flotation cell

Abstract

A flotation cell for treating particles suspended in a slurry is disclosed. The flotation cell comprises a flotation tank (10) comprising a center (11), a periphery (12), a generally horizontal flat bottom (13), and a sidewall (14); a launder (2) and a launder lip (21) around the periphery (12) of the tank (10); an open froth surface (Af) at the top of the flotation tank (10); and a froth choke (6) shaped to direct froth (5) in the open froth area (Af) toward the launder lip (21); and a sparge pipe (4) for introducing slurry feed (100) into the flotation tank. In addition, a flotation line and use of the flotation line are disclosed.

Description

[0001] This application is a divisional application of the invention patent application entitled "Flotation Cell" with application number 201910706195.4. Technical Field

[0002] This disclosure relates to flotation cells for separating particles containing valuable materials from particles suspended in a slurry, as well as flotation lines and their uses. Background Technology

[0003] In froth flotation of mineral ores, improving concentrate grade involves an intermediate particle size range between 40 μm and 150 μm. Therefore, fine particles are those with a diameter of 0 μm to 40 μm, and ultrafine particles can be considered to fall within the lower limit of the fine particle size range. Coarse particles have a diameter greater than 150 μm. In froth flotation of coal, improving concentrate grade involves an intermediate particle size range between 40 μm and 300 μm. Fine particles in coal processing are those with a diameter of 0 μm to 40 μm, as well as ultrafine particles falling within the lower limit of the fine particle size range. Coarse coal particles have a diameter greater than 300 μm.

[0004] Recovering very coarse or very fine particles is challenging because fine particles are not easily captured by flotation bubbles in conventional mechanical flotation cells and may therefore be lost in the tailings. Typically, in froth flotation, flotation gas is introduced into the flotation cell or flotation vessel via a mechanical agitator. The flotation bubbles thus generated have a relatively large size range (typically 0.8 mm to 2.0 mm or even larger) and are not particularly well-suited for capturing particles with finer sizes.

[0005] Fine particle recovery can be improved by increasing the number of flotation cells within the flotation line, or by recycling previously flotated material (overflow) or tailings stream (underflow) back to the start of the flotation line or to upstream flotation cells. Additionally, for fine particles, a cleaning flotation line can be used to improve fine particle recovery. Furthermore, many flotation devices employing fine flotation bubbles or even so-called microbubbles have been designed. These smaller bubbles or microbubbles can be introduced before the slurry is fed into the flotation cells; that is, the ore particles are subjected to small bubbles at feed junctions, etc., to promote the formation of ore particle-microbubble aggregates, which can then be floated in flotation cells (e.g., flash flotation cells or columnar cells). Alternatively, small bubbles or microbubbles can be introduced directly into the flotation cells, for example, by using ejectors that utilize cavitation. For mechanical flotation cells, these types of solutions are not necessarily feasible because the turbulence caused by mechanical agitation may cause ore particles—small bubble aggregates—to break down before they can rise to the froth layer to be captured in the overflow and thus recovered.

[0006] Columnar flotation cells are used as three-phase setters, where particles move countercurrently downwards relative to an upward flow of flotation bubbles generated by ejectors located near the bottom of the cell, in a hindranced settling environment. While columnar flotation cells can improve the recovery of finer particles, particle residence time depends on settling velocity, which can affect the flotation of larger particles. In other words, while the above flotation solutions can be beneficial for the recovery of fine particles, the overall flotation performance (recovery of all valuable material and the grade of the recovered material) may be compromised by the negative impact on the recovery of larger particles.

[0007] To overcome the aforementioned problems, so-called pneumatic flotation cells are used, in which flotation gas is introduced along with the slurry feed into a high-shear device (such as a lower conduit or jet tube), thereby generating smaller flotation bubbles that can capture finer particles while forming bubbles in the jet tube. However, such high-throughput flotation cells may require the creation of a vacuum in the jet tube to effectively achieve the desired bubble formation rate in order to capture the desired particles during the short period of time the slurry feed remains in the jet tube.

[0008] Once they have left the jet, the flotation bubble-particle aggregate immediately rises toward the foam layer located at the top of the flotation cell, and no further capture of the particles occurs in the section of the flotation cell downwards from the jet outlet. This can result in a significant portion of the particles containing the desired material (mineral) simply falling to the bottom of the flotation cell and eventually becoming tailings, which reduces the recovery rate of the flotation cell.

[0009] However, commonly referred to high-throughput flotation cells or Jameson-type pneumatic flotation cells do not include any flow restrictions for controlling the pressure within the injection tubes after the formation of flotation bubble-particle agglomerates. Such pressure control is advantageous considering the pressure at the time of flotation bubble formation (its effect on bubble size), and also for regulating the relative pressure of the flotation bubbles when they are used in the flotation cell. This minimizes bubble aggregation after its formation. This is particularly advantageous because the ratio of particles captured by flotation bubbles decreases with increasing bubble size (assuming the air-to-liquid ratio remains constant).

[0010] Additionally, so-called high-throughput flotation cells can be used for coal liberation operations, typically involving flotation lines that include one or two such flotation cells at the end of the liberation loop for the recovery of particularly fine coal particles. In the liberation loop, a treated water recirculation system returns water from the end portion of the loop (i.e., from the flotation line and dewatering loop) back to the preceding loop (the starting point of the liberation loop). Flotation chemicals (particularly frothers) often cause problems in the treatment preceding the flotation line. These 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 treatment, foam formation in the lower conduit can deteriorate according to existing techniques. This leads to unstable treatment conditions in the flotation cells, as well as particularly unstable jet pipe operation and foam layers, which in turn negatively impacts the recovery of desired particles, especially coarse particles. As bubble size increases with lower frother dosages, particle recovery across the entire particle size distribution of the slurry is affected, particularly the recovery of coarse particles.

[0011] In existing injection tubes, flotation gas is introduced via self-priming due to the vacuum created within the lower conduit. The residence time of the flotation air to be carried into the slurry is very short (3 to 5 seconds), making the system highly sensitive to processing variations. Continuous addition of frother is required to overcome the limiting effect on the airflow required to maintain or even increase the vacuum within the lower conduit, in order to keep conditions as constant as possible for bubble-particle bonding, as the frother prevents bubble aggregation and the rising back into the unfilled air space within the injection tube. However, the dosage of frother required for stable use of existing lower conduits creates problems in other parts of the process, particularly in coal operations, as described above. Therefore, the solution is to reduce the dosage of frother, which negatively impacts the lower conduit vacuum, bubble formation, and bubble size and surface area, and significantly reduces the recovery of desired particles, rendering the high-throughput flotation cells known in the prior art inefficient in such applications.

[0012] By using the flotation cell according to the invention, the amount of frother required to optimize the flotation process can be significantly reduced without significantly impairing bubble formation, bubble-particle bonding, stable foam layer formation, or recovery of desired materials. Simultaneously, problems associated with recirculating treated water from the downstream loop to the upstream loop can be mitigated. The jet tubes, operating under pressure, are completely independent of the flotation cell. Better flotation gas flow rates can be obtained, smaller bubbles are generated, and the use of frothers is optimized because the operation of the jet tubes is independent of the frother dosage.

[0013] In solutions known from the prior art, the problem specifically involves limitations on the amount of flotation gas that can be supplied relative to the amount of liquid flowing through the lower conduit, and the need for relatively high concentrations of frothers or other expensive surfactants to generate small bubbles. Using the invention proposed herein, flotation of fine and ultrafine particles, such as mineral or coal, can be improved by reducing the size of flotation bubbles introduced into the slurry feed into the jet tube, by increasing the flotation gas supply rate relative to the flow velocity of particles suspended in the slurry, and by increasing the shear strength or energy dissipation rate in or near the jet tube. The likelihood of finer particles attaching to or being captured by smaller flotation bubbles increases, and improved recovery of the material (e.g., mineral or coal) is desired. In the flotation cell according to the invention, sufficiently small flotation bubbles (so-called ultrafine bubbles) can be generated to ensure effective capture of fine ore particles. Typically, ultrafine bubbles can have a bubble size distribution of 0.05 mm to 0.7 mm. For example, reducing the average flotation bubble size to a diameter of 0.3 mm to 0.4 mm means that 1 m 3 The number of air bubbles in the slurry can be as high as 30 million to 70 million, and the total average surface area of ​​the air bubbles can be as high as 15 m². 2 Up to 20 m 2 In contrast, if the average bubble size is approximately 1 mm, then 1 m 2 The slurry contains approximately 2 million air bubbles, with a total average surface area of ​​6 m². 2 Therefore, in the flotation cell according to the present invention, a bubble surface area 2.5 to 3 times higher can be achieved compared to that in a flotation cell according to a prior art solution. Needless to say, this increase in bubble surface area has a significant effect on the recovery of particles containing valuable materials.

[0014] Meanwhile, by achieving a high flotation gas fraction in the slurry and by eliminating highly turbulent regions below the froth layer, the recovery of coarser particles can be maintained at an acceptable level. That is, the known advantages of mechanical flotation cells can be utilized even if no mechanical agitation may necessarily be present in the flotation cell. Furthermore, the upward movement of the slurry or pulp within the flotation cell increases the likelihood that coarser particles will rise towards the froth layer with the slurry flow. Summary of the Invention

[0015] A flotation cell is provided for treating particles suspended in a slurry and separating the slurry into underflow and overflow. The flotation cell includes: a flotation cell comprising a center, a periphery, a generally horizontal, flat bottom, and sidewalls; a channel surrounding the periphery of the cell and a channel edge; an open foam surface at the top of the flotation cell; and a foam plug shaped to guide foam in the open foam region toward the channel edge. The flotation cell is characterized in that the flotation cell further includes a jet pipe for introducing slurry feed into the flotation cell. The jet pipe includes an inlet nozzle for feeding slurry feed into the jet pipe; an inlet for pressurized gas, through which the slurry feed is subjected as it exits from the inlet nozzle; an elongated chamber arranged to receive the slurry feed under pressure; and an outlet nozzle configured to restrict the flow of the slurry feed from the outlet nozzle and to maintain the slurry feed in the elongated chamber under pressure.

[0016] According to one aspect of the invention, a flotation line is provided. The flotation line comprises a plurality of fluidly connected flotation cells, and the flotation line is characterized in that at least one of the flotation cells is a flotation cell according to the invention.

[0017] According to another aspect of the invention, the flotation line according to the invention is intended for the recovery of particles containing valuable materials suspended in a slurry.

[0018] The invention described herein can be used to improve the recovery of fine particles in flotation processes. These particles may include, for example, mineral ore particles, such as particles containing metals.

[0019] One of the effects achievable through this invention is the increased depth or thickness of the foam layer. A thicker foam layer contributes to higher grades and improves the recovery of smaller particles, and eliminates the need for a separate foam washing step typically used in column flotation cells.

[0020] By arranging multiple jets in the flotation cell according to the invention, the likelihood of collisions between flotation bubbles and between bubbles and particles can be increased. Having multiple jets ensures improved distribution of flotation bubbles within the flotation cell, and that bubbles exiting the jets are uniformly distributed throughout the entire flotation cell. The distribution areas of each jet have the potential to intersect and converge, thereby promoting a broad and uniform distribution of flotation bubbles within the flotation cell. This, in turn, can beneficially influence the recovery of particularly smaller particles and also contributes to the aforementioned uniform and thick foam layer. The presence of multiple jets promotes collisions between flotation bubbles and / or particles in the slurry feed from different jets because the different flows mix and create locally mixed sub-regions. As collisions increase, more bubble-particle aggregates are generated and captured in the foam layer, thus improving the recovery of valuable materials.

[0021] By generating fine or ultrafine flotation bubbles, contacting these bubbles with particles, and controlling the mixture of flotation bubbles, particle aggregates, and liquid in the slurry, the recovery of hydrophobic particles into the froth layer and into the flotation cell overflow or concentrate can be maximized, thereby increasing the recovery of the desired material regardless of its particle size distribution within the slurry. High grades can be achieved for a portion of the slurry stream, while high recovery can be achieved for the entire slurry stream passing through the flotation line.

[0022] By setting the outlet nozzle of the jet tube at an appropriate depth—that is, at a specific vertical distance from the edge of the flotation cell—the distribution of flotation bubbles can be optimized in a uniform and constant manner. Because the appropriate depth of the jet tube outlet nozzle maintains a sufficiently high residence time of the bubbles in the mixing zone, the bubbles can effectively contact and adhere to fine particles in the slurry, thereby improving the recovery of smaller particles and also promoting foam depth, stability, and uniformity at the top of the flotation cell.

[0023] In this context, a mixing zone refers to a vertical portion or section of a flotation cell where effective mixing of particles suspended in the slurry with flotation bubbles occurs. In addition to this mixing zone formed throughout the entire vertical section of the flotation cell, separate and localized independent mixing sub-regions can also be formed where the slurry flows, guided radially outward by the individual impactors, meet and become mixed. This further promotes contact between flotation bubbles and particles, thereby increasing the recovery of valuable particles. Moreover, this additional mixing eliminates the need for mechanical mixers to suspend solids in the slurry.

[0024] The settling zone refers to the vertical portion or section of a flotation cell in which particles not connected to flotation bubbles, or particles that cannot rise toward the foamy area at the top of the flotation cell, descend toward the bottom of the flotation cell and settle, so as to be removed in the tailings as underflow. The settling zone is located below the mixing zone.

[0025] By positioning the tailings outlet on the sidewall of the flotation cell, underflow can be removed from the area where most of the slurry comprises particles descending or settling towards the bottom of the flotation cell. In the flotation cell according to the invention, the settling zone is relatively deep near the sidewall of the flotation cell. In this zone, the mixing and turbulence generated by the jet pipe do not affect the settling particles, and most of the settling particles contain no valuable material or only a very small amount of valuable material. In this part, the settling effect is most pronounced because there is no turbulence interfering with the descent of particles under gravity. In addition, the friction generated by the sidewall of the flotation cell further reduces turbulence and / or flow. Therefore, removing the underflow from the flotation cell at a location arranged in this relatively calm settling zone ensures that as few particles containing valuable material as possible are removed from the flotation cell—instead, these particles should be floated, or if they end up in the settling zone for some reason, they should be recycled back to the flotation cell as slurry feed through the jet pipe. Furthermore, by removing the underflow from the settling area near the sidewalls of the flotation cell, the entire volume of the flotation cell can be effectively utilized—eliminating the need for a separate lower settling area below the jet, as is the case in, for example, the Jameson cell. In some embodiments, it is even foreseeable that the volume of the flotation cell can be reduced at its center, thereby reducing the volume of the settling area where turbulence caused by the slurry feed from the jet might affect the particle settling toward the bottom of the flotation cell, and allowing for full utilization of the flotation cell's volume. For example, the volume of the flotation cell can be reduced at its center by arranging a bottom structure at the bottom of the flotation cell. Additionally, the jet (outlet nozzle) can be positioned relatively deep within the flotation cell, while still ensuring a sufficiently calm settling area at the sidewalls of the flotation cell. This further promotes the efficient utilization of the entire volume of the flotation cell.

[0026] By using the invention described herein, so-called "breakable foam," a loosely textured foam layer comprising typically large flotation bubbles aggregated with mineral particles intended for recovery, can be guided more efficiently and reliably toward the foam overflow edge and foam collecting channel. Breakable foam is prone to collapse because the bubble-ore particle aggregate is unstable and has reduced toughness. Such foam or foam layer cannot easily sustain the transport of ore particles, especially coarser ones, toward the foam overflow edge for capture in the channel, thus causing particles to fall back into the pulp or slurry within the flotation cell or cell, and reducing the recovery of the desired material. Breakable foam is often associated with low mineralization, which is a limited amount of bubble-ore particle aggregate containing the desired mineral (which has already been able to adhere to the bubbles during flotation processing within the flotation cell or cell). This problem is particularly pronounced in large flotation cells or cells with large volumes and / or large diameters. Using this invention, foam can be squeezed and guided toward the foam overflow edge to reduce the foam transport distance (thus reducing the risk of backflow) while maintaining or even reducing the overflow edge length. In other words, the treatment and guidance of the foam layer in a foam flotation cell or flotation vessel can become more efficient and direct.

[0027] It can also improve foam recovery, thus particularly improving the recovery of valuable mineral particles from easily broken foam in large flotation cells or flotation tanks in later stages of the flotation line (e.g., in the roughing and / or scavenging stages of the flotation process).

[0028] Furthermore, using the invention described herein, the area of ​​foam on the surface of the slurry inside the flotation cell can be reduced in a robust and simple mechanical manner. Simultaneously, the total overflow edge length in the froth flotation unit can be reduced. In this context, robustness is considered to imply structural simplicity and durability. By reducing the foam surface area of ​​the flotation unit using foam plugs instead of adding additional foam collecting channels, the froth flotation unit can have a simpler overall construction, for example, because there is no need to guide the collected foam and / or overflow away from the added plugs. In contrast, the collected overflow would have to be diverted from additional channels, which would increase the number of structural components in the flotation unit.

[0029] Especially downstream of the flotation line, the amount of desired material that can be captured in the foam within the slurry may be very low. To capture this material from the foam layer into the foam collecting stream, the foam surface area should be reduced. By arranging foam plugs in the flotation cell, the open foam surface between the foam overflow edges can be controlled. Plugs can be used to guide or direct the upward flow of slurry within the flotation cell closer to the foam overflow edge of the foam collecting stream, thereby enabling or facilitating foam formation very close to the foam overflow edge, which can increase the capture of valuable ore particles. Foam plugs can also affect the overall coalescence of flotation bubbles and / or bubble-ore particle agglomerates within the foam layer. For example, if the bubble and / or bubble-ore particle agglomerate stream is directed towards the center of the flotation cell, foam plugs can be used to increase the foam area at the periphery of the flotation cell and / or the foam area closer to any desired foam overflow edge. In addition, the open foam surface can be reduced relative to the overflow edge length, thereby improving the recovery efficiency in the foam flotation cell.

[0030] The flotation cells, flotation lines, and their applications according to the present invention offer the technical advantages of allowing flexible recovery of various particle sizes and efficient recovery of ore particles containing valuable minerals from lean ore feedstocks initially containing relatively low amounts of valuable minerals. The structure of the flotation line provides the advantage of allowing precise adjustment of the structural parameters of the flotation line according to the target valuable material at each unit.

[0031] By processing the slurry according to the present invention as defined herein, the recovery of particles containing valuable material can be increased. The initial grade of the recovered material may be low, but the material (i.e., the slurry) is therefore readily prepared for further processing, which may include, for example, regrinding and / or cleaning.

[0032] In this disclosure, the following definitions are used to refer to flotation.

[0033] Essentially, flotation aims to recover concentrates containing ore particles with valuable minerals. In this context, concentrate refers to the portion of the slurry recovered from the overflow or underflow of the flotation cell. Valuable minerals are any minerals, metals, or other materials that have commercial value.

[0034] Flotation involves phenomena related to the relative buoyancy of the materials. The term flotation encompasses all flotation techniques. Flotation can be, for example, froth flotation, dissolved air flotation (DAF), or induced gas flotation. Foam flotation is a process used to separate hydrophobic materials from hydrophilic materials by adding a gas (such as air or nitrogen or any other suitable medium) to the process. Foam flotation can be based on natural hydrophilic / hydrophobic differences or on hydrophilic / hydrophobic differences obtained by adding surfactants or collector chemicals. Gases can be added to the feedstock (slurry or pulp) in a variety of different ways.

[0035] Flotation cells are used to process mineral ore particles suspended in a slurry by flotation. Thus, ore particles containing valuable metals are recovered from the ore particles suspended in the slurry. A flotation line, as used herein, refers to a flotation apparatus in which multiple flotation cells are arranged in fluid connection with each other such that the underflow from each preceding flotation cell is introduced as feed into subsequent flotation cells, up to the last flotation cell of the flotation line, from which the underflow is directed as tailings or waste stream. Slurry is fed through a feed inlet to the first flotation cell of the flotation line to initiate the flotation process. A flotation line may be part of a larger flotation apparatus or unit comprising one or more flotation lines. Therefore, as is known to those skilled in the art, many different pretreatment and posttreatment units or stages can be operatively connected to the components of the flotation apparatus.

[0036] The flotation cells in a flotation line are fluidly connected to each other. This fluid connection can be achieved through conduits (such as pipes or tubes) of varying lengths, the length of which depends on the overall physical construction of the flotation unit. Pumps or grinding / re-grinding units can also be arranged between the flotation cells in the flotation line. Alternatively, the flotation cells can be arranged in direct cell connections to each other. A direct cell connection, as used herein, refers to an arrangement in which the outer walls of any two consecutive flotation cells are connected to each other, allowing the outlet of the first flotation cell to be connected to the inlet of the subsequent flotation cell without the aid of any separate conduit. Direct contact reduces the need for piping between two adjacent flotation cells. Therefore, it reduces the need for components during the construction of the flotation line, accelerating the process. Furthermore, it reduces grinding and simplifies the maintenance of the flotation line. Fluid connections between flotation cells can include various regulating mechanisms.

[0037] The term "adjacent," "nearby," or "adjoining" flotation cell, as used herein, refers to the relationship between a flotation cell in a roughing flotation line or a flotation cell in a scavenging flotation line that is immediately following or preceding (downstream or upstream) any other flotation cell, or between a flotation cell in a roughing flotation line and a flotation cell in a scavenging flotation line to which the underflow from the roughing flotation cell is directed.

[0038] The term "flotation cell," as used herein, refers to a tank or vessel in which flotation processes are performed. Flotation cells are typically cylindrical in shape, defined by one or more outer walls. They generally have a circular cross-section. Flotation cells may also have polygonal (e.g., rectangular, square, triangular, hexagonal, or pentagonal) or other radially symmetrical cross-sections. As is known to those skilled in the art, the number of flotation cells can vary depending on the specific flotation line and / or operation used to process a particular type and / or grade of ore.

[0039] Flotation cells can be froth flotation cells, such as mechanically agitated cells or tank cells, column flotation cells, Jameson cells, or dual flotation cells. In a dual flotation cell, the flotation cell comprises at least two separate containers: a first mechanically agitated pressure vessel with a mixer and flotation gas input, and a second container with tailings output and overflow froth discharge, the second container being arranged to receive the agitated slurry from the first container. Flotation cells can also be fluidized bed flotation cells (e.g., HydroFloat). TM A fluidized bed flotation cell (FLCC) is a flotation cell in which air bubbles or other flotation bubbles dispersed by a fluidization system permeate through a sedimentation-impeded region and attach to the hydrophobic component, altering the density of the hydrophobic component and giving it sufficient buoyancy for flotation and recovery. Axial mixing is not required in a fluidized bed flotation cell. The flotation cell can also be an overflow flotation cell operating with a constant slurry overflow. In an overflow flotation cell, the slurry is processed by introducing flotation bubbles into the slurry and by generating a continuous upward slurry flow along the vertical direction of the first flotation cell. At least a portion of the ore particles containing valuable metals attach to the bubbles and rise due to buoyancy, and at least a portion of the ore particles containing valuable metals rise with the continuous upward slurry flow. The ore particles containing valuable metals are recovered by drawing the continuous upward slurry flow as a slurry overflow from at least one overflow flotation cell. Because the overflow trough operates with virtually no foam depth or foam layer, no actual foam zone forms on the surface of the slurry at the top of the flotation cell. The foam can be discontinuous throughout the flotation cell. As a result, more ore particles containing valuable minerals can be carried into the concentrate stream, and the overall recovery of valuable material can be improved.

[0040] According to the present invention, all flotation cells in a flotation line can be of a single type; that is, the roughing flotation cells in the roughing section, the scavenging flotation cells in the scavenging section, and the scavenging cleaning flotation cells in the scavenging cleaning flotation line can have a single flotation cell type, such that the flotation apparatus includes only one type of flotation cell as listed above. Alternatively, multiple flotation cells can have one type, while other flotation cells have one or more types, such that the flotation line includes two or more types of flotation cells as listed above.

[0041] Depending on the type of flotation cell, the flotation cell may include a mixer for agitating the slurry to keep it suspended. The term "mixer," as used herein, refers to any suitable device for agitating the slurry within the flotation cell. The mixer may be a mechanical agitator. A mechanical agitator may include a rotor-stator structure with a motor and drive shaft, arranged at the bottom portion of the flotation cell. The flotation cell may also have auxiliary agitators arranged higher along the vertical direction of the flotation cell to ensure a sufficiently strong and continuous upward flow of slurry.

[0042] The term "foam plugging component" in this document refers to a foam plugging component, foam baffle, or plugging plate, or plugging plate device, or any other such structure or side structure (e.g., an inclined or vertical sidewall with a plugging effect, i.e., a plugging sidewall), which may also be a plugging sidewall inside a flotation cell, i.e., an internal peripheral plugging component.

[0043] The flotation cell may include a bottom structure disposed on the bottom of the flotation cell and having a shape that allows particles suspended in the slurry to mix in a mixing zone above the bottom structure and settle in a settling zone surrounding the bottom structure, the mixing zone being generated by a slurry feed flow from an outlet nozzle of a jet pipe.

[0044] By arranging a bottom structure at the bottom of the flotation cell (which extends upwards within the cell), a better distribution of fine and / or small particles suspended in the slurry can be achieved. At the center of the flotation cell, particles cannot descend and settle because the slurry feed from the jet reaches the central portion of the cell's bulge, ensuring good mixing. Due to the turbulent conditions in the mixing zone, particles that may have detached from the flotation bubbles and begun to descend can be recaptured by the bubbles. On the other hand, the bottom of the flotation cell closer to the periphery has a sufficiently deep region that allows unfloated, most likely worthless particles to settle and descend for efficient removal from the cell. This settling region is unaffected by the slurry feed from the jet. Moreover, this relatively calm region suppresses short-circuiting slurry flows within the cell (where the same slurry material remains recycled within the cell without proper separation or settling). These features facilitate improved recovery of fine particles.

[0045] By arranging the bottom structure to have specific dimensions relative to the mixing zone, the mixing and settling zones can be designed with desired characteristics (size, depth, turbulence, particle residence time in the mixing zone, settling velocity and likelihood of worthless fractions in the settling zone, etc.). In conventional flotation cells, most of this zone (where there is no mechanical mixing at the bottom of the flotation cell) will undergo grinding due to little or no mixing. If this zone is filled with solids, there is a risk that this solid material will collapse and simultaneously block the tailings outlet and / or recycling outlet located in the settling zone.

[0046] The term "jet tube" refers to a dual high-shear device in which flotation gas is introduced into the slurry feed, thereby generating finer flotation bubbles that can capture similarly finer particles during bubble formation within the jet tube. Specifically, the jet tubes in the flotation cell according to the invention operate under pressure and do not require a vacuum.

[0047] The term "overflow," as used herein, refers to the portion of the slurry that is captured into the flow channel of the flotation cell and thus exits the flotation cell. Overflow may include foam, foam, and slurry, or in some cases, only slurry or primarily slurry. In some embodiments, overflow may be a receiving flow containing particles of valuable material captured from the slurry. In other embodiments, overflow may be a discharge flow. This is the case when flotation apparatus, equipment, and / or methods are used for reverse flotation.

[0048] The term "underflow" in this document refers to the portion or portion of the slurry that does not float to the surface during the flotation process. In some embodiments, the underflow may be a discharge stream exiting the flotation cell via an outlet typically located in the lower portion of the flotation cell. Ultimately, the underflow from the last flotation cell of the flotation line or flotation unit may exit the entire unit as tailings or final residue. In some embodiments, the underflow may be a receiving stream containing valuable mineral particles. This is the case when the flotation unit, equipment, and / or method are used in reverse flotation.

[0049] Reverse flotation, in this context, refers to the reverse flotation process commonly used in iron recovery. In this case, flotation is used to capture the less valuable portion of the slurry stream into the overflow. The overflow in reverse flotation processes for iron typically contains silicates, while mineral particles containing valuable iron are captured in the underflow. Reverse flotation can also be used for industrial minerals—geological minerals mined for their commercial value (which are neither fuel nor metal source)—such as bentonite, silica, gypsum, and talc.

[0050] In this paper, downstream refers to the direction consistent with the slurry flow toward the tailings (forward flow, indicated by arrows in the diagram), while upstream refers to the direction opposite to or relative to the slurry flow toward the tailings.

[0051] In this context, concentrate refers to the flotation portion or fraction of a slurry containing ore particles of valuable minerals. In normal flotation, concentrate is the portion of the slurry that floats to the froth layer and is thus collected as overflow into the flow channel. A first concentrate may include ore particles containing one valuable mineral, while a second concentrate may include ore particles containing another valuable mineral. Alternatively, the distinguishing definitions of "first" and "second" may refer to two concentrates containing the same valuable mineral but with two distinctly different particle size distributions.

[0052] Roughing flotation, in this context, refers to the roughing section, stage, and / or cell of a flotation line, specifically the flotation stage that produces the roughing concentrate. Its purpose is to remove the maximum amount of valuable minerals at the coarsest possible particle size. Roughing flotation does not require complete liberation; sufficient liberation of gangue from the valuable minerals is sufficient to achieve high recovery. The primary objective of the roughing stage is to recover as much valuable mineral as possible, with less emphasis on the quality of the resulting concentrate.

[0053] Rougher concentrate is typically subjected to a further cleaning flotation stage in the rougher cleaning flotation line to discard more unwanted minerals that have been entrained in the froth during a process known as cleaning. The product of cleaning is called cleaning concentrate or final concentrate.

[0054] Scavenging flotation is typically applied to rougher tailings after rougher flotation. The terms scavenging flotation, the scavenging section of a flotation line, scavenging stage, and / or scavenging cell refer to a flotation stage whose purpose is to recover any valuable mineral material not recovered during the initial rougher stage. This can be achieved by modifying the flotation conditions to be more stringent than the initial rougher stage, or, in some embodiments of the invention, by introducing microbubbles into the slurry. Concentrate from the scavenging cell or stage can be returned to the rougher feed for reflotation or directed to a regrinding step and subsequently to a scavenging cleaning flotation line.

[0055] The terms "cleaning flotation," "roughing / scavenging cleaning line," "cleaner / cleaning stage," and / or "cleaning pool" refer to the flotation stage in which the purpose of cleaning is to produce the highest possible concentrate grade.

[0056] Pretreatment and / or posttreatment and / or further treatment refers to processes such as crushing, grinding, separation, screening, sorting, fractionation, conditioning, or cleaning, all of which are conventional processes known to those skilled in the art. Further treatment may also include at least one of the following: another flotation cell, recovery cell, roughing cell, or scavenging cell that can be a conventional cleaning flotation cell.

[0057] The term "slurry surface level" in this paper refers to the height of the slurry surface within a flotation cell, measured from the bottom of the cell to the rim of the flotation channel. In practice, the slurry height is equal to the height of the rim of the flotation channel measured from the bottom of the cell to the rim of the flotation channel. For example, any two consecutive flotation cells can be arranged in a stepped manner in a flotation line, such that the slurry surface level of such cells differs (i.e., the slurry surface level of the first flotation cell is higher than that of the second flotation cell). This difference in slurry surface level is defined in this paper as a "step" between any two consecutive flotation cells. The step or difference in slurry surface level allows for a difference in slurry flow through gravity or gravity-driven forces by generating a hydraulic head between the two consecutive flotation cells.

[0058] A flotation line, as used herein, refers to an assembly or apparatus comprising multiple flotation units or cells in which flotation stages are performed to form a flotation line, and said multiple flotation units or cells are arranged in fluid communication with each other to allow gravity-driven or pumped slurry to flow between the cells. In a flotation line, multiple flotation cells are arranged in fluid communication with each other such that the underflow from each preceding flotation cell is directed as feed to subsequent flotation cells until the last flotation cell of the flotation line, whereby the underflow is directed as tailings or discharge from the last flotation cell away from the flotation line. It is also conceivable that a flotation line may comprise only one flotation stage performed in one flotation cell or, for example, in two or more parallel flotation cells.

[0059] The slurry is fed through a feed inlet into the first flotation cell of the flotation line to initiate the flotation process. The flotation line may be part of a larger processing facility that includes one or more flotation lines and numerous other processing stages for the dissociation, cleaning, and other treatments of the desired material. Therefore, as is known to those skilled in the art, many different pretreatment and posttreatment devices or equipment can be operatively connected to components of the flotation line.

[0060] In this paper, ultrafine bubbles are defined as flotation bubbles ranging in size from 0.05 mm to 0.7 mm that are introduced into the slurry in the jet tube. In contrast, “normal” flotation bubbles used in froth flotation exhibit a size range of approximately 0.8 mm to 2 mm. Larger flotation bubbles may tend to coalesce into even larger bubbles during their residence in the mixing zone, where collisions occur between particles and flotation bubbles, as well as between flotation bubbles themselves. Because ultrafine bubbles are introduced into the slurry feed before being fed into the flotation cell, such coalescence is less likely, and their size can remain small throughout their residence in the flotation cell, thus not affecting their ability to capture fine particles.

[0061] In an embodiment of the flotation cell according to the present invention, the outlet nozzle is configured to generate a supersonic shock wave in the slurry feed, which causes the formation of flotation bubble-particle agglomerates.

[0062] When the velocity of the slurry feed through the outlet nozzle exceeds the speed of sound, a supersonic shock wave is generated. This occurs when the pressure ratio between the absolute pressure upstream of the outlet nozzle and the absolute pressure downstream of the outlet nozzle's throttle valve exceeds a critical value, causing obstruction of the slurry feed flow. When the pressure ratio is above this critical value, the slurry feed flow downstream of the throttle valve portion of the outlet nozzle becomes supersonic and forms a shock wave. Small flotation bubbles in the slurry feed mixture are forced through the shock wave, breaking into even smaller bubbles and coming into contact with hydrophobic ore particles in the slurry feed, thus creating flotation bubble-ore particle agglomerates. The supersonic shock wave generated in the slurry feed at the outlet nozzle discharge point is carried into the slurry immediately adjacent to the outlet nozzle within the flotation cell, thereby also promoting flotation bubble formation in the slurry outside the outlet nozzle. After leaving the outlet nozzle, fine ore particles can have secondary contact with fine flotation bubbles because there are several such jets / outlet nozzles discharging into a common mixing zone, where the mixing flow of the slurry leaving the jets increases the possibility of secondary contact between the bubbles and particles.

[0063] In one embodiment of the flotation cell, the foam plug is a conical central foam plug arranged co-centered with the center of the flotation cell.

[0064] In another embodiment of the flotation cell, the central foam plug is arranged to block 25 to 40% of the open foam surface.

[0065] In another embodiment of the flotation cell, the included angle of the central foam plug is 20 to 80°.

[0066] In one embodiment of the flotation cell, the foam plug is an internal peripheral plug, which is arranged in the side wall of the flotation cell such that the lowest point of the internal peripheral plug is located at a certain distance from the bottom of the flotation cell.

[0067] In another embodiment of the flotation cell, the distance from the lowest point of the internal peripheral plug to the bottom of the flotation cell is 1 / 2 to 2 / 3 of the height of the flotation cell, which is the distance from the bottom to the edge of the flow channel.

[0068] In another embodiment of the flotation cell, the internal peripheral plug includes a diagonal inlet starting from the lowest point, angled toward the center of the flotation cell, and extending between a first portion and a second portion of the sidewall of the flotation cell, such that the angle of the diagonal inlet relative to the first portion of the sidewall is 20 to 80°.

[0069] In another embodiment of the flotation cell, the internal peripheral plugs are arranged to block 1 / 5 to 1 / 4 of the slurry area, which is measured at a certain distance from the bottom of the flotation cell at the outlet nozzle.

[0070] In another embodiment of the flotation cell, in addition to the internal peripheral plugging member, the flotation cell also includes a central foam plugging member arranged co-centered with the center of the flotation cell.

[0071] In another embodiment of the flotation cell, the central foam plug is arranged to block 25 to 40% of the open foam surface.

[0072] In another embodiment of the flotation cell, the included angle of the central foam plug is 20 to 80°.

[0073] By utilizing the foam plug in the manner described above, the foam load on the open foam surface surrounding the central foam plug can be easily and simply balanced and controlled, and the guiding and / or plugging of foam, especially fragile foam, can be effectively influenced. The foam load, as used herein, refers to the amount of foam in the open surface area over any given time period. The slurry area, as used herein, refers to the effective open area of ​​the flotation cell available for foam formation, as measured in the flotation cell at the height of the mixing zone, which is the vertical portion or region of the flotation cell where the slurry is agitated or otherwise induced to mix the ore particles suspended in the slurry with the flotation bubbles. This mixing zone is variable depending on the type of flotation unit and / or flotation cell.

[0074] By arranging the foam plugs at an angle relative to the vertical plane of the flotation cell, collisions and aggregation of flotation bubbles can be prevented, while still effectively reducing the foam zone. This effect can be particularly advantageous when the foam plugs include internal peripheral plugs arranged to extrude foam away from the sidewalls of the flotation cell. For sufficient extrusion, the internal peripheral plugs can have an angle of inclination of 20-40° or even 20-80°, preferably about 30°, relative to the vertical plane of the flotation cell. For the same reason, a similar angle of inclination (angle) can be equally advantageous in the central foam plug.

[0075] By arranging the central foam extruder at an angle of 20 to 80°, foam can be extruded from areas where only a single jet has influence, as opposed to the center of the flotation cell, where abundant mixing and flotation bubble-particle agglomeration occur due to the combined action of several jets. Extrusion further closer to the sidewalls and / or periphery of the flotation cell also ensures particle recovery in areas with sparser foam and / or fewer bubbles.

[0076] In one embodiment of the flotation cell, the injection tube further includes an impactor configured to contact the slurry feed flow from the outlet nozzle and to guide the slurry feed flow radially outward and upward from the impactor.

[0077] The impactor deflects the slurry feed radially outward toward the flotation cell sidewalls and upward toward the upper surface of the flotation cell (i.e., the froth layer), thus preventing short circuits of small flotation bubble-ore particle agglomerates into the tailings. All slurry feed from the jet is forced upward toward the froth layer located in the top region of the flotation cell before gravity has a chance to affect particles not attached to flotation bubbles, forcing them down and ultimately entraining them in the tailings or underflow. This reduces the likelihood of short circuits of particles containing valuable material. The slurry is highly agitated by the energy of the deflected flow, forming mixing eddies in which the size of the bubbles can be further reduced due to the shear forces acting on them. These high shear conditions also advantageously induce significant contact between flotation bubbles and particles within the slurry in the flotation cell. As the slurry flow is forced upward toward the froth layer, turbulence decreases and the flow becomes relatively uniform, which contributes to the stability of the already formed bubbles and the flotation bubble-particle agglomerates (especially those containing coarser particles).

[0078] By arranging the outlet nozzles and impactors at optimal distances, the impactors can be configured to deflect and guide the slurry feed flow radially outward and upward to create the previously mentioned mixing zone within the flotation cell and promote particle ascent toward the foam layer. Simultaneously, it may be necessary to minimize wear caused by the high-speed slurry flow on the impactors. By positioning the outlet nozzles and impactors relative to each other in a specific relationship, the flotation process within the flotation cell equipped with the injection pipes can be optimized, and wear on the impactor components can be minimized.

[0079] In one embodiment of the flotation cell, the ratio of the height of the flotation cell, measured as the distance from the bottom to the edge of the flow channel, to the diameter of the flotation cell, measured at a certain height from the bottom at the outlet nozzle, is 0.5 to 1.5. In other words, the height-to-diameter ratio can be 0.5 to 1.5.

[0080] In one embodiment of the flotation cell, the volume of the flotation cell is at least 20 m³. 3 20 m is preferred 3 Up to 1000 m 3 .

[0081] By arranging flotation cells with sufficient volume, the flotation process can be better controlled. The rise distance to the froth layer at the top of the flotation cell does not become too large, which helps ensure that the flotation bubble-ore particle agglomerates remain together until the froth layer, and also ensures reduced particle fallback. Furthermore, suitable bubble rise velocities can be obtained to maintain good concentrate quality. Using flotation cells with sufficient volume increases the likelihood of collisions between bubbles generated in the flotation cell, for example by a rotor, and particles containing valuable minerals, thereby improving the recovery of valuable minerals and the overall efficiency of the flotation unit. Larger flotation cells have higher selectivity because the longer residence time of the slurry in the flotation cell allows for more collisions between bubbles and ore particles. Therefore, a large portion of the ore particles, including valuable minerals, can be flotated. Additionally, the fallback of buoyant ore particles can be higher, meaning that ore particles containing very small amounts of valuable minerals fall back to the bottom of the flotation cell. Therefore, the grade of overflow and / or concentrate from larger flotation cells can be higher. These types of flotation cells ensure high grades. Furthermore, this can improve the overall efficiency of the flotation cells and / or the entire flotation line. Additionally, if the first flotation cell in the flotation line has a relatively large volume, large subsequent flotation cells may not be necessary; instead, one or more flotation cells downstream of the first flotation cell can be smaller and therefore more efficient. In the flotation treatment of certain minerals, it may be easy to flotate a significant portion of high-grade ore particles containing valuable minerals. In this case, smaller flotation cells can be set up downstream of the flotation line, yet high recovery rates can still be achieved.

[0082] In one embodiment of the flotation cell according to the present invention, the flotation cell includes 2 to 40 injection tubes, preferably 4 to 24 injection tubes.

[0083] The number of injection nozzles directly affects the amount of flotation gas that can be dispersed in the slurry. In conventional foam flotation, an increased amount of dispersed flotation gas will lead to an increase in flotation bubble size. For example, in the Jameson cell, an air-to-bubble ratio of 0.50 to 0.60 is used. Increasing the average bubble size will adversely affect the bubble surface area flux (Sa). b This means that recovery may be reduced. In the flotation cell according to the invention, by using a pressurized injection pipe, significantly more flotation gas can be introduced into the process without increasing bubble size or reducing S. b This is because, compared to conventional processes, the flotation bubbles generated in the slurry feed are kept relatively small. On the other hand, by keeping the number of injection tubes as small as possible, the cost of retrofitting existing flotation cells or the capital expenditure for setting up such cells can be kept under control without causing any loss of flotation performance.

[0084] In one embodiment of the flotation cell, the injection pipe is arranged co-centered with the periphery of the flotation cell at a distance from the foam plug.

[0085] The exact number of injection tubes in a flotation cell can depend on the size or volume of the flotation cell, the type of material to be collected, and other process parameters. By arranging a sufficient number of injection tubes in the flotation cell, and by arranging the injection tubes in a specific manner relative to the center, periphery, and / or sidewalls of the flotation cell, as well as from the foam plug, it is possible to ensure a uniform distribution of microbubbles and a uniform mixing effect caused by the shear forces within the fixed cell.

[0086] In one embodiment of the flotation cell, the flotation cell also includes a regulating loop.

[0087] In another embodiment of the flotation cell, the regulating circuit includes a pump tank in fluid communication with the flotation cell, in which a portion of the slurry taken out from the flotation cell via an outlet is arranged in combination with the new slurry feed to form a slurry feed.

[0088] In another embodiment of the flotation cell, the outlet is located on the side wall of the flotation cell at a certain distance from the bottom of the flotation cell.

[0089] In another embodiment of the flotation cell, the distance from the outlet to the bottom of the flotation cell is 0% to 50% of the height of the flotation cell.

[0090] In another embodiment of the flotation cell, the regulating circuit further includes a pump arranged to draw slurry from the flotation cell and to transport the slurry feed forward from the pump tank.

[0091] In another embodiment of the flotation cell, the regulating loop further includes a distribution unit arranged to distribute the slurry feed.

[0092] By obtaining the slurry from the bottom of the flotation cell, it can be ensured that finer particles settling to the bottom of the flotation cell can be effectively reintroduced into the portion of the flotation cell where effective flotation processing takes place before being entrained in the tailings. Therefore, the recovery rate of valuable materials can be improved because particles containing even minimal amounts of valuable material can be captured into the concentrate.

[0093] Flotation processing can be made more efficient by recycling only a portion of the slurry from the flotation cell back to the same cell via a jet pipe as slurry feed. In particular, because the impactor (designed to guide the slurry flow radially outward and upward to create turbulent conditions for the mixing zone and additional mixing sub-zones, as explained earlier) very effectively creates favorable conditions for the formation of flotation bubble-particle agglomerates and thus ensures efficient recovery of particles containing valuable material, it is unnecessary to recycle large quantities of slurry for reprocessing in the same flotation cell. Treating tailings from another flotation cell in one cell is sufficient to ensure high recovery. Due to the possibility of short-stream particles containing valuable material entering the tailings / underflow, it is unnecessary to recycle a portion of the slurry from the flotation cell, or only a small portion may need to be recycled to improve recovery in this way.

[0094] The jet pipes and, in particular, the impactors can create favorable conditions for particle recovery. The flotation cells can be arranged to process only new slurry, i.e., slurry feed from previous flotation cells or previous processing steps. It is not necessary to recirculate the slurry from the flotation cell for further processing in the same cell; however, any particles containing valuable material remaining in the slurry portion descending towards the bottom of the cell can be directed to subsequent flotation cells for further processing, and the recovery of valuable material is still improved by the present invention.

[0095] In one embodiment of the flotation line according to the invention, the flotation cell according to the invention is preceded by a flotation cell. The preceding flotation cell can be of any suitable type.

[0096] In one embodiment of the flotation line, a mechanical flotation cell precedes the flotation cell according to the invention.

[0097] In another embodiment of the flotation line, the flotation line includes: a roughing section with flotation cells; a scavenging section with flotation cells arranged to receive underflow from the roughing section; and a scavenging cleaning section with flotation cells arranged to receive overflow from the scavenging section, wherein the last flotation cell of the scavenging section and / or the scavenging cleaning section is a flotation cell according to the invention.

[0098] In another embodiment of the flotation line, a mechanical flotation cell precedes the flotation cell according to the invention.

[0099] One embodiment of the use of the flotation line according to the invention is specifically used for recovering mineral ore particles containing non-polar minerals (e.g., graphite, sulfur, molybdenite, coal, and talc).

[0100] Reverse flotation can improve the treatment of slurries used for the recovery of industrial minerals such as bentonite, silica, gypsum, or talc. In recovering industrial minerals, the goal of flotation may be, for example, to remove dark-colored particles into the overflow and to recover white particles into the receiving underflow. In this process, some lighter and finer white particles may end up in the overflow. Those particles can be effectively recovered using the invention according to this disclosure. In reverse flotation, particles containing unwanted material are removed from the slurry by arranging air bubbles to adhere to those particles and removing them from the flotation cell in the overflow, while particles containing valuable material are recovered in the underflow, thus reversing the receiving flow of conventional flotation into the overflow and the overflow into the underflow. Typically, in reverse flotation, the large mass pull of worthless material can cause significant problems in controlling the flotation process.

[0101] One embodiment of the use of the flotation line according to the invention is specifically used for recovering particles containing polar minerals.

[0102] One embodiment of the use of flotation lines is specifically for recovering particles from minerals with a Mohs hardness of 2 to 3 (e.g., galena, sulfide minerals, PGM minerals, and / or REO minerals).

[0103] Another embodiment of the use of flotation lines is specifically for the recovery of particles containing Pt.

[0104] One embodiment of the use of flotation lines is specifically for recovering Cu-containing particles from minerals with a Mohs hardness of 3 to 4.

[0105] Another embodiment of the use of flotation lines is specifically for recovering Cu-containing particles from low-grade ores.

[0106] Valuable minerals can be, for example, Cu, or Zn, or Fe, or pyrite, or metallic sulfides such as gold sulfide. According to different aspects of the invention, mineral ore particles containing other valuable minerals can also be recovered, such as Pb, Pt, PGM (platinum group metals Ru, Rh, Pd, Os, Ir, Pt), oxide minerals, industrial minerals such as Li (i.e., spodumene), petalite, and rare earth minerals.

[0107] For example, during copper recovery from low-grade ore obtained from lean mineral deposits, the amount of copper by weight may be as low as 0.1% of the feed (i.e., the slurry feed into the flotation line). The flotation line according to the invention is very practical for copper recovery because copper is a mineral that can be readily floated. A relatively high grade can be obtained from the first flotation cell of the flotation line during the liberation of copper-containing ore particles. Recovery can be further improved using the flotation cell according to the invention.

[0108] By using the flotation apparatus according to the invention, the recovery of such small amounts of valuable minerals (e.g., copper) can be effectively increased, and even lean deposits can be utilized economically and efficiently. Since known rich deposits are increasingly being used, there is also a pressing need to address less desirable deposits that may have been previously unexploited due to a lack of suitable technology and processes for recovering very low amounts of valuable material from the ore. Attached Figure Description

[0109] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this specification, illustrate embodiments of the disclosure and, together with the specification, help to explain the principles of the disclosure. In the drawings:

[0110] Figure 1 This is a 3D projection of a flotation cell according to an embodiment of the present invention.

[0111] Figure 2 The flotation cell is shown as viewed from above according to an embodiment of the invention.

[0112] Figure 3 A flotation cell according to an embodiment of the present invention is shown in a side view.

[0113] Figure 4 yes Figure 3 The vertical section along section AA of the flotation cell.

[0114] Figure 5 This is a schematic diagram of a flotation cell according to the present invention, which shows in detail the dimensions of the flotation cell.

[0115] Figure 6a and 6b This is a schematic diagram of a flotation line according to an embodiment of the present invention.

[0116] Figure 7 A schematic vertical cross-section of an embodiment of a flotation cell according to the present invention is shown, and

[0117] Figure 8 This is a schematic diagram of the bottom structure according to an embodiment of a flotation cell. Detailed Implementation

[0118] Reference will now be made specifically to embodiments of this disclosure, examples of which are illustrated in the accompanying drawings.

[0119] The following description discloses in detail some embodiments to enable those skilled in the art to utilize flotation cells, flotation lines, and their uses based on this disclosure. Not all steps of the embodiments are specifically discussed, as many steps will be obvious to those skilled in the art based on this disclosure.

[0120] For the sake of simplicity, in the case of repeated components, the component reference numerals will be retained in the following exemplary embodiments.

[0121] Appendix Figure 1-5 Figures 7 and 8 show flotation cell 1 in more detail. The figures are not drawn to scale, and many components of flotation cell 1 are omitted for clarity. Figures 6a-6b An embodiment of a flotation line is illustrated schematically. The direction of the slurry flow is indicated by arrows in the figure.

[0122] The flotation cell 1 according to the invention is intended for processing mineral ore particles suspended in a slurry and for separating the slurry into an underflow 400 and an overflow 500, the overflow 500 comprising a concentrate of the desired mineral.

[0123] The tailings are removed from or the underflow 400 is drawn out of the flotation cell via tailings outlet 140. According to one embodiment, tailings outlet 140 may be located on the side wall 14 of flotation cell 10 (see [link to embodiment]). Figure 4 The tailings outlet 140 may be located at a distance L6 from the bottom 13 of the flotation cell 10 on the side wall 14 of the flotation cell 10. This distance should be understood as the distance from the lowest point of the tailings outlet 140 or outlet opening in the side wall 14 of the flotation cell 10 to the bottom 13 of the cell. The distance L6 may be 1% to 15% of the height H of the flotation cell 10. For example, the distance L6 may be 2%, 5%, 7.5%, or 12% of the height H. Alternatively, the tailings outlet 140 may be located at the bottom 13 of the flotation cell 10 (see...). Figure 1 The tailings outlet 140 can be controlled by a dart-type valve or by any other suitable means known in the art to control the flow rate of the underflow from the flotation cell 10. Even if the tailings outlet 140 is controlled by an internal or external structure (e.g., an upflow or downflow dart box, respectively), the tailings outlet 140 is ideally located in the lower portion of the flotation cell 10, i.e., close to or adjacent to the bottom 13 of the flotation cell, or even located at the bottom 13 of the flotation cell 10. More specifically, the underflow 400 or tailings are removed from the lower portion of the flotation cell 10 and from or near the sidewall 14 of the flotation cell 10.

[0124] Special reference Figure 1-5The flotation cell 1 includes a flotation cell 10, which has a center 11, a periphery 12, a bottom 13, and sidewalls 14. The flotation cell 1 also includes a flow channel 2 and a flow channel edge 21 surrounding the periphery 12 of the flotation cell 10.

[0125] In the accompanying drawings, channel 2 is a peripheral channel. It should be understood that, as is known in the art, channel 2 may alternatively or additionally include a central channel arranged at the center 11 of the flotation cell 10. The edge of the central channel may face the periphery 12 of the flotation cell 10, or the center 11 of the flotation cell 10, or both the periphery 12 and the center 11 of the flotation cell 10. Overflow 500 is captured from the foam layer formed in the upper portion of the flotation cell 10 into channel 2 or multiple channels as it passes through the channel edge 21. The foam layer includes an open foam surface A located at the top of the flotation cell 10. f .

[0126] The flotation cell 10 has a height H, measured as the distance from the bottom 13 of the flotation cell 10 to the edge 21 of the flow channel. At the periphery 12 of the flotation cell 10, the height H is substantially equal to or greater than the height H at the center 11 of the flotation cell 10. In other words, the flotation cell 10 can have different vertical profiles (see...). Figure 7 For example, the sidewall 14 of the flotation cell 10 may include a portion that slopes toward the center 11 of the flotation cell 10 in its lower portion.

[0127] Furthermore, the flotation cell 10 has a diameter D measured at a distance h1 from the outlet nozzle 43 to the bottom 13 of the flotation cell 10. In one embodiment, the ratio H / D of the height H of the flotation cell 10 is 0.5 to 1.5.

[0128] Flotation cell 10 can have at least 20 m 3 The volume of the flotation cell 10 can be between 20 m³. 3 Up to 1000 m 3 The volume between them. For example, the volume of flotation cell 10 can be 100 m³. 3 or 200 m 3 or 450 m 3 or 630 m 3 .

[0129] The flotation cell 10 includes an injection pipe 4 for introducing slurry feed 100 into the flotation cell 10. The injection pipe 4 includes an inlet nozzle 41 for feeding slurry feed 100 into the injection pipe 4; an inlet 42 for pressurizing air or other gas so that slurry feed 100 can be subjected to pressurized air or other gas as it is discharged from the inlet nozzle 41; an elongated chamber 40 arranged to receive slurry feed 100 under pressure; and an outlet nozzle 43 configured to restrict the flow of slurry feed 100 from the outlet nozzle 43 and to maintain the slurry feed in the elongated chamber 40 under pressure.

[0130] The flotation gas is entrained by turbulent mixing caused by the jet, and is dispersed into small bubbles in the slurry feed 100 as it travels downward through the elongated chamber 40 to the outlet nozzle 43, which is configured to restrict the flow of the slurry feed 100 from the outlet nozzle 43 and is also configured to maintain the slurry feed under pressure in the elongated chamber 40.

[0131] According to one embodiment, the outlet nozzle 43 can also be configured to generate a supersonic shock wave in the slurry feed, which causes the formation of flotation bubble-particle agglomerates. For example, the outlet nozzle 43 can generate a supersonic shock wave in the slurry feed 100 as it exits the injection tube 40. Furthermore, the supersonic shock wave can extend to or around the slurry adjacent to the outlet nozzle, making it possible to generate small-sized flotation bubble-particle agglomerates even outside the injection tube.

[0132] To restrict flow, the outlet nozzle 43 may include a throttle valve, such as a throat-like constriction structure. The slurry feed 100 flows under pressure from the outlet nozzle 43, and more specifically from the throttle valve, into the flotation cell 10.

[0133] As the slurry feed 100 passes through the outlet nozzle 43 or through a throttle valve of the outlet nozzle 43, the size of the flotation bubbles decreases due to pressure changes and the high shear environment downstream of the outlet nozzle 43. When the flow becomes resistant, the velocity of the gas-liquid mixture in the outlet nozzle 43 or the throttle valve may exceed the speed of sound, and the flow downstream of the throttle valve becomes supersonic, forming a shock wave in the bifurcation portion of the outlet nozzle 43. In other words, the outlet nozzle 43 is configured to induce a supersonic shock wave in the slurry feed 100.

[0134] When the pressure ratio between the absolute pressure upstream of the outlet nozzle 43 and the absolute pressure downstream of the limiting structure of the outlet nozzle 43 exceeds a critical value, the flow of the slurry feed 100 becomes obstructed. When the pressure ratio is higher than the critical value, the flow of the slurry feed 100 downstream of the limiting structure of the outlet nozzle 43 becomes supersonic and forms a shock wave. Small flotation bubbles in the slurry feed 100 mixture are compressed by the shock wave and split into even smaller bubbles, and are forced to contact the hydrophobic ore particles in the slurry feed 100, thereby generating flotation bubble-ore particle agglomerates.

[0135] The outlet nozzle 43 can be positioned within the flotation cell 10 at a desired depth. The outlet nozzle 43 can be positioned at a vertical distance L5 from the edge 21 of the flotation cell, where L5 is at least 1.5 m. In other words, the length of the portion of the injection pipe 4 positioned inside the flotation cell 10 below the horizontal height of the edge 21 is at least 1.5 m. In one embodiment, the distance L5 is at least 1.7 m, and the distance h1 from the outlet nozzle 43 to the bottom 13 of the flotation cell 10 is at least 0.4 m. For example, the distance L5 can be 1.55 m, 1.75 m, 1.8 m, 2.2 m, 2.45 m, or 5.25 m; and regardless of the distance L5, the distance h1 can be 0.45 m, 0.55 m, 0.68 m, 0.9 m, or 1.2 m. Moreover, the ratio of the distance L5 to the height H of the flotation cell 10 can be 0.9 or lower. The depth at which the injection pipe 4 is positioned within the flotation cell 10 can depend on many factors, such as the characteristics of the slurry and / or valuable minerals to be processed in the flotation cell 1, or the construction of the flotation line in which the flotation cell 1 is arranged. The ratio h1 of the distance h1 from the outlet nozzle 43 to the bottom 13 of the flotation cell 10 to the height H of the flotation cell 10, h1 / H, can be from 0.1 to 0.75.

[0136] The diameter of the outlet nozzle 43 can be 10% to 30% of the diameter of the elongated chamber 40 of the injection pipe 4. The diameter of the outlet nozzle 43 can be 40 mm to 100 mm. For example, the diameter of the outlet nozzle 43 can be 55 mm, 62 mm, or 70 mm.

[0137] By arranging the outlet nozzle with a specific diameter, the slurry feed velocity can be maintained at a level that favors the generation of small flotation bubbles and the contact between these bubbles and ore particles in the slurry. Specifically, to maintain the shock wave following the outlet nozzle, a slurry velocity of 10 m / s or higher is required. The impact of slurry feed flow rate on different types of flotation cells can be addressed by designing the outlet nozzle relative to the jet pipe size.

[0138] The injection pipe 4 may also include an impactor 44 configured to contact the slurry feed 100 flow from the outlet nozzle 43 and to guide the slurry feed 100 flow radially outward and upward from the impactor 44. The slurry feed 100 exiting the outlet nozzle 43 is thus guided to contact the impactor 44. The distance L3 from the bottom 440 of the impactor 44 to the outlet nozzle 43 can be 2 to 20 times the diameter of the outlet nozzle 43. For example, the distance L3 can be 5, 7, 12, or 15 times the diameter of the outlet nozzle 43.

[0139] The ratio L3 / h1 of the distance L3 to the distance h1 from the outlet nozzle 43 to the bottom 13 of the flotation cell 10 can be less than 1.0. Furthermore, the distance h3 from the bottom 440 of the impactor 44 to the bottom 13 of the flotation cell 10 can be at least 0.3 m. For example, the distance h3 can be 0.4 m, 0.55 m, 0.75 m, or 1.0 m.

[0140] The impactor 44 may include an impact surface for contacting the slurry feed 100 stream exiting the outlet nozzle 43. The impact surface may be made of a wear-resistant material to reduce the need for replacement or maintenance.

[0141] The slurry (essentially a gas-liquid two-phase mixture) rising from the impactor 44 enters the upper portion of the flotation cell 10, and flotation bubbles rise and separate from the liquid to form a foam layer. The foam rises and, as overflow 500, is discharged over the trough edge 21 into the trough 2 and then from the flotation cell 1. The tailings or underflow 400, from which the desired material has been substantially removed, exits the flotation cell 10 through an outlet located at or near the bottom 13 of the flotation cell 10.

[0142] Due to the aggregation of bubbles in the foam, some coarse hydrophobic particles carried into the foam may subsequently separate from the flotation bubbles and fall back into the flotation cell 10. However, most of these particles fall back into the flotation cell 10 in such a manner and location that they can be captured by bubbles newly entering the flotation cell 10 from the injection pipe 4 and carried back into the foam layer.

[0143] 2-40 or 4-24 injection pipes 4 can be arranged in the flotation cell 1. In one embodiment, there are 16 injection pipes 4. In another embodiment, there are 24 injection pipes 4. In yet another embodiment, there are 8 injection pipes 4. The exact number of injection pipes 4 can be selected based on specific operations (e.g., the type of slurry being processed in the flotation cell 1, the volumetric feed rate to the flotation cell 1, the mass throughput to the flotation cell 1, or the volume or size of the flotation cell 10). Four to six injection pipes 4 can be used to properly disperse the flotation gas within the flotation cell 10.

[0144] The injection pipes 4 can be arranged concentrically with the periphery 12 of the flotation cell 10 at a certain distance from the center 11 of the flotation cell 10. This may be the case when the cross-section of the flotation cell 10 is circular. The injection pipes 4 can also be arranged such that each injection pipe 4 is located at a distance L1 from the center 11 of the flotation cell 10 to the outlet nozzle 43, said distance being preferably equal for each injection pipe 4. For example, the distance L1 can be 10% to 40% of the diameter D of the flotation cell 10. Depending on different embodiments of the flotation cell 1, the distance L1 can be 12.5%, 15%, 25%, or 32.5% of the diameter D of the flotation cell 10.

[0145] The injection pipe 4 can be arranged parallel to the sidewall 14 of the flotation cell 10 at a certain distance from the sidewall 14. This may be the case when the cross-section of the flotation cell 10 is rectangular. The distance L2 between the outlet nozzle 43 of the injection pipe 4 and the sidewall 14 of the flotation cell 10 can be 10% to 40% of the diameter D of the flotation cell 10. In one embodiment, the distance L2 is 25% of the diameter D of the flotation cell 10. Depending on different embodiments of the flotation cell 10, the distance L2 can be 12.5%, 15%, 27%, or 32.5% of the diameter D of the flotation cell 10. Alternatively, the parallel injection pipes 4 can also be arranged in a straight line within the flotation cell 10.

[0146] Moreover, in all the above embodiments, the injection pipes 4 can be arranged at equal distances from each other, such that the distance between any two adjacent outlet nozzles 43 is the same.

[0147] A portion 300 of slurry can be removed from the flotation cell 10 via an outlet 31 located on the sidewall 14 of the flotation cell 10. This portion 300 of slurry is recycled back to the injection pipe 4 as feed slurry. In one embodiment, the slurry feed 100 comprises 40% or less of the portion 300 of slurry. In another embodiment, the slurry feed 100 comprises 50% or less of the portion 300 of slurry. For example, the slurry feed may comprise 5%, or 12.5%, or 20%, or 30%, or 45% of the portion 300 of slurry. Alternatively, the slurry feed 100 may comprise 0% of the portion 300 of slurry, meaning that the slurry removed from the flotation cell 10 is not recycled back to the flotation cell, but rather the slurry feed 100 comprises 100% new slurry 200, which may be from a previous flotation cell (i.e., from the underflow 400 of a previous flotation cell) or from a previous processing step.

[0148] The slurry portion 300 can be recycled to all the injection tubes 4 of the flotation cell 10, or alternatively to some injection tubes 4, while the other injection tubes 4 receive new slurry 200, which includes the underflow 400 from a previous flotation cell or a slurry flow from a previous processing step, depending on the location of the flotation cells 1 within the flotation line 8. The outlet 31 can be arranged at a distance L4 from the bottom 13 of the flotation cell 10. This distance should be understood as the distance from the lowest point of the outlet or outlet opening in the sidewall 14 of the flotation cell 10 to the bottom 13 of the cell. The distance L4 is 0% to 50% of the height H of the flotation cell 10. The outlet 31 can be advantageously located in a settling zone where particles suspended in the slurry but not captured by flotation bubbles and / or the upward slurry flow descend toward the bottom 13 of the flotation cell 10. In one embodiment, the outlet 31 is arranged in the lower portion of the flotation cell 10. For example, the distance L4 can be 2%, 8%, 12.5%, 17%, or 25% of the height H of the flotation cell 10. Even if the outlet 31 is controlled by an internal or external structure (e.g., an upflow or downflow dartbox), the outlet 31 is ideally located in the lower portion of the flotation cell 10, i.e., close to or adjacent to the bottom 13 of the flotation cell. More specifically, the pulp portion 300 is removed from the lower portion of the flotation cell 10.

[0149] Flotation cell 10 further includes a foam plug 6, which is shaped to guide the open foam surface A toward the flow channel edge 21. f The foam in the middle, or towards the open foam surface A f The froth layer 5 guides the rising flotation bubbles-ore particle aggregation stream (see in particular). Figure 4 The foam plug 6 can be a central foam plug 61 or an internal peripheral plug 62, which is arranged in the flotation cell 10 at a desired depth on the side wall 14 of the flotation cell 10.

[0150] The central foam plug 61 is arranged co-centered with the center 11 of the flotation cell 10. The central foam plug 61 can have a conical or truncated conical shape. The central foam plug 61 can also have a pyramidal or truncated pyramidal shape. In other words, the vertical cross-section of the central foam plug 61 can be an inverted triangle, with the apex pointing towards the bottom 13 of the flotation cell. If the central foam plug 61 has a truncated structure or shape, the apex is merely functional; that is, it will be considered the lowest point of the structure or shape as it continues into its complete untruncated form, thereby identifying the included angle α, regardless of the actual shape or form of the central foam plug. The included angle α can be from 20 to 80°. For example, the included angle α can be 22°, or 37.5°, or 45°, or 55°, or 63.75°, or 74°. In one embodiment, the central foam plug 61 is arranged to block the open foam surface A.f 25% to 40%.

[0151] As an alternative to or supplement to the central foam plug 61, the flotation cell may include an internal peripheral plug 62 disposed in the sidewall 14 of the flotation cell 10 such that the lowest point 620 of the internal peripheral plug is located at a distance h2 from the bottom 13 of the flotation cell 10. The distance h2 may be 1 / 2 to 2 / 3 of the height H of the flotation cell 10. The internal peripheral plug 62 may be formed to include a diagonal inlet 14c starting from the lowest point 620, angled toward the center 11 of the flotation cell 10, and extending between a first portion 14a and a second portion 14b of the sidewall 14 of the flotation cell 10, such that the angle β of the diagonal inlet 14c relative to the first portion 14a of the sidewall 14 is 20 to 80°. The angle β may be, for example, 22°, or 37.5°, or 45°, or 55°, or 63.75°, or 74°. The internal peripheral plugging component 62 can be arranged to block the slurry area A at the mixing zone A. p The slurry area A is measured at a distance h1 from the bottom 13 of the flotation cell 10, at 1 / 5 to 1 / 4 of the distance from the outlet nozzle 43 of the injection pipe 4. p The mixing zone A (i.e., the vertical portion or area of ​​the flotation cell where the slurry is agitated or otherwise induced to mix the ore particles suspended in the slurry with the flotation bubbles) generally surrounds the lower portion of the injection tube 4 and the impact bowl 44 formed in the vertical portion of the flotation cell 10 (see [reference]). Figure 5 ).

[0152] Additionally, the flotation cell 10 may further include a bottom structure 7 (see Figure 5 and 7 The bottom structure 7 is arranged on the bottom 13 and has a shape that allows particles suspended in the slurry to mix in the mixing zone A formed on the bottom structure 7 and to settle in the settling zone surrounding the bottom structure 7.

[0153] The shape of the bottom structure 7 can be defined as follows (see Figure 8The vertical cross-section of the bottom structure can be understood as presenting the form of a functional triangle 700, which includes a first (top) vertex 71 pointing away from the bottom 13 of the flotation cell 10; a second vertex 71a; and a third vertex 71b, the latter two vertices being arranged at the bottom 13 of the flotation cell 10. A first side a is formed between the first vertex 71 and the second vertex 71a. A second side b is formed between the first vertex 71 and the third vertex 71b. A base c is formed between the second vertex 71a and the third vertex 71b, and thus the base c is parallel to and located on the bottom 13 of the flotation cell 10. The central axis 70 of the functional triangle 700 is approximately concentric with the center 11 of the flotation cell 10. In this document, "approximately" should be understood as meaning that a slight deviation from the center 11 of the flotation cell 10 may naturally occur during the manufacture and / or installation of the bottom structure 7. However, the aim is for the two axes (i.e., the central axis 70 of the functional triangle (which is also the central axis of the bottom structure 7) and the central axis of the flotation cell 10) to be coaxial.

[0154] The base angle α between the first side a and the base c (and / or between the second side b and the base c) with respect to the bottom 13 of the flotation cell 10 is between 20° and 60°. For example, angle α can be 22°, or 27.5°, or 35°, or 45°, or 53.75°. Furthermore, the included angle β between the first side a and the second side b is between 20° and 100°. Preferably, the included angle β is between 20° and 80°. For example, the included angle β can be 22°, or 33.5°, or 45°, or 57.75°, or 64°, or 85.5°. Therefore, the functional triangle can be an isosceles triangle or an equilateral triangle.

[0155] The functional triangle is essentially a form that can be determined by the above features regardless of the actual form of the bottom structure 7. The actual form of the bottom structure 7 can be, for example, conical, truncated conical, pyramidal, or truncated pyramidal, depending on the cross-section and other structural details of the flotation cell 10. A conical or truncated conical shape can be a form suitable for flotation cells with a circular cross-section. A pyramidal or truncated pyramidal shape can be a form suitable for flotation cells with a rectangular cross-section.

[0156] The bottom structure 7 includes a base 73, which corresponds 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 bottom structure 7), and is arranged on the bottom 13 of the flotation cell 10. Furthermore, the bottom structure includes a cover 72. The cover 72 is defined at least by the first vertex 71, the second vertex 71a, and the third vertex 71b of the functional triangle 700. Therefore, regardless of the actual form of the bottom structure 7, the functional 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 form but is still rotationally symmetric, the bottom structure 7 will fit entirely into the functional triangle 700 (see...). Figure 8 (The last radius). In one embodiment, the cover 72 is at least partially defined by a first side a and a second side b of a functional triangle. An example of this embodiment is a bottom structure 7 having a truncated conical form (see the last radius). Figure 8 (See the middle diagram). In one embodiment, the cover 72 is substantially entirely defined by the first side a and the second side b of the functional triangle 700, i.e., the bottom structure 7 has a conical shape (see the middle diagram). Figure 8 (The first picture).

[0157] The bottom structure 7 has a height h4 measured from its highest point to the bottom 13 of the flotation cell 10. If the bottom structure is conical or pyramidal, the highest point is also the first vertex 71 of the functional triangle 700. If the bottom structure 7 has a truncated form, the height h4 is measured from the horizontal top of the truncated form (see...). Figure 8 The height h4 is measured from the bottom 13 of the flotation cell 10 (intermediate view). Height h4 is greater than 1 / 5 and less than 3 / 4 of the height H of the flotation cell 10. Further, the diameter d3 of the base 73 of the bottom structure 7 can be 1 / 4 to 3 / 4 of the diameter d1 of the bottom 13 of the flotation cell 10. If the flotation cell 10 and / or the bottom structure 7 have a non-circular cross-section, the diameter is measured as the maximum diagonal of the corresponding portion (base 73 and bottom 13). In one embodiment, the surface area of ​​the base 73 of the bottom structure 7 is less than 80% of the surface area of ​​the bottom 13 of the flotation cell 10. The surface area of ​​the base 73 can be 25% to 80% of the surface area of ​​the bottom 13 of the flotation cell 10.

[0158] Furthermore, the volume occupied by the bottom structure 7 in the flotation cell 10 can be 30% to 70% of the volume occupied by the mixing zone A in the flotation cell 10.

[0159] The bottom structure 7 may additionally include any suitable support structure and / or connection structure located on the bottom 13 of the flotation cell 10 for mounting the bottom structure 7 into the flotation cell 10. The bottom structure 7 may be made of any suitable material such as metal (e.g., stainless steel).

[0160] Flotation cell 1 may also include a regulating loop 3. The regulating loop 3 may include a pump tank 30 or other such additional container in fluid communication with flotation cell 10. In the pump tank 30, the feed of slurry portion 300 and new slurry 200 taken from flotation cell 10 via outlet 31 is arranged to combine as slurry feed 100. The new slurry 200 may be, for example, underflow 400 from a previous flotation cell, or, if flotation cell 1 is the first flotation cell of a flotation line, slurry feed from a grinding unit / step or a sorting unit / step. It is also possible that slurry portion 300 and new slurry 200 are dispensed into injection pipe 4 without first combining in pump tank 30.

[0161] The combined slurry can be recycled to all the injection tubes 4 of the flotation cell 10, or alternatively to some injection tubes 4, while the other injection tubes 4 receive new slurry 200, which includes the underflow 400 from the previous flotation cell or the slurry flow from a previous processing step, depending on the location of the flotation cell 1 within the flotation line 8.

[0162] The outlet 31 can be located at a distance L4 from the bottom 13 of the flotation cell 10 on the side wall 14 of the flotation cell 10. The distance L4 can be 0% to 50% of the height H of the flotation cell 10. For example, the distance L4 can be 2%, 8%, 12.5%, 20%, or 33% of the height H of the flotation cell 10.

[0163] Additionally, the regulating circuit may include a pump 32 arranged to draw slurry portion 300 from the flotation cell 10 and to advance slurry feed 100 from the pump tank 30 to the jet tube 4. Slurry portion 300 may include particles with low settling velocities, such as slowly floating fine particles. The slurry portion may be removed from the bottom of the flotation cell 10 or from near the bottom of the flotation cell 10. Alternatively or additionally, the regulating circuit 3 may also include a distribution unit (not shown) arranged to distribute slurry feed 100 into the jet tube 4. Pump 32 may also be used to advance slurry feed 100 into the jet tube 4. To uniformly distribute slurry feed 100 into the jet tube 4, the distribution unit may be used. The distribution unit may, for example, include a feed pipe located inside the flotation cell 10 configured to directly distribute slurry portion 300 into the jet tube 4. For example, the distribution unit may include a conduit disposed outside the flotation cell 10 leading to a separate feed distributor configured to distribute slurry portion 300 or a combination of slurry portion 300 and new slurry 200 into the injection pipe 4.

[0164] According to another aspect of the invention, in Figure 6a and 6bThe flotation line 8 is shown. The flotation line 8 includes a plurality of fluidly connected flotation cells 1a, and at least one of the flotation cells is a flotation cell 1 according to the above-described embodiment of the flotation cell 1 according to the invention. In one embodiment of the flotation line 8, the flotation cell 1 according to the invention is preceded by a flotation cell 1a. The flotation cell 1a can have any type known in the art. Alternatively or additionally, the flotation cell 1 may be preceded by a mechanical flotation cell 1b (see [link to flotation line 8]). Figure 6a ).

[0165] In one embodiment of flotation line 8, flotation line 8 includes a roughing section 81 with flotation cells 1a; a scavenging section 82 with flotation cells 1a arranged to receive underflow 400 from the roughing section 81; and a scavenging cleaning section 820 with flotation cells 1a arranged to receive overflow 500 from the scavenging section 82 (see [link to documentation]). Figure 6b In flotation line 8, the last flotation cell 1 of the scavenging section 82, and alternatively or otherwise the last flotation cell 1 of the scavenging and cleaning section 820, is a flotation cell 1 with an injection pipe 4 according to the present invention. Additionally, in flotation line 8, as described above, the flotation cell 1 with an injection pipe 4 according to the present invention may precede a mechanical flotation cell 1b.

[0166] Before flotation line 8, other treatments may be performed, such as grinding, sorting, screening, heavy media treatment, coarse particle recovery treatment, spiral flotation, and other separation treatments; as well as other flotation treatments. After flotation line 8, various treatments may be performed, such as regrinding, cleaning or other flotation treatments, centrifugation, filtration, screening, or dewatering.

[0167] According to another aspect of the invention, flotation line 8 can be used to recover particles containing valuable materials suspended in a slurry. In one embodiment, this use may involve recovering particles containing non-polar minerals (e.g., graphite, sulfur, molybdenite, coal, talc).

[0168] According to another embodiment, the use may involve the recovery of particles containing polar minerals.

[0169] In another embodiment, the use relates to recovering particles from minerals with a Mohs hardness of 2 to 3 (e.g., galena, sulfide minerals, PGM, and / or REO minerals). In yet another embodiment, the use specifically relates to recovering particles containing platinum.

[0170] In another embodiment, the use relates to recovering copper-containing particles from mineral particles with a Mohs hardness of 3 to 4. In yet another embodiment, the use specifically relates to recovering copper-containing particles from low-grade ore.

[0171] The embodiments described above can be used in any combination with each other. Several embodiments can be combined together to form other embodiments. The flotation cell involved in this disclosure may include at least one of the embodiments described above. It will be apparent to those skilled in the art that the basic concept of the invention can be implemented in various ways as technology advances. Therefore, the invention and its embodiments are not limited to the examples described above; rather, they may vary within the scope of the claims.

Claims

1. A flotation cell (1) for treating particles suspended in a slurry and for separating the slurry into an underflow (400) and an overflow (500), the flotation cell comprising: The flotation cell (10) includes a center (11), a periphery (12), a generally horizontal and flat bottom (13), and sidewalls (14). The flow channel (2) surrounding the periphery (12) of the flotation cell (10) and the edge of the flow channel (21); The open foam surface (A) at the top of the flotation cell (10) f ); as well as Foam plug (6), which is shaped to guide the open foam surface (A) toward the channel edge (21). f The foam in (5), The flotation cell is characterized in that it further includes an injection pipe (4) for introducing slurry feed (100) into the flotation cell, the injection pipe comprising: Used to feed slurry feed (100) into the inlet nozzle (41) in the jet pipe; Inlet (42) for pressurized gas, the slurry feed is subjected to the pressurized gas as it is discharged from the inlet nozzle; An elongated chamber (40) is arranged to receive the slurry feed under pressure; and The outlet nozzle (43) includes a throttle valve and is configured to restrict the flow of slurry feed from the outlet nozzle and to maintain the slurry feed in the elongated chamber under pressure. The outlet nozzle (43) is configured to generate a supersonic shock wave in the slurry feed (100), which causes the formation of flotation bubble-particle agglomerates.

2. The flotation cell according to claim 1, characterized in that, The height (H) of the flotation cell (10), measured as the distance from the bottom (13) to the edge (21) of the flotation cell, is at least 20% lower at the periphery (12) of the flotation cell than at the center (11) of the flotation cell.

3. The flotation cell according to claim 1, characterized in that, The foam plug (6) is a conical central foam plug (61) arranged co-centered with the center (11) of the flotation cell.

4. The flotation cell according to claim 3, characterized in that, The central foam plug (61) is arranged to block the open foam surface (A). f 25% to 40%.

5. The flotation cell according to claim 3 or 4, characterized in that, The included angle (α) of the central foam plug (61) is 20° to 80°.

6. The flotation cell according to claim 1, characterized in that, The foam plug (6) is an internal peripheral plug (62) arranged in the side wall (14) of the flotation cell (10) such that the lowest point (620) of the internal peripheral plug is located at a distance (h2) from the bottom (13) of the flotation cell.

7. The flotation cell according to claim 6, characterized in that, The distance (h2) is 1 / 2 to 2 / 3 of the height (H) of the flotation cell (10), which is the distance measured from the bottom (13) to the edge of the flow channel (21).

8. The flotation cell according to claim 6 or 7, characterized in that, The internal peripheral plug (62) includes a diagonal inlet (14c) starting from the lowest point (620), the diagonal inlet being angled toward the center (11) of the flotation cell, and extending between a first portion (14a) and a second portion (14b) of the sidewall (14) of the flotation cell (10), such that the angle (β) of the diagonal inlet (14c) relative to the first portion (14a) of the sidewall is 20° to 80°.

9. The flotation cell according to claim 6 or 7, characterized in that, The internal peripheral plug (62) is arranged to block the slurry area (A) p The slurry area (A) is measured at a distance (h1) from the outlet nozzle (43) to the bottom (13) of the flotation cell (10), which is 1 / 5 to 1 / 4 of the total slurry area. p ).

10. The flotation cell according to claim 6, characterized in that, The flotation cell (10) also includes a central foam plug (61) arranged co-centered with the center (11) of the flotation cell.

11. The flotation cell according to claim 10, characterized in that, The central foam plug (61) is arranged to block the open foam surface (A). f 25% to 40%.

12. The flotation cell according to claim 10 or 11, characterized in that, The included angle (α) of the central foam plug (61) is 20° to 80°.

13. The flotation cell according to claim 1, characterized in that, The jet pipe further includes an impactor (44) configured to contact the slurry feed flow from the outlet nozzle (43) and to guide the slurry feed (100) flow radially outward and upward from the impactor.

14. The flotation cell according to claim 1, characterized in that, The ratio (H / D) of the height (H) of the flotation cell (10), which is the distance from the bottom (13) to the edge (21) of the flow channel, to the diameter (D) of the outlet nozzle (43) of the flotation cell at the height (h1) from the bottom (13), is 0.5 to 1.

5.

15. The flotation cell according to claim 1, characterized in that, The volume of the flotation cell (10) is at least 20 m³. 3 .

16. The flotation cell according to claim 15, characterized in that, The volume of the flotation cell (10) is 20 m³. 3 up to 1000m 3 .

17. The flotation cell according to claim 1, characterized in that, The flotation cell includes 2-40 injection tubes (4).

18. The flotation cell according to claim 17, characterized in that, The flotation cell includes 4-24 injection tubes.

19. The flotation cell according to claim 1, characterized in that, The injection pipe (4) is arranged at a certain distance from the foam plug (6) and is co-centered with the periphery (12) of the flotation cell (10).

20. The flotation cell according to claim 1, characterized in that, The flotation cell further includes a regulating loop (3).

21. The flotation cell according to claim 20, characterized in that, The regulating circuit includes a pump tank (30) in fluid communication with the flotation cell (10), in which a new slurry feed (200) and a portion (300) of slurry obtained from the flotation cell (10) via an outlet (31) are arranged to combine into a slurry feed (100).

22. The flotation cell according to claim 21, characterized in that, The outlet (31) is located at an outlet distance (L4) from the bottom (13) of the flotation cell (10) at the side wall (14) of the flotation cell (10).

23. The flotation cell according to claim 22, characterized in that, The outlet distance (L4) is 0% to 50% of the height (H) of the flotation cell (10), which is measured as the distance from the bottom (13) to the edge of the flow channel (21).

24. The flotation cell according to any one of claims 21 to 23, characterized in that, The regulating circuit (3) further includes a pump (32) arranged to draw the slurry portion (300) from the flotation cell (10) and to transport the slurry feed (100) forward from the pump tank (30).

25. The flotation cell according to any one of claims 20 to 23, characterized in that, The regulating circuit (3) further includes a distribution unit arranged to distribute slurry feed (100).

26. A flotation line (8) comprising multiple fluidly connected flotation cells, characterized in that, At least one flotation cell A in the flotation cells is a flotation cell according to any one of claims 1 to 25.

27. The flotation line according to claim 26, characterized in that, The preceding flotation cell A is a flotation cell B, which is different from the preceding flotation cell A.

28. The flotation line according to claim 26 or 27, characterized in that, The flotation cell A is preceded by a mechanical flotation cell (1b).

29. The flotation line according to claim 27, characterized in that, The flotation line includes: The roughing section with flotation cell B (81); A scavenging section (82) with flotation cell B is arranged to receive underflow (400) from the coarsening section; and A scavenging and cleaning section (820) with flotation cell B is arranged to receive overflow (500) from the scavenging section, wherein the last flotation cell of the scavenging section and / or the scavenging and cleaning section is flotation cell A according to any one of claims 1-25.

30. The flotation line according to claim 29, characterized in that, The flotation cell A is preceded by a mechanical flotation cell (1b).

31. Use of the flotation line (8) according to any one of claims 26 to 30 for recovering particles containing valuable materials suspended in a slurry.

32. The use according to claim 31, for recovering particles comprising nonpolar minerals.

33. The use according to claim 32, wherein the nonpolar mineral is graphite, sulfur, molybdenite, coal, or talc.

34. The use according to claim 31, for recovering particles comprising polar minerals.

35. The use according to claim 34, for recovering particles from minerals having a Mohs hardness of 2 to 3.

36. The use according to claim 35, wherein the mineral is a sulfide mineral, PGM, and / or REO mineral.

37. The use according to claim 35, for recovering particles including Pt.

38. The use according to claim 34, for recovering particles comprising Cu from minerals having a Mohs hardness of 3 to 4.

39. The use according to claim 38, for recovering Cu-containing particles from low-grade ore.

40. The use according to claim 35, wherein the mineral is galena.

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