CN217313905U

CN217313905U - Flotation equipment

Info

Publication number: CN217313905U
Application number: CN202121476193.XU
Authority: CN
Inventors: I·谢雷尔
Original assignee: Metso Outotec Finland Oy
Current assignee: Metso Finland Oy
Priority date: 2020-06-30
Filing date: 2021-06-30
Publication date: 2022-08-30
Anticipated expiration: 2031-06-30
Also published as: EP4171827A1; AU2021302771A1; CL2022003791A1; WO2022003241A1; CA3184583A1; CN113856912A

Abstract

A flotation plant (100) is provided. The flotation unit comprises: fluidized bed apparatus, including apparatus for forming a fluidized bed, and/or foam apparatus, including apparatus for forming a foam layer, wherein particles are supplied to interact with the foam layer. A mill (2) is connected to the flotation unit (1) for receiving a product stream from the mill. The mill (2) comprises: -a grinding structure (3) arranged to concentrate grinding energy to the particles of the product flow, and-a classification structure (4) at least partly integrated with the grinding structure (3) and arranged to direct the particles to face the grinding structure on the basis of particle size, such that the coarsest end of the particle size distribution is ground more than the finest end of the particle size distribution.

Description

Flotation equipment

Technical Field

The utility model relates to a flotation equipment.

Background

There is a need to improve the effectiveness of flotation in the release of valuable minerals from mineral ores.

SUMMERY OF THE UTILITY MODEL

Viewed from a first aspect, there may be provided a flotation unit comprising: a fluidized bed apparatus comprising means for forming a fluidized bed; and/or a froth device comprising a device for forming a froth layer, wherein particles are fed to interact with the froth layer in, in close proximity to, below, or above the froth layer, or any combination thereof, the flotation plant further comprising a mill, wherein the mill is connected to a flotation unit for receiving a product stream from the flotation unit, the mill comprising: an abrasive structure arranged to concentrate abrasive energy to particles of the product stream; and a graded structure at least partially integral with the abrasive structure and arranged to direct particles to face the abrasive structure based on particle size such that a coarsest end of the particle size distribution is more abrasive than a finest end of the particle size distribution.

It is thereby possible to realize an apparatus in which fine particles are not unnecessarily ground and which is capable of efficiently processing both finer particles and coarser particles. The feed into the rougher flotation plant can vary and fluctuate more than in known plants, so that the equipment arranged before rougher flotation can be chosen more freely. Furthermore, flotation of coarser particles containing valuable minerals is more efficient when combined with finer particles. Still further, a better or more uniform feeding into further steps, such as flotation systems, may be achieved.

The apparatus is characterized by what is described in the embodiments of the present disclosure. Embodiments of the invention are also disclosed in the description and drawings of the present patent application. The inventive content of the patent application can also be defined in other ways than is done in the claims below. The inventive content may also be formed by several separate utility models, especially if the utility models are reviewed in light of explicit or implicit subtasks or in view of gains or groups of gains accrued. Some of the limitations contained in the accompanying claims may not be necessary in view of the separate utility concepts. The features of the different embodiments of the invention can be applied to other embodiments within the scope of the basic inventive idea.

In one embodiment, the mill comprises: a grinding chamber; and a rotating element arranged in the grinding chamber for rotation therein. One advantage is that an energy-efficient grinding process can be achieved.

In one embodiment, the mill comprises grinding media (such as silica sand, smelter slag, ceramic balls, metal balls) arranged in a grinding chamber. One advantage is that automatic classification of the crushed particles due to specific gravity differences and/or particle convection between the grinding media and the ore in the mill can be achieved. Another advantage is that contamination of the mill can be minimized. An advantage of the mentioned types of grinding media is their high durability and thus the use of grinding media can be minimized.

In one embodiment, the available volume of the grinding chamber is filled to 70% -80% with grinding media. One advantage is that the automatic classification of the comminuted particles can be enhanced by reducing the void fraction and increasing the velocity of the advancing fluid. Another advantage is that contact with the ore can be increased, thereby increasing the grinding speed.

In one embodiment, the grinding media comprises ceramic balls. One advantage is that the comminution of the particles can be enhanced. Another advantage is that contamination of the mill can be minimized. Another advantage is the high durability of the ceramic balls, thus minimizing the use of grinding media.

In one embodiment, the mill comprises: a cylindrical grinding chamber (cylindrical grinding chamber); a rotating shaft arranged concentrically with the grinding chamber and arranged within the grinding chamber; a series of discs mounted on a rotating shaft, the discs forming grinding volumes between the discs, wherein the discs comprise at least one aperture extending from one grinding volume to another grinding volume. One advantage is that a high intensity grinding can be achieved in the grinding volume.

In one embodiment, the mill comprises a counter ring arranged in at least some of the grinding volumes, said counter ring being attached to a wall of the grinding chamber and extending towards the shaft. One advantage is that the pulverizing efficiency can be improved by preventing short-circuiting of the material.

In one embodiment, at least one of the discs comprises a profiled surface. One advantage is that wear of the disc can be suppressed.

In one embodiment, the mill comprises an agitator screw arranged concentrically with and inside the grinding chamber for rotation therein. One advantage is that a simple but effective mill structure can be achieved.

In one embodiment, at least a portion of the walls of the grinding chamber comprise a liner, such as a grid liner. One advantage is that wear of the wall can be suppressed.

In one embodiment the flotation unit is provided with overflow members (overflow means) to which the mills are connected, whereby the product flow comprises a rougher flotation concentrate flow received from the overflow members. One advantage is that a simplified flow may be achieved, thus requiring less equipment, plant space, instrumentation, control, etc.

In one embodiment the flotation unit is provided with a classification unit or a dewatering unit, to which the mill is connected, whereby the product stream arranged to be fed into the mill comprises coarse particles or solids of the dewatering unit of a size above the classification threshold of the classification unit. One advantage is that only particles that need to be ground can be fed into the mill.

In one embodiment, the classifying unit comprises a classifying cyclone. One advantage is that a simple structure without moving parts can be achieved.

In one embodiment, the recovery system is provided with a dewatering unit, such as a dewatering cyclone, a filter, a concentrator or a centrifuge. One advantage is that the proportion of solids in the product stream to be fed into the mill can be increased. This achieves higher grinding efficiency and higher throughput by increasing the interaction between particles.

In one embodiment, the dewatering unit comprises a dewatering cyclone. One advantage is that a simple structure without moving parts can be achieved.

In one embodiment, the flotation unit comprises means for forming a fluidized bed. One advantage is that valuable particles are floated and at least a major portion of the fine particles are recovered. This allows immediate treatment of the coarse tailings. Another advantage is that the fine particles can be processed downstream in standard flotation equipment with higher separation efficiency.

In one embodiment, the flotation cell comprises means for forming a froth layer, wherein the particles are fed to interact with the froth layer in the froth layer, below the froth layer in close proximity thereto, or above the froth layer, or any combination thereof. One advantage is that the size of the flotation cell can be reduced, high throughput per volume of flotation cell can be achieved, and direct interaction with froth/bubbles results in potentially higher recovery.

In one embodiment, the flotation unit comprises means for forming a fluidized bed and means for forming a froth layer, wherein the particles are fed to interact with the froth layer in, below, in close proximity to, above, or any combination thereof. One advantage is that valuable minerals can be recovered to a maximum extent.

In one embodiment, the pre-grinding section is arranged to feed a flotation cell. One advantage is that the percentage of particles that are too large to feed into the flotation cell can be reduced.

In one embodiment, the apparatus comprises a separation unit arranged before the flotation unit or after the flotation unit for receiving tailings from the flotation unit. One advantage is that particles containing valuable minerals that are too large to enter the product stream can be recovered. A separation unit arranged before the flotation unit may remove large particles that may block tailing discharge or impede separation, for example by breaking up the froth layer.

In one embodiment, the separation unit comprises a grizzly or grid (grating). One advantage is that a simple construction of the separation unit can be achieved.

In one embodiment, the separation unit is connected to a pre-grinding section for further grinding. One advantage is that large particles containing valuable minerals can be ground to a size that can enter the product stream of the flotation cell.

In one embodiment, a dewatering unit is arranged before the flotation unit for removing water from the product stream to be fed into the flotation unit. One advantage is that the proportion of solids in the feed to the flotation unit can be increased.

In one embodiment, the outlet of the mill is connected to a flotation system for feeding said flotation system, said flotation system comprising at least one flotation vessel. One advantage is that valuable minerals can be recovered.

In one embodiment, the flotation vessel is a fluidized bed apparatus comprising means for forming a fluidized bed. One advantage is that the recovery of larger particles, such as larger sized material ground in a mill, or particles passed through a mill before reaching the final ground size, can be improved.

In one embodiment, the flotation vessel includes means for forming a froth layer, wherein the particles are fed to interact with the froth layer in the froth layer, below the froth layer in close proximity thereto, or above the froth layer, or any combination thereof. One advantage is that the recovery of larger particles, such as larger sized material ground in a mill, or particles passed through a mill before reaching the final ground size, can be improved.

In one embodiment, the flotation system comprises at least three flotation vessels arranged in series such that the outlet for removing the underflow of a previous flotation vessel is connected to the inlet of a subsequent flotation vessel. One advantage is that valuable minerals in the underflow can be recovered.

In one embodiment, the flotation vessel includes an apparatus comprising: an inlet connected to receive feed to be treated in the flotation vessel and arranged in a lower portion of the flotation vessel; an overflow member for removing flotation concentrate, arranged in the upper part of the flotation vessel; and an outlet for removing the underflow, arranged in the lower part of the flotation vessel. One advantage is that high recovery rates can be achieved due to high energy input and good mixing performance.

In one embodiment, the flotation vessel includes a mechanical agitator for agitating the slurry in the vessel. One advantage is that separation of particles containing valuable minerals from other particles can be enhanced.

In one embodiment, the flotation vessel comprises a mechanical agitator for forming bubbles in said vessel. One advantage is that separation of particles containing valuable minerals from other particles can be enhanced.

In one embodiment the flotation vessel comprises a closed vessel for pressure flotation, wherein flotation concentrate is removed from the vessel by means of pressure. One advantage is that high recovery rates can be achieved since there is no loss in the foam.

In one embodiment, the flotation vessel comprises means for pneumatic gas addition. One advantage is that better product grades and/or improved fine particle recovery can be achieved.

In one embodiment, at least one of the flotation vessels is a froth separation device comprising means for forming a froth layer, the flotation vessel comprising: an inlet connected to receive feed to be treated in the flotation vessel and arranged in an upper portion of the flotation vessel; an overflow member for removing flotation concentrate, arranged in the upper part of the flotation vessel; and an outlet for removing the underflow, arranged in the lower part of the flotation vessel. One advantage is that high product grades can be obtained.

In one embodiment, the flotation vessel comprises a downcomer for the slurry feed, said downcomer being equipped with a nozzle for feeding pressurized flotation gas into the slurry in the downcomer. One advantage is that high recovery rates can be achieved due to the local high energy input. Another advantage is that especially the fines recovery can be improved.

In one embodiment, the downcomer includes an outlet nozzle configured to introduce an ultrasonic shock wave into the slurry as it exits the downcomer. One advantage is that flotation of fine and ultrafine particles including, for example, mineral ores or coal, can be improved.

In one embodiment, the mill is deployed in an open circuit configuration. One advantage is that a simple configuration can be achieved, reducing energy usage and low capital and operating costs.

An embodiment of the present disclosure provides a flotation device, including: a flotation cell comprising: fluidized bed apparatus, comprising means for forming a fluidized bed, and/or froth apparatus, comprising means for forming a froth layer, wherein particles are supplied to interact with the froth layer, the flotation plant further comprising: a mill, wherein the mill is connected to a flotation unit for receiving a product stream from the flotation unit, the mill comprising: the apparatus comprises a grinding structure arranged to concentrate grinding energy to particles of the product stream, and a classification structure at least partially integral with the grinding structure and arranged to direct particles to face the grinding structure based on particle size such that a coarsest end of the particle size distribution is ground more than a finest end of the particle size distribution.

Preferably, the mill comprises: a grinding chamber, and a rotating element arranged in the grinding chamber for rotation therein.

Preferably, the mill comprises grinding media disposed in the grinding chamber.

Preferably, the useable volume of the milling chamber is filled to 70-80% with the milling media.

Preferably, the grinding media comprises one of: silica sand, smelting waste slag, ceramic balls and metal balls.

Preferably, the grinding media are ceramic balls.

Preferably, the cylindrical grinding chamber is arranged at least substantially horizontally.

Preferably, the cylindrical grinding chamber is arranged at least substantially vertically.

Preferably, the rotating element comprises at least one of: a disk, a stirrer screw.

Preferably, the mill comprises: a cylindrical grinding chamber, a rotation shaft arranged concentrically with the grinding chamber and arranged within the grinding chamber, a series of discs mounted on the rotation shaft, the discs forming grinding volumes between the discs, the discs comprising at least one aperture extending from one grinding volume to another grinding volume.

Preferably, the mill comprises: a counter ring disposed in at least some of the grinding volumes, the counter ring attached to a wall of the grinding chamber and extending toward the rotational axis.

Preferably, at least one of the discs comprises a profiled surface.

Preferably, the mill comprises: an agitator screw arranged concentrically with and within the grinding chamber for rotation therein.

Preferably, at least a portion of the walls of the grinding chamber comprise a grid liner.

Preferably, the flotation unit is provided with: an overflow member, and the mill is connected to the overflow member such that the product stream comprises a flotation concentrate stream received from the overflow member.

Preferably, the flotation unit is provided with: a classification unit or a dewatering unit connected to an overflow member of the flotation unit or to a second outlet of the flotation unit, the mill being connected to the classification unit or the dewatering unit so that the product stream arranged to be fed into the mill comprises coarse particles of a size above a classification threshold of the classification unit or solids of the dewatering unit.

Preferably, the classifying unit or the dewatering unit is connected to the second outlet of the flotation unit.

Preferably, the flotation unit is provided with a classifying unit.

Preferably, the classifying unit comprises a classifying cyclone.

Preferably, the flotation plant further comprises a recovery system provided with a dewatering unit.

Preferably, the dewatering unit comprises at least one of a dewatering cyclone, a filter, a settling unit or a centrifuge.

Preferably, the dewatering unit comprises the dewatering cyclone.

Preferably, the flotation unit comprises means for forming a fluidised bed.

Preferably, the flotation unit comprises means for forming a froth layer, wherein particles are fed to interact with the froth layer in the froth layer, below the froth layer in close proximity thereto, or above the froth layer, or any combination thereof.

Preferably, the flotation unit comprises means for forming a fluidised bed and means for forming a froth layer, wherein particles are supplied to interact with the froth layer in the froth layer, below the froth layer in close proximity thereto, or above the froth layer, or any combination thereof.

Preferably, a pump is arranged between the flotation unit and the mill for promoting the flow of the product stream between the flotation unit and the mill.

Preferably, a pre-grinding section is arranged to feed the flotation unit.

Preferably, the pre-grinding section comprises an autogenous mill, or a semi-autogenous mill, or a high pressure grinding roll.

Preferably, the apparatus comprises: a separation unit for recovering large particles, the separation unit being arranged before the flotation unit or after the flotation unit for receiving tailings from the flotation unit.

Preferably, the separation unit is arranged before the flotation unit.

Preferably, the separation unit is arranged after the flotation unit for receiving tailings from the flotation unit.

Preferably, the separation unit comprises a screen or a grid.

Preferably, the separation unit is connected to a pre-grinding section for further grinding.

Preferably, the apparatus comprises: a dewatering unit arranged before the flotation unit for removing water from the product stream to be fed into the flotation unit.

Preferably, the outlet of the mill is connected to a flotation system for feeding the flotation system, the flotation system comprising: at least one flotation vessel.

Preferably, the flotation vessel is: fluidized bed apparatus, comprising means for forming a fluidized bed, or comprising means for forming a froth layer, wherein particles are fed to interact with the froth layer in the froth layer, in close proximity thereto below the froth layer, or above the froth layer, or any combination thereof, or comprising means for pneumatic gas addition, or comprising means for a closed vessel for pressurized flotation, wherein flotation concentrate is removed from the vessel by means of pressure, or a device comprising: an inlet connected to receive feed to be treated in the flotation vessel and arranged in a lower part of the flotation vessel, an overflow member for removing flotation concentrate, arranged in an upper part of the flotation vessel, and an outlet for removing underflow, arranged in a lower part of the flotation vessel.

Preferably, the flotation vessel is: the apparatus comprising means for pneumatic gas addition or the apparatus comprising a closed vessel for pressurized flotation, wherein flotation concentrate is removed from the vessel by means of pressure, or the apparatus comprising: an inlet connected to receive feed to be treated in the flotation vessel and arranged in a lower part of the flotation vessel, an overflow member for removing flotation concentrate, arranged in an upper part of the flotation vessel, and an outlet for removing underflow, arranged in a lower part of the flotation vessel.

Preferably, the flotation vessel is: the apparatus comprising a closed vessel for pressurized flotation, wherein flotation concentrate is removed from the vessel by means of pressure, or the apparatus comprising: an inlet connected to receive feed to be treated in the flotation vessel and arranged in a lower portion of the flotation vessel, an overflow member for removing flotation concentrate arranged in an upper portion of the flotation vessel, and an outlet for removing underflow arranged in a lower portion of the flotation vessel.

Preferably, the flotation system comprises at least three flotation vessels arranged in series such that the outlet for removing the underflow of a preceding flotation vessel is connected to the inlet of a subsequent flotation vessel.

Preferably, the flotation vessel includes an apparatus comprising: an inlet connected to receive feed to be treated in the flotation vessel and arranged in a lower part of the flotation vessel, an overflow member for removing flotation concentrate, arranged in an upper part of the flotation vessel, and an outlet for removing underflow, arranged in a lower part of the flotation vessel.

Preferably, the flotation vessel comprises: means for forming a foam layer.

Preferably, the flotation vessel comprises a closed vessel for pressurized flotation, wherein flotation concentrate is removed from the vessel by means of pressure.

Preferably, the flotation vessel comprises: a mechanical agitator for agitating the slurry in the vessel.

Preferably, the flotation vessel comprises: a mechanical stirrer for forming bubbles in the vessel.

Preferably, the flotation vessel comprises means for pneumatic gas addition.

Preferably, the flotation vessel is a froth separation device comprising means for forming a froth layer, the flotation vessel comprising: an inlet connected to receive feed to be processed in the flotation vessel and arranged in an upper part of the flotation vessel, and an overflow member for removing flotation concentrate, arranged in the upper part of the flotation vessel.

Preferably, at least one of the flotation vessels comprises: an outlet for removing underflow is arranged in the lower part of the flotation vessel.

Preferably, the flotation vessel comprises a downcomer for the slurry feed, the downcomer being equipped with a nozzle for feeding pressurized flotation gas into the slurry in the downcomer.

Preferably, the downcomer comprises an outlet nozzle configured to introduce an ultrasonic shock wave into the slurry as it exits the downcomer.

Preferably, the mill is deployed in an open circuit configuration.

Drawings

Some embodiments illustrating the disclosure are described in more detail in the accompanying drawings, in which

Figure 1 is a schematic partial cross-sectional view of an apparatus,

figure 2 is a schematic partial cross-sectional view of another apparatus,

figure 3 is a side elevational schematic view in partial cross-section of a third grinding mill,

figure 4 is a schematic view of a flotation system,

figure 5 is a schematic view of another flotation system,

FIG. 6 is a schematic view of a flotation cell, an

Fig. 7 is a schematic of a third flotation system.

In the drawings, some embodiments are shown simplified for clarity. Similar parts are marked in the figures with the same reference numerals.

List of reference numerals

1 flotation cell

2 grinding machine

3 grinding structure

4 hierarchical structure

5 grinding chamber

6 rotating element

7 grinding media

8 dish

9 shaft

10 grinding volume

11 holes

12 counter ring

13 stirrer screw

14 grid liner

15 Overflow Member

16 recovery system

17 grading unit

18 pump

19 outlet port

20 flotation system

21 flotation vessel

22 inlet of flotation vessel

23 separation unit

24 dehydration unit

25 outlet for underflow

26 Pre-grinding part

100 device

Detailed Description

Figure 1 is a schematic partial cross-sectional view of a flotation plant. The apparatus 100 comprises a flotation unit 1 and a mill 2.

A mill 2 is connected to the flotation unit 1 for receiving a product stream (here flotation concentrate) from the flotation unit. The mill 2 comprises: a grinding structure 3 arranged to concentrate the grinding energy to the particles of the flotation concentrate; and a graded structure 4 at least partly integral with the abrasive structure 3 and arranged to direct particles to face the abrasive structure 3 based on particle size such that a coarsest end of the particle size distribution is more abrasive than a finest end of the particle size distribution.

The physics of grinding ore can depend on a combination of impact, abrasion and attrition. Impact crushing relies on the fracture through the ore particles breaking the particles into smaller pieces. Abrasion and wear relies on surface pressure and shear forces to strip smaller pieces from larger ore particles. The largest particles are generally more efficiently milled by impact and the smallest particles are generally more efficiently milled by attrition and abrasion.

According to one aspect, the mill 2 comprises a grinding chamber 5, preferably fixedly arranged, and a rotating element 6 arranged in the grinding chamber 5 for rotation therein. In an embodiment, mill 2 further comprises grinding media 7 disposed in grinding chamber 5. The available volume of the milling chamber 5 can be filled with milling media to, for example, 70% -80%. The grinding media 7 may include, for example, silica sand, smelter slag, ceramic balls, metal balls.

In an embodiment, at least a portion of the walls of the grinding chamber 5 comprise a liner, such as a grid liner 14.

In an embodiment, the grinding chamber 5 has an at least substantially vertically arranged cylindrical shape.

In an embodiment, the mill 2 comprises an agitator screw 13 arranged concentrically with the grinding chamber 5 and located inside the grinding chamber 5 for rotation therein. Mills 2 may be, for example, those produced by the company Metso Oyj

Or produced by Eirich GmbH

As the agitator screw 13 rotates, it continually lifts any mineral ore and grinding media (such as steel or ceramic balls, which aid in comminution) upwardly until they eventually fall back onto the material and grinding media that are now at the bottom of the mill. The lifting and lowering of the material and the grinding media causes the material to break down primarily by impact.

In an embodiment the flotation unit 1 is provided with an overflow member 15 for outflow of a flotation concentrate flow, i.e. particles having exposed minerals on their surface that have entered the top of the flotation unit 1. The mill 2 is connected to said overflow member 15 such that the product flow comprises a flotation concentrate flow received from the overflow member 15.

In an embodiment, the flotation unit 1 comprises a fluidized bed arrangement comprising means for forming a fluidized bed in the flotation unit 1. In another embodiment, such as shown in fig. 6, the flotation unit 1 comprises a froth device with means for forming a froth layer in the flotation unit 1. The foam layer may interact with the particles of the product stream. In an embodiment, the product stream is arranged to be fed into the foam layer, below the foam layer to be in close proximity thereto, or above the foam layer, or any combination thereof. The term "in close proximity" herein refers to a distance of 20cm or less from the foam layer.

In an embodiment, the product stream is arranged to be fed into the foam layer, below the foam layer no more than 2cm therefrom, or above the foam layer, or any combination thereof.

In an embodiment, the flotation unit 1 comprises means for forming a fluidized bed and means for forming a froth layer.

In an embodiment, the apparatus 100 comprises a pump 18 arranged between the flotation unit 1 and the mill 2 for promoting a flow of the product flow between the flotation unit and the mill.

In an embodiment, the apparatus 100 comprises a pre-grinding section 26 arranged to feed the flotation unit 1. The pre-grinding section 26 may be, for example, an autogenous mill, or a semi-autogenous mill, or a high pressure grinding roll.

In an embodiment, the apparatus 100 comprises a separation unit 23, which is arranged before or after the flotation unit 1. The separation unit 23 may remove such large particles from the material flow that may not enter the overflow of the flotation unit and feed them to a further process or processes to release valuable minerals therefrom. For example, the separation unit 23 may be connected to the pre-grinding section 26 for further grinding. The separation unit 23 may comprise, for example, a screen or a grating.

In an embodiment, the apparatus 100 comprises a dewatering unit arranged before the flotation unit 1. The dewatering unit removes water from the product stream to be fed into the flotation unit 1.

Fig. 2 is a partial cross-sectional schematic view of another apparatus.

In an embodiment, the flotation unit 1 is provided with a classifying unit 17 (e.g. a classifying cyclone) or a dewatering or solids removal unit 24 (e.g. a dewatering cyclone, a filter, a settling unit such as a concentrator or clarifier, or a centrifuge). The classifying or dewatering unit may be connected to the overflow member 15 of the flotation unit or to the second outlet 27 of the flotation unit (as shown in fig. 2).

The mill 2 is connected to the classification unit 17 or the dewatering unit 24 such that the product stream arranged to be fed into the mill 2 comprises coarse particles of a size above the classification threshold of the classification unit 17 or solids of the dewatering unit 24.

In an embodiment, the product stream fed into mill 2 comprises not only the feed from the classification unit 17 or the dewatering or solids removal unit 24, but also other feeds.

In an embodiment, the overflow member 15 of the flotation unit is connected to the mill 2 by a dewatering or solids removal unit 24.

In an embodiment, the mill 2 comprises a counter ring 12 arranged in at least some of the grinding volumes 10. The counter ring 12 is attached to the wall of the grinding chamber 5 and it extends towards the shaft 9. In one embodiment, the plurality of grinding volumes 10 includes a counter ring 12. In an embodiment, each grinding volume 10 comprises a counter ring 12. Mill 2 may be, for example, that produced by Outotec Oyj

In an embodiment, at least one of the discs 8 comprises a profiled surface. The profiled surface may comprise protective elements such as blocks protruding from the disc 8.

In one embodiment, mill 2 comprises: an inlet located at the top of the mill or within the upper 20% of the mill for receiving mineral ore; and an outlet located at the bottom of the mill or within the lower 20% of the mill for removing ground material from the mill. In another embodiment, mill 2 comprises: an inlet located at the bottom of the mill or within the lower 20% of the mill for receiving mineral ore; and an outlet located at the top of the mill or within the upper 20% of the mill.

Figure 3 is a side schematic view in partial cross section of a third mill.

In an embodiment, the mill 2 comprises an at least substantially horizontally arranged cylindrical grinding chamber 5. The rotation shaft 9 is arranged concentrically with the grinding chamber 5 and the rotation shaft is arranged inside the grinding chamber. A series of discs 8 are mounted on the rotorOn the spindle 9 so that the disc 8 creates a grinding volume 10 between them. The disc 8 comprises at least one aperture 11 extending from one grinding volume 10 to the other. Such a mill 2 may be, for example, an IsaMill manufactured by Glencore Technology ^TM 。

Fig. 4 is a schematic view of a flotation system and fig. 5 is a schematic view of another flotation system. The flotation system 20 is arranged in fluid communication with the mill 2 described in this specification such that the outlet 19 of the mill is connected to the flotation system 20, which comprises at least one flotation vessel 21.

Mill 2 is operated in an open circuit configuration, i.e., no separate classification and material recirculation back into the mill.

In one embodiment, the flotation vessel 21 is one of:

fluidized bed apparatus, including apparatus for forming a fluidized bed, or

Apparatus, including apparatus for forming a foam layer, wherein particles are fed to interact with the foam layer in the foam layer, in close proximity thereto below the foam layer, or above the foam layer, or any combination thereof, or

Apparatus, including means for pneumatic gas addition, or

Closed vessels for pressure flotation, in which the flotation concentrate is removed from the vessel by means of pressure, or

An apparatus (such as shown in fig. 4) comprising: an inlet 22 connected for receiving feed to be treated in the flotation vessel and arranged in a lower part of the flotation vessel 21; an overflow member 15 for removing flotation concentrate, arranged in the upper part of the flotation vessel (21); and an outlet 25 for removing the underflow, arranged in the lower part of the flotation vessel 21.

In an embodiment, the flotation system 20 comprises at least three flotation vessels 21 arranged in series such that the outlet 25 for removing the underflow of a previous flotation vessel 21 is connected to the inlet 22 of a subsequent flotation vessel 21. In an embodiment, all flotation vessels 21 in the flotation system 20 are of the same type. In another embodiment, there are at least two types of flotation vessels 21 in the flotation system 20.

In an embodiment, the flotation vessel 21 comprises a mechanical agitator for agitating the slurry in said vessel. Additionally or alternatively, a mechanical stirrer may be used to form bubbles in the vessel.

In an embodiment, the flotation vessel 21 (such as shown in fig. 5) is a froth separation device comprising means for forming a froth layer, wherein an inlet 22 connected for receiving feed to be treated in said flotation vessel is arranged in an upper part of the flotation vessel 21, an overflow member 15 for removing flotation concentrate is arranged in an upper part of the flotation vessel 21, and an outlet 25 for removing underflow is arranged in a lower part of the flotation vessel 21.

In an embodiment, the flotation vessel 21 includes at least one downcomer that feeds slurry into the vessel. The downcomer is equipped with a nozzle for feeding pressurized flotation gas into the slurry in the downcomer. Further, the downcomer includes an outlet nozzle configured to introduce the ultrasonic shock wave into the mixture of gas and slurry as the mixture of gas and slurry exits the downcomer.

Figure 7 is a schematic of a third flotation system. As already disclosed, in an embodiment the flotation vessel 21 is a closed pressurized vessel, in which pressurized flotation can take place and from which flotation concentrate is removed by means of pressure. In one embodiment, no foam is formed in the container, but the loaded bubbles are collected before the foam is generated.

The inlet 22 may be arranged in the lower part of the flotation vessel 21, the overflow member 15 for removing flotation concentrate may be arranged in the upper part of the flotation vessel 21, and the outlet 25 for removing underflow may be arranged in the lower part of the flotation vessel 21. Since flow from one vessel to the next occurs due to the pressure generated in the vessels, the flotation vessels 21 can be installed at the same level (as shown).

In an embodiment, the outlet 25 for removing the underflow may be arranged in the upper part of the flotation vessel 21.

In one embodiment, the pressurized container comprises a mechanical stirrer. One example of such a vessel is known as a "direct flotation reactor" (DFR).

It should be noted here that all flotation vessels 21 arranged in the flotation system 20 may be of the same type, or alternatively there may be at least two types of flotation vessels.

The invention is not limited to the above-described embodiments only, but many variations are possible within the scope of the inventive concept defined by the appended claims. The attributes of different embodiments and applications may be combined with or replace the attributes of another embodiment or application within the scope of the present inventive concept.

The drawings and the related description are only intended to illustrate the idea of the invention. The invention can be varied in detail within the scope of the inventive idea defined in the appended claims.

Claims

1. A flotation plant, characterized in that it comprises:

flotation cell (1) comprising:

fluidized bed apparatus, including apparatus for forming a fluidized bed, and/or

Foaming device comprising means for forming a foam layer, wherein particles are supplied to interact with the foam layer,

the flotation plant further comprises:

a mill (2) in which, among other things,

the mill (2) being connected to a flotation unit (1) for receiving a product stream from the flotation unit,

the mill (2) comprises:

-a grinding structure (3) arranged to concentrate grinding energy to the particles of the product flow, an

A graded structure (4) at least partially integral with the abrasive structure (3) and arranged to direct particles to face the abrasive structure based on particle size such that a coarsest end of the particle size distribution is more abrasive than a finest end of the particle size distribution.

2. The flotation plant according to claim 1, characterized in that the mill (2) comprises:

a grinding chamber (5), and

a rotating element (6) arranged in the grinding chamber (5) for rotating therein.

3. The flotation plant according to claim 2,

the mill (2) comprises grinding media (7) arranged in the grinding chamber (5).

4. The flotation plant according to claim 3,

the usable volume of the grinding chamber (5) is filled to 70-80% with the grinding medium.

5. Flotation plant according to claim 3,

the grinding media (7) comprises one of the following: silica sand, smelting waste slag, ceramic balls and metal balls.

6. The flotation plant according to claim 5,

the grinding medium (7) is ceramic balls.

7. The flotation plant according to any of claims 2 to 6,

the cylindrical grinding chamber (5) is arranged at least substantially horizontally.

8. The flotation plant according to any of claims 2 to 6,

the cylindrical grinding chamber (5) is arranged at least substantially vertically.

9. The flotation plant according to any of claims 2 to 6,

the rotating element (6) comprises at least one of the following: a disc (8), a stirrer screw (13).

10. The flotation plant according to any of the claims 2 to 6, characterized in that the mill (2) comprises:

a cylindrical grinding chamber (5),

a rotating shaft (9) arranged concentrically with the grinding chamber (5) and arranged within the grinding chamber,

a series of discs (8) mounted on the rotating shaft (9),

the discs (8) forming a grinding volume (10) between the discs,

the disc (8) comprises at least one aperture (11) extending from one grinding volume (10) to the other.

11. The flotation plant according to claim 10, characterized in that the mill (2) comprises:

a counter ring (12) arranged in at least some of the grinding volumes (10), the counter ring being attached to a wall of the grinding chamber (5) and extending towards the rotation axis (9).

12. The flotation plant according to claim 10, wherein at least one of the trays (8) comprises a profiled surface.

13. The flotation plant according to any of the claims 2 to 6, characterized in that the mill (2) comprises:

an agitator screw (13) arranged concentrically with and within the grinding chamber (5) for rotation therein.

14. The flotation plant according to any one of claims 2 to 6, wherein at least a part of the wall of the grinding chamber (5) comprises a grid lining (14).

15. The flotation plant according to any one of claims 1 to 6, characterized in that the flotation unit (1) is provided with:

an overflow member (15), and

the mill (2) is connected to the overflow member (15) so that the product stream comprises a flotation concentrate stream received from the overflow member (15).

16. The flotation plant according to any of the claims 1 to 6, characterized in that the flotation unit (1) is provided with:

a classification unit (17) or a dewatering unit (24),

the classifying unit (17) or the dewatering unit (24) is connected to an overflow member (15) of the flotation unit or to a second outlet (27) of the flotation unit,

the mill (2) is connected to the classification unit (17) or the dewatering unit (24) so that the product stream arranged to be fed into the mill comprises coarse particles of a size above the classification threshold of the classification unit or solids of the dewatering unit.

17. The flotation plant according to claim 16,

the classifying unit (17) or the dewatering unit (24) is connected to a second outlet (27) of the flotation unit.

18. The flotation plant according to claim 16,

the flotation unit (1) is provided with a classifying unit (17).

19. The flotation plant according to claim 18,

the classifying unit (17) comprises a classifying cyclone.

20. The flotation plant according to claim 16,

the flotation plant further comprises a recovery system (16) provided with a dewatering unit (24).

21. The flotation plant according to claim 20,

the dewatering unit (24) includes at least one of a dewatering cyclone, a filter, a settling unit, or a centrifuge.

22. The flotation plant according to claim 21,

the dewatering unit (24) comprises the dewatering cyclone.

23. The flotation plant according to any one of claims 1 to 6,

the flotation unit (1) comprises means for forming a fluidized bed.

24. The flotation plant according to any one of claims 1 to 6,

the flotation unit (1) comprises means for forming a froth layer, wherein particles are fed to interact with the froth layer in the froth layer, below the froth layer in close proximity thereto, or above the froth layer, or any combination thereof.

25. The flotation plant according to any one of claims 1 to 6,

the flotation unit (1) comprises means for forming a fluidized bed and means for forming a froth layer, wherein particles are fed to interact with the froth layer in the froth layer, below the froth layer in close proximity thereto, or above the froth layer, or any combination thereof.

26. The flotation plant according to any one of claims 1 to 6,

a pump (18) is arranged between the flotation unit (1) and the mill (2) for facilitating flow of the product stream between the flotation unit and the mill.

27. The flotation plant according to any one of claims 1 to 6, comprising:

a pre-grinding section (26) arranged to feed the flotation unit (1).

28. The apparatus of claim 27,

the pre-grinding part (26) comprises an autogenous grinding machine, a semi-autogenous grinding machine or a high-pressure grinding roller.

29. The flotation plant according to any one of claims 1 to 6, comprising:

a separation unit (23) for recovering large particles, the separation unit (23) being arranged before the flotation unit (1) or after the flotation unit (1) for receiving tailings from the flotation unit (1).

30. The flotation plant according to claim 29,

the separation unit (23) is arranged before the flotation unit (1).

31. The flotation plant according to claim 30,

the separation unit (23) is arranged after the flotation unit (1) for receiving tailings from the flotation unit.

32. The flotation plant according to claim 29,

the separation unit (23) comprises a screen or a grid.

33. The flotation plant according to claim 29,

the separation unit (23) is connected to a pre-grinding section (26) for further grinding.

34. The flotation plant according to any one of claims 1 to 6, comprising:

a dewatering unit arranged before the flotation unit (1) for removing water from the product stream to be fed into the flotation unit (1).

35. The flotation plant according to any one of claims 1 to 6,

the outlet (19) of the mill is connected to a flotation system (20) for feeding the flotation system, the flotation system (20) comprising:

at least one flotation vessel (21).

36. The flotation plant according to claim 35,

the flotation container (21) is:

fluidized bed apparatus, including apparatus for forming a fluidized bed, or

An apparatus comprising means for forming a foam layer, wherein particles are fed to interact with the foam layer in the foam layer, below the foam layer in close proximity thereto, or above the foam layer, or any combination thereof, or

Devices comprising means for pneumatic gas addition, or

Apparatus comprising a closed container for pressure flotation, wherein flotation concentrate is removed from the container by means of pressure, or

An apparatus, comprising:

an inlet (22) connected for receiving feed to be treated in the flotation vessel and arranged in a lower part of the flotation vessel (21),

an overflow member (15) for removing flotation concentrate, arranged in the upper part of the flotation vessel (21), an

An outlet (25) for removing underflow is arranged in the lower part of the flotation vessel (21).

37. The flotation plant according to claim 35,

the flotation container (21) is:

said means comprising means for pneumatic gas addition, or

The apparatus comprising a closed vessel for pressure flotation, wherein flotation concentrate is removed from the vessel by means of pressure, or

The apparatus, comprising:

an overflow member (15) for removing flotation concentrate, arranged in the upper part of the flotation vessel (21), and

38. The flotation plant according to claim 35,

the flotation system (20) comprises at least three flotation vessels (21) arranged in series such that an outlet (25) for removing the underflow of a preceding flotation vessel (21) is connected to an inlet (22) of a subsequent flotation vessel (21).

39. The flotation plant according to claim 35,

the flotation vessel (21) comprises an apparatus comprising:

40. The flotation plant according to claim 39, wherein the flotation container (21) comprises:

means for forming a foam layer.

41. The flotation plant according to claim 35,

the flotation vessel (21) comprises a closed vessel for pressurized flotation, wherein flotation concentrate is removed from the vessel by means of pressure.

42. The flotation plant according to claim 39, wherein the flotation container (21) comprises:

a mechanical agitator for agitating the slurry in the vessel.

43. The flotation plant according to claim 39, wherein the flotation container (21) comprises:

a mechanical stirrer for forming bubbles in the vessel.

44. The flotation plant according to claim 37,

the flotation vessel (21) comprises means for pneumatic gas addition.

45. The flotation plant according to claim 44,

the flotation vessel (21) is a froth separation device comprising means for forming a froth layer, the flotation vessel comprising:

an inlet (22) connected for receiving a feed to be treated in the flotation vessel and arranged in an upper part of the flotation vessel (21), and

an overflow member (15) for removing flotation concentrate is arranged in the upper part of the flotation vessel (21).

46. The flotation plant according to claim 45, wherein at least one of the flotation containers (21) comprises:

47. The flotation plant according to claim 45,

the flotation vessel (21) comprises a downcomer for the slurry feed, which downcomer is equipped with a nozzle for feeding pressurized flotation gas into the slurry in the downcomer.

48. The flotation plant according to claim 47,

the downcomer includes an outlet nozzle configured to introduce an ultrasonic shock wave into the slurry as it exits the downcomer.

49. The flotation plant according to any one of claims 1 to 6,

the mill (2) is deployed in an open circuit configuration.