IE66832B1

IE66832B1 - Copper recovery

Info

Publication number: IE66832B1
Application number: IE382589A
Authority: IE
Inventors: Patrick Carney
Original assignee: Patrick Carney
Priority date: 1989-11-30
Filing date: 1989-11-30
Publication date: 1996-02-07
Also published as: GB9021564D0; GB2241181A; IE893825A1; GB2241181B

Abstract

Shredded cable has added to it an absorbent material to absorb the material, such as petroleum gel, which formed a moisture barrier in the cable sheath, and subsequently the absorbent (material) is separated from the shredded cable and the copper separated front the plastics of the sheath. Coating apparatus for coating the shredded cable with absorbent material comprises a drum rotatably mounted in a housing. The drum has an inlet for shredded cable and a side outlet for shredded cable coated with absorbent. The drum has a plurality of elongate slots through which excess absorbent material passes. A brush is provided for cleaning the slots.

Description

The invention relates to a method and apparatus for recovering copper from waste cable. More particularly, the invention relates to a method and apparatus for recovering copper from waste cable of the type comprising a copper core surrounded by an inner plastics sheath, an outer cover sheath and a moisture barrier such as petroleum gel type material between the outer sheath and the core.

According to the invention there is provided a method for recovering copper from a cable of the type comprising a copper core surrounded by an inner plastics sheath, and outer cover sheath and a moisture barrier such as petroleum gel type material between the outer sheath and the core, the method comprising the steps of: shredding tne cable, adding a finely divided moisture barrier absorbent material to the shredded material, further shredding the cable in a second shredding stage after addition of the absorbent material to reduce the size of the shredded material to ensure that the absorbent covers substantially all of the shredded cable, separating the absorbent material from the shredded material, and recovering copper from the shredded material.

In a preferred embodiment of the invention the shredded cable is further shredded in a third shredding stage after separation of the absorbent material from the shredded material.

Preferably the shredded material from the third shredding stage is granulated and the granulated material is separated into copper and plastics.

Typically the copper and plastics are separated in a two stage separation method.

The invention also provides an apparatus for carrying out the method of the invention for recovering copper from a cable of the type comprising a copper core surrounded by an inner plastics sheath, an outer cover sheath and a moisture barrier such as petroleum gel type material between the outer sheath and the core, the apparatus comprising shredding apparatus for shredding the cable, coating apparatus for coating the moisture barrier contaminated shredded cable material with a finely divided moisture barrier absorbent material, means for separating the absorbent material from the shredded material, and means to recover the copper from the shredded material, the coating apparatus comprising; a housing having an inlet for shredded cable and outlets for excess absorbent material and shredded cable coated with the absorbent material, a drum rotatably mounted in the housing, the drum having an inner circumferential surface onto which the shredded cable is passed, the absorbent material being applied onto the shredded cable in the drum, the drum having slots of a size sufficient to retain substantially all the shredded cable on the drum while allowing excess absorbent material to pass through to the absorbent material outlet.

Xn a particularly preferred embodiment of this aspect of the invention the drum is inclined at an angle to the horizontal to deliver shredded cable coated with the absorbent material to the outlet.

In another preferred embodiment of this aspect of the invention brush means are provided to clean the slots of the drum, in use.

Xn one embodiment of this aspect of the invention the brush is rotatably mounted for rotation about an axis which is substantially parallel to the axis of the drum and means are provided for adjusting the position of the brush relative to the drum.

Preferably, the brush is mounted on a shaft which is carried by a frame which is pivotally mounted to the housing.

Preferably, means are also provided for adjusting the frame relative to the housing.

In one case, the adjusting means comprises a turnbuckle type arrangement.

In another embodiment of this aspect of the invention the outer cylindrical surface of the drum includes at least one, and, preferably, a plurality of axially extending and circumferentially spaced-apart dimples for improved turbulence within the coating apparatus to improve coating of the shredded cable with the finely divided absorbent material.

The invention will be more clearly understood from the following description thereof, given by way of example only with reference to the accompanying drawings in which; Fig. 1 is a diagrammatic representation of a copper recovery process according to the invention, Fig. 2 is a longitudinal cross sectional view of a coating apparatus according to the invention, Fig. 3 is a top plan, partially cross sectional view of the apparatus of Fig. 2, Fig. 4 is a cross sectional view of the apparatus of Fig. 2, Fig. 5 is a perspective view of the detail of the apparatus of Fig. 2, Fig. 6 is a cross sectional view of the detail of Fig. 5, and Figs. 7 and 8 are respectively plan and sectional views of portions of the drum forming part of the apparatus of the invention.

Referring to Fig. 1 the copper recovery process according to the invention will now be described in detail. The raw material 1 is generally in the form of a multi-core cable comprising a plurality of copper cores each individually covered by an inner sheath of plastics material. The cores are confined within an outer sheath which may also be of plastics material. For improved insulation, petroleum jelly type material is provided between the inner cores and the outer sheath.

The raw material is first broken up in a primary shredder 2 and then passed to a pre-granulator 3 to which sufficient dry finely divided petroleum gel absorbent material 4 is added either mechanically or by hand. The absorbent is added in sufficient quantity to coat the shredded pieces of cable. The coated pieces of cable from the absorbent addition stage then pass under an overband belt magnet 5 which extracts any steel 6 which may be present. The material then passes to a second shredding stage 7 where the size of the pieces of cable is substantially reduced to ensure that the absorbent covers all surfaces of the cable.

The product from the second shredding stage 7 passes to a shaker 8 which removes absorbent and some of the paper or fibre 9 from the cable mix. Shredded plastic and copper pieces 10 from this stage are then passed to a third shredding stage 11 which further breaks up the particles in a smaller size range. The particles are then passed through a drum magnet 12 to extract any remaining steel 13 from the material. The cable is then generally granulated by passing it once through a granulator 14, then passed to a separator 15, where in the first run, typically a 10mm screen 20 is used to extract the majority of the plastics material allowing the copper and some of the plastics to be recycled through the granulator for a second stage and then through the separator 15 for a second time using a smaller mesh screen 20, typically of 4mm diameter, which removes substantially any remaining plastics material 16. This produces an almost pure copper 17 product from the process. Dry absorbent material from the process is recovered through a dust extraction system 21 for re-use.

The use of a finely divided dry petroleum jelly absorbent material allows substantially all of the petroleum jelly to be removed from the cable thus allowing waste cable to be processed through conventional copper recovery equipment.

This has not heretofore been possible.

Referring to Figs. 2 to 8 there is illustrated a coating apparatus according to the invention indicated generally by the reference numeral 40 for coating shredded cable with petroleum jelly absorbent material in the process described above with reference to Fig. 1. The apparatus 40 comprises a drum 42 which is rotatably mounted on a shaft 43 driven by a motor 44. The drum 42 is mounted within a housing 45 having an inlet 45 for shredded plastic particles which are delivered to the inlet 45 by an auger type arrangement 47, a lower outlet 48 for collecting excess absorbent material which is delivered into a container 49 through a chute 50 and a side outlet 51 for shredded plastics material coated with the absorbent material from which the material is delivered onto a conveyor 52 for further processing. The periphery of the drum 42 is provided by a cylindrical body 55 having a plurality of axially and circumferentially spaced-apart slots 50 which are of a size sufficient to allow excess absorbent material to pass through but are small enough to prevent the shredded cable material from passing through. For improved turbulence the cylindrical body 55 is provided with a plurality of longitudinally extending circumferentially spaced-apart dimples 65.

Means for cleaning the slots 50 in the cylindrical body 55 is provided by a cylindrical brush 70 which is rotatably mounted on a shaft 71 which extends substantially parallel to the shaft 43 of the drum 42 and which is driven by a brush motor 72. The shaft 71 of the brush 70 is carried by a frame 75 which is pivotally mounted on a bracket 75 at 77 and means are provided for adjusting the position of the frame 75 relative the bracket 75. The means for adjustment in this case comprises a turnbuckle 80 extending between the bracket 75 and frame 75. Adjustment of the turnbuckle 80 varies the position of the frame 75 and hence the brush 70 relative to the peripheral surface of the cylindrical body of the drum 42.

Dust generated within the coating apparatus is collected by a dust extracting system through a dust outlet 85 in the housing 45. The housing 45 also has a side access cover 86 for cleaning.

The apparatus according to the invention is used to coat shredded cable with a petroleum gel absorbent material. Cable pieces to be coated are delivered in the direction of the arrow A from the auger 47 and into the drum 42 through the inlet 46. Absorbent material is added to the drum 42, for example, by hand through the inlet 46 and absorbent material cascades through the drum 42, the absorbent material coating the shredded cable and excess absorbent material being passed through the slots 60 in the cylindrical body 55 of the drum 42 through the outlet 48 and into the collection bin 49. Coated shredded cable passes along the inner periphery of the drum 42 and passes out through the outlet 51 onto the conveyor 52 for further processing. The further processing includes the step of removing the absorbent material with the petroleum gel absorbed in it from the shredded cable.

Many variations on the specific embodiments of the invention described will be readily apparent and accordingly the invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims

CLAIMS:

1. A method for recovering copper from a cable of the type comprising a copper core surrounded by an inner plastics sheath, and outer cover sheath and a moisture barrier such as petroleum gel type material between the outer sheath and the core, the method comprising the steps of: shredding the cable, adding a finely divided moisture barrier absorbent material to the shredded material, further shredding the cable in a second shredding stage after addition of the absorbent material to reduce the size of the shredded material to ensure that the absorbent covers substantially all of the shredded cable, separating the absorbent material from the shredded material, and recovering copper from the shredded material.

2. . A method as claimed in claim 1 wherein the shredded cable is further shredded in a third shredding stage after separation of the absorbent material from the shredded material.

3. A method as claimed in claim 2 wherein the shredded material from the third shredding stage is granulated and the granulated material is separated into copper and plastics . A method as claimed in claim 3 wherein the copper and plastics are separated in a two stage separation method. A method substantially as hereinbefore described with reference to the drawings. Apparatus for carrying out the method of any preceding claim for recovering copper from a cable of the type comprising a copper core surrounded by an inner plastics sheath, an outer cover sheath and a moisture barrier such as petroleum gel type material between the outer sheath and the core, the apparatus comprising shredding apparatus for shredding the cable, coating apparatus for coating the moisture barrier contaminated shredded cable material with a finely divided moisture barrier absorbent material, means for separating the absorbent material from the shredded material, and means to recover the copper from the shredded material, the coating apparatus comprising s a housing having an inlet for shredded cable and outlets for excess absorbent material and shredded cable coated with the absorbent material, a drum rotatably mounted in the housing, the drum having an inner circumferential surface onto which the shredded cable is passed, the absorbent material being applied onto the shredded cable in the drum, the drum having slots of a size sufficient to retain substantially all the shredded cable on the drum while allowing excess absorbent material to pass through to the absorbent material outlet. 7. Apparatus as claimed in claim β wherein, the drum is inclined at an angle to the horizontal to deliver shredded cable coated with the absorbent material to the outlet. 8. Apparatus as claimed in claim 6 or 7 wherein brush means are provided to clean the slots of the drum, in use. 9. Apparatus as claimed in claim 8 wherein the brush is rotatably mounted for rotation about an axis which is substantially parallel to the axis of the drum and means are provided for adjusting the position of the brush relative to the drum. 10. Apparatus as claimed in claim 9 wherein the brush is mounted on a shaft which is carried by a frame which is pivotally mounted to the housing. 11. Apparatus as claimed in claim 10 wherein means are provided for adjusting the frame relative to the housing. 12. Apparatus as claimed in claim 11 wherein the adjusting means comprises a turnbuckle type arrangement. 13. Apparatus as claimed in any of claims 6 to 12 wherein the outer cylindrical surface of the drum includes at least one axially extending dimple for improved turbulence within the coating apparatus to improve coating of the shredded cable with the finely divided absorbent material. 14. Apparatus as claimed in claim 13 wherein there are a plurality of axially extending circumferentially spacedapart dimples in the outer cylindrical surface of the drum. 15. Apparatus substantially as hereinbefore reference to the accompanying drawings. 16. Copper whenever recovered by a method as of claims 1 to 5 or using an apparatus as

4. 5 of claims 6 to 15.