GB2098091A

GB2098091A - Spiral separator

Info

Publication number: GB2098091A
Application number: GB8201114A
Authority: GB
Original assignee: Inheed Pty Ltd
Current assignee: Inheed Pty Ltd
Priority date: 1981-01-20
Filing date: 1982-01-15
Publication date: 1982-11-17
Also published as: GB2098091B; MY8700183A; IN155472B

Abstract

A spiral separator includes a helical sluice 12-14 which comprises a plurality of helical turns mounted or arranged coaxially about a tubular upright column 11 and adapted for the gravitational separation of particles contained in a pulp comprising water and said particles fed to the helical sluice. The spiral separator includes in at least one helical turn a primary throat gap member which defines the throat gap or clearance 17 between one end of a primary slot 29, located in said at least one helical turn transverse to the direction of flow of the pulp and the proximal end of the primary throat gap member. There is further included a secondary throat gap member defining the throat gap or clearance 19 between one end of a secondary slot 31, located in said at least one helical turn transverse to the direction of flow of the pulp, and the proximal end of the secondary throat gap member 18. <IMAGE>

Description

SPECIFICATION Spiral separator This invention relates to improvements in spiral separators.

A spiral seperator for mineral separation has a helical sluice or helical trough mounted coaxially about an upright column which is usually tubular. A pulp of water and minerals to be separated may be fed to the top of the helical sluice and as the pulp flows down the helical sluice it may form bands or strata containing minerals of different density characteristics. Particles having the smallest size normally form a strata on the innermost part ofthe helical sluice.

These relatively small particles are normally known as concentrates and they contain the minerals of interest.

Particles having the greatest size normally form a strata on the outermost part of the helical sluice and these are usually known as tailings or debris as they normally are not required. They may contain sand particles or silica particles.

Particles having a size intermediate between the small particles or concentrates and the large particles or tailings are known as middlings and they may be requiredforfurther processing so as to obtain a great yield of minerals. They normally flow down the middle part of the helical sluice.

In Australian Patent Specification 37175178 there is described a spiral separator having take-off open ingsto withdraw mineral bearing strata of the pulp wherein the take-off opening included a slot in the bottom portion of the helical sluice which wastrans- verse to the direction of flow and which was provided with a tongue slidably mounted in the slot and adapted to be advanced or retracted to vary the effective clearance between the inner end of the slot and the slidable tongue.

While the invention of Australian Patent Specification 37175/78 has been found to be useful in many ways, it was found that by the provision of a single tongue it was not particularly efficacious in the separating of middlings from tailings. Thus when tailings were collected from the spiral separator of Australian Patent Specification 37175/78 often particles of intermediate size or middlings were included and thus further separation processing was often found to be necessary. Also the apparatus of Patent 37175/78 was not particularly useful in the treatment of milled ores or pulp having particles of a substantially uniform size because of its inability to satisfactorily separate middlings from tailings.Further more by the employment of a splitter blade at an inner end of the slidable tongue there was a tendency for the apparatus of Patent Specification 37175/78 to collect debris or trash in the middle part of the spiral column.

It is therefore an object of the invention to provide a spiral separator which alleviates the above mentioned problems associated with the prior art.

The spiral separator of the invention includes a helical sluice mounted or arranged coaxially about an upright column which is suitably tubular. There is included a primary throat gap memberwhich defines the throat gap or clearance between one end of a primary slot provided in the helical sluice transverse to the direction of flow and the proximal end of the throat gap member. There also is included a secondary throat gap member which defines the throat gap or clearance between one end of a secondary slot located adjacent to the primary slot and also transverse to the direction of flow and the proximal end of the secondary throat gap adjustment member.

Both primary and secondary throat gap members are preferably adjustable and may be of the same type and in the most preferred form they may be constituted by a tongue slidably mounted and closing part of their respective slots.

Preferably in relation to the secondary tongue there is provided an additional slot transverse to the direction of flow to which is mounted a further or tertiary throat gap member or slidable tongue of the same type as described above for both primary and secondary tongues.

The primary slot suitably communicates with a channel or passage which leads directly to the interior bore of the upright tube and is thus suitable for the collection of concentrates or small particles.

The secondary slot may communicate with a take-off conduit which is separate from the interior bore of the upright tube and is thus suitable for the collection of middlings or intermediate particles. The helical sluice or column may be provided with an outer extension or collection conduit downstream of the primary and secondary slots and this collection conduit is suitable for the collection of tailings.

Reference is now made to a preferred embodiment of the invention as shown in the attached drawings, wherein: FIG 1 is a perspective view of part of a spiral separator constructed in accordance with the invention; FIG 2 is a sectional view taken along line ll-ll of FIG 1; FIG 3 is a sectional view taken along line Ill-Ill of FIG 1; FIG 4 is a top plan view of the assembly of primary and secondary tongues mounted in their respective slots; FIG 5 is an end view of the assembly of FIG 4; FIG 6 is a side view of the assembly of FIG 4; and FIG 7 is a sectional view along line VII-VII of FIG 4.

In the drawings, there is shown tubular upright 11 and a helical sluice mounted thereto comprising ledge orflange 12, outside wall 13, and bottom wall 14. There is also included an assembly 15 comprising primarytongue 16, primary throat gap 17, secondary tongue 18 comprising three separate components-i.e. a pair of side components 18B and tertiary tongue 20. There is also shown secondary throat gap 19. The wall 13 is undercut or recessed as shown in the arrowed portion 21 so as to facilitate the removal of assembly 15 from a supporting cavity 15A in bottom wall 14.

Gap 17 communicates with space 23 which leads into the bore 24 of tube 11 through an aperture 28 in the side wall thereof. Gap 19 communicates with space 27 which communicates with collection con duit 25 for middlings. There is also shown collection conduit 26 for tailings.

Tongue 16 is mounted in primary slot 29 by guide ribs 16A engaging with mating grooves 35 of slot 29.

Tongue 18 is mounted in a secondary slot 31 with guide ribs 18A engaging with mating grooves 33.

Tertiary tongue 20 is mounted in tertiary slot 32 with guide ribs 20A engaging with mating grooves 33 of slot 32.

There are also shown markings 36 of tongue 16 as well as a chamfer or rounded portion 38 of slot 31 which is useful in that it induces material to enter the slot31.

There are also shown projections 30 and39. Projection 30 prevents small particles or concentrates from entering the middlings collection space 27 and projection 39 prevents tailings flowing into middlings collection space 27. There is shown chamfered or rounded portion 40 of the secondary tongue 78 which prevents material from bridging or jumping out of slot 31 after it has already entered slot 31.

The advantage of secondary tongue 18 is that it assists in separation of milled ores which have a substantially uniform particles size. Such milled ores are often difficult to process so asto effectively separate middlingsfrom tailings. The use oftertiaryton- gue 20 allows for side cuts of material to be taken as well as undercuts.

The spiral separator of the present invention is more effective than the spiral separator shown in Patent Specification 37175178 for the reasons already mentioned and also because it is much more versatile in performance making iteasierto adjust the tongues for different grades of pulp and also making it much easier to adjust for the length of the adjustment gaps so as to take appropriate cuts of material from the pulp. The use of the secondary tongue also gives a precise visual indication when to take suitable cuts of middlings.

Also the provision of the secondary tongue being comprised ofthree separate components as described above is advantageous in that more effective and versatile variation of the throat gap 19 may be achieved as will be appreciated from a study of FIG 4. Thus component 20 and the pair of components 1 8B may be moved independently of each otherthus providing for an almost limitless variation in the length and width of the throat gap 19.

Also by the omission of an upright splitter blade such as that numbered 24 in Patent Specification 37175/78, it will be appreciated that the tendecy of particles to bridge or jump across the relevant throat gap (i.e. 17 or 19) is substantially minimized.

It is also possible using a spiral separator constructed in accordance with the present invention to mount four helical sluices on a single vertical col umn (quadruple start) as well as triple start and twin start applications.

It is also within the scope of the present invention that the primary and/or secondary tongues may be set at a desired setting for the collection of concen trates, middlings or tailings which could be pre determined by experimentation and the primary and/or secondary tongues installed in their respec tive slots fixedly at their desired settings. Thus after installation in the upright column 11 each tongue 16 and 18 may be mounted in slots 29 and 31 fixedly so asto leave gaps 17 and 19 which are non-variable after installation. Tertiary tongue 20 may also, if desired be left at a desired setting and then rigidly mounted in slot32 so as to be non-variable after installation in column 11.

It will also be noted from the drawings that the respective top surfaces of both primary throat gap member and the secondary throat gap member are substantially flush with the top surface of the helical turn containing the primary and secondary throat gap members.

It is also preferred thatthe tertiary tongue 20 is also substantially flush with the top surface of the helical turn containing the primary and secondary throat gap members.

Claims

1. A spiral separator including a helical sluice comprising a plurality af helical turns and mounted or arranged coaxially about atubular upright column and adapted for the gravitational separation of particles contained in a pulp comprising water and said particles fed to the helical sluice, said spiral separator including in at least one helical turn a primary throat gap member which defines the throat gap or clearance between one end of a primary slot located in said at least one helical turn transverse to the direction of flow of said pulp and the proximal end of the primary throat gap member and there being further included a secondary throat gap member defining the throat gap or clearance between one end of a secondary slot located in said at least one helical turn transverse to the direction of flow of said pulp and the proximal end of the secondary throat gap member.

2. A spiral separator as claimed in claim 1 wherein both primary and secondary throat gap members are movable in the primary and secondary slots respectively whereby both primary and secondary throat gap members may be advanced or retracted so as to vary their respective throat gaps.

3. A spiral separator as claimed in claim 2 wherein the primary and secondary throat gap members are constituted by a tongue slidably mounted and closing part of their respective slots.

4. A spiral separator as claimed in any one of claims 1 to 3 wherein there is provided an additional ortertiaryslottransversetothe direction of flow of pulp in one or both of the primary and secondary throat gap members for mounting of a tertiary throat gap member in the or each tertiary slot for extending said throat gap in said primary or secondary slots.

5. A spiral separator as claimed in claim 4 wherein there is provided a single tertiary throat gap member mounted in a tertiary slot located in said secondary throat gap member.

6. A spiral separator as claimed in claim 4 or 5 wherein said tertiary throat gap member is a tongue slidably mounted in said tertiary slot.

7. A spiral separator as claimed in any preceding claim wherein the primary slot communicates with the interior of the tubular upright column and said secondary slot communicates with a take-off conduit which is separate from the interior of the tubular upright column and thereby being suitable for the collection of middlings.

8. A spiral separator as claimed in claim 1 substantially as herein described with reference to the accompanying drawings.

9. A take-off assembly suitable for mounting in a spiral separator including: a primary throat gap adjustment member slidably mounted in a primary slot and movable so as to define a throat gap or clearance between one end of the primary slot and a proximal end of the primary throat gap adjustment member; and a secondary throat gap adjustment member slidably mounted in a secondary slot and movable so as to define a throat gap or clearance between one end of the secondary slot and a proximal end of the sec ondarythroat gap adjustment member.

10. A take-off assembly as claimed in claim 9 substantially as herein described with reference to the accompanying drawings.

New claims or amendments to claims filed on 7 May 1982.

Superseded claim 1.

New or amended claim :- 1.

1. A spiral separator including a helical sluice comprising a plurality of helical turns and mounted or arranged coaxially about a tubular upright column and adapted for the gravitational separation of particles contained in a pulp comprising water and said particles fed to the helical sluice, said spiral separator including in at least one helical turn a primary throat gap member which defines the throat gap or clearance between one end of a primary slot located in said at least one helical turn transverse to the direction of flow of said pulp and the proximal end of the primary throat gap member and there being further included a secondary throat gap member defining the throat gap or clearance between one end of a secondary slot located adjacent to said primary slot in said at least one helical turn transverse to the direction of flow of said pulp and the priximal end of the secondary throat gap member.