EP2377620A1 - Gas injection device for a flotation cell - Google Patents

Abstract

The device (1''') has a container (2) with a gas inlet opening (2a) and a set of gas outlet openings (2b). A deflecting plate (4) is connected downstream to the container, and a gas-permeable sieve or grid-like component is arranged parallel to a plane of the plate between the outlet openings and the deflecting plate. A pipe section is connected to the container and provided for receiving gas emerging from the outlet openings. The component has sieve or grid-like openings with diameter ranging from 1 to 10 mm, where the container has an outer pipe (2c) closed at one side. Independent claims are also included for the following: (1) a flotation cell comprising a housing with a flotation chamber (2) a method for flotation of valuable material particles.

Description

The invention relates to a gassing device for a flotation cell, a flotation cell equipped with at least one such gassing device, and a method for flotation of valuable particles from a suspension.

Flotation is a physical separation process for separating fine-grained mixtures of solids, such as ores and gangue, in an aqueous slurry by means of air bubbles due to a different surface wettability of the particles contained in the suspension. It is used for the treatment of mineral resources and in the processing of preferably mineral substances with a low to moderate content of a useful component or a valuable material, for example in the form of non-ferrous metals, iron, metals of rare earths and / or precious metals and non-metallic mineral resources.

The WO 2006/069995 A1 describes a pneumatic flotation cell with a housing comprising a flotation chamber, with at least one nozzle arrangement, here referred to as ejectors, further with at least one gassing device, when using air aeration devices or aerators called, and a collecting container for a foam product formed during the flotation.

In pneumatic flotation, a suspension of water and fine-grained solid mixed with reagents is generally introduced into a flotation chamber via at least one nozzle arrangement. The purpose of the reagents is to ensure that, in particular, the valuable particles or valuable material particles which are preferably to be separated off are made hydrophobic in the suspension become. In most cases, xanthates are used as reagents, in particular to hydrophobize sulfidic ore particles selectively. Simultaneously with the suspension, the at least one nozzle arrangement is supplied with gas, in particular with air, which comes into contact with the hydrophobic particles in the suspension. The hydrophobic particles adhere to forming gas bubbles, so that the gas bubble structures, also called aeroflocs, float and form the foam product on the surface of the suspension. The foam product is discharged into a collecting container and usually thickened.

The quality of the foam product or the separation efficiency of the flotation process depends inter alia on the probability of collision between a hydrophobic particle and a gas bubble. The higher the probability of collision, the greater the number of hydrophobic particles that adhere to a gas bubble, rise to the surface and together with the particles form the foam product.

A preferred diameter of the gas bubbles is less than about 5 mm and is in particular in the range between 1 and 5 mm. Such small gas bubbles have a high specific surface area and are therefore able to bind and take up significantly more valuable material particles, in particular ore particles, per amount of gas used than larger gas bubbles are capable of doing.

In general, gas bubbles larger in diameter increase faster than gas bubbles of smaller diameter. The smaller gas bubbles are collected by larger gas bubbles and combine with them to even larger gas bubbles. This reduces the available specific surface of the gas bubbles in the suspension, can be bound to the valuable particles.

In columnar flotation cells in which a diameter of the flotation chamber is many times smaller than its height, the path which a gas bubble must travel in the suspension or the flotation chamber in order to reach the surface of the suspension is particularly large. Due to the particularly long way, particularly large gas bubbles are formed in the suspension. This reduces the specific discharge of valuable particles from the suspension and thus also the efficiency of the flotation cell.

In so-called hybrid flotation cells, which represent a combination of a pneumatic flotation cell with a columnar flotation cell, larger particulate matter having particle diameters in the range of 50 microns and larger are not completely bound to the existing gas bubbles and thus can only be partially separated from the suspension. Fines with particle diameters in the range of 20 microns and less, however, are particularly well deposited.

Gas bubbles having a diameter in the range from 1 to 5 mm are continuously present in a column-like flotation cell over the height of the flotation chamber, so that a reduction in the diameter of the gas bubbles generated in the lower region of the flotation chamber or by a gassing device in the flotation chamber is required. So far, in the flotation gassing with gas outlet openings are used, whose diameter is in the range of 3 to 5 mm and in columnar flotation cells to gas bubble formation with significantly large gas bubbles, in particular greater than 5 mm in diameter, lead.

A further reduction in the diameter of the gas outlet openings of gassing devices is hardly possible in practice. Thus, gas outlet openings with diameters of up to 1 mm on gassing devices easily clog, as long as usually suspensions with solids contents to be processed in the range of 30 to 40%. Even with short downtimes of the flotation cell particles from the suspension penetrate into the gas outlet openings and close them. When restarting the cell, the gas pressure of the gas to be introduced into the suspension is often insufficient to flush such small gas outlet openings of a gassing device freely again.

It is therefore an object of the invention to provide a gassing device improved to this effect, which is able to produce gas bubbles with a particularly small diameter, and further to provide a flotation cell with such a gassing device and a method for their operation.

The object is achieved by a gassing device for a flotation cell, comprising a vessel with at least one gas inlet opening and a number of gas outlet openings, as well as a, the vessel downstream baffle plate, and at least one arranged between the gas outlet openings and the baffle plate parallel to the plate plane of the baffle plate, gas-permeable sieve - or lattice-shaped component.

The screen or lattice-shaped component is arranged in the transport direction of the gas bubbles generated at the gas outlet openings. The gas bubbles pass through the sieve or grid-shaped component, whereby the gas bubbles are broken up. As a result, the diameter of the gas bubbles, regardless of the diameter of the gas outlet openings, reduced. The diameters of the gas outlet openings of the gassing device according to the invention can therefore be chosen so large that clogging by particles from the suspension is reliably avoided at all times, for example in the range of at least 3 mm, in particular in the range of 3 to 5 mm. Depending on which screen or lattice-shaped component or which mesh size is selected for the component, exclusively gas bubbles are present over the entire height of the flotation chamber in the suspension with a diameter in the range of 1 to 5 mm, which allow optimal separation of the valuable material particles and a high yield.

The baffle plate of the at least one gassing device is preferably arranged in the flotation chamber of the flotation cell above the vessel of the at least one gassing device. Due to the buoyancy, the gas bubbles formed at the gas outlet openings move upwards in the direction of the baffle plate.

In particular, a center of the baffle plate and a center of the at least one screen or lattice-shaped component are arranged on a longitudinal axis LA of the vessel.

In a preferred embodiment of the invention, the gassing device has a tube section adjoining the vessel for receiving gas exiting via the gas outlet openings, wherein the baffle plate is assigned to an end of the tube section facing away from the vessel and its plate plane is oriented perpendicular to a tube longitudinal axis of the tube section, wherein a center of the baffle plate and a center of the at least one screen or lattice-shaped component lie on the tube longitudinal axis. In a flotation cell, the suspension penetrates into the tube section of the gassing device and gas emerging from the gas outlet openings is mixed with the suspension in the tube section.

It has proven useful if the gassing device has at least two screen or lattice-shaped components. These are preferably connected in series in such a way that the gas bubbles must successively pass through all existing sieve or lattice-shaped components and at least part of them are divided into smaller gas bubbles at each of the components. It is advantageous if with increasing distance of a screen or lattice-shaped component of the gas outlet openings decrease the mesh sizes of the components.

Furthermore, it is advantageous if viewed in the ascent direction of the gas bubbles, the meshes of the at least two screen or lattice-shaped component not arranged congruent to each other, but rather offset or rotated to each other. As a result, the probability that a gas bubbles already divided at a first screen or lattice-shaped component is divided a further time on a subsequent screen-like or latticed component is significantly increased.

In this case, a screen or lattice-shaped component is advantageously arranged in the optionally present pipe section and / or at the end of the optional pipe section facing away from the vessel and covers a pipe cross-section of the pipe section as seen in the direction of the pipe longitudinal axis.

In a preferred embodiment, at least one modified baffle plate with an opening is present between the vessel and the baffle plate, optionally between the tube section and the baffle plate, wherein a screen or lattice-shaped component is inserted into the opening. Preferably, the opening is arranged centered to the pipe longitudinal axis of the optionally existing pipe section.

In this case, at least one modified baffle plate comprising a screen or lattice-shaped component and at the same time at least one further screen or lattice-shaped component, optionally in the region of the pipe section of the gassing device, be present.

It has proven useful if a diameter of the opening of the at least one modified baffle plate corresponds to at least one pipe diameter of the optionally present pipe section. As a result, a large part of the gas bubbles, which rise from the pipe section, passes through the sieve or lattice-shaped component of the modified impact plate (s).

Preferably, the screen or grid-shaped component comprises at least one screen element in the form of a braid, fabric, knitted fabric or knitted fabric. Alternatively or in combination, the screen or grid-shaped component may comprise at least one grid element, which is formed from connected tubes, rods or plates.

In particular, the screen or lattice-shaped component is formed from metal or plastic. In particular, metal wires or plastic fibers with diameters of up to 1 mm are used to form the sieve-like or latticed component in order to form as sharp as possible a separating edge for the impinging gas bubbles.

Particularly preferably, the screen or lattice-shaped component screen or grid openings with a diameter in the range of 1 to 10 mm. Impact gas bubbles of larger diameter are reliably cut.

In a particularly preferred embodiment of the invention, the vessel of the gassing comprises a closed on one side outer tube having the at least one gas inlet opening, and at least one closed inner tube, which has the gas outlet openings, wherein the at least one inner tube is disposed in the outer tube, and wherein a open end of the outer tube is gas-tightly connected to an open end of the at least one inner tube. Such an arrangement allows a particularly intensive fumigation of a suspension in a flotation cell.

The at least one gas inlet opening is in this case arranged in particular on the outer tube such that a radial feed of the gas takes place. This causes the gas along the circumference of the annular gap between the outer tube and inner tube is injected into this and does not bounce directly at right angles to the inner tube. In addition, the gas inlet opening is preferably arranged close to the region in which the open ends of the outer tube and of the inner tube are connected to one another are. This measure (s) lead to a good distribution of the gas in the annular gap and an intensive mixing with suspension in a flotation cell.

In a further preferred embodiment, the vessel comprises at least one vane, which are arranged in the region between the at least one gas inlet opening and the gas outlet openings and direct the injected gas in a desired direction. For example, a vessel comprising an inner tube and an outer tube may be formed with a vane such that the vane on the inside of the outer tube extends helically from one end to the other of the outer tube. But other arrangements of one or more vanes are possible depending on the design of the vessel.

Preferably, only an inner tube is present, which is arranged concentrically to the outer tube. This simplifies the design and lowers the manufacturing cost of the gassing device. Preferably, an optionally existing pipe section and the inner tube have an identical outer and inner diameter and are arranged in alignment with each other.

In a particularly preferred embodiment of the invention, the inner tube has at least one gas outlet opening per square centimeter. The diameter of a gas outlet opening is preferably in the range of 1 to 5 mm.

The object is achieved for the flotation cell by comprising a housing with a flotation chamber, at least one nozzle arrangement for supplying gas and a suspension into the flotation chamber and at least one gasification device according to the invention for further supply of gas into the flotation chamber, which in the flotation below the at least one nozzle arrangement is arranged such that a longitudinal axis of the gassing device, which passes through the center of the baffle plate, is vertically aligned.

The flotation cell according to the invention ensures a high separation efficiency and thus a yield of recyclable particles since the setting of suitable diameters of the gas bubbles in the entire flotation chamber can be achieved by means of the at least one gassing device. The flotation cell is preferably a columnar flotation cell in which a diameter of the flotation chamber is many times smaller than its height. In particular, it is a hybrid flotation cell formed by a columnar flotation cell combined with a pneumatic flotation cell. The effect of formation of gas bubbles of excessive diameter, which is reinforced here due to the columnar construction of these flotation cells, is reliably counteracted by means of the gassing device according to the invention. Already existing flotation cells can be equipped in a simple manner with at least one gassing device according to the invention and thereby their performance can be increased.

The housing of the flotation cell has, in a preferred embodiment, a cylindrical housing section whose axis of symmetry is arranged vertically. Gas supply lines, which supply the at least one gassing device with gas, are preferably led through the housing.

As gas which is introduced into a flotation chamber in a pneumatic flotation cell by means of the gassing device and / or the nozzle arrangement, preference is given to using air or nitrogen.

The object is further for the process for flotation of valuable particles, in particular ore minerals, from a suspension having a solids content in the range of 30 to 40% dissolved to form a foam product by means of a flotation cell according to the invention. Such high solids contents do not lead to clogging of the gas outlet openings of the gassing device, since their gas outlet openings can be dimensioned correspondingly large in the presence of a sieve or lattice-shaped component.

In particular, a suspension comprising particles having a maximum particle diameter is floated, in which a ratio of the maximum particle diameter of the particles to a mesh size of the screen or grid openings of the at least one screen or lattice-shaped component is in the range from 1: 5 to 1:10. This ensures that the at least one sieve or lattice-shaped component can not be clogged by particles of the suspension.

FIG 1

eine erste Begasungseinrichtung in der Vorderansicht;

FIG 2

die erste Begasungseinrichtung gemäß FIG 1 im Teil-Längsschnitt;

FIG 3

die erste Begasungseinrichtung gemäß FIG 1 und FIG 2 im Schnitt III - III;

FIG 4

die erste Begasungseinrichtung gemäß FIG 1 und FIG 2 im Schnitt IV - IV;

FIG 5

eine zweite Begasungseinrichtung im Teil-Längsschnitt;

FIG 6

die zweite Begasungseinrichtung gemäß FIG 5 im Schnitt VI - VI;

FIG 7

eine dritte Begasungseinrichtung im Teil-Längsschnitt;

FIG 8

einen Teil des Rohrabschnitts, in welchen ein sieb- oder gitterförmiges Bauteil eingesetzt wird;

FIG 9

eine Ansicht der beiden sieb- oder gitterförmigen Bauteile gemäß FIG 7 in der Draufsicht;

FIG 10

eine vierte Begasungseinrichtung im Teil-Längsschnitt;

FIG 11

schematisch eine pneumatische Flotationszelle im Teil-Längsschnitt; und

FIG 12

eine Draufsicht auf die pneumatische Flotationszelle gemäß FIG 11.

The FIGS. 1 to 12 For example, gassing devices according to the invention, a flotation cell and their mode of operation will be explained. So shows

FIG. 1

a first gassing device in front view;

FIG. 2

the first gassing device according to FIG. 1 in partial longitudinal section;

FIG. 3

the first gassing device according to FIG. 1 and FIG. 2 in section III - III;

FIG. 4

the first gassing device according to FIG. 1 and FIG. 2 in section IV - IV;

FIG. 5

a second gassing device in partial longitudinal section;

FIG. 6

the second gassing device according to FIG. 5 in section VI - VI;

FIG. 7

a third gassing device in partial longitudinal section;

FIG. 8

a part of the pipe section in which a screen or lattice-shaped component is used;

FIG. 9

a view of the two screen or lattice-shaped components according to FIG. 7 in the plan view;

FIG. 10

a fourth gassing device in partial longitudinal section;

FIG. 11

schematically a pneumatic flotation cell in partial longitudinal section; and

FIG. 12

a plan view of the pneumatic flotation cell according to FIG. 11 ,

FIG. 1 shows a first gassing device 1 in front view. FIG. 2 shows the first gassing according to FIG. 1 in a partial longitudinal section. The first gassing device 1 comprises a vessel 2 with an outer tube 2c which has an eccentrically arranged gas inlet opening 2a for a gas 7 and a closed end 2c 'on one side. The vessel 2 further comprises an inner tube 2d, which is arranged inside and concentric with the outer tube 2c. The inner tube 2d has a closed end 2d 'on one side. The position of the inner tube 2d in the outer tube 2c is in FIG. 1 indicated by dashed lines and in the sectional view of FIG. 2 recognizable in detail. The inner tube 2d shown in front view has a number of gas outlet openings 2b, see FIG. 2 , And is connected at its open end via a likewise shown in front view connecting element 2e gas-tight with the outer tube 2c. The connecting element 2e has a central opening whose diameter corresponds to the inner diameter of the inner tube 2d. To the connecting element 2e of the vessel 2 here includes a pipe section 3, which is connected via a flange 3b shown in front view gas-tight with the connecting element 2e. The flange 3b also has a central opening, which is arranged in alignment with the opening of the connecting element 2e. Furthermore, an end of the tube section 3 facing away from the vessel 2 is assigned a baffle plate 4 whose plate plane is oriented perpendicular to a tube longitudinal axis 3 a of the tube section 3. The baffle plate 4 is dimensioned such that the opening 3e of the tube section 3 is covered as seen in the direction of the tube longitudinal axis 3a. The baffle plate 4 may be attached to the pipe section 3, the vessel 2 or on the inner wall of a flotation cell.

However, this is not shown in detail here. Finally, the first gassing device 1, the gas outlet openings 2b downstream and arranged parallel to the plate plane of the baffle plate 4, gas-permeable screen or lattice-shaped component 5, for example in the form of a metal mesh, plastic mesh or the like, see FIG. 2 , A center of the baffle plate 4 and a center of the at least one screen or lattice-shaped component 5 lie on the pipe longitudinal axis 3 a of the pipe section. 3

If the first gassing device 1 in a flotation cell (see also FIG. 11 ) used, occurs to be floated suspension through the opening 3e in the pipe section 3 and fills this and the interior of the inner tube 2d. Via the gas inlet opening 2a, a gas 7, in particular in the form of air, is introduced with pressure into the outer pipe 2c. The space between the outer tube 2c and the inner tube 2d fills with the gas 7. Subsequently, the gas 7 flows through the gas outlet openings 2b in the interior of the inner tube 2d and is introduced in the form of gas bubbles in the suspension, wherein the size of the formed gas bubbles Diameter of the gas outlet openings 2b is dependent. In the FIG. 2 shown gas outlet openings 2b have, in order to prevent clogging by particles from the suspension, a diameter in the range of 3 to 5 mm. The gas bubbles ascending in the inner tube 2d and the adjoining tube section 3 pass through the sieve-like or grid-shaped component 5 in the tube section 3, gas bubbles in particular having a diameter exceeding the mesh size of the sieve or grid openings of the sieve-like or grid-shaped component 5 being divided , Subsequently, the gas bubbles, whose maximum diameter is dependent on the mesh size of the screen or lattice-shaped component, pass out of the pipe section via the opening 3e and are thrown against the baffle plate 4 and ideally split further due to the impact and / or intimately with the suspension mixed. On their way through the suspension, the gas bubbles bind hydrophobicized recyclable material per se, rise up to the surface of the suspension and form there a foam product comprising desired the valuable particles.

FIG. 3 shows the first gassing device 1 according to the figures 1 and 2 in section III - III. Here, the staggered arrangement of the gas inlet opening 2a is particularly easy to recognize.

FIG. 4 shows the first gassing device 1 according to the figures 1 and 2 in section IV - IV. The screen or lattice-shaped component 5 covers the pipe cross-section of the pipe section 3 completely.

FIG. 5 shows a second gassing device 1 'in partial longitudinal section, in which the inner tube 2c, the connecting element 2e and the flange 3b in the front view and the remaining components of the second gassing device 1' are shown in section. The same reference numerals as in FIGS. 1 to 4 designate the same elements. The second gassing device 1 'has three modified baffle plates 4 a, 4 b, 4 c, which are arranged between the baffle plate 4 and the opening 3 e of the pipe section 3.

The baffle plate 4 and the modified baffle plates 4c, 4b may be attached to the modified baffle plate 4a, to the tube section 3, to the vessel 2 or also to the inner wall of a flotation cell. The baffle plate 4 may for example be bolted to the modified baffle plate 4c, which in turn may be bolted to the modified baffle plate 4b. The modified baffle plate 4b may be bolted to the modified baffle plate 4a attached to the tube section 3. However, the existing options are not shown in detail here.

In the pipe section 3, unlike the first gassing device 1, there is no screen or lattice-shaped component. The modified baffles 4a, 4b, 4c each have a central opening 6, which is the opening 3e of the Pipe section are arranged in alignment and in which a screen or lattice-shaped component 5a is arranged. Gas bubbles emerging from the opening 3e of the pipe section 3, pass through the three screen or grid-shaped components 5a, in particular gas bubbles with a diameter that exceeds the mesh size of the screen or grid openings of the respective screen or grid-shaped component 5a, divided become.

Preferably, the screen or grid openings of the three screen or grid-shaped components 5a are chosen to be smaller with increasing distance from the opening 3e of the tube section 3, so that the smallest possible gas bubbles reach the baffle plate 4.

FIG. 6 shows the second gassing device 1 'in section VI - VI and a plan view of one of the modified baffles 4a, in the opening 6, a screen or lattice-shaped member 5a is inserted in the form of a metal wire mesh. The mesh size MW of the metal wire mesh corresponds to the distance between adjacent wires of the fabric.

FIG. 7 shows a third gassing device 1 "in partial longitudinal section, as already shown in Figures 2 and 5. The same reference numerals designate like elements In this embodiment, in the pipe section 3 spaced apart two screen or lattice-shaped components 5, 5 'arranged, which The two screen-like or grid-shaped components 5, 5 'are here formed either from the same plastic grid, wherein the grid openings of the two plastic grids are offset, in particular offset or rotated around the longitudinal tube axis 3a FIG. 9 in which an arrangement of the two screen-like or grid-shaped components 5, 5 'in plan view, in which there is a rotation of 45 ° to each other.

Alternatively, the two screen or lattice-shaped components 5, 5 'formed of plastic lattices, which differ in their mesh sizes. In this case, the screen or grid-shaped component 5, which is arranged first in the transport direction of the gas bubbles, preferably has a larger mesh width than the screen-like or grid-shaped component 5 'following in the flow direction. In both cases, a particularly effective division of the gas bubbles is effected. Furthermore, between the opening 3e of the pipe section 3 and the baffle plate 4 two modified baffles 4b, 4c, each with an integrated screen or lattice-shaped component 5a present, through which the emerging from the opening 3e gas bubbles are further divided. The baffle plate 4 and the modified baffle plates 4c, 4b may be attached to the pipe section 3, the vessel 2 or on the inner wall of a flotation cell, etc. However, this is not shown in detail here.

FIG. 8 shows a part of the pipe section 3, for example according to the FIG. 2 and 7 in which a screen or lattice-shaped component 5 is used. Unless, as in the FIG. 2 and 7 shown, a screen or lattice-shaped member 5 is to be used at some distance from the opening 3e in the pipe section 3e, the pipe section is preferably provided for better handling with an insertion opening 3c for lateral insertion of the screen or lattice-shaped component 5, as in FIG. 8 shown. Furthermore, a fastening device 3d is provided to fix the screen or lattice-shaped component 5 in the insertion opening 3e.

FIG. 9 shows a view of the two screen or lattice-shaped components 5, 5 'according to FIG. 7 in the plan view and already became too FIG. 7 described in more detail.

FIG. 10 shows a fourth gassing device 1 '''in the partial longitudinal section, which has no adjoining the vessel 2 pipe section (see Figures 1 to 8). Same reference numerals as in FIG. 1 identify similar elements. The The fourth gassing device 1 '"comprises a vessel 2 with an outer tube 2c which has a gas inlet opening 2a for a gas 7 and a closed end 2c' on one side. The vessel 2 further comprises an inner tube 2d, which is arranged inside and concentric with the outer tube 2c. The inner tube 2d has a closed end 2d 'on one side. The inner tube 2d has a number of gas outlet openings 2b, wherein at least one gas outlet opening is present here per square centimeter. The connecting element 2e has a central opening whose diameter corresponds to the inner diameter of the inner tube 2d. In the opening of the connecting element 2e here a screen or lattice-shaped component 5b is used. Alternatively, the screen or grid-shaped component 5b may also be inserted downstream of the gas outlet openings 2b into the inner tube 2d. Furthermore, here are two modified baffles 4c, 4b with openings 6 present, in which screen or grid-shaped components 5a are used.

Furthermore, the vessel 2 is associated with a baffle plate 4, the plate plane is aligned perpendicular to a longitudinal axis LA of the vessel 2. The baffle plate 4 is dimensioned such that the opening in the connecting element 2e is covered. The baffle plate 4 and the modified baffle plates 4c, 4d may be attached to the connecting element 2e, to the vessel 2 or also to the inner wall of a flotation cell. However, this is not shown in detail here.

If the fourth gassing device 1 '''in a flotation cell (see also FIG. 11 ) used, occurs to be floated suspension through the opening in the connecting element 2e and fills the interior of the inner tube 2d. Via the gas inlet opening 2a, a gas 7, in particular in the form of air, is introduced with pressure into the outer pipe 2c. The space between the outer tube 2c and the inner tube 2d fills with the gas 7. Subsequently, the gas 7 flows through the gas outlet openings 2b in the interior of the inner tube 2d and is introduced in the form of gas bubbles in the suspension, wherein the size of the gas bubbles formed depends on the diameter of the gas outlet openings 2b.

In the FIG. 10 illustrated gas outlet openings 2b have, in order to prevent clogging by particles from the suspension, a diameter in the range of 1 to 5 mm. The gas bubbles ascending in the inner tube 2d pass through the sieve-like or grid-shaped component 5b in the connecting element 2e, with gas bubbles in particular having a diameter exceeding the mesh width of the sieve or grid openings of the sieve-like or latticed component 5b being divided. Subsequently, the gas bubbles whose maximum diameter is dependent on the mesh size of the screen or lattice-shaped component 5b, from the vessel 2 and are guided through the screen and lattice-shaped components 5a in the modified baffles 4c, 4b, further divided and finally against the baffle plate 4 thrown and ideally further divided due to the impact and / or intimately mixed with the suspension. On their way through the suspension, the gas bubbles bind to hydrophobized recyclable material per se, rise up to the surface of the suspension and form a foam product comprising the valuable particles desired there.

FIG. 11 FIG. 2 shows a columnar flotation cell 100, here a hybrid flotation cell, with a housing 110 that includes a flotation chamber 120. The diameter of the flotation chamber 120 is greater than the height thereof. The left side of the flotation cell 100 is shown in front view, the right side in section. Within the flotation chamber 120 is a foam channel 130 with nozzle 131 for discharging the foam product formed. The flotation chamber 120 is equipped with at least one nozzle arrangement 140 for supplying gas 8, in particular air, and a suspension into the flotation chamber 120. The suspension here has a high solids content in the range of 30 to 40%. The housing 110 has a cylindrical housing portion 110a, at the lower end of four gassing assemblies 1 are arranged (only three of them visible). The housing 110 also has a bottom discharge opening 150. The upper edge of the outer wall of the housing 110 is located above the upper edge of the foam channel 130, whereby an overflow of the foam product formed over the upper edge of the housing 110 is excluded. Particles of the suspension, which are provided, for example, with an insufficiently hydrophobized surface or have not collided with a gas bubble, and hydrophilic particles sink in the direction of the bottom discharge opening 150 and are discharged via this. By means of the gassing devices 1, additional gas 7, in particular air, is blown into the cylindrical housing section 110a, so that further hydrophobic particles are bound thereto and rise. Ideally, especially the hydrophilic particles continue to sink and are discharged via the bottom discharge opening 150. The foam product containing the valuable material particles passes from the flotation chamber 120 into the foam channel 130 and is discharged via the nozzles 131 and optionally thickened.

FIG. 12 shows the flotation cell 100 in plan view, wherein the position of the gassing devices 1 in the flotation chamber 120 can be seen.

In the flotation cell 100, a suspension having a solids content in the range of 30 to 40% comprising particles having a maximum particle diameter is floated, wherein a ratio of the maximum particle diameter of the particles to a mesh MW of the screen or grid openings of the at least one screen or lattice-shaped component 5 in the respective gassing device 1 in the range of 1: 5 to 1:10. This ensures that the at least one screen or lattice-shaped component 5 can not be clogged by particles of the suspension.

The in the FIGS. 1 to 12 illustrated gassing and flotation cells provide only examples of a variety of other possible embodiments of gassing according to the invention and thus provided Flotation cells. A person skilled in the art can also equip other flotation cells with one or a suitable number of fumigation devices according to the invention. Thus, suitable flotation cells with regard to the design and arrangement of the flotation chamber, the foam collector, the number of nozzle arrangements for injecting suspension and gas can differ for the use of a gassing device according to the invention, without departing from the basic idea of the invention. Furthermore, the gassing devices can have a different number of gas inlet openings, on sieve or lattice-shaped components and / or a different number of modified impact plates, a different arrangement of the gas inlet opening (s), other combinations of mesh sizes or materials for the screen or lattice-shaped components Have guide vanes in the vessel of the gassing device and the like.

Claims (16)

Begasungseinrichtung (1, 1 ', 1 ", 1' '') for a flotation cell (100), comprising a vessel (2) having at least one gas inlet opening (2a) and a number of gas outlet openings (2b), and one, the vessel ( 2) downstream baffle plate (4), and at least one between the gas outlet openings (2) and the baffle plate (4) parallel to the plate plane of the baffle plate (4) arranged, gas-permeable screen or lattice-shaped component (5, 5 ', 5a, 5b). A gassing device according to claim 1, wherein a pipe section (3) adjoining the vessel (2) is provided for receiving gas (7) exiting via the gas outlet openings (2b), the baffle plate (4) facing away from the vessel (2) a plate plane of the baffle plate (4) perpendicular to a tube longitudinal axis (3a) of the tube section (3) is aligned, wherein a center of the baffle plate (4) and a center of the at least one screen or lattice-shaped component ( 5, 5 ', 5a) lie on the tube longitudinal axis (3a). Fumigation device according to claim 1 or claim 2, wherein at least two screen or lattice-shaped components (5, 5 ', 5a, 5b) are present. Fumigation device according to one of claims 2 or 3, wherein a screen or lattice-shaped component (5, 5 ', 5a) in the pipe section (3) and / or on the, the vessel (2) facing away from the end of the pipe section (3) is arranged and in the direction of the pipe longitudinal axis (3a) seen a pipe cross-section of the pipe section (3) covered. Fumigation device according to one of claims 1 to 4, wherein between the vessel (2) and the baffle plate (4) at least one modified baffle plate (4a, 4b, 4c) having an opening (6) is present, wherein a screen or lattice-shaped component ( 5a) is inserted into the opening (6). Fumigation device according to claim 5, wherein a diameter of the opening (6) of the at least one modified baffle plate (4a, 4b, 4c) corresponds to at least one pipe diameter of the pipe section (3). Fumigation device according to one of claims 1 to 6, wherein the screen or lattice-shaped component (5, 5 ', 5a, 5b) comprises at least one screen element in the form of a braid, fabric, knitted fabric or knitted fabric. Fumigation device according to one of claims 1 to 7, wherein the screen or lattice-shaped member (5, 5 ', 5a, 5b) comprises at least one grid element, which is formed from connected tubes, rods or plates. Fumigation device according to one of claims 1 to 8, wherein the screen or lattice-shaped component (5, 5 ', 5a, 5b) sieve or grid openings having a diameter in the range of 1 to 10 mm. Fumigation device according to one of claims 1 to 9, wherein the vessel (2) comprises a closed on one side outer tube (2c), which has the at least one gas inlet opening (2a), and at least one closed on one side inner tube (2d), which the gas outlet openings (2b ), wherein the at least one inner tube (2d) in the outer tube (2c) is arranged, and wherein an open end of the outer tube (2c) is connected in a gastight manner with an open end of the at least one inner tube (2d). Fumigation device according to claim 10, wherein only an inner tube (2d) is present, which is arranged concentrically to the outer tube (2c). Fumigation device according to claim 11, wherein the tube section (3) and the inner tube (2d) have an identical outer and inner diameter and are arranged in alignment with each other. Flotation cell (100), in particular a columnar flotation cell or hybrid flotation cell, comprising a housing (110) with a flotation chamber (120), at least one nozzle arrangement (140) for supplying gas and a suspension into the flotation chamber (120) and at least one fumigation device (1, 1 ', 1' ', 1' '') according to one of claims 1 to 12 for the further supply of gas (7) into the flotation chamber (120), which in the flotation chamber (120) below the at least one nozzle arrangement (140) is arranged so that a longitudinal axis LA of the gassing device (1, 1 ', 1 ", 1"'), which extends through the center of the baffle plate (4), is vertically aligned. Flotation cell according to claim 13, wherein the baffle plate (4) of the at least one gassing device (1, 1 ', 1 ", 1' '') in the flotation chamber (120) above the vessel (2) of the at least one gassing device (1, 1 ' , 1 ", 1 '' ') is arranged. Process for flotation of valuable particles, in particular ore minerals, from a suspension having a solids content in the range of 30 to 40% to form a foam product by means of a flotation cell (100) according to one of claims 13 or 14. The method of claim 15, wherein a suspension comprising particles having a maximum particle diameter is floated, wherein a ratio of the maximum particle diameter of the particles to a mesh size MW of the screen or grid openings of the at least one screen or lattice-shaped component (5, 5 ', 5a , 5b) is in the range of 1: 5 to 1:10.

Images