EP2389251B1

EP2389251B1 - Method for separating particles in hydrous slurry

Info

Publication number: EP2389251B1
Application number: EP09834182.9A
Authority: EP
Inventors: Timo Niitti
Original assignee: Outotec Finland Oy
Current assignee: Outotec Finland Oy
Priority date: 2008-12-22
Filing date: 2009-12-22
Publication date: 2019-07-24
Anticipated expiration: 2029-12-22
Also published as: FI121650B; WO2010072901A1; FI20086227A; CA2747833A1; EP2389251A1; FI20086227A0; CN202570362U; PL2389251T3; EP2389251A4

Description

Field of the invention

The invention relates to a method for separating particles in hydrous slurry.
The present invention relates to a hindered-bed separator or hindered-bed settler or similar separator or settler apparatus (hereinafter "hindered-bed settler") to partition solid particles in a hydrous slurry or pulp into two or more fractions containing particles of different size and density.
Many sizing and classifying methods employ gravity of solid material in hydrous slurry with an incoming feed containing the material encountering an upward teeter water flow. The variation in size and/or density will result in heavier particles falling to a lower level of the hindered-bed settler and lighter particles being uplifted to an overflow level of the hindered-bed settler thus affecting the desired separation.
The operation of so called hindered-bed settlers is based on even distribution of a controlled amount of teeter water into an in inner space of the body of the hindered-bed separator with teeter water distributor means arranged in the inner space of the body of the hindered-bed separator. Usually, the teeter water is pumped into teeter pipes of the teeter water distributor means from one side only, but if the water is "dirty" and contains for example much fine solids, the teeter water pipes will get clogged because of the fine solids settling at the end of the teeter pipe where the flow velocity is lowest. Gradually this clogging then is proceeding towards the feed end of the teeter pipes and relatively soon the teeter water feed into the hindered-bed settler becomes biased and operation becomes poor. The hindered-bed settler has to be stopped for pipe cleaning meaning production losses etc. In some cases teeter water is pumped into the teeter pipes from both ends, but then the clogging starts from the middle of the teeter pipes.
Publication US 6,425,458 presents an air-assisted density separator device and method.

Short description of the invention

The aim of the invention is to solve the above-identified problem.
A first alternative of the method for separating particles in hydrous slurry of the invention is characterized by the definitions of independent claim 1.
Preferred embodiments of the first alternative of the method are defined in the dependent claims 2 to 5 and 9.
A second alternative of the method for separating particles in hydrous slurry of the invention is characterized by the definitions of independent claim 6.
Preferred embodiments of the second alternative of the method are defined in the dependent claims 7 to 9.
The invention is based on discharging part of the teeter water that is fed into the teeter water distributor means by using a teeter water discharging means that is in fluid connection with the teeter water distributor means. This means for example that a certain amount of teeter water is fed into the teeter water distributor means. This amount can for example be the double compared to the amount actually used for teetering in the hindered-bed separator, so the other half just runs through the teeter water pipes of the teeter water distributor means inside the hindered-bed separator. This way the flow speed in the teeter water pipes system is high or large enough to keep the teeter water pipes clean by transporting fine solids effectively through the teeter water pipes. This way an arrangement can be created that does not need cleaning of the teeter pipes at all or very seldom.
In a method somewhat dirty teeter water i.e. teeter water containing particles can be used. The new arrangement is essentially useful in cases where dirty circulating water e.g. from the tailings pond or thickener is used. Because of environmental reasons this is nowadays the most common situation in the industry.
In the suggested system the pipes could also be cleaned, if necessary, just by increasing momentarily the flow speed of water. The opening of the unit for cleaning would then not be necessary at all.
In the first alternative of the method both the intake pipe for feeding teetering water to the teeter water distributor means and the return pipe for leading teetering water from the teeter water discharging means is provided with a flow measuring means, such as a flow meter, for measuring the flow before the hindered-bed separator and respectively for measuring the flow after the hindered-bed separator. The difference in the flows naturally flows into the interior of the hindered-bed separator. In this first alternative of the method, the amount of teeter water entering the inner space of the body of the hindered-bed separator and correspondingly the amount of teeter water flowing through the inner space of the body of the hindered-bed separator is controlled by a valve means such as an automatic valve in the return pipe.

List of figures

In the following the invention will be described in more detail by referring to the figures, of which

Fig 1 shows a hindered-bed separator having a teeter water distributor means,
Fig 2 shows the principle of a teeter water distribution system means according to a first preferred embodiment of the invention,
Fig 3 shows the principle of a teeter water distribution system means according to a second preferred embodiment of the invention,
Fig 4 shows the principle of a teeter water distribution system means according to a third preferred embodiment of the invention,
Fig 5 shows the principle of a teeter water distribution system means according to a fourth preferred embodiment of the invention
Fig 6 shows the principle of a teeter water distribution system means according to a fifth preferred embodiment of the invention,
Fig 7 shows the principle of a teeter water distribution system means according to a sixth preferred embodiment of the invention,
Fig 8 shows the principle of a teeter water distribution system means according to a seventh preferred embodiment of the invention, and
Fig 9 shows the principle of a teeter water distribution system means according to an eight preferred embodiment of the invention.

Detailed description of the invention

The invention relates to a method for separating particles (not shown in the figures) in hydrous slurry 38.
The method for separating particles in hydrous slurry 38 comprises a step for using a hindered-bed separator comprising a body 2 defining an inner space 3, feed well means 4 for introducing hydrous slurry 38 into the inner space 3 of the body 2, overflow launder means 5 for discharging light particles 34 from the inner space 3 of the body 2, coarse feed means 6 for discharging heavy particles 35 from the inner space 3 of the body 2, and teeter water distributor means 7 comprising teeter water pipes 8 arranged in the inner space 3 of the body 2 for introducing teeter water 9 into the inner space 3 of the body 2.
The method includes a step for introducing hydrous slurry 38 into the inner space 3 of the body 2.
The method includes steps for feeding teeter water 9 into the teeter water distributor means 7 and introducing teeter water 9 into the inner space 3 of the body 2 by means of the teeter water distributor means 7. The amount of teeter water 9 fed into the teeter water distributor means 7 exceeds preferably, but not necessarily, the amount of teeter water 9 needed for the separation process performed in the inner space 3 of the body 2 of the hindered-bed separator. In one embodiment of the method of the invention, the method includes a step for feeding between about 110 % to about 200 %, for example between about 125 % to about 150 %, the amount of teeter water 9 into the teeter water distributor means 7 of the amount of teeter water 9 that is needed for the separation process performed in the inner space 3 of the body 2 of the hindered-bed separator 1.
The method includes a step for discharging light particles 34 from the inner space 3 of the body 2.
The method includes a step for discharging heavy particles 35 from the inner space 3 of the body 2.
The method includes a step for connecting at least one teeter water pipe 8 of the teeter water distributor means 7 in fluid connection with a teeter water discharging means 10.
The method includes a step for discharging teeter water 9 from the at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10 to the teeter water discharging means 10.
The method includes preferably a step for connecting all teeter water pipes 8 of the teeter water distributor means 7 in fluid connection with a teeter water discharging means 10 and a step for discharging teeter water from all teeter water pipes 8 to the teeter water discharging means 10.
The method comprises in a preferable embodiment of the method using a hindered-bed separator 1 having a teeter water distributor means 7 having at least one teeter water pipe 8 that has a first end 11, which is in fluid connection with a first manifold 12 configured for receiving teeter water 9 from an intake pipe 32 and configured for distributing teeter water 9 to the at least one teeter water pipe 8 that is in fluid connection with the first manifold 12, and which has an opposite second end 13. This preferred embodiment of the method of the invention comprises a step for connecting the opposite second end 13 of the at least one teeter water pipe 8 that is in fluid connection with the first manifold 12, in fluid connection with the teeter water discharging means 10. This preferred embodiment of the method of the invention comprises preferably a step for connecting the opposite second end 13 of the at least one teeter water pipe 8 that is in fluid connection with the first manifold 12, in fluid connection with a second manifold 14 of the teeter water discharging means 10.
The method comprises in a preferable embodiment of the method using a hindered-bed separator 1 having a teeter water distributor means 7 having several teeter water pipes 8 each having a first end 11, which is in fluid connection with a first manifold 12 configured for receiving teeter water 9 from an intake pipe 32 and configured for distributing teeter water 9 to the several teeter water pipes 8 that are in fluid connection with the first manifold 12, and each of which teeter water pipes 8 has a opposite second end 13. This preferred embodiment of the method of the invention comprises a step for connecting the opposite second end 13 of each teeter water pipe 8, which are in fluid connection with the first manifold 12, in fluid connection with the teeter water discharging means 10. This preferred embodiment of the method of the invention comprises preferably a step for connecting the opposite second end 13 of each teeter water pipe 8, which are in fluid connection with the first manifold 12, in fluid connection with a second manifold 14 of the teeter water discharging means 10.
The method comprises in a first alternative of the method a step for arranging a first valve means 15 to the teeter water discharging means 10 to adjust the amount of teeter water 9 that is discharged from the teeter water discharging means 10. This first alternative of the method includes a step for measuring by means of a first flow measuring means 17 the amount of inflowing teeter water 9 flowing into the teeter water distributor means 7 and a step for measuring by means of a second flow measuring means 19 the amount of outflowing teeter water 9 flowing from the teeter water discharging means 10. This first alternative of the method includes a step for calculating the difference between the inflowing teeter water 9 and the outflowing teeter water 9, and a step for controlling the first valve means 15 in accordance with the calculated difference to adjust the flow in the teeter water discharging means 10, in other words to adjust the flow of teeter water 9 flowing through the inner space 3 of the body 2 of the hindered-bed separator 1. Figure 3 and 5 illustrates arrangements suitable for this first alternative of the method. In this first alternative of the method the amount of teeter water entering the inner space 3 of the body 2 of the hindered-bed separator 1 can also be calculated by means of the calculated difference, i.e. the amount of teeter water 9 going into the separation process can also be calculated from the calculated difference.
A preferable embodiment of the first alternative of the method includes a step for measuring by means of a pressure measuring means 39 the pressure of inflowing teeter water 9 flowing into the teeter water distributor means 7. This preferable embodiment of the first alternative of the method includes a step for controlling the first valve means 15 in accordance with the measured pressure to adjust the flow in the teeter water discharging means 10, in other words to adjust the flow of teeter water flowing through the inner space 3 of the body 2 of the hindered-bed separator. Figure 3 and 4 illustrate arrangements suitable for this preferred embodiment of the first alternative of the method.
A preferable embodiment of the first alternative of the method of the invention includes steps for controlling the first valve means 15 by means of a timer 40 for example according to a pre-set time schedule. Figure 3 and 8 illustrate arrangements suitable for this preferred embodiment of the first alternative of the method.
The method comprises in a second alternative of the method a step for arranging a second valve means 16 in the at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10. This second alternative of the method of the invention includes a step for measuring by means of a first flow measuring means 17 the amount of inflowing teeter water 9 flowing into said at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10 and a step for measuring by means of a second flow measuring means 19 the amount of outflowing teeter water 9 flowing from said at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10. This second alternative of the method of the invention includes a step for calculating the difference between the inflowing teeter water 9 and the outflowing teeter water 9 and a step for controlling the second valve means 16 in accordance with the calculated difference to adjust the flow in said at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10, in other words to adjust the flow of teeter water flowing through the inner space 3 of the body 2 of the hindered-bed separator 1 in said at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10.
A preferable embodiment of the second alternative of the method of the invention includes steps for measuring by means of a first pressure measuring means 39 the pressure of teeter water 9 flowing into said teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10 and for controlling the second valve means 16 in accordance with the measured pressure to adjust the flow in said at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10, in other words to adjust the flow of teeter water flowing through the inner space 3 of the body 2 of the hindered-bed separator 1 in said at least one teeter water pipe 8 that is in fluid connection with the teeter water discharging means 10. Figure 10 illustrate an arrangement suitable for this preferred embodiment of the second alternative of the method.
A preferable embodiment of the second alternative of the method of the invention includes steps for controlling the second valve means 16 with a timer 40 for example in accordance with a pre-set schedule. Figure 9 illustrates an arrangement suitable for this preferred embodiment of the second alternative of the method.
The method comprises in a preferable embodiment of the second alternative of the method a step for arranging second valve means 16 in all the teeter water pipes 8 that are in fluid connection with the teeter water discharging means 10. This preferable embodiment of the second alternative of the method of the invention includes a step for individually measuring the amount of inflowing teeter water 9 flowing into each teeter water pipe 8 that are in fluid connection with the teeter water discharging means 10 and a step for individually measuring the amount of teeter water 9 flowing out from each teeter water pipe 8 that are in fluid connection with the teeter water discharging means 10 into the teeter water discharging means 10. This preferable embodiment of the second alternative of the method of the invention includes a step for calculating the difference between the inflowing teeter water and the outflowing teeter water in each individual teeter water pipe 8 that are in fluid connection with the teeter water discharging means 10 and a step for controlling each second valve means 16 in each teeter water pipe 8 that are in fluid connection with the teeter water discharging means 10 in accordance with the calculated difference to individually adjust the flow in each teeter water pipe 8 that are in fluid connection with the teeter water discharging means 10, in other words to individually adjust the flow of teeter water 9 flowing through the inner space 3 of the body 2 of the hindered-bed separator 1 in each individual teeter water pipe 8.
The method comprises in a preferable embodiment of the second alternative of the method a step for arranging second valve means 16 in all teeter water pipes 8 that are in fluid connection with the teeter water discharging means 10. This preferable embodiment of the second alternative of the method of the invention includes a step for measuring the pressure of teeter water 9 flowing into each teeter water pipe 8 that are in fluid connection with the teeter water discharging means 10 and for individually controlling each second valve means 16 in each teeter water pipe 8 in accordance with the measured pressure to individually adjust the flow in each teeter water pipe 8 that are in fluid connection with the teeter water discharging means 10, in other words to adjust the flow of teeter water 9 flowing through the inner space 3 of the body 2 of the hindered-bed separator 1 individually in each individual teeter water pipes 8.
The method comprises in a preferable embodiment of the second alternative of the method a step for arranging second valve means 16 in all the teeter water pipes 8 that are in fluid connection with the teeter water discharging means 10. This preferable embodiment of the second alternative of the method of the invention includes a step for individually controlling each second valve means 16 in each teeter water pipe 8 with a timer 40 for example according to a pre-set time schedule.
It is apparent to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not restricted to the above examples, but they may vary within the scope of the claims.

List of reference numerals

1. Hindered-bed separator
2. Body
3. Inner space
4. Feed well means
5. Overflow launder means
6. Coarse feed means
7. Teeter water distributor means
8. Teeter water pipe
9. Teeter water
10. Teeter water discharging means
11. First end
12. First manifold
13. Opposite second end
14. Second manifold
15. First valve means
16. Second valve means
17. First flow measuring means
18. Calculating means
19. Second flow measuring means
20. Control means
21. Upper part
22. Middle part
23. Lower part
24. Open top
25. Bottom
26. Upper portion
27. Middle portion
28. Lower portion
29. Apertures
30. Feed well
31. Slurry introducer
32. Intake pipe
33. Return pipe
34. Light particles
35. Heavy particles
36. Overflow weir
37. Third valve means
38. Hydrous slurry
39. Pressure measuring means
40. Timer

Claims

A method for separating particles in hydrous slurry (38), which method comprises steps for
using a hindered-bed separator (1) comprising a body (2) defining an inner space (3), feed well means (4) for introducing hydrous slurry (38) into the inner space (3) of the body (2), overflow launder means (5) for discharging light particles (34) from the inner space (3) of the body (2), coarse feed means (6) for discharging heavy particles (35) from the inner space (3) of the body (2), and teeter water distributor means (7) comprising teeter water pipes (8) arranged in the inner space (3) of the body (2) for introducing teeter water (9) into the inner space (3) of the body (2),
introducing hydrous slurry (38) into the inner space (3) of the body (2),
feeding teeter water (9) into the teeter water distributor means (7) and introducing teeter water (9) into the inner space (3) of the body (2) by means of the teeter water distributor means (7),
discharging light particles (34) from the inner space (3) of the body (2), and
discharging heavy particles (35) from the inner space (3) of the body (2),
connecting at least one teeter water pipe (8) of the teeter water distributor means (7) in fluid connection with a teeter water discharging means (10),
discharging teeter water (9) from the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) to the teeter water discharging means (10),
feeding an amount of teeter water (9) into the teeter water distributor means (7) that exceeds the amount of teeter water (9) needed for the separation process performed in the inner space (3) of the body (2) of the hindered-bed separator (1),
characterized by
arranging a first valve means (15) in the teeter water discharging means (10),
discharging teeter water(9) from the teeter water discharging means (10),
controlling the first valve means (15) adjust the amount of teeter water (9) discharged from the teeter water discharging means (10),
measuring the amount of teeter water (9) flowing into the teeter water distributor means (7) from an intake pipe (32),
measuring the amount of discharged teeter water (9) discharged from teeter water discharging means (10) into a return pipe (33),
calculating the difference between the amount of teeter water (9) flowing into the teeter water distributor means (7) and the amount of teeter water (9) discharged from the teeter water discharging means (10), and
controlling the first valve means (15) in accordance with the calculated difference to adjust the amount of teeter water (9) discharged from the teeter water discharging means (10).
The method according to claim 1, characterized by
using a hindered-bed separator (1) having a teeter water distributor means (7) having at least one teeter water pipe (8), which has a first end (11) that is in fluid connection with a first manifold (12) configured for receiving teeter water (9) from an intake pipe (32) and configured for distributing teeter water (9) to the at least one teeter water pipe (8), and which has an opposite second end (13), and
connecting the opposite second end (13) of the at least one teeter water pipe (8) in fluid connection with the teeter water discharging means (10).
The method according to claim 2, characterized by
connecting the opposite second end (13) of the at least one teeter water pipe (8) in fluid connection with a second manifold (14) of the teeter water discharging means (10).
The method according to any of the claims 1 to 3, characterized by
measuring the pressure of the teeter water (9) flowing into the teeter water distributor means (7), and
controlling the first valve means (15) in accordance with the measured pressure to adjust the amount of teeter water (9) discharged from the teeter water discharging means (10).
The method according to any of the claims 1 to 4, characterized by controlling the first valve means (15) with a timer (40) to adjust the amount of teeter water (9) discharged from the teeter water discharging means (10).
A method for separating particles in hydrous slurry (38), which method comprises steps for
using a hindered-bed separator (1) comprising a body (2) defining an inner space (3), feed well means (4) for introducing hydrous slurry (38) into the inner space (3) of the body (2), overflow launder means (5) for discharging light particles (34) from the inner space (3) of the body (2), coarse feed means (6) for discharging heavy particles (35) from the inner space (3) of the body (2), and teeter water distributor means (7) comprising teeter water pipes (8) arranged in the inner space (3) of the body (2) for introducing teeter water (9) into the inner space (3) of the body (2),
introducing hydrous slurry (38) into the inner space (3) of the body (2),
feeding teeter water (9) into the teeter water distributor means (7) and introducing teeter water (9) into the inner space (3) of the body (2) by means of the teeter water distributor means (7),
discharging light particles (34) from the inner space (3) of the body (2), and
discharging heavy particles (35) from the inner space (3) of the body (2),
connecting at least one teeter water pipe (8) of the teeter water distributor means (7) in fluid connection with a teeter water discharging means (10),
discharging teeter water (9) from the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) to the teeter water discharging means (10),
feeding an amount of teeter water (9) into the teeter water distributor means (7) that exceeds the amount of teeter water (9) needed for the separation process performed in the inner space (3) of the body (2) of the hindered-bed separator (1),
characterized by
arranging a second valve means (16) in at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10),
controlling the second valve means (16) to adjust the amount of teeter water (9) that is discharged from said at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) to the teeter water discharging means (10),
measuring the amount of teeter water (9) flowing into the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10),
measuring the amount of teeter water (9) discharged from the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) to the teeter water discharging means (10),
calculating the difference between the teeter water (9) flowing into the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) and the teeter water (9) that is discharged from the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10), and
controlling the second valve means (16) in accordance with the calculated difference to adjust the amount of teeter water (9) discharged from the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) to the teeter water discharging means (10).
The method according to claim 6, characterized by
measuring the pressure of teeter water (9) flowing into the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10), and
controlling the second valve means (16) in accordance with the measured pressure to adjust the amount of teeter water (9) discharged from the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) to the teeter water discharging means (10).
The method according to claim 6 or 7, characterized by
controlling the second valve means (16) with a timer (40) to adjust the amount of teeter water (9) discharged from the at least one teeter water pipe (8) that is in fluid connection with the teeter water discharging means (10) to the teeter water discharging means (10).
The method according to any of the claims 1 to 8, characterized by feeding between about 110 % to about 200 % the amount of teeter water (9) into the teeter water distributor means (7) of the amount of teeter water (9) that needed for the separation process performed in the inner space (3) of the body (2) of the hindered-bed separator (1).