JPH0622699B2 - Method for separating spiral separator and slurry - Google Patents

Description

TECHNICAL FIELD The present invention relates to spiral separators and a method for separating slurries. The spiral separator is widely used for wet gravity separation of solids according to specific gravity. For example, spiral separators range from silica sands to various mineral sands.
and or)) or crushed coal,
By removing ash or other impurities,
It is used for coal preparation. An example of such a spiral separator is shown in Australian Patent Application No. 55205 /
No. 80 is described.

BACKGROUND OF THE INVENTION Discussed that kind of separator is a helical trough having an inner wall and an outer wall connected by a floor.
h) or has a sluice. In operation, the trough is fed with a pulp or slurry containing the material to be separated. The material in the slurry is such that the largest and heaviest materials move to one side of the flow, and the smaller and lighter materials flow upwards from the bottom of the flow and from the inside to the outside of the curve. Are distributed in layers and water accumulates on the outside of the bend and is separated according to size and specific gravity. When gravity is greater than centrifugal force, the largest and heaviest substances are concentrated in bands near the inner wall and are beneficiated to form the "concentrate zone" or "inner zone", while the smaller and lighter substances are the outer wall. To form an outer zone. A separating means is arranged to take out the inner zone via a take-off and the separation is repeated on the outer zone.

DISCLOSURE OF THE INVENTION While this conventional type of spiral has proven to be of high utility, it presents several problems in practical operation. First, the lighter and smaller materials in the slurry (eg silica sand or other gangue) have very small particle sizes compared to the particle size of the denser material to be separated. When having, it was observed that some of the lighter material would move inward toward the inner wall of the spiral with the concentrate of the denser particles, even though there were very large differences in their specific gravities. ing. When separating the concentrate from the silica sand, the presence of the silica sand can be observed as a strip or layer that at least partially overlies the concentrate. This overlying outer zone or layer adversely affects the yield and / or quality of the concentrate removed from the slurry.

Second, the current trend is to operate such spirals without additional wash water as the pulp flows down the spiral. A spiral with a large pitch and / or a bed with a relatively large slope to the horizontal in the longitudinal direction of the trough allows the water in the pulp to quickly move outwards towards the outer wall of the spiral under centrifugal action. It has been observed that as the concentrate migrates and residual concentrate and gangue in the pulp flow down the spiral, it quickly becomes sluggish.

It is an object of the present invention to provide a method and apparatus that overcomes or at least ameliorate these drawbacks, and in a preferred embodiment improve the yield and / or quality of concentrates obtainable from spiral separators. is there.

The method according to the invention achieves the first object by the step of diverting the overlying outer zone or outer layer outward from the underlying concentrate at a position upstream of the take-off for beneficiation.

In a preferred embodiment, the deflection means (def
Lector) is located inside the outer zone. The shape of the deflecting means and the velocity of the slurry are selected so that a "bow wave" is created that urges the overlying outer zone outward. Preferably, the deflection means serves to divert the overlying outer zone outward and further widen the width of the inner zone, wherein the widened inner zone optimizes the concentrate quality and / or yield. To facilitate the adjustment by the operator of the separating means for extraction in order to obtain

In a preferred embodiment of the invention, tailings below the spiral
The dewatered inner zone is repulped with water to maintain tailings flow and separate residual concentrate in the pulp from the pulp.

As used herein, the terms "pulp" and "slurry" are interchangeable. The “outward” orientation is toward the outer wall of the trough, and the “inward” orientation is toward the inner wall of the trough.

The number of turns of the spiral, the pitch and the angle of the bed can be selected to suit the particular concentrate to be screened, and the multiple concentrates in the spiral can receive and carry the concentrate extracted from the pulp. In order to do this, the spiral has an internal groove (g
utter) may be provided. The outlet may be of any suitable type, for example the type disclosed in Australian Patent No. 522914 or a slot provided in the inner wall leading towards the inner trough.
Or it may have discontinuities,
A fixed or movable separating means blade may also be provided for directing the concentrate via the take-off. The deflecting means is preferably provided about 50-200 mm upstream of the outlet and may be provided on any or all turns of the spiral. However, it is preferred that the deflecting means be provided every other turn of the spiral so that the pulp can reach the deflecting speed before hitting the deflecting means. The "deflection velocity" is the velocity at which, for example, silica sand (or gangue) is deflected outward from the inner wall of the spiral by "head waves" created by the deflection means.

The deflecting means may be fixed in, on or adjacent to the inner wall of the spiral, or may be movable relative to the inner wall, and when not required to impede the pulp below the spiral. The deflecting means may be made to hide in a recess formed in the inner wall to allow for no flow. Where the gangue or silica do not lie on the inside of the mineral stream for the separation of high quality minerals, the deflecting means not only obstruct a portion of the mineral stream and It may be spaced from the inner wall to allow the operation to deflect the gangue or silica from the outside of the mineral stream. The deflecting means may have a vane shape, finger shape or other shape extending upwards from the floor, or the inner zone may flow unobstructed downstream of the spiral (see the passage of claim 5). Vane-shaped, finger-shaped or otherwise having slots or holes adjacent to the floor to the extent that it deflects outwardly the band or layer that overlies the inner band while allowing It may have a shape.

According to a first embodiment, the present invention provides a spiral separator for separating a first substance from a second substance having a different specific gravity, the spiral separator having a spiral trough composed of an inner wall and an outer wall connected by a floor, wherein: The trough receives the flow of the slurry containing the first and second substances, and the inner zone in which the first substance is relatively concentrated in the trough, and the first substance is relatively small in amount, and a part of the inner substance is in the trough. Configured to form an outer band that overlies the band, and (b) the separator is provided within the trough and is projecting across the trough in the flow of the slurry. , A deflection means for diverting at least a part of the outer zone lying on the inner zone to the outer side with respect to the inner zone lying underneath, and provided so as to substantially face the inner wall of the trough downstream of the deflection means, The first Further includes a take-out portion capable of at least partially sorting the quality.

According to the second embodiment, the present invention provides: (a) a slurry comprising a first substance and a second substance, an inner zone in which one of the substances is concentrated, and an outer zone in which the substance is relatively small. And supplying the slurry downwardly through a trough of a spiral separator having an inner wall and an outer wall connected by a floor so that at least a portion of the outer band overlies the inner band, and (b) separating At a position upstream of the means, at least the inner portion of the overlying outer zone with respect to the underlying inner zone by the deflecting means projecting across the trough in the slurry flow. And a step of separating the first substance from the second substance having a specific gravity different from that of the first substance without using additional wash water from the outside.

In addition, in the above-described second embodiment, a step of allowing the slurry to flow through a passage having a limited width between the inner wall and the outer wall and a step of deflecting water inward in the limited passage. By adding, the water separated from the slurry by centrifugal force can remix the mass of the slurry in the water flowing down the spiral separator.

The restricted passage is preferably defined between an outer wall of the spiral and an outwardly projecting wall provided integrally with the inner wall of the spiral. Further, it is preferable that the outer wall is also provided with a portion integrally formed with the outer wall and projecting inward.

A roof may be provided over the restricted passage to prevent water from splashing or deflecting out of the spiral, and the roof may have a narrow width passage. It may have a downwardly sloping leading edge and / or a trailing edge in order to deflect downwards and to enhance remixing or repulping of water and tailings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The spiral assembly has four similar spirals mounted around a substantially vertical central column 11, the upper end of each spiral holding the feed pulp from which the concentrate is to be separated. It is connected to the usual supply box that houses it. Only one spiral is shown in the drawing for clarity. In this embodiment,
The separator corresponds to the second substance in the claims,
It is also used to separate the mineral concentrate, which also corresponds to the first substance, from the silica sand deflected outward by the deflector described later.

Each spiral 12 has an outer wall 13 connected to a spiral floor 14 which is tilted with respect to the horizontal. During most of the first turn, the inner wall 15 is fixed to the column 11 and is then provided to carry the separated concentrate towards the concentrate outlet (not shown) at the bottom of the spiral. The groove 16 is separated from the column. For ease of manufacture, the spiral 12 is preferably formed from fiberglass.

For most of the second turn of Spiral 12, the first
As shown in FIGS. 3 and 3, an ejector of the type disclosed in Australian Patent No. 522914 having a laterally extending slot 18 and a blade 19 of a movable separating means. 17 is provided to convey the concentrate separated from the silica sand towards the groove 16 and the steep angle of the groove with respect to the horizon ensures that the concentrate will flow freely down the groove. Assure.

The deflector 20 which is a deflecting means having a width of about 15 to 20 mm (corresponding to the deflecting means in the first aspect of the present invention) includes about 15 to 20
It is provided integrally with the inner wall 15 at 0 mm upstream. As shown in FIG. 1, the tip of the deflector 20 is rounded so that the concentrate 21a can flow around the deflector 20 in a relatively smooth flow. However, the deflector 20 creates a "head wave" in the water containing the silica sand partially lying on the concentrate 21a, and this "head wave" has a wide but high purity inner zone. Bend the silica outward, away from the inner wall, as per (21a). That is, the width of the inner zone widens in the width direction upstream of the splitter in a fan shape (the width of the inner zone can increase from a width of, for example, 15 mm upstream of the deflector 20 to, for example, 25 mm downstream of the deflector 20).

By observing the inner zone, the operator can adjust the blade 19 of the separating means in order to remove almost all the concentrate 21a. Separated from silica sand,
The wider inner zone allows for the removal of concentrate 21a with higher quality and yield compared to conventional spirals.

Referring to FIG. 6, the first deflector (with deflector 20
The vane 30 (corresponding to the deflecting means in claim 1) is attached by a pin 31, whereby the angle of the vane 30 with respect to the flow direction of the slurry can be adjusted.
A second embodiment is shown schematically. The inner wall 15 is provided with a recess which allows the vane 30 to be moved out of the flow when not in use. If desired, the height of the lower edge of the vane 30 above the trough floor (corresponding to the passageway in claim 5 between the floor and the lower edge) may be adjustable. Although the inner zone in FIG. 6 lies radially inward of line 32, it will be appreciated that in practice the inner zone and outer zone are not separated by a single line. Streamlines 33 and 34 indicate head waves near vane 30.

Second deflector (corresponding to the deflecting means in claim 9)
A repulping assembly 21 consisting of 22, a third deflector (corresponding to the means for inwardly directing according to claim 8) 26 and a roof member 27 is provided immediately downstream of the take-out section 17.

The second deflector 22 has a crescent shape in plan view.
Is formed by diverting the inner wall 15 of the spiral outward in a smooth curved shape and then smoothly returning it to its original state, and as a result, a passage 23 (a It corresponds to the passage referred to in the section 8). The inner wall 15 is connected to the groove outer wall 24 by a connecting panel 25.

The third deflector 26 is integrally provided on the outer wall 13 immediately downstream of the take-out portion 17, and may have the same width as the first deflector 20. A roof member having a downwardly sloping leading edge and trailing edge 28
27 covers the restricted passage 23.

In operation, the concentrate is taken off by the take-off part 17.
Water moves towards the outer wall 13 of the spiral under centrifugal force,
An unseparated residue consisting of tailings and residual concentrates in the pulp continues adjacent the inner wall 15 past the unloading section 17. The water is struck or struck against the third deflector 26, directed inward and upward with respect to the spiral 12, and hits the roof member 27. At the same time, the tailings and residual concentrate are moved outwards by the second deflector 22 and remixed with water diverted inward by the third deflector or repulped with water. The leading or trailing edge 28 of the roof member directs the water that strikes the residual concentrate downward to aid this mixing process. Preferably, the spiral pitch may be increased over a short section of the restricted passage 23 to further aid mixing, ie to accelerate tailings and residual concentrates. Downstream of the repulping assembly, the residual concentrate begins to separate from the tailings and can be moved into the groove 16 by means of a second withdrawal 17 provided on the fourth turn, for example At the bottom follows a middling and / or tailing outlet (or outlets). (These outlets may be of the type disclosed in Australian Application No. 55205/80.) A deflector, similar to deflector 20, is provided with a second deflector to aid in removing residual concentrate. It may be provided upstream of the take-out section 17. For example, if the concentrate reaches the speed at which it is moved into or above the tailings by centrifugal force, another deflector on the third turn of the spiral may be used to create a third deflector of the spiral. And the flow rate of the concentrate downward in the fourth turn may be reduced.

Since the spiral is compact, it does not require any equipment for additional wash water, and the repulping assembly ensures the flow of pulp down the spiral so that each of the four suitable spirals Column 11 may be provided.

It will be readily apparent to those skilled in the art that the deflector 20, take-off 17 and repulping assembly 21 may be provided on any or all spiral turns. However, for effective operation, the pulp preferably reaches a "deflection rate" where "head waves" are created to deflect silica or other gangue, and usually the first deflector. 20 is provided in the second turn, and also includes a deflector or take-out part which is continuously provided and the like. Each of these may be followed by a deceleration deflector (if necessary) for controlling the upper pulp velocity limit between the outlets. In the experiments so far, the best results have been obtained with a spiral having 5 or 6 turns, with the first deflector 20 and the take-off 17 being provided on the second turn and the decelerating deflector being the first. It is provided in 3 turns, the second deflector 20 and the take-out part 17 are provided in the 4th turn,
A repulping assembly 21 is provided on the second turn.

Where high quality minerals have been separated from the pulp, it can be observed that the remaining gangue or silica only lies on the outer part of the concentrate. The first deflector 20 (and a series of deflectors) is inwardly of the inner wall to provide an unobstructed passage to the inner part of the concentrate, so as to obstruct the flow of the concentrate as much as possible. It may be spaced at regular intervals. As mentioned above, the outer portion is deflected, but the gangue or silica is deflected outwards to create a clean stream of mineral concentrates downstream of the deflector, thus allowing minerals to flow inward and deflect. Fill the downstream area of the vessel. The deflector may be moveable across the spiral to suit the particular mineral to be separated from the pulp.

If desired, a vane-shaped deflector may be used, which may be rotatably mounted.

The size, shape and location of the repulping assembly will be determined by the nature of the pulp to be separated and the pitch of the spiral. By repulping assembly,
The spiral should ensure a good flow of pulp down the spiral to allow a high feed rate to be fed to the spiral, while minimizing interruption to the partially separated concentrate. It will be readily apparent that proper repulping of water and tailings will be possible to ensure a continuous flow downwards. For some applications, such as separation of high quality minerals at low feed rates, it is preferred that a portion of the wash water flow over the second deflector 26 to prevent excessive turbulence created in the repulping assembly. In such an application, the deflector is an outer wall
The height of 13 may extend only partially. The height of the deflector may be adjustable where spirals should be used to separate minerals of different qualities and / or different feed rates. For example, a deflector may be a fixed low wall integrally formed with a wall and an internal self-contained portion that can be raised and lowered to adjust its height, operated by a suitable control stick, rod or bar. You may have a part.

Previously known methods of facilitating the flow of pulp down the spiral by the addition or pouring of wash water had auxiliary pulping means. Wash water
This has been a source of operational and other problems such as the generation of algae in the pipe and the need to adjust as many as five taps per spiral. Water must be finely filtered to remove debris, is costly to supply, and water distribution equipment is difficult to maintain in good operating condition. The addition of wash water to the pulp also causes a bin overflow problem.

Re-pulping with the water contained in the initial feed significantly reduces the operational effort of the operator at virtually no cost.

Various changes and modifications can be made to the design and construction of the spiral separator without departing from this invention, to the extent that would be apparent to one skilled in the art from the teachings herein.

BRIEF DESCRIPTION OF THE DRAWINGS The spiral separator of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view of a turn of the first embodiment of the spiral separator according to the present invention.

2, FIG. 3, FIG. 4 and FIG.
FIG. 2 is a side sectional view taken along line 2-2, 3-3, 4-4, and 5-5 in the figure.

FIG. 6 is a partial plan view of a turn according to the second embodiment of the present invention.

Claims (17)

[Claims] 1. An inner wall (15) and an outer wall connected by a floor (14)
A spiral separator for separating a first substance from second substances having different specific gravities, which has a spiral trough consisting of (13), wherein (a) the trough receives a flow of a slurry containing the first and second substances. And an inner zone in which the first substance is relatively concentrated in the trough, and an outer zone in which the first substance is relatively small and a part of which lies on the inner zone. And (b) the separator is provided in the trough, projects in the flow of the slurry so as to cross the trough, and lowers at least a part of the outer zone lying on the inner zone. Deflection means deflecting outward with respect to the lying inner zone
(20) and (30), and a take-out part (17) which is provided downstream of the deflecting means so as to substantially face the inner wall of the trough and which can at least partially select the first substance. A spiral separator for selecting substances without using additional washing water from the outside. 2. The deflecting means (20), (30) are integral with the inner wall (15), are arranged adjacent to the inner wall or are arranged to adjoin the inner wall to deflect the slurry outward. The separator according to claim 1, wherein the separator is arranged with a space. 3. The deflecting means comprises a vane (30) at or near the inner wall and extending transversely to the flow of the slurry, lying at the deflection speed of the slurry. The separator according to claim 2, which produces a head wave that urges the outer band outward. 4. The separator according to claim 3, wherein the vane (30) is rotatably provided. 5. The deflecting means comprises a vane (30) which directs the upper part of the slurry outwardly and has a passage below it, whereby the lower part of the slurry is The separator of claim 1 which allows for relatively undeflected flow. 6. A trough floor (14) at the lower edge of the vane (30).
A separator as claimed in claim 5 having means for adjusting the height from above. 7. The deflecting means (20) is 50 to 200 m upstream of the take-out section.
Claims located at m
The separator according to any one of the items 1, 3, 4, 5, and 6. 8. A passage (23) of limited width downstream of the withdrawal (17) and means for directing water down the spiral inwardly in or within the passage from an outer wall (13). The spiral separator according to claim 1, further comprising (26). 9. The passage (23) of limited width is defined by the inner wall.
Route (15) outwards in a smooth curve and then the passage
Claim 8 bounded on the inside by a deflecting means (22) formed by returning (23) to the original passage
The spiral separator according to the item. 10. The spiral separator according to claim 8, wherein the passage (23) is covered with a roof member (27). 11. A spiral according to claim 10, wherein said roof member (27) has a downwardly sloping upstream edge (28) and / or a downwardly sloping downstream edge (28). Separator. 12. (a) A slurry comprising a first substance and a second substance forms an inner zone in which one of the substances is concentrated and an outer zone in which the substance is relatively small, and the outer zone Supplying the slurry downward through a trough of a spiral separator having an inner wall (15) and an outer wall (13) connected by a floor (14) so that at least a part of the inner layer overlies the inner zone; ) At a position on the upstream side of the take-out portion (17), a deflecting means that is in the flow of the slurry and projects so as to cross the trough
(20), (30) to the underlying inner band,
Diverting at least the inner portion of the overlying outer zone outward, without separating the first substance from the second substance having a specific gravity different from that of the first substance without using additional wash water from the outside. Method. 13. At least an inner portion of an outer zone overlying the inner zone is deflected by deflecting a flow of slurry outwardly such that the deflected flow causes the outer zone overlying to be deflected. 13. The method of claim 12 wherein the bias is outwardly against the underlying inner band. 14. The outward flow impinges the slurry on deflecting means (20), (30) positioned inward of the outer zone at a slurry velocity sufficient to form a head wave. 14. The method according to claim 13, which is based on the result of the above. 15. A vane of said deflecting means, wherein an overlying outer zone directs an upper portion of the slurry flow outward and substantially undeflects a lower portion of the slurry flow. 13. A method according to claim 12, which is deflected outwardly by the (30) with respect to the underlying inner zone. 16. Slurry in or adjacent to the inner wall (15) is deflected outward, whereby the inner inner zone widens in the width direction upstream of the outlet (17). 16. A method according to any of paragraphs 12, 13, 14 or 15. 17. A step of allowing slurry to flow through a passage (23) of limited width between an inner wall (15) and an outer wall (13), and inwardly within the limited passage (23). 13. The method of claim 12, further comprising the step of deflecting water, wherein the water separated from the slurry by centrifugal force remixes the mass of slurry in the water flowing down the spiral separator.