A 23.5-megawatt GMD drives this 40-ft-diameter SAG mill at Thompson Creek Metals’ Mount Milligan concentrator plant, part of an order that also included two dual-pinion ring-geared drive systems for a pair of large ball mills.
ABB has successfully commissioned three variable-speed mill drive systems at Thompson Creek Metals’ Mount Milligan copper/gold mine in Canada.
ABB’s delivery included one gearless mill drive system (GMD) for a 40-ft-diameter (12.2-m) semi-autogenous (SAG) mill and two low-speed, dual-pinion, ring-geared mill drive systems (RMDs) for two 26-ft (8-m) ball mills. The full scope of supply for the GMD system consisted of a 23.5-MW ring motor, cycloconverter transformers, excitation transformer, cycloconverter, and ABB control system for the mill and its auxiliaries. Each of the two 13-MW RMD systems comprises two 6.5-MW synchronous motors, an ACS6000 drive, transformers and ABB control system. ABB handled design, engineering, installation supervision and commissioning.
ABB said both drive systems were designed with common features and maintenance functionalities to increase overall availability and efficiency, including frozen charge protection, frozen charge remover function, controlled rollback and automatic positioning-described by the company as “key features” that enable smooth mill starts, greater flexibility and process adjustability to achieve maximum productivity with minimal mechanical stress on the equipment.
To protect its $33.5 million investment in the mill drive systems and to ensure continuous operation with maximum efficiency and reliability, Thompson Creek Metals also signed an ABB service contract covering the full scope of the delivered ABB solutions and including remote diagnostics. Quarterly reports and regular site visits by ABB service experts for preventive maintenance as well as a one-year contract for an on-site service engineer, which was extended until June 2015, are also part of the agreement.
Mount Milligan is a new copper and gold project located approximately 1,000 km north of Vancouver in central British Columbia, Canada. The mine reached full commercial production at the end of 2013 and is expected to produce 60,000 mt of copper and gold ore per day over a 22-year operating life.