CN216419787U

CN216419787U - Froth action flotation cell and mineral processing apparatus

Info

Publication number: CN216419787U
Application number: CN202121477689.9U
Authority: CN
Inventors: I·谢雷尔; A·林内
Original assignee: Metso Outotec Finland Oy
Current assignee: Metso Finland Oy
Priority date: 2020-06-30
Filing date: 2021-06-30
Publication date: 2022-05-03
Anticipated expiration: 2031-06-30
Also published as: AU2021302770A1; CN113856917A; WO2022003239A1; CL2022003790A1; EP4171828A1

Abstract

The present disclosure relates to a froth action flotation unit for separating an input slurry and a mineral processing apparatus, the froth action flotation unit comprising: a tank for holding a volume of slurry and a layer of foam over the volume of slurry; a coarse slurry feeding device for feeding a coarse slurry to the foam layer; and flotation gas feed apparatus for feeding flotation gas into the slurry volume such that the froth layer is maintained above the slurry volume, wherein the froth action flotation unit comprises: a fine slurry feed device for feeding fine slurry into the slurry volume; and a classification apparatus configured to classify the input slurry into a coarser slurry sub-portion and a finer slurry sub-portion to feed the coarser slurry sub-portion to the coarse slurry feed apparatus and the finer slurry sub-portion to the fine slurry feed apparatus.

Description

Froth action flotation cell and mineral processing apparatus

Technical Field

The present invention relates to mineral processing. In particular, the present invention relates to the separation of minerals from their ores by flotation, and more particularly to a froth action flotation unit and a mineral processing apparatus including the same.

Background

The energy consumption of the comminution process (especially grinding) usually constitutes a large part of the total energy consumption in mineral processing. Therefore, a great deal of effort has been put into reducing the energy consumption of grinding. This can generally be achieved by reducing the degree of dissociation of the ore, i.e. by increasing the average size of the ore particles prior to concentration. Standard mechanical flotation units are best suited for separating particles in the size range of about 20 to 150 μm. Therefore, alternatives are needed to increase the average particle size of the ore to over 150 μm.

One method of increasing the recovery of coarser particles is generally referred to as "separation-in-froth" flotation (separation in froth) or SIF flotation. However, conventional separation flotation cells in froth may be limited in their throughput due to their size relationship. In view of this, it may be desirable to develop new protocols relating to the separation of coarser particles.

SUMMERY OF THE UTILITY MODEL

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

According to a first aspect, there is provided a froth-interaction flotation unit for separating an input slurry. The froth action flotation unit includes: a tank for holding a volume of slurry (slurry volume) and a foam layer above the slurry volume; a coarse slurry feeding device (feeding arrangement) for feeding the coarse slurry to the foam layer; and flotation gas feed means to feed flotation gas into the volume of slurry. The froth action flotation unit includes: a fine slurry feed device to feed fine slurry into the slurry volume; and a classification apparatus configured to classify the input slurry to form a coarser slurry sub-section and a finer slurry sub-section, to feed the coarser slurry sub-section to the coarse slurry feeding apparatus and the finer slurry sub-section to the fine slurry feeding apparatus.

Said finer slurry sub-fraction having a solids sub-fraction phi^fsA solids sub-fraction phi which may be lower than the coarser slurry sub-fraction^cs。

The coarser slurry subportion has a solids subportion phi^csMay be in the range of 0.5 to 0.8, or in the range of 0.55 to 0.75, or in the range of 0.6 to 0.7.

Said finer slurry sub-fraction having a solids sub-fraction phi^fsMay be in the range of 0.05 to 0.35, or in the range of 0.1 to 0.25, or in the range of 0.15 to 0.2.

The classification apparatus may comprise a classification cyclone.

The classifying cyclone has a cut-off particle size, as measured under normal cyclone operating conditions

May be in the range of 15 μm to 200 μm, or 40 μm to 175 μm, or 60 μm to 150 μm, or 75 μm to 125 μm.

The can body may include: a launder having a launder lip for collecting foam from the foam layer; a fine slurry outlet located below the launder lip to collect output slurry from the slurry volume; and a coarse slurry outlet located below the fine slurry outlet for discharging a coarse output slurry from the slurry volume.

The froth action flotation unit may include: a solid-liquid separation device configured to collect an output slurry from the slurry volume via the fine slurry outlet and separate suspended solids and flotation liquid from the output slurry to form a solid portion and a liquid portion.

The solid-liquid separation device may be configured to direct the solids fraction out of the froth flotation unit.

The froth action flotation unit may include: a circulation device to circulate flotation liquid collected from the tank via the fine slurry outlet back to the tank.

The circulation device may be configured such that circulation of flotation liquid collected from the tank via the fine slurry outlet is achieved by adding this flotation liquid to fine slurry, wherein the fine slurry feed device is configured to feed the fine slurry into the slurry volume.

The tank may comprise a circulation inlet, and the circulation device may be configured to feed flotation liquid collected from the tank via the fine slurry outlet back into the tank via the circulation inlet.

The flotation gas feed apparatus may be configured to feed flotation gas into the volume of slurry by injecting flotation gas into flotation liquid, wherein the circulation apparatus may be configured to feed the flotation liquid back into the tank via the circulation inlet.

The tank may comprise a fine slurry inlet and a flotation gas inlet located below the fine slurry inlet, the fine slurry feeding apparatus being configured to feed fine slurry into the slurry volume via the fine slurry inlet, and the flotation gas feeding apparatus being configured to feed flotation gas into the slurry volume via the flotation gas inlet.

The tank may comprise a fine slurry-flotation gas mixture inlet and the flotation gas feed apparatus may be configured to feed flotation gas into the slurry volume by injecting flotation gas into the fine slurry, wherein the fine slurry feed apparatus is configured to feed the fine slurry into the slurry volume via the fine slurry-flotation gas mixture inlet.

The fine slurry feed device may comprise a slurry tank having a tank slurry outlet in a lower part of the slurry tank, the classification device may be configured to convey the finer slurry sub-fraction to the slurry tank, and the fine slurry feed device may be configured to feed fine slurry into the slurry volume via the tank slurry outlet.

The froth action flotation unit may include a flotation liquid feed apparatus to feed flotation liquid into the slurry volume.

The tank may comprise a flotation liquid inlet and the flotation liquid feed apparatus may be configured to feed flotation liquid into the volume of slurry via the flotation liquid inlet.

The flotation liquid feed apparatus may be configured to feed flotation liquid into the slurry volume by adding flotation liquid to fine slurry, wherein the fine slurry feed apparatus is configured to feed into the slurry volume.

The can may include a downwardly tapering base cone.

The froth action flotation unit may include a slurry agitation device to agitate the volume of slurry.

The froth flotation unit may be implemented as a fluid bed flotation unit

Throughout the specification, "flotation" may refer to separation of the mixture by adhesion of substances in the mixture at an interface. In flotation, the separation of the mixture can be based on the difference in hydrophobicity of the substances in the mixture. As used herein, "separating" may refer to extracting or removing material from a mixture for use or disposal.

Further, "froth flotation" may refer to flotation that utilizes froth for separation. Herein, "froth" may refer to a dispersion comprising a larger volume portion of the flotation gas dispersed as bubbles in a smaller volume portion of the flotation liquid. In general, the foam may or may not be stabilized by solid particles. In froth, the flotation gas bubbles may generally have an average diameter greater than or equal to 1 mm. Additionally or alternatively, the average distance between adjacent flotation gas bubbles in the froth that is not stabilized by solid particles may be substantially less than or equal to a few tens of microns, for example, less than or equal to 50 μm or 30 μm. Naturally, in froth stabilized by solid particles, the average distance between adjacent flotation gas bubbles increases in proportion to the average size and number of said solid particles.

In the present disclosure, a "layer" may refer to a generally sheet-like element disposed on a surface. A layer may or may not be path connected. Some layers may be locally path connected and disconnected. Although a layer may generally comprise a plurality of sub-layers of different material compositions, a "foam layer" may also refer to a layer comprising, or consisting essentially of, foam.

The term "flotation gas" may refer to any gaseous substance suitable for use in flotation. Although air is often used as the flotation gas in practice, other types of gaseous substances as known to the person skilled in the art may also be used.

"flotation solution" on the other hand may refer to any liquid substance or mixture suitable for use in flotation. Although water or an aqueous solution is often used as the flotation liquid in practice, other types of liquid substances known to the person skilled in the art may also be used.

Throughout the specification, "froth flotation" may refer to froth flotation in which slurry is fed to a froth layer. Herein, "feeding the slurry to the foam layer" may mean feeding said slurry onto and/or into and/or immediately below said foam layer, for example at most 50cm, or at most 40cm, or at most 30cm, or at most 20cm, or at most 10cm or less. Additionally or alternatively, in embodiments, the height of the launder lip defines the height of the upper surface of the foam layer, and feeding the slurry into the foam layer may refer to feeding the slurry into the tank at the height of the launder lip and/or at a position of at most 60cm, or at most 50cm, or at most 40cm, or at most 30cm, or at most 20cm below the height of the launder lip.

Herein, a "unit" may refer to an apparatus adapted or configured to perform at least one specific process. Naturally, a "flotation unit" may refer to a unit adapted or configured to subject a material to flotation. Naturally, a "froth action flotation unit" may refer to a unit configured or adapted to separate material by froth action flotation. A unit may generally comprise one or more components, and each of the one or more components may be categorized as a device belonging to the unit.

A "device" of a unit configured to perform a process may refer to a set of components of the unit adapted or configured to perform at least one particular sub-process of the process. Thus, a "unit comprising a device" may mean that the unit comprises the components belonging to the device. In general, a device may include any components, such as mechanical, electrical, pneumatic, and/or hydraulic components, necessary and/or beneficial for performing its particular sub-process.

In the present disclosure, a "flotation gas feed apparatus" may refer to an arrangement of components (apparatus) of a flotation cell adapted or configured to feed flotation gas into a tank of the flotation cell. In general, the flotation gas supply apparatus may comprise any component suitable for supplying flotation gas into the tank (or necessary for such supply), for example, one or more distributors (bubblers), such as sparging and/or cavitation distributors, and/or one or more static mixers.

In this specification, a "can" may refer to a container adapted or configured to hold a fluid, such as a liquid.

Also, "slurry" may refer to a dispersion (dispersion) comprising solid particles suspended in the continuous phase of the flotation liquid. Thus, a "slurry volume" may refer to a quantity of slurry. In flotation, the slurry may be generally referred to as coarse slurry or fine slurry, depending on its properties.

Throughout this specification, "raw slurry" may refer to a slurry containing solid particles of large diameter. As known to those skilled in the art, the definition of coarse slurry may be application-specific and/or ore-specific. For example, in some embodiments, a coarse slurry may refer to a slurry having a particle size distribution with a percent screen less than 80% at a mesh size of 425 μm (sieve size ), or at a mesh size of 355 μm, or at a mesh size of 250 μm, or at a mesh size of 180 μm, or at a mesh size of 150 μm, or at a mesh size of 125 μm, or at a mesh size of 105 μm.

Thus, a "coarse slurry feeding apparatus" may refer to an arrangement of components of a flotation cell that is adapted or configured to feed coarse slurry into a tank of the flotation cell. In general, coarse slurry feeding equipment may or may not also be suitable for feeding fine slurry into the tank of the flotation cell.

On the other hand, "fine slurry" may refer to a slurry containing solid particles of small diameter. As known to those skilled in the art, the definition of fine slurry may be application specific and/or ore specific. For example, in some embodiments, a fine slurry may refer to a slurry having a particle size distribution with a percent sieving greater than or equal to 80% at a mesh size of 425 μm, or at a mesh size of 355 μm, or at a mesh size of 250 μm, or at a mesh size of 180 μm, or at a mesh size of 150 μm, or at a mesh size of 125 μm, or at a mesh size of 105 μm.

Thus, a "fine slurry feeding apparatus" may refer to an arrangement of components of a flotation cell that is adapted or configured to feed fine slurry into a tank of the flotation cell. In general, the fine slurry feeding apparatus may or may not be adapted to feed coarse slurry into the tank of the flotation cell. The fine slurry feeding device may or may not be configured to feed fine slurry into the tank of the flotation cell below the fine slurry outlet and/or at a lower part of said tank.

Throughout this specification, "classification" may refer to sorting of solid particles in a slurry to form at least two (i.e., two, three, or more) slurry sub-fractions based on differences in settling (settling) velocities of the solid particles in the slurry. In practice, the classification of the slurry results in the coarser particles in the slurry being preferentially directed to one or more coarser slurry sub-fractions and the finer particles in the slurry being preferentially directed to one or more finer slurry sub-fractions. Naturally, "classification equipment" may just refer to an arrangement of components of a flotation cell configured or adapted to classify a slurry.

Also, a "subpart" may refer to a portion of a mixture resulting from the separation of the mixture. Thus, a "slurry sub-fraction" may refer to a sub-fraction that comprises slurry and results from separation of the slurry; "coarser pulp sub-fraction" may refer to a pulp sub-fraction containing solid particles of larger average size (median size) by mass; and "finer slurry sub-fraction" may refer to a slurry sub-fraction comprising solid particles of smaller average size by mass compared to the larger average size by mass of a coarser slurry sub-fraction.

In general, a classification apparatus of a froth flotation unit configured to feed a coarser pulp sub-fraction to a coarse pulp feeding apparatus and a finer pulp sub-fraction to a fine pulp feeding apparatus may increase the throughput (throughput) and/or the overall collection efficiency of the froth flotation unit. In particular, by configuring the classifying equipment of the froth action flotation unit in this way, the ability of the froth action flotation unit to feed slurry to the froth layer can be distributed more towards the coarse slurry separation. Additionally or alternatively, the recovery of fine slurry may be increased, since the probability of attachment of finer particles to flotation gas bubbles is higher in the slurry than in the froth.

In an embodiment of the first aspect, the finer slurry sub-fraction has a solids sub-fraction φ^fsA sub-fraction of solids phi smaller (lower) than the sub-fraction of the coarser slurry^cs。

As used herein, a "solids sub-fraction" may refer to the mass (m) of solids in a slurry sample_s) Mass (m) of the slurry sample_sl) The ratio of (a) to (b).

In general, maintain a higher phi^csIs favorable for froth flotation.On the other hand, lower phi^fsIntroduction of the fine slurry into the slurry volume can be facilitated.

In an embodiment of the first aspect, the coarser slurry fraction has a solids sub-fraction φ^csIn the range of 0.5 to 0.8, or in the range of 0.55 to 0.75, or in the range of 0.6 to 0.7.

In general, the coarser slurry fraction has a solids fraction φ in the range of 0.5 to 0.8, or in the range of 0.55 to 0.75, or in the range of 0.6 to 0.7^csThe feeding of slurry from the coarser slurry subportion to the foam layer may be facilitated.

In an embodiment of the first aspect, the finer slurry sub-fraction has a solids sub-fraction φ^fsIn the range of 0.05 to 0.35, or in the range of 0.1 to 0.25, or in the range of 0.15 to 0.2.

In general, the finer slurry sub-fraction has a solids sub-fraction φ in the range of 0.05 to 0.35, or in the range of 0.1 to 0.25, or in the range of 0.15 to 0.2^fsThe feeding of slurry from the finer slurry sub-portion into the slurry volume may be facilitated. Additionally or alternatively, with such a solid sub-portion phi^fsThe finer slurry sub-fraction of (a) may facilitate maintaining the viscosity of the slurry volume within a particular viscosity range. Additionally or alternatively, a finer slurry sub-fraction having such a solids sub-fraction may facilitate maintaining a suitable level of stability of the froth layer by the solid particles.

In an embodiment of the first aspect, the classification apparatus comprises a classification cyclone.

Throughout the specification, "cyclone" or "cyclone" may refer to a device suitable for separating suspended solid particles in a slurry. Generally, a cyclone comprises: a generally cylindrical feed portion; an overflow pipe extending upward from the feeding part; and a generally conical base extending from the feed portion and terminating in a tip opening. During operation of the cyclone, the slurry is fed tangentially into the feed portion so as to create a vortex flow within the cyclone. In a cyclone, the slurry fed into the cyclone is divided into an underflow and an overflow.

Herein, "underflow" and "overflow" from the cyclone may refer to the product stream discharged via the tip opening of the cyclone and the overflow pipe, respectively.

In the present disclosure, "classification cyclone" may refer to a cyclone configured or adapted to classify solid particles in a slurry. In mineral processing, classification cyclones are usually used to separate coarser particles from finer particles in order to limit the resource consumption of the grinding circuit. In general, classifying cyclones can have a cutoff particle size greater than 10 μm, as measured under typical cyclone operating conditions. Additionally or alternatively, the classifying cyclone may have an inner diameter, measured across its feed, greater than or equal to 8 cm.

Here, "normal cyclone operating conditions" may at least mean that the cyclone is kept upright; a feed slurry consisting essentially of water and spherical particles was used, having a density of 2650kg/m with a feed slurry solids fraction of 0.02³(ii) a And a pressure drop of 70kPa was maintained. While the cut-off particle size of the cyclone may be measured under normal cyclone operating conditions, any cyclone may or may not be operated in a flotation cell under normal cyclone operating conditions.

Herein, the "cut-off particle size" of a cyclone may refer to a particle size such that a first half and a second half of solid particles in a feed slurry of said particle size are distributed to the underflow and overflow, respectively, of said cyclone. In general, solid particles smaller than the cut-off size are preferentially directed towards the overflow, whereas solid particles larger than the cut-off size are preferentially directed towards the underflow.

In general, a classification apparatus comprising a classification cyclone may provide a higher throughput with a reduced footprint and/or simplify the classification apparatus.

In an embodiment of the first aspect, the classifying cyclone has a cut-off particle size, measured under normal cyclone operating conditions

At a temperature of from 15 μm to 200 μm, or from 40 μm to 175 μm,Or 60 μm to 150 μm, or 75 μm to 125 μm.

In general, the cut-off particle size in the range of 15 μm to 200 μm, or 40 μm to 175 μm, or 60 μm to 150 μm, or 75 μm to 125 μm, as measured under typical cyclone operating conditions

A froth action flotation unit (even with a single classification stage) can be provided with an advantageous distribution of the input slurry to form a coarser slurry sub-fraction and a finer slurry sub-fraction.

In an embodiment of the first aspect, the tank comprises: a launder having a launder lip to collect foam from the foam layer; a fine slurry outlet located below the launder lip to collect the output slurry from the slurry volume; and a coarse slurry outlet located below the fine slurry outlet for discharging a coarse output slurry from the slurry volume.

Throughout the specification, "launder" may refer to a trough arranged in the upper part of a tank for collecting flotation product from the tank. Typically, the launder comprises a launder lip. Here, the "launder lip" may refer to the part of the launder over which the flotation product is arranged to flow into the launder for collection.

In the present specification, "outlet" may refer to a discharge means (means) for fluid, such as an opening or a through hole. In general, the outlet may be arranged in the tank in any suitable manner, for example at the side wall or bottom of the tank, or at one end of a conduit or other suitable pipe through which fluid passes, or at one end of a conduit or other suitable pipe through which fluid flows on the side wall of the tank.

Thus, a "fine slurry outlet" may refer to an outlet configured or adapted to allow fine slurry to exit the tank. The fine slurry outlet may additionally be configured or adapted to discharge any other suitable type of slurry (e.g., coarse slurry and/or virgin slurry) out of the tank. Typically, the fine slurry outlet is arranged in the upper part of the tank. In various embodiments, the tank includes a launder having a launder lip, and the fine slurry outlet may be arranged below the launder lip. Additionally or alternatively, in various embodiments, the tank includes a coarse slurry outlet, and the fine slurry outlet may be disposed above the coarse slurry outlet.

On the other hand, the "raw slurry outlet" may refer to an outlet configured or adapted to discharge raw slurry out of the tank. The raw slurry outlet may additionally be configured or adapted to discharge any other suitable type of slurry (e.g., fine slurry and/or virgin slurry) out of the tank. Typically, a coarse slurry outlet is arranged in the lower part of the tank for collecting flotation products from said tank.

In general, arranging the fine slurry outlet below the launder lip of the launder of a tank and above the coarse slurry outlet of said tank may enable the major collection of coarser particles of a first type (e.g. mineral particles) and finer particles of a second type (e.g. gangue particles) from the slurry volume, which may be relatively easily further separated. Additionally or alternatively, arranging the fine slurry outlet below a launder lip of a launder of a tank and above a coarse slurry outlet of the tank may enable the fine slurry outlet to be used to provide a discharge path from the tank such that a fluidized bed may extend below the fine slurry outlet.

In an embodiment of the first aspect, the froth action flotation unit comprises a solid-liquid separation device configured to collect an output slurry from the slurry volume via the fine slurry outlet and to separate suspended solids and flotation liquid from the output slurry to form a solid fraction and a liquid fraction.

Throughout this specification, "solid-liquid separation" may refer to the separation of suspended solid particles and flotation solution from a slurry. Thus, a "solid-liquid separation device" may refer to an arrangement of components of a flotation unit configured or adapted for solid-liquid separation of a slurry.

Furthermore, the "solids fraction" formed by separating suspended solid particles and flotation liquid from a slurry may refer to a sub-fraction of the slurry resulting from the solid-liquid separation of the slurry, wherein at least 90% by mass, or at least 95% by mass, or at least 98% by mass of the suspended solid particles in the slurry have been collected in the sub-fraction.

On the other hand, the "liquid fraction" formed by separating suspended solid particles and flotation liquid from the slurry may refer to a sub-fraction of the slurry resulting from the solid-liquid separation of the slurry and which comprises at least 90% of the mass, or at least 95% of the mass, or at least 98% of the mass, or at least 99% of the mass of the flotation liquid.

In general, a froth action flotation unit including a solid-liquid separation device configured to collect an output slurry from a slurry volume via a fine slurry outlet and separate suspended solids and flotation liquid from the output slurry to form a solid portion and a liquid portion, flotation of the solid portion may be further facilitated. Additionally or alternatively, a froth action flotation unit comprising such a solid-liquid separation device may enable guiding (channel) of flotation liquid from the output slurry within the mineral processing apparatus in order to maintain operability of the apparatus and/or unit with higher flotation liquid consumption.

In an embodiment of the first aspect, the solid-liquid separation device is configured to direct the solid fraction out of the froth flotation unit.

In general, the solid-liquid separation equipment of a froth action flotation unit configured to direct a solids fraction out of the froth action flotation unit may enable further processing (e.g., flotation) of the solid particles in the solids fraction at a distance from the froth action flotation unit.

In an embodiment of the first aspect, the froth action flotation unit comprises a circulation device for circulating flotation liquid collected from the tank via the fine slurry outlet back into the tank.

Throughout the specification, "circulation" may refer to a fluid path along a generally circular path. In general, the cycle may be intermittent, repeated (e.g., periodic), or continuous. Thus, "circulation equipment" may refer to equipment configured and adapted to circulate flotation liquid collected from a tank of the flotation cell back to the flotation cell in the tank. In general, the flotation liquid may be fed back into the tank in any suitable form (e.g. in liquid form and/or as part of a slurry or slurry-flotation gas mixture) by means of a circulation device.

In general, a flotation unit including circulation equipment may enable the formation of an internal slurry feedback loop for the tank that may increase the recovery of solid particles from the slurry. Additionally or alternatively, a flotation unit comprising a circulation device may reduce the consumption of flotation liquid of a froth action flotation unit.

In an embodiment of the first aspect, the circulation device is configured to circulate the flotation liquid collected from the tank via the fine slurry outlet by adding such flotation liquid to the fine slurry, the fine slurry feed device being configured to feed the fine slurry into the slurry volume.

In general, the structure of the flotation unit can be simplified by circulating flotation liquid by adding it to the fine slurry to be fed into the tank by the fine slurry feeding device.

In an embodiment of the first aspect, the tank comprises a circulation inlet, and the circulation device is configured to feed the flotation liquid collected from the tank via the fine slurry outlet back into the tank via the circulation inlet.

Throughout the specification, "inlet" may refer to an access means for a fluid, such as an opening or through-hole. In general, the inlet may be arranged in the tank in any suitable manner, for example at the side wall or bottom of the tank, or at one end of a conduit or other suitable pipe for fluid to pass through the side wall or bottom of the tank, or at one end of a conduit or other suitable pipe for fluid to pass over the side wall of the tank.

Thus, a "circulation inlet" may refer to an inlet configured or adapted to introduce fluid conveyed along a generally annular path into a tank. Additionally or alternatively, the circulation inlet of the tank may be configured or adapted to feed flotation liquid collected from the tank back into the tank. In general, the flotation liquid may be fed as a fluid through a circulating inlet of the tank, which includes the flotation liquid and optionally one or more of solid particles and flotation gas collected from the tank.

In general, by feeding flotation liquid into the tank for circulating the flotation liquid via a circulation inlet separate from any inlet into which fine pulp is fed, it is possible to make it possible to operate the circulation equipment independently of the fine pulp feeding equipment, which in turn may increase the reliability of the flotation unit.

In an embodiment of the first aspect, the flotation gas feed device is configured to feed flotation gas into the slurry volume by injecting flotation gas into the flotation liquid, and the circulation device is configured to feed the flotation liquid back into the tank via the circulation inlet.

In an embodiment of the first aspect, the tank comprises a fine slurry inlet and a flotation gas inlet below the fine slurry inlet, the fine slurry feeding device is configured to feed fine slurry into the slurry volume via the fine slurry inlet, and the flotation gas feeding device is configured to feed flotation gas into the slurry volume via the flotation gas inlet.

In this specification, "fine slurry inlet" may refer to an inlet configured or adapted to let fine slurry into the tank, and/or "flotation gas inlet" may refer to an inlet configured or adapted to let flotation gas into the tank.

In general, arranging the flotation gas inlet below the fine slurry inlet may increase the recovery of solid particles entering the tank via the fine slurry inlet.

In an embodiment of the first aspect, the tank comprises a fine slurry-flotation gas mixture inlet, the flotation gas feed apparatus is configured to feed flotation gas into the slurry volume by injecting flotation gas into the fine slurry, and the fine slurry feed apparatus is configured to feed the fine slurry into the slurry volume via the fine slurry-flotation gas mixture inlet.

In the present disclosure, a "fine slurry-flotation gas mixture inlet" may refer to an inlet configured or adapted to let a mixture of fine slurry and flotation gas enter the tank.

In general, feeding flotation gas into a slurry volume by injecting the flotation gas into a fine slurry (wherein a fine slurry feed device is configured to feed the fine slurry into the slurry volume) can promote adhesion of flotation gas bubbles to solid particles in the fine slurry.

In an embodiment of the first aspect, the fine pulp feeding device comprises a pulp chest with a chest pulp outlet in a lower part of the pulp chest, the classifying device is configured to direct a sub-fraction of the fine pulp to the pulp chest, and the fine pulp feeding device is configured to feed the fine pulp into the pulp volume via the chest pulp outlet.

In the present disclosure, "well" may refer to a reservoir, such as a pit or container, adapted or configured to collect and/or hold (hold) a liquid. Thus, "slurry tank" may refer to a tank for collecting and/or holding slurry.

In general, collecting the fine slurry to be fed to the slurry volume from the slurry tank may increase the solids sub-fraction of the fine slurry to be fed to said slurry volume, which in turn may increase the solids sub-fraction of the coarse slurry collected via the coarse slurry outlet. This may help to reduce the consumption of flotation liquid in the flotation cell. Additionally or alternatively, when the froth action flotation unit comprises a classification apparatus to separate the input slurry into a coarser slurry sub-fraction to be fed to the froth layer and a finer slurry sub-fraction to be fed into the volume of slurry below the froth layer, the finer slurry sub-fraction may have a relatively low solids sub-fraction, and increasing the solids sub-fraction may increase the solids particles recovered from both the coarser slurry sub-fraction and the finer slurry sub-fraction.

In an embodiment of the first aspect, the froth action flotation unit comprises a flotation liquid feed apparatus for feeding flotation liquid into the slurry volume.

In the present disclosure, "flotation liquid feed apparatus" may refer to an arrangement of components (arrangement) of a flotation unit configured or adapted to feed flotation liquid into a tank of the flotation unit from a source external to the flotation unit, such as a process water unit or a body of water of a mineral processing plant.

The beneficial effects of the utility model mainly comprise: a flotation unit including a flotation liquid feed apparatus can facilitate maintaining a top surface of the slurry volume at a set distance from a launder lip of a launder of a tank. Additionally or alternatively, a flotation unit including a flotation liquid feed apparatus may facilitate control of the viscosity of the slurry in the tank.

In an embodiment of the first aspect, the tank comprises a flotation liquid inlet, and the flotation liquid feed apparatus is configured to feed flotation liquid into the slurry volume via the flotation liquid inlet.

Herein, a "flotation liquid inlet" may refer to an inlet configured or adapted to let flotation liquid into the tank.

In an embodiment of the first aspect, the flotation liquid feed device is configured to feed flotation liquid into the slurry volume by adding flotation liquid to the fine slurry, wherein the fine slurry feed device is configured to feed the fine slurry into the slurry volume.

In an embodiment of the first aspect, the can body comprises a downwardly tapering base cone.

Throughout the specification, the "bottom cone" of a tank may refer to a generally funnel-shaped and downwardly tapering bottom structure of the tank that is adapted or configured to direct settled solid particles towards an outlet or inlet.

In general, a can body including a base cone may reduce sanding in the can body.

In an embodiment of the first aspect, the froth action flotation unit comprises a slurry agitation device for agitating the volume of slurry.

Throughout this specification, "agitating" may refer to agitating, mixing, and/or disturbing a fluid, such as a liquid.

Thus, "slurry stirring device" may refer to an arrangement of components of a flotation unit that are configured or adapted to stir slurry.

In general, the slurry-agitating apparatus may increase the uniformity of the volume of slurry in the tank. Additionally or alternatively, a froth action flotation unit including a slurry agitation device may facilitate maintaining a fluidized bed within the volume of slurry in the tank.

In an embodiment of the first aspect, the froth action flotation unit is implemented as a fluid bed flotation unit.

Throughout this disclosure, "fluidized bed" may refer to a mixture of solids and liquids that exhibits fluid-like properties. As known to those skilled in the art, a fluidized bed may be maintained by passing a pressurized fluid (i.e., a liquid and/or a gas) through the particulate medium.

Thus, "fluidized bed flotation" may refer to a flotation in which a fluidized bed is maintained in a slurry volume by passing a flotation liquid and/or a flotation gas through the volume as appropriate, and a "fluidized bed flotation unit" may refer to a unit adapted or configured to subject a material to fluidized bed flotation.

In general, maintaining a fluidized bed in the tank of a flotation cell can increase the recovery of coarser particles. Additionally or alternatively, when coarse slurry is fed to a froth layer for froth flotation, and a fluidized bed is maintained in the slurry volume below the froth layer, coarser particles of the coarse slurry that have inadvertently fallen into the slurry volume may settle through the fluidized bed and may be more efficiently recollected to the froth layer.

According to a second aspect, the present disclosure relates to the use of a froth action flotation unit according to the first aspect or any embodiment thereof for separating valuable material suspended in a slurry.

In an embodiment of the second aspect, the present disclosure relates to the use of a froth action flotation unit according to the first aspect or any embodiment thereof for separating particles comprising copper (Cu) from low grade ore.

According to a third aspect, there is provided a mineral processing apparatus comprising a froth action flotation unit according to the first aspect or any embodiment thereof.

Throughout the specification, "apparatus" may refer to equipment adapted or configured to perform a systematic series of processes. The device may comprise any suitable means, such as one or more units. Thus, "mineral processing apparatus" may refer to apparatus adapted or configured to separate minerals from ore. The mineral processing plant may in principle comprise any unit suitable or necessary for flotation and, optionally, for pre-processed material before flotation and/or post-processed material after flotation.

In an embodiment of the third aspect, the mineral processing apparatus comprises a comminution unit configured to grind ore to form ground ore, mix the ground ore with a flotation liquid to form a raw slurry, and feed the raw slurry to a froth action flotation unit.

Throughout the specification, "pulverization" may refer to any action taken to reduce the average particle size of a solid material. Thus, crushing may include, for example, crushing and/or grinding. In mineral processing, comminution is commonly used to dissociate valuable minerals from gangue.

Thus, a "size reduction unit" may refer to a device adapted or configured to reduce the average particle size of a solid material.

In general, a comminution unit configured to feed raw slurry to a froth action flotation unit may allow a greater amount of gangue to be removed at an earlier stage, which may in turn simplify the structure of the mineral processing apparatus downstream of the froth action flotation unit and/or reduce the overall energy and/or flotation liquid consumption of the mineral processing apparatus. The froth action flotation unit according to the present description may be particularly suitable for flotation of slurries with a broad particle size distribution. Thus, the comminution unit may feed such a froth action flotation unit with raw pulp, which may have a particle size distribution that mainly depends on the characteristics of the comminution process performed by the comminution unit. As is known to the person skilled in the art, such a particle size distribution may (substantially) follow, for example, the so-called Weibull distribution (Weibull distribution), also known as the roxn-solomon distribution (Rosin-Rammler distribution) in connection with mineral processing.

In an embodiment of the third aspect, the mineral processing apparatus comprises a comminution unit, a pre-classification unit and a primary flotation unit. The comminution unit is configured to grind ore to form ground ore, mix the ground ore with a flotation liquid to form a raw slurry, and feed the raw slurry to the pre-classification unit. The pre-classification unit is configured to classify the raw slurry to form a coarser raw slurry sub-fraction and a finer raw slurry sub-fraction, and to feed the finer raw slurry sub-fraction to the primary flotation unit. The primary flotation unit is configured to sub-divide the finer raw slurry into an overflow and an underflow and feed the underflow to the froth action flotation unit.

In general, in standard flotation, the underflow from the primary flotation unit may include a considerable amount of coarser particles of the valuable mineral mixed with finer gangue particles. Since the froth action flotation unit according to the present description may be particularly suitable for flotation of slurries having a wide particle size distribution, a primary flotation unit configured to feed its underflow to the froth action flotation unit according to the present description may facilitate further flotation of the underflow. Naturally, in the case of reverse flotation, similar considerations apply mutatis mutandis.

According to a fourth aspect, a method of separating an input slurry using froth action flotation is provided. The method comprises the following steps: providing a tank for holding a volume of slurry and a foam layer over the volume of slurry; feeding flotation gas into the slurry volume; classifying the input slurry to form a coarser slurry sub-fraction and a finer slurry sub-fraction; feeding a coarser slurry sub-portion to the foam layer; and feeding a sub-portion of the finer slurry to the slurry volume.

In an embodiment of the fourth aspect, the method comprises maintaining a fluidised bed in the volume of slurry.

In an embodiment of the fourth aspect, the finer slurry sub-fraction has a solids sub-fraction φ^fsA sub-fraction of solids phi lower than the coarser slurry sub-fraction^cs。

In an embodiment of the fourth aspect, the coarser slurry sub-fraction has a solids sub-fraction φ^csIn the range of 0.5 to 0.8, or in the range of 0.55 to 0.75, or in the range of 0.6 to 0.80.7 in the range.

In an embodiment of the fourth aspect, the finer slurry sub-fraction has a solids sub-fraction φ^fsIn the range of 0.05 to 0.35, or in the range of 0.1 to 0.25, or in the range of 0.15 to 0.2.

Drawings

The disclosure will be better understood from a reading of the following detailed description taken in conjunction with the drawings in which:

figure 1 shows a schematic of a froth action flotation cell,

FIG. 2 depicts a schematic of another froth action flotation unit, an

Figure 3 shows a schematic view of a mineral processing plant,

FIG. 4 depicts a schematic view of another mineral processing plant, an

Figure 5 illustrates a method of separating an input slurry using froth action flotation.

Unless specifically stated to the contrary, any of the preceding figures may not be drawn to scale, such that any elements in the figures may be drawn to an imprecise scale relative to other elements in the figures, so as to highlight certain structural aspects of the embodiments of the figures.

Moreover, corresponding elements in the embodiments of any two of the preceding figures may not be to scale relative to each other in the two figures to highlight certain structural aspects of the embodiments of the two figures.

[ List of reference numerals ]

Cut-off particle size of classifying cyclone

Cut-off particle size of solid-liquid separation cyclone

φ^csSolids subportion of the coarser slurry subportion

φ^foSolids sub-fraction of the finer slurry sub-fraction

φ^spSolid sub-fraction of the solid fraction

φ^osSolids subsection of output slurry

φ^lpSolid sub-fraction of the liquid fraction

d^fDepth of foam layer

Opening diameter of coarse slurry outlet

1000 froth flotation cell

1001 volume of slurry

1002 foam layer

1003 foam

1004 fluidized bed

1100 tank

1101 flow groove

1102 runner lip

1103 fine pulp inlet

1104 fine slurry-flotation gas mixture inlet

1105 bottom cone part

1106 crude slurry outlet

1107 coarse output slurry

1108 flotation gas inlet

1109 flotation liquid inlet

1110 fine slurry outlet

1111 circulation inlet

1200 coarse slurry feeding apparatus

1201 coarse pulp

1300 flotation gas supply apparatus

1301 flotation gas

1302 flotation gas

1303 flotation gas

1400 fine pulp feeding apparatus

1401 fine pulp

1402 slurry pool

1403 pond slurry outlet

1500 flotation solution feed apparatus

1501 flotation solution

1502 flotation solution

1600 grading equipment

1601 inputting slurry

1602 coarser pulp subportion

1603 finer slurry sub-fraction

1604 grading cyclone

1700 solid-liquid separation equipment

1701 output pulp

1702 solid part

1703 liquid part

1704 solid-liquid separation cyclone

1800 circulating equipment

1801 flotation solution

1802 flotation solution

1900 slurry stirring equipment

1901 rotor

1902 drive shaft

2000 froth flotation cell

2001 volume of slurry

2002 foam layer

2003 foam

2100 tank body

2101 flow groove

2102 launder lip

2103 Fine pulp inlet

2106 crude slurry outlet

2107 coarse output slurry

2018 flotation gas inlet

2019 flotation liquid inlet

2200 coarse pulp feeding device

2201 coarse slurry

2300 flotation gas supply equipment

2301 flotation gas

2400 fine pulp feeding apparatus

2401 Fine pulp

2500 flotation liquid supply equipment

2501 flotation solution

2600 grading plant

2601 inputting the slurry

2602 coarser pulp subportion

2603A sub-fraction of a finer slurry

3000 mineral processing device

3100 grinding unit

3101 the virgin size

3200 froth flotation cell

3201 grading apparatus

4000 mineral processing device

4100 pulverizing unit

4101 raw slurry

4200 froth flotation unit

4201 grading apparatus

4300 Pre-classification unit

4301 coarser raw pulp subportion

4302 finer subportion of the original slurry

4400 Primary flotation Unit

4401 Overflow

4402 underflow

5000 method

5100 provides a can body

5200 supplying flotation gas

5300 grading the input slurry

5400 feeding a coarser pulp sub-fraction

5500 feeds a finer slurry sub-fraction

5600 maintenance fluidized bed

Detailed Description

Fig. 1 depicts a froth action flotation unit 1000 according to an embodiment.

The froth action flotation unit 1000 of the embodiment of fig. 1 may be used in so-called "standard flotation" where valuable minerals in the input slurry 1601 are collected as an overflow and gangue is directed to an underflow.

In other embodiments, a froth action flotation unit may be used in any suitable manner, for example in standard flotation and/or in so-called "reverse flotation" where the valuable minerals in the input slurry are directed to the underflow and gangue is collected as the overflow.

The froth action flotation unit 1000 of the embodiment of fig. 1 may be used in particular in so-called "rougher flotation", where a slurry containing a considerable amount of coarser solid particles is used as feed material for flotation.

In the embodiment of fig. 1, the froth action flotation unit 1000 includes a tank 1100.

The tank 1100 of the embodiment of fig. 1 is configured to hold (hold) a volume of slurry 1001 and a foam layer 1002 over the volume of slurry (slurry volume) 1001. In other embodiments, the tank may be configured or adapted to hold a volume of slurry and a foam layer above the volume of slurry (slurry volume).

Although a single tank is depicted in fig. 1, a froth action flotation unit may generally include one or more (e.g., one, two, three, four, etc.) tanks.

Can body 1100 of the embodiment of fig. 1 includes a spout 1101 having a spout lip 1102. Flow cell 1101 is configured to collect foam 1003 from foam layer 1002. In general, a tank including a launder may facilitate collection of flotation product from the tank. In other embodiments, the tank may include any suitable means (e.g., a launder with a launder lip) for collecting flotation product from an upper portion of the tank.

The froth action flotation unit 1000 may be configured to adjust the froth depth d of the froth layer 1002^fMaintained at about 10 cm.

Herein, "foam depth" may refer to the thickness of the foam layer in a tank, measured as the vertical distance between the surface of the slurry volume in the tank and the launder lip when the tank is in use.

In other embodiments, any suitable, substantially non-zero may be usedd^fE.g. d^fIn the range of 1cm to 20 cm.

The tank 1100 of the embodiment of fig. 1 comprises a fine slurry inlet 1103. In other embodiments, the tank may or may not include such a fine slurry inlet.

The tank 1100 of the embodiment of fig. 1 includes a fine slurry-flotation gas mixture inlet 1104. In other embodiments, the tank may or may not include such a fine slurry-flotation gas mixture inlet.

The tank 1100 of the embodiment of fig. 1 includes a raw slurry outlet 1106 to discharge a raw output slurry 1107 from the slurry volume 1001.

The coarse slurry outlet 1106 of this embodiment may have an opening diameter of about 10cm

In general, have a larger

May facilitate the passage of coarser solid particles through the coarse slurry outlet, which in turn may facilitate the flotation of (very) coarse slurries. In other embodiments, the raw slurry outlet may have any suitable outlet

For example

In the range of 2cm to 20 cm.

Herein, "opening diameter" may refer to the shortest lateral measurement of an opening, measured perpendicular to the expected fluid flow direction through the opening.

In the embodiment of fig. 1, can 1100 includes a bottom taper 1105 that tapers downward. In other embodiments, the can may or may not include such a bottom cone.

In the embodiment of fig. 1, the coarse slurry outlet 1106 is disposed at the bottom of the bottom cone 1105. In general, a tank including a base cone and a coarse slurry outlet at the base of the base cone may facilitate the discharge of very coarse slurry out of the tank and/or reduce sanding in the tank. In other embodiments, the coarse slurry outlet may be arranged in any suitable manner, such as at the bottom of the bottom cone. For example, in some embodiments, the canister may include: a flat bottom; a sidewall extending from the bottom; and a coarse slurry outlet disposed at the sidewall, and in some embodiments, the tank may include a bottom cone and a fine slurry inlet at a bottom of the bottom cone.

The tank 1100 of the embodiment of fig. 1 includes a flotation gas inlet 1108. In other embodiments, the tank may or may not include such a flotation gas inlet.

The flotation gas inlet 1108 of this embodiment is arranged below the fine slurry inlet 1103. In other embodiments, the flotation gas inlet and the fine slurry inlet may be arranged in any suitable manner, for example such that the flotation gas inlet is arranged below the fine slurry inlet.

The tank 1100 of the embodiment of fig. 1 includes a fine slurry outlet 1110 to collect the output slurry 1701 from the slurry volume 1001. In other embodiments, the tank may or may not include such a fine slurry outlet.

In the embodiment of fig. 1, the fine slurry outlet 1110 is disposed below the chute lip 1102 and above the coarse slurry outlet 1106. In other embodiments, the fine slurry outlet may be arranged in any suitable way, for example below the launder lip of the launder and above the coarse slurry outlet.

In the embodiment of fig. 1, the output slurry 1701 collected from the slurry volume 1001 via the fine slurry outlet 1110 may include coarse particles of valuable minerals and fine gangue particles. In other embodiments, the output slurry collected from the slurry volume via the fine slurry outlet may comprise any suitable type of particles, such as coarse particles and fine gangue particles of the value minerals, or fine particles and coarse gangue particles of the value minerals.

The tank 1100 of the embodiment of fig. 1 includes a flotation solution inlet 1109. In other embodiments, the tank may or may not include such a flotation liquid inlet.

The flotation liquid inlet 1109 of this embodiment is arranged below the fine slurry outlet 1110. In general, when a fluidized bed is to be maintained in a volume of slurry, arranging the flotation liquid inlet below the fine slurry outlet may enable the fluidized bed to be maintained with flotation liquid fed into the tank via the flotation liquid inlet. In other embodiments, the flotation liquid inlet may be arranged in any suitable manner, for example below the fine slurry outlet.

The tank 1100 of the embodiment of fig. 1 includes a circulation inlet 1111. In other embodiments, the tank may or may not include such a recycle inlet.

The circulation inlet 1111 of the embodiment of fig. 1 is arranged below the fine slurry outlet 1110. In general, when a fluidized bed is to be maintained in the slurry volume, arranging the recycle inlet below the fine slurry outlet may enable the fluidized bed to be maintained with flotation liquid fed into the tank via the recycle inlet. In other embodiments, the recycle inlet may be arranged in any suitable manner, for example below the fine slurry outlet.

The froth flotation unit 1000 is implemented as a fluidized bed flotation unit. Thus, when using the froth flotation unit 1000, a fluidized bed 1004 is maintained in the slurry volume 1001. In other embodiments, the froth action flotation unit may or may not be implemented as a fluidized bed flotation unit.

Although in fig. 1 the fluidized bed 1004 extends from above the recycle inlet 1111 to above the fine slurry outlet 1110, the fluidized bed may generally be arranged in any suitable manner in the tank of a froth action flotation unit, for example extending between any suitable horizontal positions of the tank.

In the embodiment of fig. 1, the froth action flotation unit 1000 includes a coarse slurry feed apparatus 1200. The coarse slurry feeding device 1200 of the embodiment of fig. 1 is configured to feed a coarse slurry 1201 to the foam layer 1002. In general, feeding the raw slurry to the froth layer may increase the recovery of mineral particles in the raw slurry. In other embodiments, the coarse slurry feeding device may be adapted or configured to feed the coarse slurry to the foam layer.

In the embodiment of fig. 1, the froth action flotation unit 1000 includes a fine slurry feed apparatus 1400. As indicated with dashed arrows in fig. 1, the fine slurry feeding apparatus 1400 may be configured to feed fine slurry 1401 into the slurry volume 1001 via the fine slurry inlet 1103 and/or via the fine slurry-flotation gas mixture inlet 1104. In other embodiments, the fine slurry feeding apparatus may be adapted or configured to feed fine slurry into the tank in any suitable manner, for example by feeding the fine slurry into the slurry volume via the fine slurry inlet and/or the fine slurry-flotation gas mixture inlet.

Fine slurry feed device 1400 of the embodiment of fig. 1 includes a slurry tank 1402 including a tank slurry outlet 1403 in a lower portion of slurry tank 1402. In other embodiments, the fine slurry feed apparatus may or may not include such a slurry tank.

The fine slurry feed device 1400 of the embodiment of fig. 1 is configured to collect fine slurry 1401 to be fed from slurry tank 1402 into slurry volume 1001 via tank slurry outlet 1403. In other embodiments, the fine slurry feeding apparatus may or may not be arranged in this manner.

In the embodiment of fig. 1, the froth action flotation unit 1000 includes a classification apparatus 1600 configured to classify an input slurry 1601 to form a coarser slurry sub-fraction 1602 and a finer slurry sub-fraction 1603. The classification apparatus 1600 of the embodiment of fig. 1 is configured to feed a coarser slurry sub-fraction 1602 to a coarse slurry feed apparatus 1200 and a finer slurry sub-fraction 1603 to a fine slurry feed apparatus 1400.

Although not depicted in fig. 1, the classification apparatus may generally be configured to classify the input slurry to form other products in addition to the coarser slurry sub-fraction and the finer slurry sub-fraction. In this case, the grading device may be configured to direct such other products to any suitable location, device, or unit.

The staging device 1600 of the embodiment of FIG. 1 is configured to feed finer slurry sub-portions 1603 into slurry chest 1402. In other embodiments, the sizing device may be configured to feed the finer slurry sub-fraction to the fine slurry feed device in any suitable manner, for example by feeding the finer slurry sub-fraction to a slurry pond of the fine slurry feed device.

In the embodiment of FIG. 1, the finer slurry sub-portion 1603 may have a solids sub-portion φ that is greater than the coarser slurry sub-portion 1602^csLow fraction of solids phi^fs. In other embodiments, the finer slurry sub-fraction fed to the fine slurry feed apparatus by the classifying apparatus may or may not have the coarser slurry sub-fraction φ fed to the coarse slurry feed apparatus by the classifying apparatus^csLow fraction of solids phi^fs。

In the embodiment of FIG. 1, the coarser slurry subportion 1602 may have a solids subportion φ of about 0.6^cs. In other embodiments, the coarser slurry sub-fraction may have any suitable solids sub-fraction φ^csE.g. phi^csIn the range of 0.5 to 0.8, or in the range of 0.55 to 0.75, or in the range of 0.6 to 0.7.

In the embodiment of FIG. 1, finer slurry subsection 1603 may have a solids subsection φ of about 0.2^fs. In other embodiments, the finer slurry sub-fraction may have any suitable solids sub-fraction φ^fsE.g. phi^fsIn the range of 0.05 to 0.35, or in the range of 0.1 to 0.25, or in the range of 0.15 to 0.2.

The classifying apparatus 1600 of the embodiment of fig. 1 includes a classifying cyclone 1604. In other embodiments, the classification apparatus may or may not include a classification cyclone.

Although a single classifying cyclone 1604 is depicted in fig. 1, the classifying apparatus may generally comprise one or more classifying cyclones.

In some embodiments, the classification apparatus may comprise, in addition to or as an alternative to the classification cyclone: one or more non-mechanical deposition (segmentation) classifiers, such as a settling cone; mechanical sedimentation classifiers, such as rake classifiers or screw classifiers; a free settling classifier; and hindered settling classifiers, such as hydraulic classifiers.

In the embodiment of FIG. 1, classifying cyclone 1604 may have a cutoff particle size of about 100 μm when measured under typical cyclone operating conditions

In other embodiments, the classifying cyclone may have any suitable characteristic when measured under typical cyclone operating conditions

For example

In the range of 15 μm to 200 μm, or 40 μm to 175 μm, or 60 μm to 150 μm, or 75 μm to 125 μm.

In the embodiment of fig. 1, the froth action flotation unit 1000 includes a solid-liquid separation apparatus 1700 configured to collect an output slurry 1701 from the slurry volume 1001 via a fine slurry outlet 1110, and separate suspended solids and flotation liquid from the output slurry 1701 to form a solid portion 1702 and a liquid portion 1703. In other embodiments, the froth action flotation unit may or may not include such solid-liquid separation equipment. For example, in some embodiments, the output slurry collected via the fine slurry outlet may be classified to form a substantially finer-sized slurry and a substantially coarser-sized slurry. In the various embodiments, such a substantially finer-sized slurry may be recycled back into the tank, and/or such a substantially coarser-sized slurry may be directed out of the solid-liquid separation apparatus.

The solid-liquid separation apparatus 1700 of the embodiment of fig. 1 is configured to direct the solid fraction 1702 out of the froth action flotation unit 1000, for example to another flotation unit. In other embodiments, the solid-liquid separation device may or may not be configured to direct the solid fraction out of the froth action flotation unit. For example, in some embodiments, solid particles in the output slurry collected via the fine slurry outlet may be directed from the solid-liquid separation apparatus to the classification apparatus.

The solid-liquid separation apparatus 1700 of the embodiment of fig. 1 is configured to feed a liquid fraction 1703 to the circulation apparatus 1800 of the froth action flotation unit 1000 (see below). In other embodiments, the solid-liquid separation device may or may not be configured to feed the liquid portion to the circulation device.

Although not depicted in fig. 1, the solid-liquid separation apparatus may generally be configured to separate suspended solids and flotation liquid from the output slurry, thereby also forming other products in addition to the solid and liquid fractions. In such a case, the solid-liquid separation device may be configured to direct such other products to any suitable location, device, or unit.

In the embodiment of FIG. 1, solid portion 1702 may have a solid portion φ of about 0.3^sp. In general, a solid fraction having a sufficiently high sub-fraction of solids may facilitate further flotation of the solid fraction. In other embodiments, the solid portion may have any suitable solid sub-portion, such as a solid sub-portion greater than or equal to 0.2, or greater than or equal to 0.3, or greater than or equal to 0.4.

In the embodiment of FIG. 1, the liquid portion 1703 may have a solid sub-portion φ of about 0.05^lp. In general, a liquid portion having a lower solids sub-portion may facilitate use of the liquid portion to maintain operability of devices and/or units having higher flotation liquid consumption. In other embodiments, the liquid portion may have any suitable solid sub-portion, such as a solid sub-portion of less than or equal to 0.1, or less than or equal to 0.05, or less than or equal to 0.02, or less than or equal to 0.01.

The solid-liquid separation apparatus 1700 of the embodiment of fig. 1 includes a solid-liquid separation cyclone 1704. In other embodiments, the solid-liquid separation apparatus may or may not include a solid-liquid separation cyclone.

In some embodiments, the solid-liquid separation apparatus may comprise, in addition to or as an alternative to the solid-liquid separation cyclone: one or more gravity settling devices, such as an thickener or inclined plate settler; a centrifuge; and filtration devices such as pressure filters, tube presses, vacuum filters or drum filters.

Throughout the specification, "solid-liquid separation cyclone" or "dewatering cyclone" may refer to a cyclone configured or adapted for solid-liquid separation of a slurry. In general, the solid liquid separation cyclone may have a cut-off particle size of less than or equal to 10 μm, as measured under typical cyclone operating conditions. Additionally or alternatively, the solid-liquid separation cyclone may have an internal diameter of less than 8cm, as measured across its feed.

The solid-liquid separation cyclone 1704 of the embodiment of FIG. 1 may have a cut-off particle size of about 10 μm when measured at typical cyclone operating conditions

In other embodiments, the solid-liquid separation cyclone may have any suitable design

For example

Less than or equal to 10 μm, or less than or equal to 8 μm, or less than or equal to 6 μm.

In the embodiment of fig. 1, the froth action flotation unit 1000 comprises circulation equipment 1800 for circulating

flotation liquid

1801, 1802 collected from the tank 1100 via the fine slurry outlet 1110 back into the tank 1100.

The circulation arrangement 1800 of the embodiment of fig. 1 is configured to feed

flotation liquid

1801, 1802 collected from the tank 1100 via the fine slurry outlet 1110 back into the tank 1100, so that said

flotation liquid

1801, 1802 is reintroduced into the tank 1100 below the fine slurry outlet 1110. In general, the circulation arrangement being configured to feed flotation liquid collected from the tank via the fine slurry outlet back into the tank so that the flotation liquid is introduced into the tank below the fine slurry outlet may enable a fluidized bed to be maintained in the tank with circulation of the flotation liquid. In other embodiments, the circulation device may be configured to feed the flotation liquid collected from the tank via the fine slurry outlet back into the tank in any suitable manner, for example such that the flotation liquid is introduced into the tank below the fine slurry outlet.

As indicated in fig. 1 using dashed arrows, the circulation arrangement 1800 of the embodiment of fig. 1 may be configured such that feed flotation liquid 1801 collected from the tank 1100 via the fine slurry outlet 1110 is returned to the tank 1100 via the circulation inlet 1111 and/or such flotation liquid 1802 is added to the fine slurry 1401, wherein the fine slurry feed arrangement 1400 is configured to feed the fine slurry 1401 into the slurry volume 1001. In other embodiments, the circulation device may or may not be configured in this manner.

The circulation arrangement 1800 of the embodiment of fig. 1 may be particularly configured to add flotation liquid 1802 collected from the tank 1100 via the fine slurry outlet 1110 to the fine slurry 1401 by feeding said flotation liquid 1802 into the slurry tank 1402, wherein the fine slurry feeding arrangement 1400 is configured to feed the fine slurry 1401 into the slurry volume 1001. In other embodiments, the circulation device may be configured to add flotation liquid to the fine slurry to be fed into the tank by the fine slurry feeding device in any suitable manner, for example by feeding said flotation liquid into a slurry tank.

The circulation arrangement 1800 of the embodiment of fig. 1 is configured to receive a liquid fraction 1703, wherein the solid-liquid separation arrangement 1700 is configured to direct the liquid fraction 1703 to the circulation arrangement 1800. In other embodiments, the circulation device may or may not be configured to receive the liquid fraction formed by the solid-liquid separation device by separating suspended solids and flotation liquid from the output slurry collected via the fine slurry outlet. For example, in some embodiments, a froth action flotation unit may be configured to operate without solid-liquid separation equipment. In such embodiments, the circulation device may be configured to collect the output slurry via the fine slurry outlet.

In the embodiment of fig. 1, the flotation liquid 1801 and/or flotation liquid 1802 may be extracted from the liquid portion 1703 directed to the circulation device 1800 by the solid-liquid separation device 1700, wherein the circulation device 1800 may be configured to feed the flotation liquid 1801 back into the tank 1100 via the circulation inlet 1111, and/or the circulation device 1800 may be configured to add the flotation liquid 1802 to the fine slurry 1401, and the fine slurry feed device 1400 is configured to feed the fine slurry 1401 into the slurry volume 1001. In other embodiments, the circulation device may or may not be configured to feed the flotation liquid from the liquid portion back into the tank via the circulation inlet and/or to add the flotation liquid from the liquid portion to the fine slurry, wherein the fine slurry feed device is configured to feed the fine slurry into the slurry volume.

In the embodiment of fig. 1, the froth action flotation unit 1000 includes a flotation gas feed apparatus 1300. The flotation gas feed apparatus 1300 is configured to feed

flotation gases

1301, 1302, 1303 into the slurry volume 1001. In other embodiments, the flotation gas feed apparatus may be adapted or configured to feed flotation gas into a volume of slurry held in the tank.

In the embodiment of fig. 1, air may be used as the

flotation gas

1301, 1302, 1303. In other embodiments, any suitable flotation gas may be used, such as air, argon, nitrogen, hydrogen, or mixtures thereof.

The flotation gas supply apparatus 1300 of the embodiment of fig. 1 is configured to supply

flotation gases

1301, 1302, 1303 into the slurry volume 1001 such that the froth layer 1002 is maintained above the slurry volume 1001. In other embodiments, the flotation gas feed apparatus may be adapted or configured to feed flotation gas into the slurry volume such that a froth layer is maintained above the slurry volume.

As illustrated in fig. 1 by the dashed arrows, the flotation gas feed apparatus 1300 of the embodiment of fig. 1 may be configured to feed flotation gas 1301 into the slurry volume 1001 via the flotation gas inlet 1108. In other embodiments, the flotation gas feed apparatus may be configured to feed flotation gas into the tank in any suitable manner, for example by feeding flotation gas into the slurry volume via the flotation gas inlet.

As indicated by the dashed arrows in fig. 1, the flotation gas feed apparatus 1300 of the embodiment of fig. 1 may be configured to feed flotation gas into the slurry volume 1001 by injecting flotation gas 1302 into fine slurry 1401, wherein the fine slurry feed apparatus 1400 is configured to feed fine slurry 1401 into the slurry volume via the fine slurry-flotation gas mixture inlet 1104 and/or by injecting flotation gas 1303 into flotation liquid 1801 collected via the fine slurry outlet 1110, wherein the circulation apparatus 1800 is configured to feed flotation liquid 1801 back into the tank 1100 via the circulation inlet 1111. In other embodiments, the flotation gas feed apparatus may or may not be configured in this manner.

In the embodiment of fig. 1, the froth action flotation unit 1000 comprises a flotation liquid feed apparatus 1500 for feeding

flotation liquid

1501, 1502 into the slurry volume 1001. In other embodiments, the flotation unit may or may not include such a flotation liquid feed apparatus. For example, in some embodiments, maintaining the top surface of the slurry volume at a set distance from the launder lip of the launder of a tank may be achieved by controlling the operation of the slurry outlet of the tank and the slurry feeding device.

As indicated by the dashed arrows in fig. 1, the flotation liquid feed apparatus 1500 of the embodiment of fig. 1 may be configured to feed flotation liquid 1501 into the slurry volume 1001 via the flotation liquid inlet 1109 and/or to feed flotation liquid 1502 into the slurry volume 1001 by adding flotation liquid 1502 to fine slurry 1401, wherein the fine slurry feed apparatus 1400 is configured to feed fine slurry 1401 into the slurry volume 1001. In other embodiments, the flotation liquid feed apparatus may be configured to feed flotation liquid into the tank in any suitable manner, for example by feeding flotation liquid into the volume of slurry via the flotation liquid inlet and/or by adding flotation liquid to the fine slurry, wherein the fine slurry feed apparatus is configured to feed fine slurry into the tank.

The flotation liquid feed apparatus 1500 of the embodiment of fig. 1 may be particularly configured to feed flotation liquid 1502 into the slurry volume 1001 by feeding flotation liquid 1502 into the slurry tank 1402. In other embodiments, the flotation liquid feed apparatus may be configured to add flotation liquid to the fine slurry, wherein the fine slurry feed apparatus is configured to feed the fine slurry into the tank in any suitable manner, for example by feeding flotation liquid to a slurry pond of the fine slurry feed apparatus.

In the embodiment of fig. 1, the froth action flotation unit 1000 includes a slurry agitation apparatus 1900 for agitating the slurry volume 1001. In other embodiments, the froth action flotation unit may or may not include such slurry agitation equipment. In various embodiments, the froth action flotation unit includes a slurry agitation device, which may be implemented in any suitable manner.

The slurry stirring apparatus 1900 of the embodiment of fig. 1 includes a rotor 1901 fixed to a drive shaft 1902. In other embodiments, the slurry agitation equipment of a froth action flotation unit may or may not include such a rotor and such a drive shaft.

The rotor 1901 of the embodiment of fig. 1 is disposed at a lower portion of the can 1100. In general, arranging the rotor of the slurry stirring device in the lower part of the tank may facilitate further flotation of the particles undergoing sedimentation of the sediment formed in the tank in said tank. In other embodiments, the rotor of the slurry stirring device may be arranged in the tank in any suitable way, for example at a lower part of said tank.

In various embodiments, the slurry stirring apparatus comprises a rotor and a drive shaft, the slurry stirring apparatus may further comprise a stator, such that the rotor and the stator form a rotor-stator mechanism and/or a standpipe surrounding the drive shaft, such that the flotation gas feed apparatus may be configured to feed flotation gas through the standpipe into a volume of slurry held in the tank.

Fig. 2 depicts a froth flotation unit 2000 for separating an input slurry 2601 according to an embodiment. Although not explicitly shown in fig. 2, the froth flotation unit 2000, any component thereof, and/or any equipment of the froth flotation unit 2000 may generally include any features and/or elements of the embodiment of fig. 1 or any other embodiment disclosed with reference to, in conjunction with, and/or in conjunction with fig. 1.

The froth action flotation unit 2000 of the embodiment of fig. 2 includes a tank 2100 to hold a slurry volume 2001 and a froth layer 2002 located above the slurry volume 2001.

The can 2100 of the embodiment of fig. 2 includes: spout 2101 with spout lip 2102 to collect foam 2003 from foam layer 2002; a fine slurry inlet 2103; a coarse slurry outlet 2106 located at the lower part of the tank 2100 below the fine slurry inlet 2103 for collecting coarse output slurry 2107; and a flotation gas inlet 2108 at the bottom of the tank 2100.

The froth action flotation unit 2000 of the embodiment of fig. 2 includes: a coarse slurry feeding apparatus 2200 to feed the coarse slurry 2201 to the foam layer 2002; a fine slurry feed device 2400 to feed fine slurry 2401 into slurry volume 2001 via fine slurry inlet 2103; and a flotation gas supply apparatus 2300 configured to feed flotation gas 2301 into the slurry volume 2001 via a flotation gas inlet 2108.

The froth flotation unit 2000 of the embodiment of fig. 2 further comprises a classification apparatus 2600 configured to classify the input slurry 2601 to form a coarser slurry sub-fraction 2602 and a finer slurry sub-fraction 2603, thereby feeding the coarser slurry sub-fraction 2602 to the coarse slurry feeding apparatus 2200 and the finer slurry sub-fraction 2603 to the fine slurry feeding apparatus 2400.

As shown by the dashed arrows in fig. 2, tank 2100 may further comprise a flotation liquid inlet 2109, and froth flotation unit 2000 may further comprise a flotation liquid feed arrangement 2500 for feeding flotation liquid 2501 into slurry volume 2001.

As shown in fig. 2, the froth flotation unit 2000 differs from the froth flotation unit 1000 of the embodiment of fig. 1 at least in that the froth flotation unit 2000 is configured to operate without a bottom cone in the tank 2100 and without a fluidized bed in the slurry volume 2001.

It should be appreciated that the embodiments of the first aspect described above may be used in any combination with each other. Several embodiments may be combined together to form another embodiment.

The structural aspects of a froth action flotation unit are discussed primarily above. In the following, more emphasis will be placed on aspects relating to mineral processing apparatus. The manner of implementation, definition, details and advantages described above in connection with the froth action flotation unit is, mutatis mutandis, applied to the mineral processing plant discussed below. And vice versa.

Fig. 3 depicts a mineral processing apparatus 3000 according to an embodiment. The mineral processing apparatus 3000 of the embodiment of fig. 3 comprises a froth action flotation unit 3200 with a classifying device 3201.

Although not explicitly shown in fig. 3, the froth action flotation unit 3200, any component thereof, and/or any equipment of the froth action flotation unit 3200 may generally include any features and/or elements of the embodiment of any of fig. 1-2 or any other embodiment disclosed with reference to, in conjunction with, and/or with any of fig. 1-2.

The mineral processing apparatus 3000 of the embodiment of fig. 3 also includes a comminution unit 3100. In other embodiments, the mineral processing apparatus may or may not include a comminution unit.

The comminution unit 3100 of the embodiment of fig. 1 is configured to grind ore to form ground ore, mix the ground ore with a flotation solution to form a raw slurry 3101, and feed the raw slurry 3101 to the froth action flotation unit 3200. In various embodiments, the mineral processing apparatus includes a comminution unit, which can be configured to operate in any suitable manner.

As indicated by the dashed arrows in fig. 3, the classification apparatus may generally be configured to classify the input slurry such that a product is also formed in addition to the coarser slurry sub-fraction and the finer slurry sub-fraction. In this case, the grading device may be configured to direct these other products to any suitable location, device, or unit.

Fig. 4 depicts a mineral processing apparatus 4000 according to an embodiment. The mineral processing plant 4000 of the embodiment of fig. 4 comprises a froth action flotation unit 4200 with a classifying equipment 4201.

Although not explicitly shown in fig. 4, the froth flotation unit 4200, any component thereof, and/or any equipment of the froth flotation unit 4200 may generally include any of the features and/or elements of the embodiment of any of fig. 1-2 or any other embodiment disclosed with reference to, incorporated into, and/or appended to any of fig. 1-2.

The mineral processing apparatus 4000 of the embodiment of fig. 4 further comprises a comminution unit 4100, a pre-classification unit 4300 and a primary flotation unit 4400. In other embodiments, the mineral processing apparatus may or may not include one or more of the grinding unit, the pre-staging unit 4300, and the primary flotation unit 4400.

The comminution unit 4100 of the embodiment of fig. 4 is configured to grind ore to form ground ore, mix the ground ore with a flotation solution to form an original slurry 4101, and feed the original slurry 4101 to the pre-classification unit 4300.

The pre-classification unit 4300 of the embodiment of fig. 4 is configured to classify the raw slurry 4101 to form a coarser raw slurry sub-portion 4301 and a finer raw slurry sub-portion 4302 and to feed the finer raw slurry sub-portion 4302 to the primary flotation unit 4400.

The primary flotation unit 4400 of the embodiment of fig. 4 is configured to separate the finer raw slurry sub-portion 4302 to form an overflow 4401 and an underflow 4402, and feed the underflow 4402 to the froth action flotation unit 4200.

As depicted using dashed lines in fig. 4, the primary flotation unit may generally include one or more tanks. In various embodiments, the primary flotation unit includes a plurality of tanks, individual tanks of which may be arranged in series.

Herein, a single tank of the plurality of tanks being "arranged in series" may mean that the underflow from one tank is fed to the next tank until the last single tank of the plurality of tanks.

In the above, the structural aspects of the froth action flotation unit and the mineral processing plant have been mainly discussed. In the following, more emphasis will be placed on aspects related to the method of separating a slurry using froth action flotation. The manner of implementation, definition, details and advantages described above in connection with the froth action flotation unit and the mineral processing plant apply mutatis mutandis to the method discussed below. And vice versa.

It is to be specifically understood that any method according to the present description may be used to operate a froth action flotation unit according to the present description. Accordingly, any froth action flotation unit according to the present description may be operated according to the method according to the present description.

Fig. 5 illustrates a method 5000 of separating an input slurry using froth action flotation according to an embodiment.

In the embodiment of fig. 5, method 5000 includes: in process 5100, a tank is provided for holding a volume of slurry and a layer of foam over the volume of slurry.

As used herein, a "process" can refer to a set of operations that results in a final result. A process may be divided into multiple sub-processes, where individual sub-processes of such multiple sub-processes may or may not share common operations.

Here, "operation" may refer to a measure taken to achieve an effect. Individual operations of a process may in principle be performed at least partly consecutively or at least partly simultaneously with each other.

Throughout this disclosure, "providing" may refer to arranging the discussed elements or portions as available.

In the embodiment of fig. 5, the method 5000 includes, in the sub-process 5200, feeding a flotation gas into the volume of slurry.

In the embodiment of fig. 5, the method 5000 includes, in sub-process 5300, classifying the input slurry to form a coarser slurry sub-fraction and a finer slurry sub-fraction.

In the embodiment of fig. 5, the method 5000 includes, in sub-process 5400, feeding a coarser slurry sub-portion to the foam layer.

In the embodiment of fig. 5, the method 5000 includes, in sub-process 5500, feeding a sub-portion of finer slurry into a volume of slurry.

As depicted in fig. 5 using dashed lines, the method 5000 of the embodiment of fig. 5 may further include, in the subprocess 5600, maintaining a fluidized bed in the slurry volume. In other embodiments, the method of separating the input slurry using froth flotation may or may not include maintaining a fluidized bed in the volume of the slurry.

In general, the method of separating an input slurry using froth action flotation may include any process, operation, and/or feature not disclosed herein in connection with method 5000 of the embodiment of fig. 5.

For example, in some embodiments, the finer slurry sub-portion may have a solids sub-portion φ that is a comparison of the coarser slurry sub-portion^csLow fraction of solids phi^fs。

In some embodiments, the coarser slurry subportion may have a solids subportion φ^csIn the range of 0.5 to 0.8, or in the range of 0.55 to 0.75, or in the range of 0.6 to 0.7.

In some embodiments, the finer slurry sub-fraction may have a solids sub-fraction φ^fsIn the range of 0.05 to 0.35, or in the range of 0.1 to 0.25, or in the range of 0.15 to 0.2.

In some embodiments, a method of separating an input slurry using froth flotation may include: the foam from the can is collected into a spout of the can, for example, above a spout lip of the spout.

In some embodiments, a method of separating an input slurry using froth flotation may include: the raw output slurry is collected from the volume of slurry at a first height h1 below the launder lip of the launder.

In some embodiments, a method of separating an input slurry using froth flotation may include: the output slurry is collected from the slurry volume at a second height h2, which may be above the first height h1, and/or below the launder lip.

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

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

The term "comprising" is used in this specification to specify the presence of stated features or actions followed by the inclusion of stated features or actions, but does not exclude the presence of one or more additional features or actions. It will be further understood that the terms "a" and "an" as referred to herein refer to one or more of those terms.

Claims

1. A froth action flotation unit for separating an input slurry, the froth action flotation unit comprising:

a tank for holding a volume of slurry and a layer of foam over the volume of slurry;

a coarse slurry feeding device for feeding a coarse slurry to the foam layer; and

a flotation gas feed apparatus for feeding flotation gas into the slurry volume such that the froth layer is maintained above the slurry volume,

wherein the froth action flotation unit comprises: a fine slurry feed device for feeding fine slurry into the slurry volume; and a classification apparatus configured to classify the input slurry into a coarser slurry sub-portion and a finer slurry sub-portion to feed the coarser slurry sub-portion to the coarse slurry feed apparatus and the finer slurry sub-portion to the fine slurry feed apparatus.

2. The froth action flotation unit of claim 1 wherein the classification apparatus comprises a classification cyclone.

3. The froth action flotation unit according to claim 2, wherein the classifying cyclone has a cut-off particle size in the range of 15 μm to 200 μm, measured under normal cyclone operating conditions.

4. A froth action flotation unit according to claim 3, wherein the cut-off particle size is in the range of 40 to 175 μ ι η.

5. A froth action flotation unit according to claim 3, wherein the cut-off particle size is in the range of 60 to 150 μm.

6. A froth action flotation unit according to claim 3, wherein the cut-off particle size is in the range of 75 to 125 μm.

7. The froth action flotation cell according to any one of claims 1 to 6 wherein the tank comprises: a launder having a launder lip for collecting bubbles from the foam layer; a fine slurry outlet located below the launder lip to collect output slurry from the slurry volume; and a coarse slurry outlet located below the fine slurry outlet for discharging a coarse output slurry from the slurry volume.

8. The froth action flotation unit of claim 7, wherein the froth action flotation unit comprises: a solid-liquid separation device configured to collect an output slurry from the slurry volume via the fine slurry outlet and separate suspended solids and flotation liquid from the output slurry to form a solid portion and a liquid portion.

9. The froth action flotation unit of claim 8 wherein the solid liquid separation equipment is configured to direct the solids fraction out of the froth action flotation unit.

10. The froth action flotation unit of claim 7, wherein the froth action flotation unit comprises: a circulation device to circulate flotation liquid collected from the tank via the fine slurry outlet back to the tank.

11. The froth action flotation unit according to claim 10, wherein the circulation equipment is configured such that circulation of flotation liquid collected from the tank via the fine slurry outlet is achieved by adding this flotation liquid to fine slurry, the fine slurry feed equipment being configured to feed the fine slurry into the slurry volume.

12. The froth action flotation unit according to claim 10, wherein the tank includes a circulation inlet and the circulation apparatus is configured to feed flotation liquid collected from the tank via the fine slurry outlet back into the tank via the circulation inlet.

13. The froth action flotation unit according to claim 12, wherein the flotation gas feed apparatus is configured to feed flotation gas into the slurry volume by injecting flotation gas into flotation liquid, the circulation apparatus being configured to feed the flotation liquid back into the tank via the circulation inlet.

14. The froth action flotation unit according to any one of claims 1 to 6, wherein the tank comprises a fine slurry inlet and a flotation gas inlet located below the fine slurry inlet, the fine slurry feeding apparatus being configured to feed fine slurry into the slurry volume via the fine slurry inlet and the flotation gas feeding apparatus being configured to feed flotation gas into the slurry volume via the flotation gas inlet.

15. The froth action flotation unit according to any one of claims 1 to 6, wherein the tank includes a fine slurry-flotation gas mixture inlet and the flotation gas feed apparatus is configured to feed flotation gas into the slurry volume by injecting flotation gas into the fine slurry, the fine slurry feed apparatus being configured to feed the fine slurry into the slurry volume via the fine slurry-flotation gas mixture inlet.

16. The froth action flotation unit according to any one of claims 1 to 6, wherein the fine slurry feed apparatus comprises a slurry tank having a tank slurry outlet in a lower part of the slurry tank, the classification apparatus is configured to direct the finer slurry sub-fraction to the slurry tank, and the fine slurry feed apparatus is configured to feed fine slurry into the slurry volume via the tank slurry outlet.

17. The froth action flotation unit according to any one of claims 1 to 6, comprising a flotation liquid feed apparatus to feed flotation liquid into the slurry volume.

18. The froth action flotation unit according to claim 17, wherein the tank includes a flotation liquid inlet and the flotation liquid feed apparatus is configured to feed flotation liquid into the slurry volume via the flotation liquid inlet.

19. The froth action flotation unit according to claim 17, wherein the flotation liquid feed apparatus is configured to feed flotation liquid into the slurry volume by adding flotation liquid to fine slurry, the fine slurry feed apparatus being configured to feed the fine slurry into the slurry volume.

20. The froth action flotation cell according to any one of claims 1 to 6 wherein the tank includes a downwardly tapering bottom cone.

21. The froth action flotation unit according to any one of claims 1 to 6, comprising a slurry agitation device to agitate the slurry volume.

22. The froth action flotation unit according to any one of claims 1 to 6, wherein the froth action flotation unit is implemented as a fluid bed flotation unit.

23. A mineral processing apparatus, characterized in that it comprises a froth action flotation unit according to any one of claims 1-22.

24. The mineral processing apparatus of claim 23, characterized in that the mineral processing apparatus includes a comminution unit configured to grind ore to form ground ore, mix the ground ore with a flotation liquid to form a raw slurry, and feed the raw slurry to the froth action flotation unit.

25. The mineral processing apparatus of claim 23, characterized in that the mineral processing apparatus comprises a comminution unit, a pre-classification unit and a primary flotation unit; the comminution unit is configured to grind ore to form ground ore, mix the ground ore with a flotation solution to form a raw slurry, and feed the raw slurry to the pre-classification unit; the pre-classification unit is configured to classify the raw slurry to form a coarser raw slurry sub-fraction and a finer raw slurry sub-fraction and to feed the finer raw slurry sub-fraction to the primary flotation unit; the primary flotation unit is configured to sub-divide the finer raw slurry to form an overflow stream and an underflow stream and feed the underflow stream to the froth action flotation unit.