The largest thickener yet featuring Outokumpu’s Australian-engineered high-torque, low-maintenance SCD drive is scheduled to be installed early this year at Newcrest Mining’s Telfer gold and copper project in Western Australia.

The 62-metre thickener featuring the SCD (Supaflo^® Column Drive) is part of a $19 million order won by Outokumpu Technology to supply a package of technologies to Telfer, including 60 flotation cells designed to maximise gold recoveries.

"The new thickener, fabricated by GRD Kirfield in Perth, features a feedwell with auto dilution and turbo dilution, which allows for dilution under all operating conditions", says Outokumpu Technology’s Regional Manager – Thickeners, Mr Brad Garraway.

For further performance, the Telfer thickener’s drive features five gearboxes and pinions, which drive the rakes via a slew ring. An extra gearbox was provided specifically for the Telfer application to provide enhanced torque characteristics.

The SCD family of rake drives and lifting devices is custom-built for thickeners in excess of 40 metre diameter, to achieve higher production efficiencies, including minimising tailings volumes and maximising solution recovery.

Outokumpu thickener featuring SCD drive technology as incorporated in the Telfer design

Mr Garraway says the SCD family was introduced for local and international applications, being designed to set new industry standards in design and performance, including such areas as torque ratings, design innovation, ease of manufacture, ease of maintenance and prime cost. The first SCD drive was designed and built in Australia for export to the Skorpion project in Namibia.

Telfer will treat 17-19 million tonnes of rock a year to recover 770,000 ounces of gold and about 27,000 tonnes of copper.

This new family of drives is designed in Australia for ease of manufacture and ease of installation globally. The drives feature advanced technology developed in Australia, drawing on the global experience of Outokumpu operations spanning 40 countries.

Suitable for use with the latest high efficiency thickening equipment - including Supaflo^® High Compression Paste thickeners from Outokumpu - the SCD family is available with torque capacities up to 6,500 kNm.

Design features include:

• Commercial one-piece ring gear and bearing
• Oil bath lubrication of gear and bearing
• Splined drive from reducer to pinion
• Self-aligning lower pinion bearing for long life
• Hydraulic drive for load balancing between pinions
• Fabricated base housing designed by Finite Element Analysis (FEA)

Another feature is the complementary rake lifting device with travel of up to 1200mm. Torque reaction from the drive is transmitted through slide plates onto guides attached to the extended centre column. These long-life devices require no lubrication and are easily replaced.

Outokumpu Technology says its new order is the result of global technology leadership coupled with local expertise. Winning the $A15 Million flotation cell order at Telfer, then going on to successfully bid for the $A4.0 million thickener package, follows previous successful partnerships with Newcrest, including the introduction of advanced technologies at Cadia and Ridgeway mines.