WO2025233571A1

WO2025233571A1 - Overflow collection launder arrangement and separation circuit

Info

Publication number: WO2025233571A1
Application number: PCT/FI2025/050226
Authority: WO
Inventors: Tatu Miettinen; Pekka TÄHKIÖ; Janne Kemppainen
Original assignee: Metso Finland Oy
Current assignee: Metso Finland Oy
Priority date: 2024-05-08
Filing date: 2025-05-06
Publication date: 2025-11-13
Anticipated expiration: 2026-11-08
Also published as: FI131527B1; FI20245574A1; CN120920207A

Abstract

An overflow collection launder arrangement (100) and a separation circuit (200). The overflow collection launder arrangement comprises a redirection device (1) arranged to receive an overflow, the redirection device comprising a feed guide (2) configured to guide said overflow out from the redirection device (1). The arrangement (100) further comprises a collection launder system (3) comprising at least three compartments (4a, 4b, 4c). The arrangement (100) comprises an alignment arrangement (5) configured to control the mutual position of the feed guide (2) and said at least three compartments (4a, 4b, 4c) for guiding said overflow in one of said at least three compartments (4a, 4b, 4c) at a time.

Description

OVERFLOW COLLECTION LAUNDER ARRANGEMENT AND SEPARATION CIRCUIT

BACKGROUND

The invention relates to an overflow collection launder arrangement .

The invention further relates to a separation circuit comprising the overflow collection launder arrangement .

A typical separation circuit for separation material flows to an accept and a rej ect comprises several separation devices , such as flotation cells . For optimi zing the separation process , information about , e . g . , elemental recirculation loads , flotation kinetics and flotation metallurgical performance of the separation devices should be known . Possibilities to get this information are , however, sparsely available .

BRIEF DESCRIPTION

Viewed from a first aspect , there can be provided an overflow collection launder arrangement , comprising a redirection device arranged to receive an overflow, the redirection device comprising a feed guide configured to guide said overflow out from the redirection device , the arrangement further comprising a collection launder system compri sing at least three compartments , each of said three compartments arranged for leading the overflow into a subsequent process , wherein the arrangement comprises an alignment arrangement configured to control the mutual position of the feed guide and said at least three compartments for guiding said overflow in one of said at least three compartments at a time .

Thereby an overflow collection launder arrangement that provides pos sibility to separate the overf low of one separation device from overflows of other separation devices may be achieved . This renders it possible to obtain information about performance of said one separation device in form of , e . g . elemental and mass recirculation loads , flotation kinetics and a metallurgical performance . Further, a separation flowsheet , such as a flotation flowsheet, may be adj usted online , as well as online flowsheets as a response to feed variables , such as grade , and amount of additives , such as talc or carbon . This all provides information that may be used for optimi zing the performance of the separation circuit .

Viewed from a further aspect , there can be provided a separation circuit comprising the overflow collection launder arrangement of the first aspect .

Thereby a separation circuit the function of which is precisely controllable may be achieved .

The overflow collection launder arrangement and the separation circuit are characterised by what is stated in the independent claims . Some other embodiments are characterised by what is stated in the other claims . Inventive embodiments are also disclosed in the description and drawings of this patent application . The inventive content of the patent application may also be defined in other ways than defined in the following claims . The inventive content may also be formed of several separate inventions , especially if the invention is examined in the light of expressed or implicit sub-tas ks or in view of obtained benef its or benefit groups . Some of the definitions contained in the following claims may then be unnecessary in view of the separate inventive ideas . Features of the different embodiments of the invention may, within the scope of the basic inventive idea, be applied to other embodiments .

Various embodiments of the first aspect may comprise at least one feature from the following paragraphs : In one embodiment , the alignment arrangement is configured to move the feed guide by at least one of a turning movement and a linear movement .

An advantage is that these movements can be reali zed by many proofed mechanisms and actuators .

In one embodiment , the redirection device comprises a cradle that is configured to receive overf low from a separator device , wherein the feed guide is arranged at a bottom part of the cradle, and wherein the cradle is configured to make the turning movement around an axi s substantially parallel with the three compartments .

An advantage is that a simple and sturdy structure of a redirection device may be achieved .

In one embodiment , the feed guide comprises a rotatable guide that is configured to direct a flow of the overflow in one of the three compartments depending on a rotational position thereof .

An advantage is that a simple structure of a redirection device may be achieved .

In one embodiment , the feed guide comprises a flexible pipe section, and the alignment arrangement is configured to direct a flow of the overflow in one of the three compartments by bending said flexible section .

An advantage is that a tight and simple structure of a redirection device may be achieved . In one embodiment , the alignment arrangement comprises an equipment for manual control of the mutual position of the feed guide and the at least three compartments .

An advantage is that a simple and reliable means for controlling the alignment arrangement may be achieved .

In one embodiment , the alignment arrangement is arranged to control the mutual position of the feed guide and said at least three compartments by an automatic control system .

An advantage is that a quick and precise control that may be based on the performance of the separator device may be achieved .

In one embodiment , a plurality of redirection devices is arranged to be controlled independently of each other .

An advantage is that each of the redirection devices can be controlled based on performance of the respective separator device .

In one embodiment , the three compartments are arranged side by s ide when seeing from above , and the feed guide is configured to feed said compartments from above .

An advantage is that a simple structure for distributing the overflow in the correct compartment may be achieved .

In one embodiment , the alignment arrangement is arranged to adj ust the at least three compartments such that the overflow is arranged to arrive in one of said at least three compartments at a time .

An advantage is that the structure of the redirection device may be simplified . In one embodiment , the three compartments are separated by separation walls , the separation walls comprising movable separation walls , and wherein the alignment arrangement i s arranged to move said movable separation walls such that the overflow is directed to one of said at least three compartments at a time .

An advantage is that the receiving area of the compartment that receives the overflow may be extended by moving the movable separation walls without need for increasing the overall dimensions of the compartments . Another advantage is that feed guide structure is simple .

In one embodiment , the collection launder system comprises a launder, and said three compartments are established in said launder .

An advantage is that the system is simple and can be retrofitted to common launders .

In one embodiment , the first compartment is connected to an analysi s arrangement for analys ing the overflow fed in the first compartment .

An advantage is that an information may be obtained about , e . g . , mass and volumetric flowrates , densities , elemental grades and metallurgical performance of the separator device , and based on said information a well-founded decis ion how to handle the overflow of said separator device may be made .

In one embodiment , the second compartment is arranged on a first side of the first compartment that is connected to the analysis arrangement , and the third compartment is arranged on a second side of the first compartment . An advantage is that the target of the overflow can be changed from the first compartment to the second compartment or to the third compartment without need to pass any other compartment and thus it can be avoided unintentional leakages of the overflow into a compartment where the overf low is not intended to flow .

In one embodiment , the second and the third compartments are arranged to extend under the first compartment , optionally separated by a vertically extending separation wall arranged under the first compartment .

An advantage is that the capacity of the second and the third compartments may be extended in relation to the first compartment .

In one embodiment , the analysis arrangement comprises an analyser for measuring contents of chemical elements in said overflow .

An advantage is that elemental grades and metallurgical performance of the separator device may be detected .

In one embodiment , the arrangement comprises a flow and/or density meter ( s ) arranged to measure the mass flow in the first compartment .

An advantage is that the performance of the separator device may be find out .

In one embodiment , the separation circuit comprises at least two separation lines , such as flotation lines , wherein a first of said separation lines is configured to feed at least part of its overflow to a second of said separation lines , and wherein one of the first and the second separation lines comprises the collection launder arrangement, and at least one of the separation lines is devoid of the collection launder arrangement .

An advantage is that overflows of at least part of the separation circuit may be controlled .

In one embodiment , the separation circuit comprises at least two separation lines , such as flotation lines , wherein a first of said separation lines is configured to feed at least part of its overflow to a second of said separation lines , and wherein all the separation lines comprise the collection launder arrangement .

An advantage is that overflows of the whole separation circuit may be controlled .

In one embodiment , the separation circuit comprises three separation lines , such as flotation lines , wherein a first separation line is a rougher line comprising at least one rougher separator device , such as a rougher flotation cell , a second separation line is a cleaner line comprising at least one cleaner separator device , such as a cleaner flotation cell , and a third separation line is a re-cleaner line comprising at least one separator device , such as a re-cleaner flotation cell , wherein at least the rougher line is provided with the collection launder arrangement .

An advantage is that overflows of at least the rougher line may be controlled . Additionally, an acceptable overf low created in the rougher line can be separated and feed out from the separation circuit as an accept , without feeding it to the cleaner separation line . Thus , the capacity of the separation line may be increased . Another advantage is that the circulation flow ( s ) may be decreased thereby resulting to decrease in pumping energy consumption . Yet another advantage is that the particle si ze of the accept may be coarser which may result to decrease in energy- , water- , and reagent consumption ( s ) in the subsequent process steps , such as cleaner flotation, dewatering, and regrinding . One more advantage is that because only part of the accept is directed to the subsequent process steps , such as cleaner flotation, dewatering, and regrinding, energy- , water- , and reagent consumption ( s ) in those steps may be decreased .

In one embodiment , the cleaner separation line is provided with a second collection launder arrangement , the second compartment of said second collection launder arrangement is configured to guide overflow to the re-cleaner separation line , and the third compartment of said second collection launder arrangement is configured to guide overflow to a recirculation arrangement for recirculating said overflow back to the cleaner separation line .

An advantage is that the overflow that needs to be recirculated can be separated from the overflow that can be fed in the re-cleaner separation line so that the process can be optimi zed .

In one embodiment , the re-cleaner separation line is provided with a third collection launder arrangement , the second compartment of said third collection launder arrangement is configured to recirculate overflow back in the recleaner separation line , and the third compartment of said third collection launder arrangement is configured to discharge overflow out from the separation circuit .

An advantage is that the overflow that needs to be recirculated can be separated from the overflow that can be fed out from the separation circuit , so that the process can be optimi zed . Based on the above mentioned, it should be noted that different embodiments mentioned in the above paragraphs may be combined in any possible suitable manner for implementing the present invention .

Definitions

This summary of def initions is provided to introduce a selection of concepts in a simpli fied 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 subj ect matter, nor i s it intended to be used to limit the scope of the claimed subj ect matter .

Basically, separation aims to separate an input slurry to an accept and a rej ect . The "accept" is a concentrate of ore particles comprising a valuable mineral . By "concentrate" herein is meant the part of slurry recovered in overflow or underflow led out of a separation device , such as a flotation cell . By "valuable mineral" is meant any mineral , metal , or other material of commercial value .

Throughout this description, "f lotation" may refer to separation of a mixture by adhering a substance in said mixture at an interface . In flotation, separation of a mixture may be based on differences in the hydrophobicity of substances in said mixture . Herein, "separation" may refer to the extraction or removal of a substance from a mixture for use or rej ection .

Further, "froth flotation" may refer to flotation, wherein froth is utili zed for separation . Herein, "froth" may refer to a dispers ion, comprising a greater portion by volume of flotation gas dispersed as bubbles in lesser portion by volume of a flotation liquid . Generally, froth may or may not be stabili zed by solid particles . Further, "slurry" may refer to a dispersion, comprising solid particles suspended in a continuous phase of liquid, such as flotation liquid .

BRIEF DESCRIPTION OF FIGURES

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

Figure 1 is a schematic view of a detail of an overflow collection launder arrangement ,

Figure 2 i s a schematic cross-sectional view of the detail shown in Figure 1 ,

Figure 3 is a schematic view of a detail of another overf low collection launder arrangement ,

Figure 4 is a schematic cross-sectional view of the detail shown in Figure 3 ,

Figure 5 is a schematic view of a detail of a third overflow collection launder arrangement ,

Figure 6 is a schematic cross-sectional view of a detail of a fourth overflow collection launder arrangement ,

Figure 7 is a schematic cross-sectional view of a detail of a fifth overflow collection launder arrangement ,

Figures 8a - 8c are schematic cross-sectional views of a detail of a sixth overflow collection launder arrangement ,

Figure 9 is a schematic view of a separation circuit , and

Figure 10 is a schematic view of another separation circuit . In the figures , some embodiments are shown simplified for the sake of clarity . Similar parts are marked with the same reference numbers in the figures .

DETAILED DESCRIPTION

Figure 1 is a schematic view of a detail of an overflow collection launder arrangement and Figure 2 is a schematic cross-sectional view of the detail shown in Figure 1 .

The overflow collection launder arrangement 100 comprises a redirection device 1 that is arranged to receive an overf low from a separator device (not shown) . The overflow is collected into a collection launder system 3 . The collection launder system 3 comprises at least three compartments 4a , 4b, 4c . Each of said three compartments 4a, 4b, 4c leads the overflow into a subsequent process . The term "subsequent process" includes not only processes following the separation circuit , but also recirculation the overflow back to the same separation circuit or separation line .

The separator device may be a flotation device , such as a flotation cell , a magnetic separator, or a gravity separator, for instance .

In one embodiment , the redirection device 1 comprises a feed guide 2 that is configured to guide the overflow out from the redirection device 1 in the collection launder system 3 . The feed guide may be , e . g . , a simple opening or comprise a chute , a pipe , etc .

In one embodiment , the feed guide 2 is arranged in a cradle 18 , preferably at a bottom part thereof . The cradle 18 is configured to receive the overf low from a separator device .

In one embodiment , the cradle 18 is configured to turn T around an axis 22 that is at least substantially parallel with the three compartments 4a, 4b, 4c such that the feed guide 2 changes its position on one of the compartments to another of said compartments when the cradle is turned .

In one embodiment , the redirection device 1 comprises a feed chute 14 . The chute 14 is arranged to receive the overflow and feed it to the cradle 18 .

In one embodiment , the redirection device 1 comprises an alignment arrangement 5 that is configured to control the pos ition of the feed guide 2 so the overflow is discharged from the redirection device 1 in one of the compartments 4a, 4b, 4c at a time . In other words , when the feed guide 2 is discharging the overflow to, for instance , a first compartment 4a of said three compartments , the overflow i s not ending up in other two compartments 4b , 4c, apart from incidental splashes .

In one embodiment , the alignment arrangement 5 comprises an equipment 6 for manual control of the position of the feed guide 2 . Said equipment 6 may comprise, e . g . , a lever ( such as shown in Figure 2 ) or a handle wheel connected directly or via an idler mechanism to the feed guide 2 . Said equipment 6 for manual control may comprise a motor or an actuator arranged for alleviating said control .

In one embodiment , the alignment arrangement 5 comprises an automatic control system 7 ( shown in Figure 9 ) through which the feed guide 2 is preferably remote controlled . In one embodiment , all feed guides 2 arranged in a launder arrangement 100 are controlled by the automatic control system 7 . In one embodiment , all feed guides 2 arranged in a separation circuit 200 are controlled by the automatic control system 7 . In one embodiment , the alignment arrangement 5 is configured to move the feed guide 2 by a turning movement T . In one embodiment , the axis 22 of said turning movement is paral lel or at least substantially parallel with the lengthwi se dimension X of a section of the compartments 4a, 4b, 4c to which the feed guide 2 is feeding the overflow . Said lengthwise dimension X is the paral lel with the direction of overflow flow in the compartments . In one embodiment , the axis 22 is arranged hori zontally, while the compartments are sloping .

In one embodiment , the collection launder system 3 comprises a launder 8 and the three compartments 4a, 4b, 4c are established in said launder 8 by arranging separation walls 9 therein . In another embodiment , the three compartments 4a, 4b, 4c are launders or channels not arranged in one launder, but the compartments are separate from each other .

In one embodiment , the three compartments 4a, 4b, 4c are arranged side by side when seeing from above , and the feed guide 2 is configured to feed said compartments from above . In one embodiment , such as shown in Figures 1 and 2 , the second and the third compartments 4b, 4c are arranged to extend under the first compartment 4a .

In one embodiment , the cross-sectional area, i . e . the area in the transverse cross-section C, is equal in all the compartments 4a, 4b, 4c . In another embodiment , one of the compartments has a smaller cross-sectional area than the rest of the compartments . In still another embodiment , all the cross-sectional areas differ from each other .

Figure 3 is a schematic view of a detail of another overf low collection launder arrangement and Figure 4 is a schematic cross-sectional view of the detail shown in Figure 3 . In one embodiment , the feed guide 2 comprises a rotatable guide 19 , such as a pipe , a hose , a conduit or a trough, that is configured to direct the overflow in one of the compartments 4a, 4b , 4c depending on a rotational position thereof .

In one embodiment , the rotatable guide 19 is arranged to rotate around axis 22 that is at least substantially parallel with the lengthwise dimension X of a section of the compartments 4a, 4b, 4c to which the feed guide 2 is feeding the overflow . In one embodiment , the rotatable guide 19 comprises an extension 23 angled to the axis 22 such that said extension 23 can be moved on one compartment on another compartment by rotating the rotatable guide 19 .

In one embodiment , the first compartment 4a is the middle one of the three compartments , and the second and the third compartments 4b, 4c extend under the first compartment 4a . In one embodiment , the second and the third compartments 4b, 4c are separated by a vertically extending separation wall 9a that is arranged under the first compartment 4a .

Figure 5 is a schematic view of a detail of a third overflow collection launder arrangement .

In one embodiment , the alignment arrangement is configured to move the feed guide 2 by a linear movement L . The linear movement may comprise a hori zontal component and a vertical component . In one embodiment , the linear movement takes place in the hori zontal plane only . In one embodiment , the alignment arrangement is configured to move the feed guide 2 by a movement that is a combination of linear and rotational movements .

In one embodiment , the feed guide 2 comprises a flexible section 20 . The flexible section 20 may be , e . g . , a flexible pipe or tube made of elastomeric material . The flexible section 20 allows the alignment arrangement to direct a flow of the overflow in one of the compartments 4 a, 4b, 4c at a time by bending said flexible section 20 .

Figure 6 is a schematic cross-sectional view of a detail of a fourth overflow collection launder arrangement and Figure 7 is a schematic cross-sectional view of a detail of a fifth overflow collection launder arrangement .

In one embodiment of the launder 8 , in the transverse crosssection C thereof , the second compartment 4b is placed on a first side of the first compartment 4a, and the third compartment 4c is arranged on a second side of the first compartment 4a . In one embodiment , such as shown in Figure 6 , all the compartments 4a-4c has a same shape and cross- sectional area . In another embodiment , one of the compartments 4a-4c has a smaller cross-sectional area that the rest of the compartments .

In one embodiment , the launder 8 comprises more than three compartments . As an example , Figure 7 is showing an embodiment that has four compartments 4a, 4b, 4c, 4d . Even more than four compartments can be provided in some embodiments .

In one embodiment that comprises four or more compartments 4a - 4d, the first compartment 4a is arranged between two other compartments such that the feed guide 2 can move from feeding the first compartment 4a to feed two other compartments ( 4b and 4c in Figure 7 ) without crossing any other compartment .

Figures 1 -7 are showing launders 8 the cross-section of which is rectangular . However, the launder may have some other cross-section as well . In one embodiment , the crosssection of the launder has a rounded bottom part . In one embodiment , the cross-section of the launder is narrowing towards its bottom . In one embodiment , the cross-section of the launder has a V-shaped bottom part .

Figures 8a - 8c are schematic cross-sectional views of a detail of a sixth overflow collection launder arrangement .

In one embodiment , the alignment arrangement (not shown) is arranged to adj ust the compartments 4a, 4b, 4c such that the overflow is arranged to arrive in one of said compartments 4a, 4b, 4c at a time . In other words , the alignment arrangement not necessarily adj usts or moves the redirection device or its feed guide 2 but acts on the compartments .

In one embodiment , the compartments 4a, 4b, 4c are separated by separation walls 9 , at least some of which are movable . The alignment arrangement is arranged to move said movable separation walls such that the overflow is directed from the feed guide 2 to one of said compartments 4a, 4b, 4c at a time . In one embodiment , the movable separation walls are movable on hinges 24 that are connected to , e . g . , a bottom of the launder 8 . The movable separation walls can be manually controlled or controlled by an automatic control system, i . e . by s imilar means as already described in connection with the feed guide .

Figure 9 is a schematic view of a separation circuit 200 that comprises an overflow collection launder arrangement 100 as described in this description .

It should be noted that the compartments 4a-4c of the overflow collection launder arrangement 100 are shown as separate launders in Figure 9 for clarity reasons . The compartments may be reali zed as separate launders as shown in Figure 9 or arranged in one launder as shown and described in this description relating to Figures 1-8.

The separation circuit 200 comprises plurality of separator devices 13 arranged in a separation line 12. The separator devices 13 receives slurry and separates it into an overflow 0 and an underflow U. In one embodiment, valuable mineral (s) , i.e., the accept, is collected as the overflow 0, and the gangue, i.e., the reject, is directed to the underflow U. The underflow of the separator device 13 may be arranged to flow via an outlet to a subsequent separator device 13 and finally out of the separation line 12 as gangue or final residue G. In another embodiment, the accept is directed to the underflow U and the reject is collected as the overflow 0.

In one embodiment, the separation circuit 200 is a flotation circuit and the separator devices 13 are flotation devices or cells. In one embodiment, the separator devices 13 are froth flotation devices or cells. The overflow collection launder arrangement 100 is arranged to receive the overflow from the separator devices 13 and convey said overflow to a subsequent process that can be, e.g., a further separation process. In one embodiment, the compartments 4a-4c are connected to respective pump sumps 21a-21c that pump and transfer the overflow.

However, it is to be noted that the separation circuit 200 and the separator devices 13 therein may be any circuit and devices, respectively, for separating a feed mixture to the overflow and the underflow. In one embodiment, the separation circuit 200 is a magnetic separation circuit and the separator devices 13 are magnetic separator devices. In one embodiment, the separation circuit 200 is a gravity separation circuit and the separator devices 13 are gravity separator devices. The launder arrangement 100 is provided with at least one redirection device 1 . In one embodiment , the launder arrangement 100 is provided with a plurality of redirection devices 1 that are arranged to be controlled independently of each other .

In one embodiment , all the separator devices 13 of the separation line are provided with the redirection device 1 that are controlled independently from each other . Thus , the first compartment 4a may be arranged to receive the overflow 0 from j ust one of the separator devices 13 at a time . In other words , one of the separator devices 13 is feeding its overflow 0 to the first compartment 4a while the rest of the separator devices 13 are feeding their overflow 0 to , e . g . , the second or third compartment 4b, 4c . This way it is possible to feed the overflow 0 from j ust one separator device 13 to the analysis arrangement 10 and thereby obtain data about the performance of that one specific separator device 13 . Based on the data, the redirection device 1 can then be controlled to guide the overf low of said specific separator device 13 to the second or third compartment 4b, 4c . All the separator devices 13 in the separation line 12 can be analysed and their redirection devices 1 controlled similar way .

In one embodiment , the first compartment 4a is connected to an analysis arrangement 10 . In other words , the overflow fed in the first compartment 4a may flow to the analysis arrangement 10 . The analysis arrangement 10 is provided with means for detecting or measuring one or more characteristics of the overflow . In one embodiment , the analysis arrangement 10 comprises an analyzer that measures contents of chemical elements in the overflow . In one embodiment , the analysis arrangement 10 comprises an on-stream x-ray fluorescence analyzer . In one embodiment , the analysis arrangement 10 comprises a flow and/or density meter ( s ) 11 for measuring the mass flow of the overflow in the first compartment 4a .

In one embodiment , the redirection devices 1 are controlled by an automatic control system 7 . The automatic control system 7 may be a dedicated part of a control system that is configured to control the operations of the separation circuit 200 . The automatic control system 7 may use data obtained by the analysi s arrangement 10 in controlling the redirection devices 1 .

In one embodiment , the overflow that has passed the analysis arrangement 10 is re-circulated through a recirculation arrangement 16 back to the separation line 12 , e . g . , to the first separator device 13 as shown in Figure 9 . The recirculation arrangement 16 may comprise a pump sump 21d .

Figure 10 is a schematic view of another separation circuit . In one embodiment , the overflow collection launder arrangement 100 is arranged in a separation circuit 200 that comprises two or more separation lines arranged such that a previous of said separation lines is configured to feed at least part of its overflow to a following separation line . In one embodiment , at least one of the separation lines arranged in the separation circuit 200 is provided with the collection launder arrangement 100 . In one embodiment , al l the separation lines that belong to the separation circuit 200 comprise a respective overf low collection launder arrangement 100 .

The embodiment of the separation circuit 200 shown in Figure 10 is a flotation circuit that comprises three separation lines 12a, 12b, 12c . In one embodiment , the separation circuit 200 is a froth flotation circuit . First 12a of said separation lines is a rougher line that comprises six rougher flotation cells 13a, second 12b is a cleaner flotation line that comprises six cleaner flotation cells 13b, and third 12c is a re-cleaner flotation line comprising six re-cleaner flotation cells 13c .

A first rougher flotation cell 13a ( the most left one in Figure 10 ) receives input slurry from a conditioner 15 . Said slurry is separated in said flotation cell into an overflow 0 and an underflow U . The overflow 0 is fed in a rougher overflow collection launder arrangement 100a, through a redirection device 1 ( shown in Figure 9 ) , whereas the underflow U is fed to a next rougher flotation cell 13a for further separation . In one embodiment , the accept is in the overflow 0, and the rej ect is in the underflow U . The underflow from the last rougher flotation cell 13a may be feed as a gangue G out from the separation circuit 200 . In another embodiment , however, the accept is directed to the underflow U and the rej ect is collected as the overflow 0. The rej ect is then handled and transferred by the overflow collection launder arrangements l O Oa- l O Oc as described herein .

In one embodiment , the rougher overflow collection launder arrangement 100a comprises three compartments 4a, 4b, 4c . The first compartment 4a may be connected to an analysis arrangement ( such as shown in Figure 9 ) for feeding the overflow therein, for instance . The overflow analysed in the analysis arrangement may be recirculated back to the first flotation line 12a .

The second compartment 4b may be arranged to feed the overflow to the second flotation line 12b, i . e . , to the cleaner flotation line . In one embodiment , such as shown in Figure 10 , this overflow is re-ground in a regrinding apparatus 17 and then fed in the second flotation line 12b . The third compartment 4c may be arranged to feed the overflow out from the separation circuit 200. This overflow is an accept A in embodiments where the overflow collection launder arrangements lOOa-lOOc are handling accepts of the flotation cells, and a reject in embodiments where the overflow collection launder arrangements lOOa-lOOc are handling rejects of the flotation cells.

The second flotation line 12b, i.e. the cleaner flotation line is arranged to receive the overflow from the second compartment 4b of the first flotation line 12a. In one embodiment, the overflow is received by the first one of the cleaner flotation cells 13b (the most left one in Figure 10) . Then, the overflow is processed in the cleaner flotation cells 13b by separating it into overflows and underflows U. The overflows are fed in a cleaner overflow collection launder arrangement 100b, through redirection devices 1 (shown in Figure 9) , whereas the underflow is fed to a next cleaner flotation cell 13b. The underflow from the last cleaner flotation cell 13b may be sent out from the separation circuit 200. This underflow is a reject or gangue G in embodiments where the overflow collection launder arrangements lOOa-lOOc are handling accepts of the flotation cells, and an accept in embodiments where the overflow collection launder arrangements lOOa-lOOc are handling rejects of the flotation cells.

In one embodiment, the cleaner overflow collection launder arrangement 100b comprises three compartments 4a, 4b, 4c. The first compartment 4a may be connected to an analysis arrangement (such as shown in Figure 9) for feeding the overflow therein, for instance. The overflow analysed in the analysis arrangement may be recirculated back to the first flotation line 12a or the second flotation line 12b. The second compartment 4b of the cleaner overflow collection launder arrangement 100b may be arranged to feed the overflow back to the second flotation line 12b, i . e . , to the cleaner flotation line . In one embodiment , this overflow is re-ground in the regrinding apparatus 17 and then fed back in the second flotation line 12b .

The third compartment 4c of the cleaner overflow collection launder arrangement 100b may be arranged to feed the overflow to the third flotation line 12c, i . e . , to the recleaner flotation line . In one embodiment, such as shown in Figure 10 , the third flotation line 12c may receive the overflow by not its first re-cleaner flotation cell 13c ( the most left one in Figure 10 ) , but by one of the cells arranged between two cells . In the embodiment shown in Figure 10 , the overflow is fed in a fourth cell of the re-cleaner flotation line 12c .

In one embodiment , the re-cleaner overflow collection launder arrangement 100c comprises also three compartments 4a, 4b, 4c . The first compartment 4a may be connected to an analysis arrangement ( such as shown in Figure 9 ) for feeding the overflow therein, for instance . The overflow analysed in the analysis arrangement may be recirculated back to a suitable point of the separation circuit 200 .

The second compartment 4b of the re-cleaner overflow collection launder arrangement 100c may be arranged to feed the overflow back to the re-cleaner flotation line 12c, such as to the first re-cleaner flotation cell 13c as shown in Figure 10 .

The third compartment 4c of the re-cleaner overflow collection launder arrangement 100c may be arranged to feed the overflow as an accept out from the separation circuit 200 . In one embodiment , the underflow U of the last re-cleaner flotation cell 13c is reground in the regrinding apparatus 17 and then fed back to a suitable point of the separation circuit 200 . In the embodiment shown in Figure 10 , the regrinding apparatus 17 is arranged to regrind overflows coming from the first flotation line 12a, the second flotation line 12b and the underflow from the third flotation line 12c, and feed reground flow in the second flotation line 12b .

In a typical flotation circuit , the amount of a floatable material , i . e . , the amount of the overflow, decreases with the cleaner stage . Thus , the si ze and/or the number of flotation cells needed in a second cleaner stage is typically less than in a first cleaner stage , for instance .

In the embodiment shown in Figure 10 , a second 26 and a third 27 cleaner stages ( indicated by dot-and-dash lines ) are arranged in the re-cleaner flotation line 12c, and they have a common launder arrangement 100c . It is to be noted that the cleaner flotation line 12b constitutes the first cleaner stage . In one embodiment , the feed of the second and the third 26 , 27 cleaner stages have two alternatives : in the first alternative feeding 25a, the feed is directed to one of the cells arranged between two cells as already described, whereas in the second alternative feeding 25b , the feed is directed to the second compartment 4b of the re-cleaner flotation line 12c . These alternative feedings give flexibility in the use of the second 26 and a third 27 cleaner stages , and the feed can be selected depending on the amount and quality of the feed .

In one embodiment , at least maj ority of the flotation cells arranged in the flotation circuit 200 are provided with the redirection devices 1 that are configured to be control led independently of each other . In one embodiment , all the separator devices of the separation circuit 200 are provided with the redirection devices 1 that are controlled independently from each other . However, in some embodiments , some of the flotation lines 12a- 12c, but not al l , comprise the collection launder arrangement 100 . In other words , at least one of the flotation lines is devoid of the collection launder arrangement 100 .

It is to be noted that although the separation circuit 200 shown in Figure 10 and explained and disclosed herein is a flotation circuit , the separation process as such taking place in the separation circuit 200 can alternatively be reali zed by using, e . g . , magnetic separators or gravity separators and corresponding separation lines . Furthermore , it is to be noted that the number of the separation lines and the number of the separation devices arranged therein may vary . It is also possible to use different types of separation lines or separation devices in the separation circuit . In other words , the separation circuit may comprise at least one flotation cell and at least one magnetic separator or gravity separator, for instance .

The invention is not limited solely to the embodiments described above , but instead many variations are possible within the scope of the inventive concept defined by the claims below . Within the scope of the inventive concept the attributes of different embodiments and applications can be used in conj unction with or replace the attributes of another embodiment or application .

The drawings and the related description are only intended to i llustrate the idea of the invention . The invention may vary in detail within the scope of the inventive idea defined in the following claims . REFERENCE SYMBOLS

1 redirection device

2 feed guide

3 collection launder system

4a-c compartment

5 alignment arrangement

6 manual control equipment

7 automatic control system

8 launder

9 separation wall

9a vertically extending separation wall

10 analysis arrangement

11 flow and/or density meter ( s )

12 separation line

13 separator device

14 feed chute

15 conditioner

16 recirculation arrangement

17 regrinding arrangement

18 cradle

19 rotatable guide

20 flexible section

21 pump sump

22 axis

23 extension

24 hinge

25 feeding

26 2^nd cleaner stage

27 3^rd cleaner stage

100 launder arrangement

200 separation circuit

A accept

C transverse cross-section G gangue

L linear movement

0 overflow

T turning movement U underflow

X lengthwise dimension

Claims

1. An overflow collection launder arrangement (100) , comprising

- a redirection device (1) arranged to receive an overflow, the redirection device comprising

- a feed guide (2) configured to guide said overflow out from the redirection device (1) , the arrangement (100) further comprising

- a collection launder system (3) comprising at least three compartments (4a, 4b, 4c) , each of said three compartments arranged for leading the overflow into a subsequent process, wherein

- the arrangement (100) comprises an alignment arrangement (5) configured to control the mutual position of the feed guide (2) and said at least three compartments (4a, 4b, 4c) for guiding said overflow in one of said at least three compartments (4a, 4b, 4c) at a time.

2. The arrangement as claimed in claim 1, wherein

- the alignment arrangement (5) is configured to move the feed guide (2) by at least one of a turning movement (T) and a linear movement (L) .

3. The arrangement as claimed in claim 2, wherein

- the redirection device (1) comprises a cradle (18) that is configured to receive overflow from a separator device (13, 13a, 13b, 13c) , wherein the feed guide (2) is arranged at a bottom part of the cradle (18) , and wherein

- the cradle (18) is configured to make the turning movement (T) around an axis (22) substantially parallel with the at least three compartments (4a, 4b, 4c) .

4. The arrangement as claimed in claim 2, wherein

- the feed guide (2) comprises a rotatable guide (19) that is configured to direct a flow of the overflow in one of the at least three compartments (4a, 4b, 4c) depending on a rotational position thereof.

5. The arrangement as claimed in claim 2, wherein

- the feed guide (2) comprises a flexible section (20) , and

- the alignment arrangement (5) is configured to direct a flow of the overflow in one of the at least three compartments (4a, 4b, 4c) by bending said flexible section (20) .

6. The arrangement as claimed in any of the preceding claims, wherein

- the alignment arrangement (5) comprises an equipment (6) for manual control of the mutual position of the feed guide (2) and the at least three compartments (4a, 4b, 4c) .

7. The arrangement as claimed in any of the preceding claims, wherein

- the alignment arrangement (5) is arranged to control the mutual position of the feed guide (2) and said at least three compartments (4a, 4b, 4c) by an automatic control system ( 7 ) .

8. The arrangement as claimed in any of claims 2-7, comprising

- plurality of redirection devices (1) , arranged to be controlled independently of each other.

9. The arrangement as claimed in any of the preceding claims, wherein

- the at least three compartments (4a, 4b, 4c) are arranged side by side when seeing from above, and

- the feed guide is configured to feed said compartments from above.

10. The arrangement as claimed in claim 1, wherein - the alignment arrangement (5) is arranged to adjust the at least three compartments (4a, 4b, 4c) such that the overflow is arranged to arrive in one of said at least three compartments (4a, 4b, 4c) at a time.

11. The arrangement as claimed in claim 10, wherein

- said at least three compartments (4a, 4b, 4c) are separated by separation walls (9) , the separation walls comprising

- movable separation walls, and wherein

- the alignment arrangement (5) is arranged to move said movable separation walls such that the overflow is directed to one of said at least three compartments (4a, 4b, 4c) at a time.

12. The arrangement as claimed in any of the preceding claims, wherein

- the collection launder system (3) comprises a launder (8) , and

- said at least three compartments (4a, 4b, 4c) are established in said launder (8) .

13. The arrangement as claimed in claim 12, wherein

- the second compartment (4b) is arranged on a first side of the first compartment (4a) , and

- the third compartment (4c) is arranged on a second side of the first compartment (4a) .

14. The arrangement as claimed in claim 13, wherein

- the second and the third compartments (4b, 4c) are arranged to extend under the first compartment (4a) .

15. The arrangement as claimed in claim 13 or 14, wherein

- the second and the third compartments (4b, 4c) are separated by a vertically extending separation wall (9a) arranged under the first compartment (4a) .

16. The arrangement as claimed in any of the preceding claims, wherein

- the first compartment (4a) is connected to an analysis arrangement (10) for analyzing overflow fed in the first compartment (4a) .

17. The arrangement as claimed in claim 16, wherein

- the analysis arrangement (10) comprises an analyzer for measuring contents of chemical elements in said overflow.

18. The arrangement as claimed in any of the preceding claims, comprising

- a flow and/or density meter (s) (11) arranged to measure the mass flow in the first compartment (4a) .

19. The arrangement as claimed in any of the preceding claims, wherein

- the separator device (13) is a flotation cell.

20. A separation circuit (200) comprising the overflow collection launder arrangement (100) as claimed in any of the preceding claims.

21. The circuit as claimed in claim 20, wherein

- the separation circuit (200) is a flotation circuit.

22. The circuit as claimed in claim 20 or 21, comprising

- a separation line, such as a flotation line (12a, 12b, 12c) , wherein said separation line is one of a rougher line, a cleaner line, and a re-cleaner line.

23. The circuit as claimed in claim 22, comprising at least two separation lines, such as flotation lines (12a, 12b, 12c) , wherein - a first (12a) of said separation lines is configured to feed at least part of its overflow to a second (12b) of said separation lines, and wherein

- one of the first and the second separation lines (12a, 12b) comprises the collection launder arrangement (100) , and

- at least one of the separation lines (12a, 12b, 12c) is devoid of the collection launder arrangement (100) .

24. The circuit as claimed in claim 22, comprising at least two separation lines, such as flotation lines (12a, 12b, 12c) , wherein

- a first (12a) of said lines is configured to feed at least part of its overflow to a second (12b) of said lines, and wherein

- all the separation lines (12a, 12b, 12c) comprise the collection launder arrangement (100) .

25. The circuit as claimed in claim 22, comprising comprising three separation lines, such as flotation lines (12a, 12b, 12c) , wherein

- a first separation line (12a) is a rougher line comprising at least one rougher separator device, such as a rougher flotation cell (13a) ,

- a second separation line (12b) is a cleaner line comprising at least one cleaner separator device, such as a cleaner flotation cell (13b) , and

- a third separation line (12c) is a re-cleaner line comprising at least one re-cleaner separator device, such as a re-cleaner flotation cell (13c) , wherein

- at least the rougher line (12a) is provided with the collection launder arrangement (100) .

26. The circuit as claimed in claim 25, wherein - the second compartment (4b) arranged in the rougher line (12a) is configured to guide overflow to the cleaner line (12b) , and

- the third compartment (4c) arranged in the rougher line (12a) is configured to discharge overflow out from the separation circuit (200) .

27. The circuit as claimed in claim 25 or 26, wherein

- the cleaner line (12b) is provided with a second collection launder arrangement (100) ,

- the second compartment (4b) of said second collection launder arrangement is configured to guide overflow to a recirculation arrangement (16) for recirculating said overflow back to the cleaner line (12b) , and

- the third compartment (4c) of said second collection launder arrangement is configured to guide overflow to the recleaner line (12c) .

28. The circuit as claimed in claim 27, wherein

- the recirculation arrangement (16) comprises a regrinding arrangement (17) for regrinding overflow to be fed in the cleaner separation line (12b) .

29. The circuit as claimed in any of claims 25 - 28, wherein

- the re-cleaner separation line (12c) is provided with a third collection launder arrangement (100) ,

- the second compartment (4b) of said third collection launder arrangement is configured to recirculate overflow back in the re-cleaner separation line (12c) , and

- the third compartment (4c) of said third collection launder arrangement is configured to discharge overflow out from the flotation line.

30. The circuit as claimed in any of claims 25 - 29, wherein

- at least majority of the separation devices arranged in the separation circuit (200) are provided with the distributor devices (1) arranged to be controlled independently of each other.