EA040012B1 - FLOTATION CHAMBER - Google Patents

Description

Technical field

The present invention relates to a flotation cell for separating valuable materials containing particles from particles suspended in the slurry, as well as to a flotation line and its application.

The essence of the invention

The flotation chamber made in accordance with the present invention is characterized in that it is presented in claim 1 of the claims.

The flotation line made in accordance with the present invention is characterized by what is presented in paragraph 25 of the claims.

The use of a flotation line in accordance with the present invention is characterized by what is presented in claim 30 of the claims.

The flotation chamber is designed to process particles suspended in the pulp and to separate the pulp into bottom and top products. The flotation cell contains a flotation tank having a center, a perimeter, a substantially horizontal even bottom and a side wall, a chute and a chute edge located along the tank perimeter, an open foam surface in the upper part of the flotation tank, and a foam thickener shaped to guide the foam in the open area. foam to the edge of the gutter. The flotation cell is characterized in that the flotation tank further comprises pressure pipes for introducing pulp into the flotation tank. The injection pipe contains an inlet nozzle for supplying pulp feed supplied to the injection pipe; a compressed gas inlet, wherein the pulp feed is exposed to the compressed gas as it exits the inlet nozzle; an elongated chamber for receiving pressurized pulp feed; and an outlet nozzle configured to restrict the flow of pulp feed from the outlet nozzle and to maintain the supply of pulp feed to the elongated pressure chamber.

In accordance with one aspect of the invention, a flotation line is provided. The flotation line contains several flow-connected flotation cells, and it is characterized in that at least one of the flotation cells is a flotation cell made in accordance with the invention.

According to yet another aspect of the invention, the use of a flotation line according to the invention is provided for recovering particles containing valuable material suspended in the pulp.

With the invention described herein, the recovery of fines in the flotation process can be improved. The particles may, for example, contain mineral ore particles such as metal-containing particles.

In mineral ore froth flotation, concentrate enrichment aims at an average particle size of 40 to 150 microns. Thus, fine particles are particles with a diameter of 0 to 40 μm, and ultrafine particles can be defined as being in the lower part of the fine particle size range. Large particles have a diameter of more than 150 microns. In coal froth flotation, concentrate enrichment is aimed at an intermediate particle size range of 40 to 300 µm. Fine particles in coal processing are particles with a diameter of 0 to 40 µm, and ultrafine particles are those that fall in the lower end of the fine particle size range. Large particles of coal have a diameter of more than 300 microns.

Recovering very large or very small particles is challenging because in a conventional mechanical flotation cell, small particles are not easily captured by the flotation gas bubbles and can therefore be lost in the tailings. Traditionally, in froth flotation, flotation gas is introduced into a flotation cell or tank using a mechanical agitator. The flotation gas bubbles thus formed have a relatively large size range, typically 0.8 to 2.0 mm or even more, and are not particularly suitable for collecting smaller particles.

Fines recovery can be improved by increasing the number of flotation cells within the flotation line, or by directing previously floated material (top product) or tailings stream (bottom product) back to the head of the flotation line or upstream flotation cells. A cleaner flotation line can be used to improve fines recovery. In addition, a number of flotation devices have been developed which use small flotation gas bubbles or even so-called microbubbles. The introduction of these smaller bubbles or microbubbles can be carried out before the pulp enters the flotation cell, i. the ore particles are exposed to fine bubbles in a feed connection or the like to promote the formation of agglomerates of fine bubbles and ore particles, which can then float in flotation cells such as a flash flotation cell or a flotation column cell. Alternatively, fine bubbles or microbubbles can be introduced directly into the flotation cell, for example by cavitation spargers. Solutions of this type are not practical for mechanical flotation cells because the turbulence caused by mechanical agitation can cause agglomerates of fine bubbles and ore particles to break down before they can rise into the froth layer to be collected in the overflow and thus be retrieved.

- 1 040012

The flotation cells act as three-phase settling tanks in which the particles move downward in a sluggish environment, in a direction opposite to the flow of rising flotation gas bubbles created by bubblers located near the bottom of the cell. Although the flotation column cells can improve the recovery of finer particles, the residence time of the particles depends on the settling rate, which can affect the flotation of large particles. In other words, while the aforementioned flotation solutions may have a positive effect on the recovery of fine particles, the overall performance of the flotation (recovery of all valuable material, the grade of material recovered) may be negated due to the negative impact on the recovery of larger particles.

To overcome the aforementioned problems, so-called pneumatic flotation cells are used, in which flotation gas is introduced into a high shear device such as a standpipe or slurry injection tube, thereby creating smaller flotation gas bubbles that can also trap smaller particles. already during the formation of bubbles in the discharge pipe. However, for such high-capacity flotation cells, it may be necessary to create a vacuum in the injection tube to effectively achieve the desired bubble rate in order to trap the desired particles for the short time that the slurry is in the injection tube.

After exiting the blowpipe, the agglomerates of flotation gas bubbles and particles immediately rise to the froth layer at the top of the flotation cell, with no further entrapment of particles in that part of the flotation cell that extends down from the blowpipe outlet. This can cause a significant portion of the particles containing the desired material (mineral) to simply fall to the bottom of the flotation tank and end up in the tailings, which reduces the recovery of the flotation cell.

However, in general, so-called high-performance flotation cells or Jameson-type pneumatic flotation cells do not include any flow restrictors to control the pressure inside the pressure tube after agglomeration of flotation gas bubbles and particles has occurred. Such pressure control is also advantageous in terms of the pressure at which flotation gas bubbles are formed (influence on bubble size) as well as for controlling the relative pressure at which they are to be used in the flotation tank. Thus, once the bubbles have formed, their coalescence can be minimized. This is a particular advantage, as the rate of entrainment of particles by the flotation gas bubbles decreases as the bubble size increases (assuming the air-to-liquid ratio remains the same).

In addition, so-called high capacity flotation cells can be used in coal separation operations where there is typically a flotation line containing one or two such flotation cells at the end of the separation cycle to recover extra fine coal particles. The recovery loop has a process water recirculation system that circulates water from the end of the loop (ie flotation line and dewatering loop) back to the front loop (beginning of the recovery loop). Flotation chemicals, especially frothers, typically cause problems in processes upstream of the flotation line. Problems can be mitigated to some extent by minimizing the use of frothers in the flotation line, but if insufficient frother is added to the flotation process, foam formation in prior art downpipes can suffer, resulting in unstable process conditions and especially unstable operation of the discharge pipe and the froth bed in the flotation cell, which, in turn, adversely affects the recovery of the required particles, especially coarse particles. The recovery of particles within the entire slurry size distribution is affected by the increase in bubble size with a lower concentration of blowing agent, especially large particles.

In prior art pressure tubes, the flotation gas is introduced by self-priming due to the creation of a vacuum inside the downcomer. The residence time of the flotation air entrained in the slurry is very short (3 to 5 s), so the system is very sensitive to process changes. It is necessary to continually add blowing agents to overcome the effect of airflow limitation needed to maintain or even increase the vacuum inside the downcomer to keep the bubble-particle interaction conditions as constant as possible, since blowing agents prevent the bubbles from sticking together and rising back into the air space inside the blowing tube not filled with sludge. However, the addition of some foaming agent, necessary for continuous use of the prior art standpipe, creates problems in other parts of the process, especially in coal operations, as described above. Therefore, the solution was to reduce the amount of frother, which negatively affects standpipe vacuum, bubble formation, as well as bubble size and surface area, which significantly reduces the recovery of the required particles, which leads to inefficiency in this application of high-performance flotation vessels.

- 2 040012 measures of the prior art.

By using a flotation cell according to the present invention, the amount of frother needed to optimize the flotation process can be substantially reduced without significantly compromising bubble formation, bubble-particle interaction, stable froth formation, or recovery of desired material. At the same time, problems associated with recirculation of process water from the lower loop to the front loop can be reduced. The pressurized injection pipe is completely independent from the flotation tank. A better flotation gas flow rate can be achieved, finer bubbles are created, and foam agent utilization is optimized since the operation of the discharge tube is independent of the amount of foam agent.

In prior art solutions, problems are associated, in particular, with limitations on the amount of flotation gas that can be supplied relative to the amount of liquid flowing through the standpipe, and the need for relatively high concentrations of foaming agents or other costly surfactants to form small bubbles. With the present invention, the flotation of fine and ultrafine particles containing, for example, mineral ore or coal, can be improved by reducing the size of the flotation gas bubbles introduced into the slurry fed to the injection tube by increasing the flotation gas feed rate relative to the flow rate. particles suspended in the slurry and by increasing the shear rate or the rate of energy dissipation either inside or near the injection tube. The chance is increased that smaller particles will attach to or be entrained in the smaller flotation gas bubbles, while the recovery rate of the desired material, such as mineral or coal, is improved. Sufficiently small flotation gas bubbles, so-called ultra-fine bubbles, can be created in the flotation cell according to the invention to ensure that fine ore particles are effectively captured. Typically, ultrafine bubbles may be 0.05 to 0.7 mm in size. For example, reducing the average size of flotation gas bubbles to a diameter of 0.3 to 0.4 mm means that the number of bubbles in 1 m ³ of the pulp can reach from 30 to 70 million, and the total average bubble surface area is from 15 to 20 m ² . On the contrary, if the average bubble size is about 1 mm, then the number of bubbles per 1 m ³ pulp is about 2 million, and the total average surface area is 6 m ² . Thus, in the flotation cell according to the present invention, it is possible to obtain a bubble surface area that is 2.5 to 3 times larger than in the flotation cell according to the solutions of the prior art. It goes without saying that the effect of such an increase in the surface area of the bubbles in recovering valuable particulate material is significant.

At the same time, the recovery of larger particles can be maintained at an acceptable level due to the achievement of a high flotation gas fraction in the pulp and the absence of areas of high turbulence in the region below the foam layer. That is, the known advantages of mechanical flotation cells can be used, even though no mechanical agitation may be provided in the flotation cells. In addition, upward movement of the slurry or slurry within the flotation tank increases the likelihood that larger particles will rise to the froth bed with the slurry flow.

One of the effects that can be obtained with the present invention is to increase the depth or thickness of the foam layer. A thicker froth layer results in a higher grade, but also an increase in the recovery of finer particles, while a separate froth washing step, typical of flotation cells, can be dispensed with.

By arranging a plurality of injection tubes in a flotation cell according to the present invention, the likelihood of collisions between flotation gas bubbles and also between gas bubbles and particles can be increased. Multiple injection tubes can provide improved distribution of flotation gas bubbles within the flotation tank, and the bubbles emerging from the injection tubes are evenly distributed throughout the flotation tank, and the distribution zones of the individual injection tubes can intersect each other and come closer, thereby contributing to a largely uniform distribution. flotation gas bubbles in the flotation tank, which in turn can favorably affect the recovery of particularly fine particles, as well as contribute to the aforementioned even and thick foam layer. When there are multiple injection tubes, collisions occur between flotation gas bubbles and/or particles in the slurry coming from different injection tubes as the different streams mix and create local mixing subzones. As the number of collisions increases, more agglomerates of bubbles and particles are formed, which are trapped in the foam layer, and therefore the recovery of valuable material can be improved.

By creating fine flotation gas bubbles or ultrafine bubbles, by bringing them into contact with the particles and by controlling the liquid mixture of agglomerates of flotation gas bubbles and particles in the slurry, it is possible to maximize the recovery of hydrophobic particles in the fourth

- 3 040012 layer and into the top product or concentrate of the flotation cell, thereby increasing the recovery of the required material, regardless of its particle size distribution in the pulp. It may be possible to achieve a high grade for a portion of the pulp stream and at the same time a high recovery for the entire pulp stream passing through the flotation line.

By positioning the outlet nozzles of the injection pipes at a suitable depth, i. e. by positioning them at a certain vertical distance from the edge of the trough, the distribution of the flotation gas bubbles can be optimized in a uniform and constant manner. Since the residence time of the bubbles in the mixing zone can be kept sufficiently high by a suitable depth of the injection pipe outlet nozzles, the bubbles can be able to contact and adhere to the fine particles in the slurry, thus improving the recovery of the finer particles, as well as helping to increase the depth of the foam. , stability and uniformity at the top of the flotation tank.

The mixing zone in this document refers to the vertical part or section of the flotation tank, in which the particles suspended in the slurry are actively mixed with flotation gas bubbles. In addition to this mixing zone created throughout the vertical section of the flotation tank, separate and localized individual mixing subzones can be created in areas where the radially outwardly directed slurry flows from individual impingers meet and mix. This can further promote contacts between the flotation gas bubbles and the particles, thereby increasing the recovery of valuable particles. In addition, this additional mixing may eliminate the need for a mechanical mixer to suspend the solids in the pulp.

The settling zone is understood to mean the vertical portion of a section of the flotation tank in which particles not associated with flotation gas bubbles or otherwise unable to rise to the froth zone at the top of the flotation tank sink to the bottom of the tank and settle on it to be removed to the tailings at as an underproduct. The settling zone is below the mixing zone.

By placing a tailings outlet on the side wall of the flotation tank, underflow can be removed in a zone where the slurries mostly contain particles sinking towards or settling on the bottom of the tank. In a flotation cell according to the invention, the settling zone is deeper near the side wall of the flotation tank. In this region, the mixing action and the turbulence generated by the injection tubes does not affect the settling particles, which for the most part do not contain any valuable material or contain only a very small amount of valuable material. In this part, settling is also most pronounced due to the absence of turbulence that prevents particles from sinking under the influence of gravity. In addition, the friction forces generated by the side wall of the tank further reduce turbulence and/or flows. Thus, by taking the underflow from the flotation tank at a location located in this relatively quiet settling zone, it can be ensured that as little valuable particulate material as possible is removed from the flotation tank - these particles should rather float or, if any, For some reason, they ended up in the settling (settling) zone, to be sent back to the flotation tank as pulp feed through the injection pipes. In addition, by removing the underflow from the settling zone near the side wall of the flotation tank, the entire volume of the flotation tank can be efficiently utilized - there is no need to provide a separate bottom settling zone under the injection tubes, as is the case, for example, with the Jameson cell. In some embodiments, it may even be possible to reduce the volume of the flotation tank at its center, thereby reducing the volume of the settling zone, where turbulence caused by the supply of slurry from the injection pipes can affect the likelihood of particles settling to the bottom of the tank, and allows full use of the volume of the flotation tank. tank. The volume of the flotation tank can be reduced in its center, for example, by placing the bottom structure of the flotation tank bottom in the center of the tank. In addition, it is possible to position the injection pipes (outlet nozzles) relatively deep in the flotation tank and still provide a fairly quiet settling zone at its side wall. This also contributes to a more efficient use of the entire volume of the flotation tank.

By using the invention described here, the so-called brittle foam can be guided more efficiently and reliably, i.e. A loosely structured froth bed containing generally larger flotation gas bubbles agglomerated with mineral ore particles to be recovered more effectively and reliably towards the froth overflow edge and froth collection trough. The brittle foam breaks easily because the agglomerates of gas bubbles and ore particles are less stable and have reduced strength. Such a foam or foam layer cannot easily support the transport of ore particles, and especially larger particles, to the froth overflow edge for collection in the trough, resulting in the particles falling back into the pulp or slurry in the flotation cell or tank and to reduced recovery of the required material. Brittle foam is usually associated with low

- 4 040012 mineralization, i.e. agglomerates of gas bubbles and ore particles with a limited number of ore particles containing the desired valuable mineral that were able to attach to the gas bubbles during the flotation process inside the flotation cell or tank. This problem is particularly pronounced in large size flotation cells or large volume and/or large diameter flotation tanks. With the present invention it is possible to thicken the foam and direct it towards the foam overflow edge in order to reduce the transport distance of the foam (thereby reducing the risk of backfall) and at the same time maintain or even shorten the length of the overflow edge. In other words, handling and guiding the froth layer in a froth chamber or flotation tank can become more efficient and simple.

It is also possible to improve froth recovery and thus the recovery of valuable mineral particles in large flotation cells or brittle froth tanks, especially in the later stages of the flotation line, for example in the coarse and/or control flotation stages of the flotation process.

In addition, with the invention described herein, the area of foam on the surface of the slurry inside the flotation tank can be reduced in a reliable and simple mechanical way. At the same time, the overall length of the froth overflow edge in the froth floater can be reduced. In this case, reliability should be understood as both structural simplicity and durability. By reducing the froth surface area of the flotation unit with a froth thickener, instead of adding additional froth collection chutes, the overall froth flotation apparatus can be of a simpler design, for example, because there is no need to direct the collected froth and/or overhead from the added thickener. On the contrary, the collected overhead product would have to be removed from the additional trough, which would increase the structural parts of the flotation plant.

Particularly at the lower end of the flotation line, the amount of material required that can be entrained in the froth within the pulp can be very low. In order to collect valuable material from the foam layer into the foam collection chutes, the surface area of the foam must be reduced. By placing a froth thickener in the flotation tank, the exposed froth surfaces between the various froth overflow edges can be controlled. The thickener can be used to orient or direct the upward flowing slurry within the flotation tank closer to the froth overflow edge of the froth collection trough, thereby providing or facilitating froth formation very close to the froth overflow edge, which can increase the collection of valuable ore particles. The froth thickener can also influence the overall convergence of the flotation gas bubbles and/or agglomerates of gas bubbles and ore particles in the froth layer. For example, if the flow of gas bubbles and/or agglomerates of gas bubbles and ore particles is directed toward the center of the flotation tank, a froth thickener can be used to increase the froth area around the perimeter of the tank and/or closer to any desired froth overflow edge. In addition, it is possible to reduce the exposed area of the froth in relation to the length of the lip, thereby improving the recovery efficiency in the froth flotation cell.

The flotation cell, the flotation line, and its use in accordance with the invention provide a technical result that makes it possible to easily extract particles of various sizes, as well as to efficiently extract valuable minerals containing ore particles from depleted ore raw materials with initially relatively low amounts of valuable mineral. The advantages provided by the design of the flotation line allow the design parameters of the flotation line to be fine-tuned to suit the target valuable material in each installation.

By treating the pulp according to the present invention, as defined herein, the recovery of valuable particulate materials can be increased. The initial grade of recovered material may be lower, but the material (ie pulp) is also readily prepared for further processing, which may include, for example, regrinding and/or refining.

In this invention, the following definitions are used in relation to flotation.

Flotation is mainly aimed at extracting a concentrate of ore particles containing a valuable mineral. By concentrate in this document refers to the part of the pulp recovered in the upper product or in the bottom product withdrawn from the flotation cell. A valuable mineral is any mineral, metal or other material that has a commercial value.

Flotation includes phenomena related to the relative buoyancy of objects. The term flotation includes all flotation methods. The flotation may be, for example, froth flotation, dissolved air flotation (DAF) or induced gas flotation. Froth flotation is the process of separating hydrophobic materials from hydrophilic materials by adding a gas such as air or nitrogen or any other suitable medium to the process. Froth flotation may be based on natural hydrophilic/hydrophobic differences or on the basis of hydrophilic/hydrophobic differences resulting from the addition of a surfactant or chemical collector. The gas can be added to the feedstock to be floated (slurry or slurry) in several different ways.

The flotation chamber is designed to process particles of mineral rue suspended in the pulp.

- 5 040012 during flotation. Thus, valuable metal-containing ore particles are recovered from the ore particles suspended in the pulp. By flotation line in this document is meant a flotation device in which several flotation cells are located in fluid connection with each other, so that the bottom product of each previous flotation cell is sent to the successor or next flotation cell as feed up to the last flotation cell of the flotation line, from which the bottom product is sent off the line as tailings or waste streams. The slurry is fed through the feed inlet to the first flotation cell of the flotation line to start the flotation process. The flotation line may be part of a larger flotation plant or device containing one or more flotation lines. Therefore, a number of different pre- and post-treatment devices or steps may be operatively associated with elements of the flotation device, as will be known to those skilled in the art.

The flotation cells in the flotation line are fluidly connected to each other. The flow connection can be achieved with pipelines of various lengths, such as pipes or tubes, which may also contain pumps or regrinding units, the length of the pipeline depending on the physical design of the flotation device as a whole. Pumps or grinding/regrinding units can also be located between the flotation cells of the flotation line. Alternatively, the flotation cells may be located in direct connection with each other. Direct cell connection is herein understood to mean an arrangement in which the outer walls of any two successive flotation cells are connected to each other to allow the outlet of the first flotation cell to be connected to the inlet of the subsequent flotation cell without any separate piping. Direct contact reduces the need for piping between two adjacent flotation cells. Thus, the need for components during the construction of the flotation line is reduced, which speeds up the process. In addition, it can reduce sanding and simplify maintenance of the flotation line. The flow connections between the flotation cells may contain various control mechanisms.

By adjacent, adjacent or adjoining flotation cell, in this document is meant a flotation cell immediately following or preceding any one flotation cell, either downstream or upstream, or in a coarse flotation line, in a control flotation line, or the interconnection between a coarse flotation cell flotation and a control flotation chamber, into which the bottom product from the rough flotation chamber is sent.

Under the flotation cell in this document is meant a tank or vessel in which the stage of the flotation process is performed. The flotation cell is typically cylindrical in shape, delimited by an outer wall or outer walls. Flotation cells usually have a circular cross section. The flotation cells may have a polygonal, for example rectangular, square, triangular, hexagonal or pentagonal, or other radially symmetrical cross section. The number of flotation cells may vary depending on the particular flotation line and/or ore type and/or grade processing operation, as known to those skilled in the art.

The flotation cell may be a froth cell such as a mechanically agitated cell such as a TankCell, column flotation cell, Jameson cell, or twin flotation cell. The dual flotation cell comprises at least two separate tanks - a first mechanically agitated high pressure tank with an impeller and a flotation gas inlet and a second tank with a tailings outlet and an overflow froth outlet configured to produce agitated slurry from the first tank. The flotation cell may also be a fluidized bed flotation cell (such as a HydroFloat™ cell) in which bubbles of air or other flotation gas that are dispersed by the fluidization system percolate through the difficult-to-set zone and attach to the hydrophobic component, changing its density and making it buoyant enough to float and be recovered. In a fluidized bed flotation cell, axial mixing is not required. The flotation cell may also be an overflow flotation cell operating with a constant pulp overhead product. In the overflow flotation cell, the slurry is treated by introducing bubbles of flotation gas into the slurry and creating a continuous upward flow of slurry in the vertical direction of the first flotation cell. At least a portion of the ore containing the valuable metal adheres to the gas bubbles and rises up due to buoyancy, at least a particles of ore containing valuable metal rises up with a continuous upward flow of pulp. The ore particles containing valuable metals are recovered by creating a continuous upward flow of pulp from at least one overflow flotation cell in the form of an overhead pulp product. Since the overflow chamber works

- 6 040012 practically without foam depth or foam layer, in fact on the surface of the pulp, in fact, no foam zone is formed in the upper part of the flotation cell. The foam in the chamber may be intermittent.

The result of this is that more valuable mineral particles can be entrained in the concentrate stream and the overall recovery of valuable material can be increased.

All flotation cells of a flotation line made in accordance with the invention may be of the same type, i. e. the flotation cells in the rougher unit, the flotation cells in the control flotation unit and the control cleaner flotation cells in the control cleaner line may be of the same type of flotation cells, so that the flotation device contains only one type of flotation cells, as listed above. Alternatively, several of the flotation cells may be of the same type, while the other cells may be of one or more types, so that the flotation apparatus comprises two or more types of flotation cells as described above.

Depending on its type, the flotation cell may contain a slurry agitator to keep the slurry in suspension. By impeller in this document is meant any suitable means for mixing the pulp in the flotation cell. The impeller may be a mechanical agitator. The mechanical agitator may comprise a rotor-stator with a motor and a drive shaft, with the rotor-stator structure located at the bottom of the flotation cell. The chamber may have auxiliary impellers located higher in the vertical direction of the chamber to provide a sufficiently strong and continuous upward flow of pulp.

By foam thickener herein is meant a foam blocker, a foam deflector, or a thickening plate, or a foam thickening device, or any other such structure or side structure, such as a side wall, inclined or vertical, having a thickening effect, i.e. thickening side wall, which can also be a thickening side wall inside the flotation tank, i. e. internal peripheral thickener.

The flotation cell may include a bottom structure located at the bottom of the flotation tank and shaped to allow particles suspended in the slurry to mix in a mixing zone created by the slurry feed flow supplied from the outlet nozzles of the injection pipes above the bottom structure; and deposited in the deposition zone surrounding the lower structure.

By placing the lower structure at the bottom of the flotation tank so that it extends upwards in the flotation tank, a better distribution of the fines and/or small particles suspended in the slurry can be obtained. In the center of the flotation tank, particles cannot sink and settle because the flow of slurry coming from the injection pipes can reach the raised center part of the flotation tank, which ensures good mixing in this part. Particles that may have already separated from the flotation gas bubbles and have begun their sinking may be re-entrained in the bubbles due to the turbulence conditions in the mixing zone. On the other hand, the bottom of the flotation tank closer to the perimeter of the tank has a zone of sufficient depth that allows non-buoyant, most likely useless particles to settle and sink for efficient removal from the flotation tank. This settling zone is not affected by the slurry flow from the injection pipes. In addition, such a relatively quiet zone can prevent the formation of overflow pulp streams within the flotation tank, where the same pulp material continues to recirculate within the tank without being properly separated or settled. The above features may contribute to an increase in the recovery of fine particles.

By designing the bottom of a certain size, especially with respect to the mixing zone, the mixing zone and the settling zone can be designed to have the desired characteristics (size, depth, turbulence, residence time of particles in the mixing zone, settling rate and the likelihood of a useless fraction in the zone). precipitation, etc.). In a conventional flotation cell, most of this area (without any mechanical agitation at the bottom of the flotation tank) will be sanded because there is little or no agitation. If the zone is filled with solids, there is a risk that this solid will settle and at the same time block the tailings outlet and/or the recycle outlet located in the settling zone.

By injection tube is meant a dual high shear device in which flotation gas is introduced into the pulp feed, thereby creating smaller flotation gas bubbles which can also trap finer particles already at the time of bubble formation in the injection tube. In particular, the injection tube in the flotation cell according to the present invention is pressurized and no vacuum is required.

Under the top product in this document means that part of the pulp, which is collected in the overflow trough of the flotation cell and, thus, leaves the flotation cell. The top product may contain foam, foam and pulp, or in some cases only or most

- 7 040012 pulp parts. In some embodiments, the top product may be a use stream containing particles of valuable material collected from the slurry. In other embodiments, the top product may be a waste stream. This is the case when the flotation apparatus, plant and/or process is used with reverse flotation.

Under the bottom product in this document refers to the fraction or part of the pulp, which does not float to the surface of the pulp during flotation. In some embodiments, the underflow may be a waste stream exiting the flotation cell through an outlet, which is typically located at the bottom of the flotation cell. Eventually, the bottom product from the last flotation cell of a flotation line or flotation device may leave the entire device as a tailings stream or flotation plant final waste. In some embodiments, the underflow may be a use stream containing valuable mineral particles. This is the case when the flotation apparatus, plant and/or method is used in reverse flotation.

Reverse flotation is used herein to refer to the reverse flotation process commonly used to recover iron. In this case, the flotation process is aimed at collecting an insignificant part of the pulp flow into the overhead product. The overhead in a reverse flotation process for iron typically contains silicates, while the valuable iron-bearing mineral particles are collected in the underflow. Reverse flotation can also be used for industrial minerals i.e. geological minerals mined for their commercial value that are not fuels; and metal sources such as bentonite, silica, gypsum and talc.

By downstream direction in this document is meant the direction coinciding with the flow of the pulp (forward flow, indicated by arrows in the drawings), and by the direction upstream in this document is meant the direction opposite to or against the flow of the pulp.

Concentrate in this document refers to the floating part or fraction of the pulp of ore particles containing a valuable mineral. In conventional flotation, the concentrate is the portion of the slurry that floats into the froth bed and is thus collected in the troughs as overhead. The first concentrate may contain ore particles containing one valuable mineral, while the second concentrate may contain ore particles containing another valuable mineral. Alternatively, the distinguishing terms first and second may refer to two ore particle concentrates comprising the same valuable mineral, but two distinctly different particle size distributions.

By rougher, rougher unit of the flotation line, rougher stage and/or rougher cells, in this document is meant the flotation stage which produces the pre-concentrate. The goal is to remove the maximum amount of valuable mineral with the largest possible particle size. Full release is not required for coarse flotation, only enough release to isolate enough gangue from the valuable mineral to achieve high recovery. The main goal of the coarse flotation stage is to recover as many valuable minerals as possible with less emphasis on the quality of the resulting concentrate.

The pre-concentrate is usually subjected to subsequent cleaning steps in a coarse cleaning line to remove unwanted minerals that also end up in the froth, in a process known as cleaning. The refining product is known as refining concentrate or final concentrate.

Coarse flotation is often followed by a control flotation, which is used for coarse tailings. By checker, checker unit of a flotation line, checker and/or checker is meant a flotation step whose purpose is to recover any valuable mineral material that was not recovered in the initial rougher flotation step. This can be achieved by changing the flotation conditions to be more stringent than the original rough treatment, or in some embodiments of the invention by introducing microbubbles into the slurry. The concentrate from the cell or control flotation stage can be returned to the rough feed for reflotation or sent to the regrinding stage and then to the control cleaner flotation line.

A cleaner flotation, a coarser/control flotation cleaner, a cleaner/cleaner flotation stage and/or a cleaning chamber is understood to be a flotation stage in which the purpose of the cleaning is to obtain the highest possible concentrate grade.

By pre-treatment and/or post-treatment and/or post-treatment is meant, for example, grinding, grinding, separating, screening, classifying, fractionating, stripping or cleaning, all of which are common processes known to the person skilled in the art. Post-treatment may also include at least one of the following: an additional flotation cell, which may be a conventional cleaner flotation cell, a complete recovery cell, a coarse flotation cell

- 8 040012 or control flotation cell.

The surface level of the pulp in this document means the height of the surface of the pulp inside the flotation cell, measured from the bottom of the flotation cell to the overflow edge of the flotation cell. In fact, the height of the pulp is equal to the height of the flotation cell overflow edge, measured from the bottom of the flotation cell to the flotation cell overflow edge. For example, any two successive flotation cells may be staggered in the flotation line so that the pulp surface level of such flotation cells is different (i.e. the pulp surface level of the first of such flotation cells is higher than the pulp surface level of the second of such flotation cells) . This difference in pulp surface levels is defined herein as the step between any two successive flotation cells. The slurry surface step or difference is the difference that allows the slurry flow to move under the influence of gravity or gravitational force, creating a hydrostatic head between said two successive flotation cells.

By flotation line in this document is meant an assembly or device containing a number of flotation units or flotation cells in which the flotation step is performed and which are located in fluid connection with each other to allow the slurry to flow between the flotation cells, either by gravity or by pumping, to form a flotation line. In a flotation line, several flotation cells are flow-through connected to each other so that the bottoms product of each previous flotation cell is sent to the next or subsequent flotation cell as feed, up to the last flotation cell of the flotation line, from which the bottom product is sent outside the line in the form of streams. tailings or waste. It is also possible that the flotation line may comprise only one flotation stage carried out either in one flotation cell or, for example, in two or more parallel flotation cells.

The slurry is fed through the feed inlet to the first flotation cell of the flotation line to start the flotation process. The flotation line may be part of a larger flotation plant containing one or more flotation lines and a number of other process steps to release, purify and otherwise process the desired material. Therefore, a number of different pre-treatment and post-treatment devices may be associated with the flotation line components, as will be known to those skilled in the art.

By ultrafine bubbles in this document refers to bubbles of flotation gas, falling in the size range from 0.05 to 0.7 mm, introduced into the slurry in the injection pipe. In contrast, normal flotation gas bubbles used in froth flotation have a size in the range of approximately 0.8 to 2 mm. Larger flotation gas bubbles may tend to coalesce into even larger bubbles during their stay in the mixing zone, where collisions occur between particles and flotation gas bubbles, and also between flotation gas bubbles alone. Because the ultrafine bubbles are introduced into the pulp feed prior to entering the flotation tank, such coalescence is unlikely with ultrafine bubbles, and their size may remain smaller throughout their stay in the flotation cell, thereby affecting the ability of the ultrafine bubbles to trap fine particles.

In one embodiment of a flotation cell according to the invention, the outlet nozzle is configured to generate a supersonic shock wave in the slurry feed, the supersonic shock wave causing agglomerations of flotation gas bubbles and particles.

A supersonic shock wave is created when the speed of the incoming pulp feed through the outlet nozzle exceeds the speed of sound, i.e. the pulp feed flow is blocked when the ratio of the absolute pressure upstream of the outlet nozzle and the absolute pressure downstream of the outlet nozzle throttle exceeds a critical value. When this pressure ratio exceeds a critical value, the slurry feed flow downstream of the outlet nozzle throttle becomes supersonic and a shock wave is generated. Small flotation gas bubbles in the slurry feed mixture are broken up into even smaller bubbles by being passed through the shock wave and forced into contact with hydrophobic ore particles in the slurry feed, thereby creating agglomerates of flotation gas bubbles and ore particles. . The supersonic shock wave generated in the pulp feed at the outlet of the outlet nozzle is transferred to the pulp inside the flotation tank immediately adjacent to the outlet nozzle, thereby promoting the formation of flotation gas bubbles also in the pulp outside the outlet nozzles. After exiting the outlet nozzle, the fine ore particles can contact the small flotation gas bubbles a second time as there are several such injection tubes/outlet nozzles exiting into a common mixing zone where the possibility of secondary contact between bubbles and particles is increased due to the mixing slurry flows exiting from injection pipes.

In one embodiment of the flotation cell, the froth thickener is a conical central froth thickener located concentric to the center of the flotation tank.

In yet another embodiment of the flotation cell, the central froth thickener is configured to block 25 to 40% of the exposed froth surface.

In yet another embodiment of the flotation cell, the apex angle of the central froth thickener is between 20° and 80°.

In one embodiment of the flotation cell, the froth thickener is an internal peripheral froth thickener installed in the side wall of the flotation tank such that the lowest point of the internal peripheral froth thickener is located at a distance from the bottom of the flotation tank.

In yet another embodiment of the flotation cell, the distance from the bottom of the inner perimeter to the bottom of the flotation tank is 1/2 to 2/3 of the height of the flotation tank, measured as the distance from the bottom to the edge of the trough.

In yet another embodiment of the flotation cell, the inner peripheral froth thickener comprises a diagonal bleeder starting at the lowest point, located at an angle to the center of the flotation tank and extending between the first part of the side wall of the flotation tank and the second part of the side wall, so that the angle of the diagonal bleeder with respect to the first part of the side wall is from 20 to 80°.

In yet another embodiment of the flotation cell, the inner peripheral froth thickener is configured to block 1/5 to 1/4 of the pulp area measured at a distance to the outlet nozzle from the bottom of the flotation tank.

In yet another embodiment of the flotation cell, the flotation tank also comprises, in addition to an internal peripheral froth thickener, a central froth thickener located concentrically to the center of the flotation tank.

In yet another embodiment of the flotation cell, the central froth thickener is configured to block 25 to 40% of the exposed froth surface.

In yet another embodiment of the flotation cell, the apex angle of the central froth thickener is between 20° and 80°.

By using the foam thickener in the above manner, the foam load on the exposed foam surface surrounding the central foam thickener can be easily and simply balanced and controlled, and the direction and/or thickening of the foam, especially brittle foam, can be effectively influenced. Foam load here refers to the amount of foam on the exposed surface for any given period of time. Pulp area here refers to the effective open area of the flotation tank available for foam formation, measured in the flotation tank at the height of the mixing zone, i.e. in a portion or zone of a flotation tank in a vertical direction where the slurry is agitated or otherwise caused to mix ore particles suspended in the slurry with flotation gas bubbles. Depending on the type of flotation unit and/or flotation tank, this mixing zone may vary.

By positioning the froth thickener at an inclination with respect to the vertical of the flotation tank, collision and coalescence of the flotation gas bubbles can be prevented, while the froth area can be effectively reduced. This effect can be particularly beneficial when the froth thickener comprises an internal peripheral froth thickener configured to remove froth from the side wall of the flotation tank. To achieve sufficient thickening, the inner perimeter may have an angle of inclination of 20 to 40° or even 20 to 80°, preferably approximately 30° with respect to the vertical of the flotation tank. A similar angle of inclination (apex angle) can be equally advantageous for the same reasons in a central foam thickener.

By placing a central froth thickener with a 20 to 80° apex angle, froth can accumulate from an area that is only affected by a single injection tube, as opposed to the center of the flotation tank where there is sufficient mixing and agglomeration of flotation gas bubbles and particles due to the combined action several injection pipes. By thickening in the area closer to the side wall and/or to the perimeter of the flotation tank, it can also be ensured that particles are recovered from areas with thinner foam and/or fewer bubbles.

In one embodiment of the flotation cell, the delivery tube further comprises an impinger configured to contact the pulp feed flow from the outlet nozzle and to direct the pulp feed flow radially outward and upward from the impinger.

The impinger deflects the incoming slurry feed radially outward towards the side wall of the flotation tank and upwards towards the top surface of the flotation tank (i.e. the froth bed) so that agglomerates of small bubbles of flotation gas and ore particles are not trapped in the tailings. All slurry feed coming from the injection tubes is forced up to the froth layer at the top of the flotation tank before gravity can affect particles not adhering to the flotation gas bubbles, causing them to sink and eventually be added to the tailings stream or to the bottom product. Thus, the possibility of overflow of valuable material containing particles can be reduced. The pulp is strongly mixed due to the energy of the deflected flow and forms mixing vortices, in which the size of the bubbles can be further reduced by the transverse forces acting on them. High shear conditions also favorably promote high contact between flotation gas bubbles and particles in the slurry within the flotation tank. As the slurry flow is forced upward towards the froth bed, the turbulence decreases and the flow becomes relatively uniform, which can contribute to the stability of already formed bubbles and agglomerates of flotation gas bubbles and particles, especially those containing larger particles.

By positioning the outlet nozzle and the impinger at an optimal distance from each other, the impinger can be configured to divert and direct the flow of pulp feed radially outward and upward from the impinger to create the previously mentioned mixing zones within the flotation tank, and also to accelerate the rise of particles to the froth bed . At the same time, there may be a need to minimize impinger wear caused by high velocity slurry flows. By positioning the outlet nozzle and the impinger in a certain way, the flotation process in the flotation cell with pressure tubes can be optimized, as well as the wear of the impinger parts can be minimized.

In one embodiment of the flotation cell, the ratio of the height of the flotation tank, measured as the distance from the bottom to the edge of the trough, and the diameter of the flotation tank, measured at the height of the outlet nozzle from the bottom, is from 0.5 to 1.5. In other words, the ratio of height to diameter can be between 0.5 and 1.5.

In one embodiment of the flotation cell, the volume of the flotation tank is at least 20 m ³ , preferably between 20 and 1000 m ³ .

By providing the flotation tank with sufficient volume, the flotation process can be better controlled. The lift distance to the froth layer at the top of the flotation tank does not become too large, which can help ensure that the agglomerates of flotation gas bubbles and ore particles stay together until they reach the froth layer and particle backfall can be reduced. In addition, a suitable bubble rise rate can be achieved to maintain good concentrate quality. The use of flotation cells with a sufficient volumetric size increases the likelihood of collisions between gas bubbles generated in the flotation cells, for example by means of a rotor, and particles containing the valuable mineral, thereby improving the recovery rate of the valuable mineral as well as the overall efficiency of the flotation device. Larger flotation cells have higher selectivity because more collisions can occur between gas bubbles and ore particles due to the longer residence time of the slurry in the flotation cell. Consequently, most of the ore particles containing the valuable mineral can float. In addition, the backfall of floating ore particles may be higher, meaning that ore particles containing very little valuable mineral fall back to the bottom of the flotation cell. Thus, the grade of overhead and/or concentrate produced from larger flotation cells may be higher. Flotation cells of this type can provide high grades along with high recovery. In addition, the overall efficiency of the flotation cell and/or the entire flotation line can be improved. Furthermore, in the case where the first flotation cells in the flotation line have a relatively large volume, there may not be a need for subsequent large flotation cells, rather, the flotation cells downstream of the first flotation cell or cells may be smaller and therefore , will be more efficient. In flotation processes for some minerals, a significant proportion of the ore particles containing a high grade valuable mineral can be easily achieved. In this case, it is possible to have smaller volume flotation cells downstream of the flotation line and still achieve a high recovery.

In one embodiment of the flotation cell according to the invention, the flotation cell comprises 2 to 40 injection tubes, preferably 4 to 24 injection tubes.

The number of injection pipes directly affects the amount of flotation gas that can be dispersed in the slurry. In conventional froth flotation, dispersing an increasing amount of flotation gas would increase the size of the flotation gas bubbles. For example, in the Jameson chamber, the ratio of air to bubbles used is between 0.50 and 0.60. Increasing the average bubble size is detrimental to the change (S _b ) of the bubble surface area, which means that recovery can be reduced. In a flotation cell made in accordance with the present invention, with pressurized injection pipes, significantly more flotation gas can be introduced into the process without increasing the bubble size or reducing S _b , since the flotation gas bubbles formed in the pulp feed remain relatively small in comparison with traditional processes. On the other hand, maintaining the quantity

- 11 040012 pressure tubes as small as possible, the cost of retrofitting existing flotation cells or the capital cost of installing such flotation cells can be controlled without resulting in a loss of performance of the flotation cells.

In one embodiment of the flotation cell, the injection tubes are located concentric to the perimeter of the flotation cell at a distance from the froth thickener.

The exact number of injection tubes in a flotation cell may depend on the size or volume of the flotation tank, the type of material being collected, and other process parameters. By placing a sufficient number of injection tubes in the flotation cell and by positioning them in a certain way in relation to the center, perimeter and/or side wall of the flotation tank, as well as from the froth thickener, an even distribution of ultrafine bubbles can be ensured, and even a mixing effect caused by forces shear inside the tank.

In one embodiment, the flotation cell further comprises a conditioning circuit.

In yet another embodiment of the flotation cell, the conditioning circuit comprises a pump tank in fluid communication with the flotation tank, wherein the pump tank is capable of combining the fresh pulp feed and the pulp fraction taken from the flotation tank through the outlet into the pulp feed.

In yet another embodiment of the flotation cell, the outlet is located on the side wall of the flotation tank at a distance from the bottom of the flotation tank.

In yet another embodiment of the flotation cell, the distance from the outlet to the bottom of the flotation tank is between 0 and 50% of the height of the flotation tank.

In yet another embodiment of the flotation cell, the conditioning circuit further comprises a pump configured to withdraw a pulp fraction from the flotation tank and to move the pulp feed from the pump tank.

In yet another embodiment of the flotation cell, the conditioning circuit further comprises a distribution block configured to distribute pulp feed.

By taking slurry from the bottom of the flotation cell, it can be ensured that the finer particles settled at the bottom of the flotation cell can be effectively reintroduced into the part of the flotation tank where the active flotation process takes place, even before the finer particles are sent to the tailings. . In this way, the recovery of valuable material can be improved since particles containing even minimal amounts of valuable material can be collected into a concentrate.

The flotation process can be made more efficient if only part of the pulp inside the flotation tank is sent back to the same flotation tank through the injection pipes as pulp feed. Particularly because impingers designed to direct the slurry flow radially outward and upward to create turbulent conditions in the mixing zone and additional mixing subzones, as explained earlier, are very effective in creating favorable conditions for the formation of agglomerates of flotation gas bubbles and particles and thus providing efficient recovery of particles containing valuable material, it may not be necessary to recirculate significant amounts of pulp for re-treatment in the same flotation cell. To achieve a high recovery, it may be sufficient to process the tailings of one flotation cell in another flotation cell. Since there is a possibility that particles containing valuable material will end up in the tailings/wastes, it may not be necessary to recycle a portion of the pulp from the flotation tank, or only a small portion may need to be recycled to improve recovery in this way.

Injection tubes and especially impingers can create favorable conditions for the recovery of particles, so that the flotation cell can be configured to process only fresh pulp, i.e. feed pulp from the previous flotation cell or the previous stage of the process. It may not be necessary to recirculate the pulp from the flotation tank for re-treatment in the same flotation tank, but any valuable material containing particles remaining in the part of the pulp that sinks to the bottom of the tank can be sent for further processing to a subsequent flotation tank, while recovering valuable material is also improved by the invention.

In one embodiment of a flotation line made in accordance with the present invention, a flotation cell made in accordance with the present invention is preceded by a previous flotation cell. Said prior flotation cell may be of any suitable type.

In one embodiment of the flotation line, a mechanical flotation cell is located upstream of the flotation cell according to the present invention.

In yet another embodiment, the flotation line comprises a rougher flotation unit with a flotation cell, a control flotation unit with a flotation cell configured to receive bottoms from the rougher flotation unit, and a check cleaner flotation unit with a flotation cell configured to receive the top product from the control flotation unit, while the last flotation cell of the control flotation unit and/or the control cleaner flotation unit is a flotation cell made in accordance with the invention.

In yet another embodiment of the flotation line, a mechanical flotation cell is located upstream of the flotation cell according to the present invention.

One embodiment relates to the use of a flotation line according to the present invention, in particular, to recover mineral ore particles containing non-polar minerals such as graphite, sulfur, molybdenite, coal and talc.

Pulp processing to recover industrial minerals such as bentonite, silica, gypsum or talc can be improved by using reverse flotation. In the recovery of industrial minerals, the purpose of flotation may be, for example, to remove dark particles in the overflow waste and to recover light particles in the bottom product used. In this type of process, some of the lighter and finer light particles may end up in the top product. These particles can be effectively recovered by the invention, in accordance with the present description. In reverse flotation, particles containing unwanted material are removed from the slurry by causing gas bubbles to adhere to these particles and remove them from the flotation cell in the upper product, while the valuable material containing the particles is recovered in the lower product, thus reversing conventional flotation flows of used substances into the upper product and wastes into the lower product. Typically, in reverse flotation, a large amount of non-value material can cause serious problems in the control of the flotation process.

One embodiment relates to the use of a flotation line according to the invention, in particular for the recovery of particles containing polar minerals.

One embodiment relates to the use of a flotation line, in particular for recovering particles from minerals having a Mohs hardness of 2 to 3, such as galena, sulfide minerals, PGM minerals (platinum group metals) and/or rare earth oxide minerals ).

Another embodiment relates to the use of a flotation line, in particular to recover particles containing Pt.

One embodiment relates to the use of a flotation line, in particular to recover particles containing Cu from minerals having a Mohs hardness of 3 to 4.

Another embodiment relates to the use of a flotation line, in particular for recovering Cu containing particles from a low copper grade ore.

The valuable mineral may be, for example, Cu, Zn, Fe, or pyrite, or a metal sulfide such as gold sulfide. Mineral ore particles containing other valuable minerals such as Pb, Pt, PGM (platinum group metals Ru, Rh, Pd, Os, Ir, Pt), oxide mineral, industrial minerals such as Li (e.g. spodumene), petalite and rare earth minerals can also be recovered in accordance with various aspects of the present invention.

For example, when extracting copper from low-grade ores obtained from poor mineral ore deposits, the amount of copper can be as low as 0.1% by weight of the raw material, i.e. supply of pulp fed to the flotation line. A flotation line made in accordance with the present invention can be very practical for recovering copper, since copper is a so-called easily floatable mineral. By releasing ore particles containing copper, a relatively high grade can be obtained in the first flotation cells of the flotation line. Recovery can be further increased by using a flotation cell according to the invention.

By using the flotation device according to the present invention, the recovery of such low amounts of a valuable mineral such as copper can be efficiently increased and even poor deposits can be economically exploited. As known rich deposits are more and more exploited, there is a perceived need to process even less favorable deposits that may previously have been left undeveloped due to the lack of suitable technology and processes to recover the valuable material present in the ore in very small quantities.

Brief description of the drawings

The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this specification, illustrate embodiments of the invention and, together with the description, help to explain the principles of the present invention. On the drawings:

fig. 1 is a 3D view of a flotation cell in accordance with one embodiment of the invention;

fig. 2 shows a flotation cell in accordance with one embodiment of the invention, seen from above;

fig. 3 shows a flotation cell according to one embodiment of the invention in side view;

fig. 4 is a vertical section through the flotation cell shown in FIG. 3, along the line A-A

- 13 040012 sections;

fig. 5 is a schematic view of a flotation cell according to the invention, detailing the dimensions of the flotation cell;

fig. 6a and 6b are schematic drawings of flotation lines constructed in accordance with embodiments of the invention;

fig. 7 shows schematic vertical sections of embodiments of flotation tanks made in accordance with the invention; and fig. 8 is a schematic view of the forms of the lower structure according to embodiments of the flotation cell.

Detailed description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings.

The following description discloses some embodiments in such detail that a person skilled in the art can use the apparatus, apparatus, and method based on the description. Not all steps of the embodiments are described in detail, as many of the steps will be apparent to a person skilled in the art based on this description.

For simplicity, in the case of repetitive components, the position numbers in subsequent exemplary embodiments are retained.

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings.

The following description discloses some embodiments in such detail that a person skilled in the art can use a flotation cell, a flotation line and its application based on the description. Not all steps of the embodiments are described in detail, as many of the steps will be apparent to a person skilled in the art based on this description.

For simplicity, in the case of repetitive components, position numbers in subsequent illustrative embodiments are retained.

The attached Figs. 1-5 and 7 illustrate the flotation cell 1 in detail. The drawings are not shown in proportion, and many components of the flotation cell 1 are not shown for clarity. Fig. 6a, 6b schematically depict embodiments of a flotation line. The direction of the pulp flow is shown in the drawings by arrows.

The flotation cell 1 according to the present invention is designed to process mineral ore particles suspended in the pulp and to separate the pulp into an underflow 400 and an overflow 500, with the overflow 500 containing the desired mineral concentrate.

The bottoms product 400 is removed from or removed from the flotation tank through the tailings outlet 140. In accordance with one embodiment, the tailings outlet 140 may be located on the side wall 14 of the flotation tank 10 (see FIG. 4). The tails outlet 140 may be located on the side wall 14 of the flotation tank 10 at a distance L6 from the bottom 13 of the tank 10. The distance should be understood as the distance to the lowest point of the tailings outlet 140 or the outlet in the side wall 14 of the flotation tank 10 from the bottom. 13 tanks. The distance L6 may be from 1 to 15% of the height H of the tank 10. For example, the distance L6 may be 2 or 5 or 7.5 or 12% of the height H. Alternatively, the tailings outlet 140 may be located at the bottom 13 tank 10 (see Fig. 1). The tails outlet 140 may be controlled by a percussion valve, or any other suitable method known in the art, to control the flow rate of the underflow from the reservoir 10. Even if the tails outlet 140 is controlled by internal or external structures, such as those located respectively above or below downstream percussion valves, the tailings outlet 140 is ideally located at the bottom of the tank 10, i.e. at or near the bottom 13 of the flotation tank, or even at the bottom 13 of tank 10. More specifically, bottoms 400 or tailings are removed from the bottom of tank 10 and at or near the side wall 14 of tank 10.

In particular, as shown in FIG. 1-5, the flotation cell 1 includes a flotation tank 10 which has a center 11, a perimeter 12, a bottom 13 and a side wall 14. The flotation cell 1 also includes a chute 2 and a chute edge 21 surrounding the tank 10 around the perimeter 12.

In the accompanying drawings, chute 2 is a chute located around the perimeter. It should be understood that the trough 2 may alternatively or additionally comprise a central trough located in the center 11 of the flotation tank 10, as is known in the art. The edge of the central trough may face the perimeter 12 of the tank 10 or the center 11 of the tank 10, or both. The top product 500 is collected in the trough 2 or troughs as it passes the edge 21 of the trough from the foam layer formed at the top of the tank 10. The foam layer has an exposed foam surface Af at the top of the tank 10.

The flotation tank 10 has a height H measured as the distance from the bottom 13 of the tank 10

- 14 040012 to the edge of 21 grooves. Along the perimeter 12 of the tank 10, the height H is not more than 20% less than the height H in the center 11 of the tank 10. In other words, the tank 10 may have different vertical cross sections (see Fig. 7), for example, the side wall 14 of the tank 10 may have in its lower part, a section that is inclined towards the center 11 of the tank 10.

In addition, the flotation tank 10 has a diameter D measured at a distance h1 to the outlet nozzle 43 from the bottom 13 of the tank 10. In one embodiment, the ratio of the height H to the diameter D (H/D) of the tank 10 is between 0.5 and 1.5 .

The flotation tank 10 may have a volume of at least 20 m ³ . The flotation tank 10 may have a volume of 20 to 1000 m ³ . For example, the volume of the tank 10 may be 100, 200, 450 or 630 m ³ .

The flotation tank 10 contains injection pipes 4 for supplying pulp feed 100 therein. The injection pipe 4 includes an inlet nozzle 41 for supplying pulp feed 100 to the injection pipe 4, an inlet 42 for compressed air or other gas, so that the pulp feed 100 can be exposed to compressed air or other gas when it exits the inlet nozzle 41, elongated a chamber 40 configured to receive pressurized pulp feed 100; an outlet nozzle 43 configured to restrict the flow of pulp feed 100 from the outlet nozzle 43 and to maintain pulp feed in the elongated chamber 40 under pressure.

The flotation gas is entrained by the turbulent mixing action caused by the jet and is dispersed into small bubbles in the pulp feed 100 as it passes down through the elongated chamber 40 to an outlet nozzle 43 configured to restrict the flow of the pulp feed 100 from the outlet nozzle 43, and further configured to maintain pressurized pulp feed 100 in elongated chamber 40.

In accordance with one embodiment, outlet nozzle 43 may also be configured to generate a supersonic shock wave in the pulp feed, the supersonic shock wave causing formation of agglomerates of flotation gas bubbles and particles. For example, the outlet nozzle 43 can induce a supersonic shock wave in the pulp feed 100 as it exits the injection tube 40. In addition, the supersonic shock wave can pass into the pulp near or around the outlet nozzle, so that even outside the injection tube, formation of agglomerates of flotation gas bubbles and small particles.

To restrict the flow, the outlet nozzle 43 may include a choke, such as a restrictive neck structure. From the outlet nozzle 43, more specifically from the orifice, the pulp supply 100 exits under pressure into the tank 10.

As the pulp feed 100 passes through the outlet nozzle 43 or through the outlet nozzle choke 43, the flotation gas bubbles decrease in size due to pressure changes and due to the high shear environment downstream of the outlet nozzle 43. the throttle can exceed the speed of sound when the flow becomes blocked flow, and the flow behind the throttle becomes supersonic, while a shock wave is formed in the expanding part of the outlet nozzle 43. In other words, the outlet nozzle 43 is configured to induce a supersonic shock wave in the pulp feed 100 .

The pulp supply stream 100 becomes a blocked stream when the ratio of the absolute pressure upstream of the outlet nozzle 43 and the absolute pressure downstream of the outlet nozzle 43 boundary structure exceeds a critical value. When the pressure ratio exceeds a critical value, the pulp feed 100 behind the restrictive structure of the discharge nozzle 43 becomes supersonic and a shock wave is generated. The small flotation gas bubbles in the slurry feed mixture 100 split into even smaller bubbles as they pass through the shock wave and are forced into contact with hydrophobic ore particles in the slurry feed 100, thereby creating agglomerates of flotation gas bubbles and ore particles.

The outlet nozzle 43 may be located within the flotation tank 10 at the desired depth. The outlet nozzle 43 may be located at a vertical distance L ₅ from the edge 21 of the chute, while the distance L ₅ is at least 1.5 m. is at least 1.5 m. In one embodiment, the distance L ₅ is at least 1.7 m, and the distance h1 to the outlet nozzle 43 from the bottom 13 of the tank 10 is at least 0.4 m. For example, the distance L ₅ can be 1.55, 1.75, 1.8, 2.2, 2.45 or 5.25 m; and the distance h1, regardless of the distance L ₅ , can be 0.45, 0.55, 0.68, 0.9 or 1.2 m. In addition, the ratio of the distance L ₅ and the height H of the tank 10 can be 0.9 or less. The depth at which the injection tubes 4 are located within the tank 10 may depend on a number of factors, such as the characteristics of the slurry and/or valuable mineral to be processed in the flotation cell 1, or the configuration of the flotation line in which the flotation cell 1 is located. h1 to the outlet nozzle 43 from the bottom 13 of the tank 10 and the height H of the tank 10, h1/H, can be between 0.1 and 0.75.

The diameter of the outlet nozzle 43 may be 10 to 30% of the diameter of the elongated chamber 40 of the injection pipe 4. The diameter of the outlet nozzle 43 may be 40 to 100 mm. For example, the diameter of the outlet nozzle 43 may be 55, 62 or 70 mm.

- 15 040012

By providing the outlet nozzle with a certain diameter, the pulp feed rate can be maintained at a level favorable to create small flotation gas bubbles and to increase the likelihood of these bubbles coming into contact with ore particles in the pulp. In particular, in order to maintain the shock wave behind the discharge nozzle, it is necessary to maintain a pulp velocity of 10 m/s or higher. By designing the outlet nozzle depending on the size of the injection tube, the influence of the slurry feed flow rate in various types of flotation cells can be taken into account.

The injection tube 4 may also include an impinger 44 configured to contact the pulp feed 100 from the outlet nozzle 43 and direct the pulp feed 100 radially outward and upward from the impinger 44. The pulp feed 100 exiting the outlet nozzle 43 is therefore directed from ensuring contact with the impinger 44. The distance L ₃ from the bottom 440 of the impinger 44 to the outlet nozzle 43 may be from 2 to 20 times the diameter of the outlet nozzle 43. For example, the distance L ₃ may be 5 times greater, 7, 12 or 15 times greater outlet nozzle diameter 43.

The ratio of the distance L ₃ and the distance h1 to the outlet nozzle 43 from the bottom 13 of the tank 10, L ₃ /h1, may be less than 1.0. In addition, the distance h ₃ to the bottom 440 of the impinger 44 from the bottom 13 of the tank 10 may be at least 0.3 m. For example, the distance h ₃ may be 0.4, 0.55, 0.75, or 1.0 m.

The impinger 44 may include an impingement surface designed to contact the slurry feed stream 100 exiting the outlet nozzle 43. The impingement surface may be made of a wear resistant material to reduce the need for replacements or maintenance.

The slurry, which is essentially a two-phase mixture of gas and liquid, rises from the impinger 44 and enters the top of the tank 10, while the flotation gas bubbles rise up and separate from the liquid, forming a layer of foam. The froth rises up and exits through the edge 21 of the chute into the chute 2 and exits the flotation cell 1 as the top product 500. The tails or bottom product 400, from which the desired material has been substantially removed, exits the tank 10 through the outlet located at the bottom 13 tank 10 or near it.

Some of the large hydrophobic particles that are carried into the froth may subsequently separate from the flotation gas bubbles and fall back into tank 10 as a result of bubble coalescence in the froth. However, most of these particles fall back into the tank 10 in such a way and in such a position that they can be captured by the bubbles re-entering the tank 10 from the injection tubes 4 and again transferred to the foam layer.

There may be 2 to 40 injection tubes 4 or 4 to 24 injection tubes 4 located in the flotation cell 1. In one embodiment, there are 16 injection tubes 4. In another embodiment, there are 24 injection tubes 4. In another embodiment, there are 8 injection tubes 4. The exact number of injection tubes 4 can be selected according to the specific operation, such as the type of pulp processed in the flotation cell 1, the volume flow rate of the feed supplied to the flotation cell 1, the mass flow rate of the feed supplied to the flotation cell 1, or the volume or dimensions of the tank 10. In order to properly disperse the flotation gas inside the flotation tank 10, 4 to 6 injection tubes 4 can be used.

The injection pipes 4 may be located concentric to the perimeter 12 of the reservoir 10 at some distance from its center 11. This may be the case when the reservoir 10 has a circular cross section. The injection tubes 4 may be further arranged such that each injection tube 4 is located at a distance L1 of the outlet nozzle 43 from the center 11 of the reservoir 10, the distance being preferably the same for each injection tube 4. For example, the distance L ₁ may be from 10 to 40% of diameter D of the tank 10. According to various embodiments of the flotation cell 1, the distance L1 can be 12.5% or 15% or 25% or 32.5% of the diameter D of the tank 10.

The injection pipes 4 can be arranged parallel to the side wall 14 of the tank 10 at some distance from it. This may be the case when the tank 10 has a rectangular cross section. The distance L ₂ to the outlet nozzle 43 of the injection pipe 4 from the side wall 14 of the reservoir 10 may be from 10 to 40% of the diameter D of the reservoir 10. In one embodiment, the distance L ₂ is 25% of the diameter D of the reservoir 10. In accordance with various embodiments flotation cell 10, the distance L2 can be 12.5% or 15% or 27% or 32.5% of the diameter D of the tank 10. In addition, the parallel injection tubes 4 can also be arranged in a straight line inside the tank 10 .

In addition, in all the above embodiments, the discharge pipes 4 can be spaced equally apart so that the distance between any two adjacent outlet nozzles 43 is the same.

A pulp fraction 300 can be withdrawn from the flotation tank 10 through an outlet 31 located on the side wall 14 of the tank 10. This pulp fraction 300 is fed back into

- 16 040012 injection pipes 4 as pulp feed. In one embodiment, the pulp feed 100 contains 40% or less of the pulp fraction 300. In one embodiment, the pulp feed 100 contains 50% or less of the pulp fraction 300. For example, the pulp nutrition may be 5%, or 12.5%, or 20%, or 30%, or 37.5%, or 45% of the 300 pulp fraction. Alternatively, pulp feed 100 may contain 0% pulp fraction 300, ie. there is no recirculation of pulp taken from reservoir 10 back to the flotation cell, but the pulp feed 100 contains 100% fresh pulp 200 from, for example, a previous flotation cell (i.e. bottoms 400 from a previous flotation cell) or from a previous stage of the process .

The pulp fraction 300 may be sent back to all injection tubes 4 of the flotation tank 10, or alternatively to some of the injection tubes 4, while the other injection tubes 4 receive fresh pulp 200 containing either the bottom stream 400 from the previous flotation cell or the pulp stream from some previous stage of the process, depending on the location of the flotation cell 1 inside the flotation line 8. The outlet 31 may be located at a distance L4 from the bottom 13 of the tank 10. This distance should be understood as the distance to the lowest point of the outlet or outlet in the side wall 14 of the tank 10 from the bottom of the tank 13. The distance L4 is from 0 to 50% of the height H of tank 10. Outlet 31 may advantageously be located in a settling zone where particles suspended in the slurry and not entrained by flotation gas bubbles and/or rising slurry sink to bottom 13 of tank 10. In one embodiment, outlet 31 is located in the bottom of the tank 10. For example, the distance L4 may be 2%, or 8%, or 12.5%, or 17, or 25% of the height H of the tank 10. Even if the outlet 31 is controlled by internal or external structures, such as located respectively upstream or downstream shock valves, the outlet 31 is ideally located at the bottom of the tank 10, i.e. near the bottom 13 of the tank or near it. More specifically, the pulp fraction 300 is removed from the bottom of the tank 10.

The flotation tank 10 further comprises a froth thickener 6 shaped to direct the froth on the exposed froth surface A _f to the edge 21 of the chute or to direct the flow of rising agglomerates of flotation gas bubbles and ore particles towards the froth layer 5 on the exposed froth surface A _f (see especially Fig. 4). The foam thickener 6 may be a central foam thickener 6 or an internal peripheral foam thickener 6 installed inside the tank 10 at the desired depth on the side wall 14 of the tank 10.

The central foam thickener 61 is located concentric to the center 11 of the tank 10. The central foam thickener 61 may be in the form of a cone or a truncated cone. The central foam thickener 61 may be in the form of a pyramid or a truncated pyramid. In other words, the vertical cross section of the central froth thickener 61 may be an inverted triangle with the apex pointing towards the bottom 13 of the flotation tank. In case the central foam thickener 61 has a truncated structure or shape, the apex is only functional, i. it should be visualized as the lowest point of the structure or shape, extended to a completely non-truncated shape, whereby the vertex angle α can be identified independently of the actual shape or shape of the central foam thickener 61. The angle α can range from 20 to 80°. For example, the angle α may be 22, 37.5, 45, 55, 63.75, or 74°. In one embodiment, the central foam thickener 61 is configured to block from 25% to 40% of the exposed foam surface _Af .

Alternatively or in addition to the central froth thickener 61, the flotation tank may comprise an internal peripheral froth thickener 62 located in the side wall 14 of the tank 10 such that the lowest point 620 of the inner peripheral froth thickener is located at a distance h ₂ from the bottom 13 of the flotation tank. 10. The distance h ₂ may be from 1/2 to 2/3 of the height H of the reservoir 10. The inner peripheral foam thickener 62 may include a diagonal sampler 14c starting from the lowest point 620, located at an angle to the center 11 of the reservoir 10 and passing between the first part of the side wall 14 of the tank 10 and the second part of the side wall 14, so that the angle of inclination of the diagonal sampler relative to the first part of the side wall 14 is from 20 to 80°. The angle of inclination may be, for example, 22, 37.5, 45, 55, 63.75 or 74°. The foam thickener 62, located along the inner perimeter, can be configured to block from 1/5 to 1/4 of the area Ap of the pulp, which is measured at a distance h1 to the outlet nozzle 43 of the injection pipe 4 from the bottom 13 of the tank 10, in the mixing zone A. Mixing zone A, i.e. the portion or zone of the flotation tank in the vertical direction where the slurry is agitated or otherwise induced mixing of ore particles suspended in the slurry with bubbles of flotation gas is formed in the approximately vertical part of the tank 10 around the lower portions of the injection tubes 4 and impingers 44 (see FIG. 5) .

Additionally or alternatively, the tank 10 may further comprise a lower structure 7 (see Fig. 5 and 7) located on the bottom (13) and having a shape that allows

- 17 040012 particles suspended in the pulp mix in the mixing zone A created above the lower structure 7 and settle in the sedimentation zone surrounding the lower structure 7.

The shape of the bottom structure 7 can be determined as follows (see Fig. 8): it should be taken into account that the vertical cross section of the bottom structure has the form of a functional triangle 700, which contains the first (upper) vertex 71 directed from the bottom 13 of the tank 10, the second a top 71a and a third top 71b, the last two tops being located on the bottom 13 of the tank 10. The first side a is formed between the first top 71 and the second top 71a. The second side b is formed between the first peak 71 and the third peak 71b. A base c is formed between the second peak 71a and the third peak 71b, with the base c parallel to and located on the bottom 13 of the tank 10. The central axis 70 of the functional triangle 700 is essentially concentric with the center 11 of the reservoir 10. As such, it should be understood in this context that during the manufacture and/or installation of the lower structure 7, it is possible that slight deviations from the center 11 of the reservoir 10 may naturally occur. at least it is assumed that the two axes, the central axis 70 of the functional triangle (which is also the central axis of the lower structure 7) and the center of the tank 10, are coaxial.

The angle α at the base between the first side a and the base c (and/or between the second side b and the base c) relative to the bottom 13 of the tank 10 is between 20° and 60°. For example, the angle α may be 22, 27.5, 35, 45 or 53.75°. In addition, the internal angle β between the first side a and the second side b is 20° to 100°. Preferably, the internal angle β is between 20° and 80°. For example, the interior angle β may be 22, 33.5, 45, 57.75, 64, or 85.5°. Thus, a functional triangle can be isosceles or equilateral.

The functional triangle is essentially a shape that can be identified by the above features, regardless of the actual shape of the bottom structure 7, which may, depending on the cross section and other structural details of the tank 10, be, for example, a cone, a truncated cone , pyramid or truncated pyramid. A cone or truncated cone may be suitable for a flotation tank with a circular cross section. A pyramid or truncated pyramid may be a suitable shape for a flotation tank with a rectangular cross section.

The lower structure 7 includes a base 73 corresponding to the base c of the functional triangle 700 (i.e., the base c of the functional triangle 700 defines the base 73 of the lower structure 7) and is located on the bottom 13 of the tank 10. In addition, the lower structure includes a casing 72. The casing 72 is limited at least the first vertex 71, the second vertex 71a and the third vertex 71b of the triangle 700. Therefore, regardless of the actual shape of the bottom structure 7, the triangle 700 defines the extreme physical dimensions of the bottom structure 7. For example, in the case where the bottom structure 7 has an irregular shape, but at the same time remains rotationally symmetrical, it completely fits into the triangle 700 (see the last image in Fig. 8). In one embodiment, the casing 72 is at least partially delimited by the first side a and the second side b of the functional triangle. An example of such an embodiment is the lower structure 7, which has the shape of a truncated cone (see the middle image in Fig. 8). In one embodiment, shroud 72 is substantially completely delimited by first side a and second side b of triangle 700, i. e. the lower structure 7 has the shape of a cone (see the first image in Fig. 8).

The bottom structure 7 has a height ID measured from the topmost part of the bottom structure 7 to the bottom 13 of the tank 10. 7 has a slightly truncated shape, the height h ₄ is measured from the level of the top of the truncated shape (see the middle image in Fig. 8) to the bottom 13 of the reservoir 10. The height h4 is greater than 1/5 and less than 3/4 of the height H of the reservoir 10. In addition , the diameter d ₃ of the base 73 of the lower structure 7 can be from 1/4 to 3/4 of the diameter d1 of the bottom 13 of the tank 10. In case the tank 10 and/or the bottom structure 7 have a non-circular cross section, the diameters are measured as the maximum diagonals of the respective parts (base 73 and bottom 13). In one embodiment, the surface area of the base 73 of the lower structure 7 is less than 80% of the surface area of the bottom 13 of the tank 10. The surface area of the base 73 can be from 25% to 80% of the surface area of the bottom 13 of the tank 10.

In addition, the volume of the tank 10 occupied by the lower structure 7 may be from 30 to 70% of the volume of the tank 10 occupied by the mixing zone A.

The bottom structure 7 may further comprise any suitable support structures and/or connection structures for mounting the bottom structure 7 into the tank 10 on its bottom 13. The bottom structure 7 may be made from any suitable material such as metal, such as stainless steel.

The flotation chamber 1 may also comprise a conditioning circuit 3.

The conditioning circuit 3 may include a pump tank 30 or other such additional tank in fluid communication with the tank 10. In the pump tank 30, the fresh pulp feed 200 and the pulp fraction 300 withdrawn from the tank 10 through the outlet 31 can be combined into nutrition 100 pulp. Fresh pulp 200 may, for example, be bottoms 400 from a previous flotation cell or, if flotation cell 1 is the first flotation cell of a flotation line, pulp feed from a grinding unit/stage or classification unit/stage. It is also possible that the slurry fraction 300 and the fresh slurry 200 are distributed into the injection pipes 4 without being combined in the pumping tank 30 beforehand.

The combined slurry may be fed back to all of the injection tubes 4 of the tank 10 or alternatively to some of the injection tubes 4 while the other injection tubes 4 receive fresh slurry 200 containing either the bottom stream 400 from the previous flotation cell or the slurry stream from some previous stage of the process, depending on the location of the flotation cell 1 in line 8 flotation.

The outlet 31 may be located on the side wall 14 of the reservoir 10 at a distance L4 from the bottom 13 of the reservoir 10. The distance L4 may be from 0 to 50% of the height H of the reservoir 10. For example, the distance L4 may be 2%, or 8%, or 12.5% or 20% or 33% of the height H of the tank 10.

In addition, the conditioning circuit may include a pump 32 configured to draw a pulp fraction 300 from the reservoir 10 and to further transfer the pulp feed 100 from the pump reservoir 30 to the injection pipes 4. The pulp fraction 300 may contain particles with a low settling rate, such as fine, slowly moving particles. The pulp fraction can be taken from the bottom of the tank 10 or near it. Additionally or alternatively, the conditioning circuit 3 may further comprise a distribution unit (not shown in the drawings) configured to distribute the pulp feed 100 to the injection pipes 4. The pump 32 can also be used to further transfer the pulp feed 100 to the injection pipes 4. To evenly distribute the supply of 100 slurry through the injection pipes 4, a switchgear can be used. The distribution device may, for example, include a supply pipe inside the tank 10, configured to distribute the pulp fraction 300 directly into the injection pipes 4.

For example, the distribution device may include pipelines located outside the tank 10, leading to a separate feed distributor, configured to distribute the pulp fraction 300 or combine the pulp fraction 300 and fresh pulp 200 into the injection pipes 4.

In accordance with another aspect of the invention, the flotation lines 8 are shown in FIG. 6a and 6b. The flotation line 8 comprises a series of flow-through connected flotation cells 1a, wherein at least one of the flotation cells is a flotation cell 1 constructed in accordance with the embodiments of the flotation cell 1 described above. with the invention, the flotation chamber 1a is located. The flotation chamber 1a may be any type of chamber known in the art. Alternatively or additionally, a mechanical flotation cell 1b can be placed in front of the flotation cell 1 (see FIG. 6a).

In one embodiment, the flotation line 8 comprises a rougher flotation unit 81 with a flotation cell 1a, a control flotation unit 82 with a flotation cell 1a capable of receiving bottoms product 400 for a rougher flotation unit 81, and a checker cleaner flotation unit 820 with a flotation cell 1a, configured to receive the top product 500 from the control flotation unit 82 (see Fig. 6b). In the flotation line 8, the last flotation cell 1 of the control flotation unit 82 and, alternatively or in addition, the last flotation cell 1 of the control cleaner flotation unit 820, is a flotation cell 1 made in accordance with the invention, having injection pipes 4. In addition, in line 8 flotation, as described above, before the flotation cell 1, made in accordance with the invention, with the injection tubes 4, can be installed mechanical flotation cell 1b.

The flotation line 8 may be preceded by other processes such as grinding, classifying, screening, heavy medium process, coarse particle recovery process, screw separators and other separation processes, and other flotation processes. The flotation line 8 may be followed by a number of processes such as regrinding, cleaning or other flotation processes, centrifugation, filtration, screening or dewatering.

According to another aspect of the invention, the flotation line 8 can be used to recover particles containing valuable material suspended in the pulp.

In one embodiment, the application may be directed to the recovery of particles containing non-polar minerals such as graphite, sulfur, molybdenite, coal, talc.

According to another embodiment, the application may be directed to the recovery of particles containing polar minerals.

In another embodiment, the application is directed to the extraction of particles from minerals,

- 19 040012 having a Mohs hardness of 2 to 3, such as galena, sulfide minerals, PGMs, rare earth minerals.

In another embodiment, the application is specifically directed to the recovery of particles containing platinum.

In yet another embodiment, the application is directed to the recovery of copper containing particles from mineral particles having a Mohs hardness of 3 to 4. In yet another embodiment, the application is specifically directed to the recovery of copper containing particles from a low copper ore.

The embodiments described above may be used in any combination with each other. Several embodiments may be combined together to form another embodiment. The flotation chamber to which the invention relates may comprise at least one of the embodiments described above. For a person skilled in the art it is obvious that with the development of technology the main idea of the invention can be implemented in various ways. Thus, the invention and its embodiments are not limited to the examples described above; instead, they may vary within the scope of the claims.

Claims (36)

CLAIM 1. Flotation chamber (1) for processing particles suspended in the pulp, and for separating the pulp into the bottom product (400) and the top product (500), and the flotation chamber contains a flotation tank (10) having a center (11), a perimeter ( 12), a substantially horizontal bottom (13) and side wall (14), a trough (2) and an edge (21) of the trough located around the perimeter (12) of the tank (10), the open surface (Af) of the foam at the top of the flotation tank (10) and a froth thickener (6) shaped to direct the froth (5) in the open area (Af) of the froth to the edge (21) of the chute, characterized in that the flotation tank additionally contains injection pipes (4) for introducing into it supply (100) of the pulp, and the injection pipe contains an inlet (41) nozzle for supplying the supply (100) of the pulp into the injection pipe (4), an inlet (42) for compressed gas, while the supply of the pulp when leaving the inlet nozzle is exposed to a compressed gas, an elongated chamber (40), capable of receiving pulp feed under pressure, and an outlet nozzle (43) configured to restrict the flow of pulp feed from the outlet nozzle and maintain pulp feed in the elongated pressure chamber. 2. A flotation cell according to claim 1, characterized in that the outlet nozzle (43) is configured to generate a supersonic shock wave in the pulp feed (100), wherein the supersonic shock wave causes formation of agglomerates of flotation gas bubbles and particles. 3. Flotation chamber according to claim 1 or 2, characterized in that the height (H) of the flotation tank (10), measured as the distance from the bottom (13) to the edge (21) of the chute, along the perimeter (12) of the flotation tank is not more than 20% less than in the center (11) of the flotation tank. 4. Flotation cell according to any one of claims 1 to 3, characterized in that the froth thickener (6) is a conical central froth thickener (61) located concentrically to the center (11) of the flotation tank. 5. Flotation cell according to claim 4, characterized in that the central foam thickener (61) is configured to block from 25 to 40% of the open surface (A _f ) of the foam. 6. Flotation cell according to claim 4 or 5, characterized in that the angle (α) at the top of the central foam thickener (61) is between 20° and 80°. 7. Flotation chamber according to any one of claims 1 to 3, characterized in that the foam thickener (6) is an internal peripheral foam thickener (62) located in the side wall (14) of the flotation tank (10) so that the lowest point (620) of the inner peripheral thickener is located at a distance (h1) from the bottom (13) of the flotation tank. 8. Flotation tank according to claim 7, characterized in that the specified distance (h ₂ ) is from 1/2 to 2/3 of the height (H) of the flotation tank (10), measured as the distance from the bottom (13) to the edge (21 ) gutters. 9. Flotation cell according to claim 7 or 8, characterized in that the inner peripheral froth thickener (62) contains a diagonal sampler (14c), starting from the specified lowest point (620), located at an angle to the center (11) of the flotation tank and passing between the first part (14a) of the side wall (14) of the flotation tank (10) and the second part (14b) of the side wall, so that the angle (β) of the diagonal sampler (14c) relative to the first part (14a) of the side wall is from 20 to 80 °. 10. Flotation chamber according to any one of claims 7 to 9, characterized in that the inner peripheral foam thickener (62) is configured to block from 1/5 to 1/4 of the area (Ap) of the pulp, measured at a distance (h1) to the outlet nozzles (43) from the bottom (13) of the flotation tank (10). 11. A flotation cell according to any one of claims 7 to 10, characterized in that the flotation tank (10) also contains a central froth thickener (61) located concentrically to the center (11) of the flotation tank. - 20 040012 12. Flotation cell according to claim 11, characterized in that the central foam thickener (61) is configured to block from 25 to 40% of the open surface (Af) of the foam. 13. Flotation chamber according to claim 11 or 12, characterized in that the angle (α) at the top of the central foam thickener (61) is between 20 and 80°. 14. Flotation chamber according to any one of claims 1 to 13, characterized in that the discharge pipe also contains an impinger (44) configured to come into contact with the pulp feed flow from the outlet nozzle (43) and direct the pulp feed flow (100) radially outward and upward from the impinger. 15. Flotation chamber according to any one of claims 1 to 14, characterized in that the ratio (H/D) of the height (H) of the flotation tank (10), measured as the distance from the bottom (13) to the edge (21) of the chute, and the diameter (D) measured at a height (h1) to the outlet nozzle (43) from the bottom (13) of the flotation tank is 0.5 to 1.5. 16. A flotation cell according to any one of claims 1 to 15, characterized in that the volume of the flotation tank (10) is at least 20 m ³ , preferably between 20 and 1000 m ³ . 17. A flotation cell according to any one of claims 1 to 16, characterized in that it comprises from 2 to 40 injection tubes (4), preferably from 4 to 24 injection tubes. 18. Flotation chamber according to any one of claims 1 to 17, characterized in that the injection pipes (4) are located concentrically to the perimeter (12) of the flotation tank (10) at a distance from the foam thickener (6). 19. Flotation chamber according to any one of claims 1 to 18, characterized in that it contains a conditioning circuit (3). 20. The flotation chamber according to claim 19, characterized in that the conditioning circuit contains a pump tank (30) in fluid communication with the flotation tank (10), and in the pump tank it is possible to combine the supply of fresh pulp (200) and the pulp fraction (300) , taken from the flotation tank (10) through the outlet (31), into the feed (100) of the pulp. 21. Flotation chamber according to claim 20, characterized in that the outlet (31) is located on the side wall (14) of the flotation tank (10) at a distance (L4) from the bottom (13) of the flotation tank (10). 22. Flotation cell according to claim 21, characterized in that said distance (L4) is between 0 and 50% of the height (H) of the flotation tank (10), measured as the distance from the bottom (13) to the edge (21) of the chute. 23. Flotation chamber according to any one of claims 19-22, characterized in that the conditioning circuit (3) also contains a pump (32) configured to take a fraction (300) of the pulp from the flotation tank (10) and transfer the feed (100) pulp from the pumping tank (30). 24. A flotation chamber according to any one of claims 19 to 23, characterized in that the conditioning circuit (3) also comprises a distribution block configured to distribute the pulp feed (100). 25. A flotation line (8) comprising flow-through connected flotation cells (1a), characterized in that at least one of the flotation cells is a flotation cell (1) according to any one of claims 1 to 24. 26. A flotation line according to claim 25, characterized in that a flotation chamber (1a) is located in front of said flotation chamber (1). 27. A flotation line according to claim 25 or 26, characterized in that a mechanical flotation cell (1b) is located in front of said flotation cell (1). 28. The flotation line according to claim 26, characterized in that it contains a coarse flotation unit (81) with a flotation chamber (1a), a control flotation unit (82) with a flotation chamber (1a) configured to obtain an underproduct (400) from the coarse flotation unit, and the control cleaner flotation unit (820) with a flotation chamber (1a) configured to receive the top product (500) from the control flotation unit, while the last flotation chamber of the control flotation unit and / or the control cleaner flotation unit represents a flotation chamber (1), made according to any one of claims 1 to 23. 29. A flotation line according to claim 28, characterized in that a mechanical flotation cell (1b) is located in front of said flotation cell (1). 30. Use of line (8) according to any one of claims 25 to 29 as a flotation line for recovering particles containing valuable material suspended in the pulp. 31. Use according to claim 30, wherein the particles to be recovered contain non-polar minerals such as graphite, sulfur, molybdenite, coal and talc. 32. Use according to claim 30, wherein the particles to be recovered contain polar minerals. 33. Use according to claim 32, wherein the minerals from which the particles are to be recovered have a Mohs hardness of 2 to 3, such as galena, sulfide minerals, PGMs, and/or PGE minerals. 34. Use according to claim 33, wherein the particles to be recovered contain Pt. - 21 040012 35. Use according to claim 32, wherein the minerals from which the Cu-containing particles are to be recovered have a Mohs hardness of 3 to 4. 36. The use according to claim 35, wherein the Cu-containing particles to be recovered are recovered from an ore with a low copper content.