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High compression thickeners are gaining wider acceptance in minerals processing
NMINERAL PROCESSING
High compression thickeners are gaining wider acceptance in minerals processing Here Dave Green of Outokumpu Canada reports on the development of Supaflo’s new High Compression Thickener, which is finding application in mineral processing installations worldwide.
T
he latest development in Supaflo’s line-up of thickeners has gained rapid acceptance with industry in North America, and appears set to be the new benchmark in high separation efficiency applications. A survey of the needs of operating plants pointed to a simple requirement that was not adequately addressed by any of the thickening technologies currently available. This single need was for better separation efficiency, and although this seems so simple in retrospect, the need was expressed by users in a variety of ways. Long hours of discussions revealed: q Desires for higher underflow density to produce thickened or paste backfill tailings. 0 A need for consistent high underflow density to feed gold leaching and autoclave circuits. 0 Concern about how to improve solution recovery in uranium and gold CCD circuits.
Supaflo engineers have succeeded in improving their High Rate Thickener performance with the invention of Autodil and the development of the Bed Mass Pressure control system. These features needed a boost from additional techniques that would enhance the action of the compression zone to obtain the next step in improved thickener performance. To achieve this, the depth of the new High Compression Thickener is increased to permit a compression zone thickness which is about double that found in normal High Rate Thickeners. Bottom slopes are steepened to assist the transport of thickener underflow material to the discharge. Torque levels are increased, to provide more raking power and higher operating security. Finally, a newly created Supapicket has been introduced to expedite the release of interstitial solution away from the compression zone. The resulting combination of new ideas with the tried and proven has addressed the needs and desires expressed above, and many operations are moving ahead today to reap the rewards of improved separation efficiency in SupaIIo High Compression Thickeners. At Mount Leyshon Gold Mines in Queensland, Australia the original Supaflo 15 m High Rate Thickener on CIP
tailings was upgraded to improve water recovery and lessen the dependency on increasingly expensive bore water. Where the original obtained an average underflow density of 58% solids with some wide swings, today a quite consistent 63% solids is achieved, and the plant can keep operating through even the most severe drought conditions. The Falconbridge Kidd Creek copperzinc operation in Timmins, Canada requires tailings with a consistent density of 63% solids in order to meet the requirements of a thickened tailings deposition plan developed in conjunction with E I Robinsky & Associates. Attempts using large conventional thickeners up to 360 feet in diameter in past years failed to achieve the results needed. As a result of a successful pilot campaign in 1994, in June this year it commissioned a 35 m diameter Supaflo High Compression Thickener. Barrick Corporation’s Goldstrike Mine in Nevada has been a huge overall success; however, the company saw significant advantages in producing a higher, constant density feed to its pressure oxidation circuit. Difficulties were experienced as a result of wlderanging clay contents, varying feed densities and variable pH levels. Furthermore, it was already operating above its designed throughput, and there were further plans for immediate expansion to 17,000 stpd (standard tonnes per day). Again, a successful pilot programme demonstrated that an improvement of 4% in average underflow density could be easily and consistently achieved. A 100 foot diameter Supaflo High Compression Thickener is currently under construction. High compression thickening addresses many process needs with an effective and proven combination of Supaflo’s proprietary technology and .expertise. The end result is improved efficiency, lower costs and maximised revenues for process plants which recognise the value of better solid/liquid separation.
SupuJo Technologies Pty 5 Slc#ine Place, Frenchs NSW 2086, Australia. Tel: Fax:
Filtration
& Separation
November/December
1995
00151882/95/US$7.00
Q 1995
Elsevier
Ltd Forest
+ 61 2 975 6060 + 61 2 975 6070
Science
Ltd
947
High compression thickeners are gaining wider acceptance in minerals processing Here Dave Green of Outokumpu Canada reports on the development of Supaflo’s new High Compression Thickener, which is finding application in mineral processing installations worldwide.
T
he latest development in Supaflo’s line-up of thickeners has gained rapid acceptance with industry in North America, and appears set to be the new benchmark in high separation efficiency applications. A survey of the needs of operating plants pointed to a simple requirement that was not adequately addressed by any of the thickening technologies currently available. This single need was for better separation efficiency, and although this seems so simple in retrospect, the need was expressed by users in a variety of ways. Long hours of discussions revealed: q Desires for higher underflow density to produce thickened or paste backfill tailings. 0 A need for consistent high underflow density to feed gold leaching and autoclave circuits. 0 Concern about how to improve solution recovery in uranium and gold CCD circuits.
Supaflo engineers have succeeded in improving their High Rate Thickener performance with the invention of Autodil and the development of the Bed Mass Pressure control system. These features needed a boost from additional techniques that would enhance the action of the compression zone to obtain the next step in improved thickener performance. To achieve this, the depth of the new High Compression Thickener is increased to permit a compression zone thickness which is about double that found in normal High Rate Thickeners. Bottom slopes are steepened to assist the transport of thickener underflow material to the discharge. Torque levels are increased, to provide more raking power and higher operating security. Finally, a newly created Supapicket has been introduced to expedite the release of interstitial solution away from the compression zone. The resulting combination of new ideas with the tried and proven has addressed the needs and desires expressed above, and many operations are moving ahead today to reap the rewards of improved separation efficiency in SupaIIo High Compression Thickeners. At Mount Leyshon Gold Mines in Queensland, Australia the original Supaflo 15 m High Rate Thickener on CIP
tailings was upgraded to improve water recovery and lessen the dependency on increasingly expensive bore water. Where the original obtained an average underflow density of 58% solids with some wide swings, today a quite consistent 63% solids is achieved, and the plant can keep operating through even the most severe drought conditions. The Falconbridge Kidd Creek copperzinc operation in Timmins, Canada requires tailings with a consistent density of 63% solids in order to meet the requirements of a thickened tailings deposition plan developed in conjunction with E I Robinsky & Associates. Attempts using large conventional thickeners up to 360 feet in diameter in past years failed to achieve the results needed. As a result of a successful pilot campaign in 1994, in June this year it commissioned a 35 m diameter Supaflo High Compression Thickener. Barrick Corporation’s Goldstrike Mine in Nevada has been a huge overall success; however, the company saw significant advantages in producing a higher, constant density feed to its pressure oxidation circuit. Difficulties were experienced as a result of wlderanging clay contents, varying feed densities and variable pH levels. Furthermore, it was already operating above its designed throughput, and there were further plans for immediate expansion to 17,000 stpd (standard tonnes per day). Again, a successful pilot programme demonstrated that an improvement of 4% in average underflow density could be easily and consistently achieved. A 100 foot diameter Supaflo High Compression Thickener is currently under construction. High compression thickening addresses many process needs with an effective and proven combination of Supaflo’s proprietary technology and .expertise. The end result is improved efficiency, lower costs and maximised revenues for process plants which recognise the value of better solid/liquid separation.
SupuJo Technologies Pty 5 Slc#ine Place, Frenchs NSW 2086, Australia. Tel: Fax:
Filtration
& Separation
November/December
1995
00151882/95/US$7.00
Q 1995
Elsevier
Ltd Forest
+ 61 2 975 6060 + 61 2 975 6070
Science
Ltd
947