply arrangement 1700 of the example embodiment of FIG . 1 is configured to supply gasified fluid bubbles 1301 into the slurry 1001 below the froth layer by feeding gasified fluid bubbles into the slurry 1001 via one or more noz zles 1704 of one or more tube distributors 1703 . The one or more noz zles 1704 may point downwards . In other embodiments , wherein gasified fluid supply arrangement is configured to supply gasified fluid bubbles into a slurry below the froth crowder, said gasified fluid supply arrangement may be configured to supply said gasif ied fluid below said froth crowder in any suitable manner ( s ) , for example , by feeding gasified fluid into a slurry via noz zles .

[0078] According to an example embodiment , the one or more noz zles 1704 are pointing downwards . Downwards means towards a bottom of the flotation cell 1100 . According to an example embodiment , the one or more tube distributors 1703 extend radially from the manifold 1701 .

[0079] According to an example embodiment , the two or more tube distributors 1703 are arranged at equal distance from each other so that a di stance between any two adj acent tube distributor 1703 is the same . The one or more tube distributors 1703 may have length or may reach from the manifold 1701 to the side wall 1108 of the tank 1100 . The one or more tube distributors 1703 may have different lengths .

[0080] According to an example embodiment , the two or more tube distributors 1703 are arranged in one or more levels . This means that one or more tube di stributors 1703 may be located above each other in vertical direction . The two or more tube distributors 1703 may be arranged in two or more levels .

[0081] According to an example embodiment , height difference between two levels of the tube distributors is less than six times a diameter of the tube distributor 1703 .

[0082] An example embodiment of FIG . 2 shows a tank 1100 seen below a manifold 1701 and tube distributors 1703 . The tank may be divided in three round areas around a vertical center axis 1221 : a center area Al around the center axis 1221 , a periphery area A3 limited to a tank side wall 1108 , and a middle area A2 between the center area Al and the periphery area A3 . According to an example embodiment , the center area Al , middle area A2 , and periphery area A3 al l cover 1 / 3 of a cross-sectional area between crowder 1109 and tank side wall 1108 . According to another example embodiment , the center area Al, middle area A2, and periphery area A3 all cover equally wide segments (1 / 3) of a cross-sectional area between crowder 1109 and tank side wall 1108. The two or more nozzles 1704 may be arranged in each of the tube distributors 1703 so that amount of the nozzles in the in the center area Al > amount of the nozzles in the middle area A2 > amount of the nozzles in the periphery area A3. This means that more nozzles 1704 may be located in the center area Al than in the middle area A2 and / or periphery area A3. The one or more nozzles may be arranged to point towards a bottom of the tank 1100.

[0083] Further, a "center axis" may refer to an imaginary line. A center axis may or may not extend through one or more center points, such as a center of mass and / or a centroid, of a tank. Additionally, or alternatively, a center axis may or may not extend along a symmetry axis and / or a symmetry plane of a tank. The center axis may be a vertical line.

[0084] According to an example embodiment, the one or more nozzles 1704 are arranged to distribute the gasified fluid so that gasified fluid center flow rate FR1 in the center area Al > gasified fluid middle flow rate FR2 in the middle area A2 > gasified fluid periphery flow rate FR3 in the periphery area A3.

[0085] According to an example embodiment, wherein superficial gas velocity JG inside the tank 1100, is volume flow of gas / area of the froth, wherein center superficial gas velocity JG1 in the center area Al is from 2 to 7 [cm / s] , middle superficial gas velocity JG2 in the middle area A2 is from 1 to 5 [cm / s] , and periphery superficial gas velocity JG3 in the periphery area A3 is from 0 to 3 [ cm / s ] .

[0086] According to an example embodiment , the superficial gas velocity JG1 in the center area Al is different from the middle superficial gas velocity JG2 in the middle area A2 , which is different from the periphery superficial gas velocity JG3 in the periphery area A3 .

[0087] According to an example embodiment , the gasified fluid supply arrangement 1700 is arranged below the froth layer 1002 .

[0088] As seen from the example of FIG . 1 the tank 1100 may be divided to a froth zone 1800 , a mixed zone 1801 , and a settling zone 1802 . The gasi fied fluid supply arrangement 1700 may be arranged below the froth layer 1002 and above a settling zone 1802 . The gasified fluid supply arrangement 1700 may be located in the mixed zone 1801 .

[0089] The froth zone 1800 may be about 1-25 % from the height of the settling zone 1802 . In the froth zone 1800 desirable minerals may be adhered to bubbles and may be transported to a launder lip . Coarse particles may be adhered to froth or gas in the froth zone 1800 . The froth zone may comprise froth and slurry . Height of the cell 1000 may be measured from the bottom of the cell- to-cell lip .

[0090] By a mixed zone is meant herein a vertical part or section of the flotation tank in which active mixing of particles suspended in slurry with gasified fluid bubbles may takes place . The mixed zone may comprise gas bubbles , slurry, and fluid . The mixed zone may be below the froth zone . In the mixed zone 1801 fine particles may still be recovered but coarse particles cannot be recovered . Gangue minerals may fall towards the settling zone .

[0091] By a settling zone i s meant a vertical part of section of the flotation tank in which particles not associated with gasified fluid bubbles or otherwise not able to ri se towards the froth zone or may not be able to stay in the froth zone on the top part of the flotation tank may descend and settle towards the tank bottom to be removed in the tailings as underflow . The settling zone is below the mixed zone . The settling zone may comprise slurry . In the settling zone 1802 gangue minerals may be settled and transported to tailing or underflow 1105 .

[0092] According to an example embodiment , the manifold 1701 is arranged paral lel to a side wall 1108 at the center of the tank 1100 .

[0093] According to an example embodiment , the manifold 1701 is arranged vertically in the tank 1100 .

[0094] According to an example embodiment , the tube distributors 1703 are arranged perpendicular to a side wal l 1108 or hori zontally in the tank 1100 .

[0095] An example of FIG 3 shows that the manifold 1701 comprises one or more manifold inlets 1706 arranged to connect the gasi fied fluid generators 1702 to the manifold 1701 by connecting means 1705 , and one or more manifold outlets 1707 arranged to connect the tube distributors 1703 to the manifold 1701 .

[0096] According to an example embodiment , the one or more manifold outlets 1707 are arranged equally spaced circumferentially around the manifold so that a distance between any two adj acent manifold outlet 1707 is the same . Manifold inlets may also be arranged above each other to form one or more levels .

[0097] According to an example embodiment , the one or more manifold inlets 1706 are arranged vertically above each other .

[0098] According to an example embodiment , the gasified fluid supply arrangement 1700 comprises one or more connecting means 1705 located between the one or more gasified fluid generators 1702 and the manifold 1701 , wherein the one or more connecting means 1705 are arranged to connect the one or more gasi fied fluid generators 1702 to the manifold 1701 . The connecting means 1705 may be used to attach the manifold to the side wall 1108 of the tank . 1100 .

[0099] According to an example embodiment , the one or more gasified fluid generators 1702 are located outside the tank 1100 .

[0100] According to an example embodiment , the flotation cell 1000 is a gravity feeding flotation cell .

[0101] By a gravity feeding f lotation cell is meant a system, wherein a slurry may be fed into a flotation tank at a froth layer . This means that the slurry may be fed on top of the froth, into the froth, into the froth slurry interface , or immediately below the froth .

[0102] According to an example embodiment , the slurry feeding arrangement is configured to feed slurry 1214 onto the froth layer 1002 , into the froth layer 1002 , into the froth slurry interface , and / or immediately below a surface of the froth layer 1002 . The slurry feeding arrangement may be configured to feed slurry 1214 to the froth layer 1002 . As such, the flotation cell 1000 is implemented as a froth-interaction flotation cell . Generally, feeding slurry to a froth layer may increase recovery of coarser mineral particles in said slurry . In other embodiments , a slurry feeding arrangement may be suitable for or configured to feed coarse slurry to a froth layer .

[0103] The slurry feeding arrangement may be used to feed slurry onto a froth layer 1002 arranged over a slurry 1001 in said tank 1100 . On the other hand, said slurry feeding arrangement may be used to feed slurry 1214 immediately below the surface of a froth layer 1002 arranged over a slurry 1001 in said tank 1100 .

[0104] According to an example embodiment , the flotation cell 1000 further comprises one or more froth crowders 1109 arranged to direct froth towards a launder 1101 .

[0105] A froth crowder herein is meant a froth blocker, a froth baffle , or a crowding board, or a crowding board device , or any other such structure or s ide structure , for example a sidewall , inclined or vertical , having a crowding effect , i . e . , a crowding sidewall , which can also be a crowding sidewall internal to the flotation tank, i . e . an internal perimeter crowder . It may be possible to crowd and direct the froth towards the froth overf low lip, to reduce the froth transportation distance ( thereby reducing the risk of drop-back) , and, at the same time , maintain or even reduce the overflow lip length (by reducing the tank diameter) . In other words , the handling and directing of the froth layer in a froth flotation cell or tank may become more efficient and straightforward .

[0106] Further, the area of froth on the surface of the slurry inside a flotation tank may be decreased in a robust and simple mechanical manner . At the same time , the overall overflow lip length in a froth flotation cell may be decreased . By decreasing the froth surface area of a flotation cell by a froth crowder instead of adding extra froth collection launders , the froth flotation cell as a whole may be a simpler construction, for example because there is no need to lead the collected froth and / or overflow out of the added crowder .

[0107] By arranging a froth crowder into the flotation tank, the open froth surface between the froth overflow lips may be controlled . The crowder may be utili zed to direct or guide the upwards-flowing slurry within the flotation tank closer to a froth overflow lip of a froth collection launder, thereby enabling or easing froth formation very close to the froth overflow lip, which may increase the collection of particles . In addition, it may be possible to reduce the open froth surface in relation to the lip length, thereby improving the efficiency of recovery in the froth flotation cell .

[0108] The tank 1100 of the example embodiment of FIG . 1 comprises an underflow outlet 1104 for discharging underflow 1105 from the slurry 1001 .

[0109] Throughout this specification, "coarse slurry" may refer to slurry, comprising solid particles of larger diameters . As known to the skilled person, the definition of coarse slurry may be application-specific and / or ore- specific . For example , in some embodiments , coarse slurry may refer to slurry, having a particle-si ze distribution with a percent passing less than 80 % at a sieve si ze of 4000 pm, or at a sieve size of 425 pm, or at a sieve si ze of 355 pm, or at a sieve si ze of 250 pm, or at a sieve si ze of 180 pm, or at a sieve si ze of 150 pm, or at a sieve si ze of 125 pm, or at a sieve size of 105 pm .

[0110] On the other hand, an "outlet" may refer to a means of discharge , e . g . , an opening or a through-hole , for a fluid . Generally, an outlet may be arranged in a tank in any suitable manner, for example , at a side wall or at a bottom of a tank, or at an end of a pipe or other suitable conduit for passing fluid through a side wall or a bottom of a tank, or at an end of a pipe or other suitable conduit for passing fluid over a side wall of a tank .

[0111] Consequently, a "coarse slurry outlet" may refer to an outlet configured to or suitable for passing coarse slurry out of a tank . A coarse slurry outlet may additionally be configured to or suitable for passing any other suitable type ( s ) of slurry out of a tank . Typically, a coarse slurry outlet is arranged at a lower section of a tank for collecting a flotation product from said tank .

[0112] In the example embodiment of FIG . 1 , the tank 1100 comprises a downwardly tapering bottom cone 1103 . Generally, a tank comprising a bottom cone may reduce sanding in said tank . In other embodiments , a tank may or may not comprise such bottom cone .

[0113] Throughout this specification, a "bottom cone" of a tank may refer to a generally funnel-shaped and downwardly tapering bottom structure of said tank suitable for or configured to guide settled solid particles towards an outlet or an inlet .

[0114] In the example embodiment of FIG . 1 , the underflow outlet 1104 is arranged at the bottom of the bottom cone 1103 . Generally, a tank comprising a bottom cone and a coarse slurry outlet at the bottom of said bottom cone may facilitate discharge of extremely coarse slurry out of said tank and / or reduce sanding in said tank . In other embodiments , a coarse slurry outlet may be arranged in any suitable manner, for example, at the bottom of a bottom cone . For example , in some embodiments , a tank may comprise a flat bottom; a side wall , extending from said bottom; and a coarse slurry outlet arranged at said side wall .

[0115] The tank 1100 of the example embodiment of FIG . 1 comprises one or more gasified fluid inlets 1106 . In other embodiments , a tank may or may not comprise such gasified fluid inlet ( s ) .

[0116] Throughout this specification, an "inlet" may refer to a means of entry, e . g . , an opening or a through-hole , for a fluid . Generally, an inlet may be arranged in a tank in any suitable manner, for example , at a side wall or at a bottom of a tank, or at an end of a pipe or other suitable conduit for passing fluid or gas through a side wall or a bottom of a tank, or at an end of a pipe or other suitable conduit for passing fluid over a side wall of a tank .

[0117] In this specification, a "gasified fluid inlet" may refer to an inlet configured to or suitable for pass ing gasified fluid into a manifold . The one or more gasified fluid inlets 1106 of the example embodiment of FIG . 1 is arranged in any suitable manner, for example , such that said one or more gasified fluid inlets are arranged below a froth layer 1002 .

[0118] The tank 1100 of the example embodiment of FIG . 1 comprises a flotation liquid inlet 1107 . In other embodiments , a tank may or may not comprise such flotation liquid inlet .

[0119] Herein, a "flotation liquid inlet" may refer to an inlet configured to or suitable for passing flotation liquid into a tank .

[0120] The tank 1100 of the example embodiment of FIG . 1 comprises a launder 1101 , which comprises a launder lip 1102 . The launder 1101 is configured to collect overflow 1003 from the froth layer 1002 . Generally, a tank comprising a launder may facilitate collection of a flotation product from said tank . In other embodiments , a tank may comprise any suitable means , for example , a launder with a launder lip , for collecting a flotation product from an upper section of said tank .

[0121] Throughout this specification, a "launder" may refer to means arranged at an upper section of a tank for collecting a flotation product from said tank . Typically, a launder comprises a launder lip . Herein, a "launder lip" may refer to a part of a launder over which a flotation product is arranged to flow into said launder for collection .

[0122] Herein, a "froth depth" may refer to a thickness of a froth layer in a tank . A froth depth may be measurable as a vertical distance between a launder lip and a surface of a slurry in a tank, when said tank is in use . In the example embodiment of FIG . 1 , the flotation cell 1000 comprises a flotation liquid supply arrangement 1400 for supplying flotation liquid 1401 into the slurry 1001 . In other embodiments , a flotation cell may or may not comprise such flotation liquid supply arrangement .

[0123] In this disclosure, a "flotation liquid supply arrangement" may refer to an arrangement of parts of a flotation cell configured to or suitable for supplying flotation liquid into a tank of a flotation cell from a source external to the flotation cell , e . g . , a process water cell or a body of water .

[0124] The flotation liquid supply arrangement 1400 of the embodiment of FIG . 1 is configured to supply flotation liquid 1401 into the slurry 1001 below the froth layer 1002 .

[0125] As indicated in FIG . 1 using dotted arrows , the gasif ied fluid arrangement 1700 is configured to convey slurry in the slurry 1001 towards the outer bottom surface 1228 of the froth crowder 1109 parallel to the center axis 1221 .

[0126] As further indicated in FIG . 1 using dotted arrows , the outer bottom surface 1228 of the froth crowder 1109 is configured to divert gasified fluid and flotation liquid rising parallel to the center axis 1221 for forming a fluid stream 1202 surrounding the outer bottom surface 1228 and to guide the fluid stream 1202 then towards the launder lip 1102 .

[0127] Generally, configuring an outer bottom surface of a froth crowder in such manner may facilitate maintaining a constant flow of slurry and froth towards a launder lip, which may, in turn , increase recovery of valuable material containing particles . In other embodiments , an outer bottom surface of a froth crowder may or may not be configured to divert gasif ied fluid and flotation liquid rising parallel to a center axis for forming a fluid stream surrounding said outer bottom surface and to guide said fluid stream towards a launder lip .

[0128] Above , mainly structural aspects of flotation cells are di scussed . In the following, more emphasis wi ll lie on aspects related to flotation methods . What is said above about the ways of implementation, definitions , details , and advantages related to flotation cells apply, mutatis mutandi s , to the methods di scussed below . The same applies vice versa .

[0129] It is speci fically to be understood that any flotation method according to this specification may be used to operate a flotation cell according to this specification . Correspondingly, any flotation cell according to this specification may be operated in accordance with a method according to this specification .

[0130] Fig . 4 il lustrates an example of a method for treating particles suspended in slurry 1214 and for separating the slurry 1214 into underflow 1005 and overflow 1003 using a flotation cell 1000 .

[0131] At operation 100 , the method may comprise providing a tank 1100 for holding the slurry 1001 and a froth layer 1002 over the slurry 1001 .

[0132] At operation 110 , the method may comprise feeding slurry to the tank 1100 with a feeding arrangement . At operation 120, the method may comprise distributing, using a manifold 1701 of a gasified fluid supply arrangement 1700, gasified fluid to one or more tube distributors 1703 comprising one or more nozzles 1704.

[0133] At operation 130, the method may comprise injecting the gasified fluid to at least a center area Al of the tank 1100 using the one or more nozzles 1704.

[0134] It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described above, instead they may vary within the scope of the claims.

[0135] It will be understood that any benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

[0136] The term "comprising" is used in this specification to mean including the feature (s) or act(s) followed thereafter, without excluding the presence of one or more additional features or acts. It will further be understood that reference to 'an' item refers to one or more of those items. REFERENCE SIGNS dffroth depth, thickness of the froth layer

[0137] Al center area

[0138] A2 middle area

[0139] A3 periphery area

[0140] 1000 flotation cell 1301 gasified fluid

[0141] 1001 slurry 1400 flotation liquid sup-

[0142] 1002 froth layer ply arrangement

[0143] 1003 overflow 1401 flotation liquid

[0144] 1100 tank 1700 gasified fluid supply

[0145] 1101 launder arrangement

[0146] 1102 launder lip 1701 manifold

[0147] 1103 bottom cone 1702 gasified fluid genera-

[0148] 1104 underflow outlet tor

[0149] 1105 underflow 1703 tube distributor

[0150] 1106 gasified fluid inlet 1704 noz zle

[0151] 1107 flotation liquid inlet 1705 connecting means

[0152] 1108 side wall 1706 manifold inlet

[0153] 1109 froth crowder 1707 manifold outlet

[0154] 1202 fluid stream 1800 froth zone

[0155] 1214 slurry 1801 mixed zone

[0156] 1221 center axis 1802 settling zone

[0157] 1228 outer bottom surface

Claims

CLAIMS1. A gasified fluid supply arrangement (1700) comprising a manifold (1701) ; and one or more tube distributors (1703) connected to the manifold (1701) , wherein the one or more tube distributors (1703) comprise one or more nozzles (1704) , wherein the manifold (1701) is configured to distribute gasified fluid from the one or more gasified fluid generators (1702) to the one or more tube distributors (1703) ; and the one or more nozzles (1704) are configured to inject the gasified fluid to at least a center area (Al) of a tank (1100) .

2. The gasified fluid supply arrangement (1700) according to claim 1, wherein the gasified fluid supply arrangement (1700) further comprises one or more gasified fluid generators (1702) connected to the manifold (1701) .

3. The gasified fluid supply arrangement (1700) according to claim 1 or 2, wherein the one or more nozzles (1704) are pointing downwards.

4. The gasified fluid supply arrangement (1700) according to any of the preceding claims, wherein the one or more tube distributors (1703) extend radially from the manifold (1701) .

5. The gasified fluid supply arrangement according to any of the preceding claims, wherein the two or more tube distributors (1703) are arranged at equal distance from each other so that a distance between any two adjacent tube distributor (1703) is the same.

6. The gasified fluid supply arrangement (1700) according to any of the preceding claims, wherein the two or more tube distributors (1703) are arranged in one or more levels.

7. The gasified fluid supply arrangement (1700) according to any of the preceding claims, wherein the manifold (1701) comprises one or more manifold inlets (1706) arranged to connect the gasified fluid generators (1702) to the manifold (1701) ; and one or more manifold outlets (1707) arranged to connect the tube distributors (1703) to the manifold (1701) .

8. The gasified fluid supply arrangement (1700) according to claim 7, wherein the one or more manifold outlets (1707) are arranged equally spaced circumferentially around the manifold so that a distance between any two adjacent manifold outlet (1707) is the same.

9. The gasified fluid supply arrangement (1700) according to any of the preceding claims, wherein the gasified fluid supply arrangement (1700) comprises one or more connecting means (1705) located between the one or more gasified fluid generators (1702) and the manifold (1701) , wherein the one or more connecting means (1705) are arranged to connect the one or more gasified fluid generators (1702) to the manifold (1701) .

10. A flotation cell (1000) for treating particles suspended in slurry (1214) and for separating the slurry (1214) into underflow (1105) and overflow (1003) , wherein the flotation cell (1000) comprises a tank (1100) for holding a slurry (1001) and a froth layer (1002) over the slurry (1001) ;a feeding arrangement configured to feed the slurry (1214) ; and a gasified fluid supply arrangement (1700) according to any one of the claims 1 to 9.

11. The flotation cell (1000) according to claim 10, wherein one or more nozzles (1704) are configured to inject gasified fluid downwards to at least a center area (Al) of the tank (1100) .

12. The flotation cell (1000) according to claim 10 or 11, wherein the tank (1100) comprises the center area (Al) , a middle area (A2) , and a periphery area (A3) ; and the two or more nozzles (1704) are arranged in each of the tube distributors (1703) so that amount of the nozzles in the in the center area (Al) > amount of the nozzles in the middle area (A2) > amount of the nozzles in the periphery area (A3) .

13. The flotation cell (1000) according any one of the claims 10 to 12, wherein the one or more nozzles (1704) are arranged to distribute the gasified fluid so that gasified fluid center flow rate (FR1) in the center area (Al) > gasified fluid middle flow rate (FR2) in the middle area (A2) > gasified fluid periphery flow rate (FR3) in the periphery area (A3) .

14. The flotation cell (1000) according claim 10 or 13, wherein superficial gas velocity inside the tank (JG) is volume flow of gas / area of the froth, wherein center superficial gas velocity (JG1) in the center area (Al) is from 2 to 7 [cm / s] ; middle superficial gas velocity (JG2) in the middle area (A2) is from 1 to 5 [cm / s] ; andperiphery superficial gas velocity (JG3) in the periphery area (A3) is from 0 to 3 [cm / s] .

15. The flotation cell (1000) according to any one of the preceding claims 10 to 14, wherein the gasified fluid supply arrangement (1700) is arranged below the froth layer (1002) .

16. The flotation cell (1000) according to any of the one of the preceding claims 10 to 15, wherein the manifold (1701) is arranged vertically in the tank (1100) .

17. The flotation cell (1000) according to any one of the preceding claims 10 to 16, wherein the tube distributors (1703) are arranged horizontally in the tank (1100) .

18. The flotation cell (1000) according to any one of the preceding claims 10 to 17, wherein the one or more gasified fluid generators (1702) are located outside the tank (1100) .

19. The flotation cell (1000) according to any one of the preceding claims 10 to 18, wherein the flotation cell (1000) is a gravity feeding flotation cell.

20. The flotation cell (1000) according to any one of the preceding claims 10 to 19, wherein the feeding arrangement is configured to feed slurry (1214) onto the froth layer (1002) , into the froth layer (1002) , into the froth slurry interface, and / or immediately below the froth layer (1002) .

21. The flotation cell (1000) according to any one of the preceding claims 10 to 20, wherein the flotation cell (1000) further comprises one or more froth crowders (1109) arranged to direct froth towards a launder (1101) .

22. A method for treating particles suspended in slurry (1214) and for separating the slurry (1214) into underflow (1105) and overflow (1103) using a flotation cell (1000) according to any one of the claims 10 to 21, the method comprising providing (100) a tank (1100) for holding the slurry (1001) and a froth layer (1002) over the slurry (1001) ; feeding (110) slurry (1214) to the tank (1100) with a feeding arrangement; distributing (120) , using a manifold (1701) of a gasified fluid supply arrangement (1700) , gasified fluid to one or more tube distributors (1703) comprising one or more nozzles (1704) ; and injecting (130) the gasified fluid to at least a center area (Al) of the tank (1100) using the one or more nozzles (1704) .

Images