The Totten Mine, Vale’s sixth mine in the Sudbury basin, became operational in February 2014. The mine, located at Worthington region, Canada, will produce copper, nickel and other precious metals.
Construction of the mine began in 2006 and full production of 2,200t per day is expected by 2016. The expected mine life of Totten is 20 years.
Vale invested approximately $760m to develop the mine over a period of seven years. The project created more than 500 construction jobs and is expected to generate approximately 200 jobs during the operations phase.
Totten nickel-copper mine history and details
Vale gained control of the Totten Mine when it acquired Inco in 2006. The nickel copper mine was explored by Inco in 1966 but was kept under maintenance and care since 1972 and was allowed to flood from 1976. The main shaft of the mine, extended up to 4,130ft below the surface, was filled with approximately 123million gallons of water.
The major challenges faced by Vale in restarting the mine was dewatering, demolishing and installing new structures, and maintaining the structural integrity of the mine as it was submerged for almost 30 years.
Vale employed Miner Operated Survey System (MOSS) and wall bar system for surveying the underground mine. Wireless information systems were used to identify the real-time geological information at the location.
Totten Mine geology and reserves
The mine is located within the Sudbury basin located on the Canadian Shield in Greater Sudbury city of Ontario. The basin is believed to have formed approximately 1.849billion years ago. The region is filled with magma comprising of nickel, copper and other metals, and is one of the world’s biggest copper and nickel ore suppliers.
The Totten Mine, located approximately 40km-west of Copper Cliff, forms a part of the Worthington Offset. It is basically a Ni-Cu-PGE deposit and comprises ore blended with low grade metals with high-grade bands.
The probable reserves at the mine are estimated to be 7.89million tonnes of ore graded at 2.07% copper, 1.47% nickel and 0.04% cobalt.
Technology used in the development of Vale’s Totten Mine
Latest technology in mining and safety automation is employed at Vale’s new copper nickel mine. An advanced distributed control system (DCS) connects all the fixed equipment such as the head frame, hoist and crusher, and forms a single unit. This technology helps in better tracking of operations and maintenance of the equipment.
Computers are placed in the working areas and are connected to the control room for monitoring the underground operations. The microseismic system, supplied by ESG Solutions, allows identifying the magnitude in case of a seismic event and conveys the same to the control room.
Mining activity at the Totten Mine
Blasthole stoping mining method is being followed based on vertically dipping orebody structure. The mine is accessible by drifts and ramps and comprises of two mining fronts – one at 3150 level and another at 3850 level.
The hydraulic fill is transmitted via two six-inch boreholes to the 1,250th level first, across a 300ft span, and finally to 3,625th level. The ore is hoisted in a service shaft and two conveyances.
The mining fleet comprises Redbore 40 raise drills, two fully automatic Atlas Copco Simba drills and Caterpillar machines for load-haul-dump activities.
Construction and infrastructure facilities
The major works undertaken at the Totten nickel copper mine included dewatering, shaft rehabilitation for the existing shaft, installation of equipment, and installing the backfill plant.
The older head frame and hoist plant was demolished and the construction of new one began in 2007. The hydraulic backfill system comprises of a dome with a storage capacity of approximately 5,000t of sand. Processed water is provided from the polishing pond situated at the mine site.
Variable speed surface fans rated at 790,000cfm were installed to supply air for the underground workers.
Contractors/suppliers involved with the Totten Mine development
Cementation was awarded the contract to engineer and construct the new headframe and hoist house. The contractual scope also included access development, waste handling process, and raise boring of the ventilation circuits. Cementation also provided the mobile equipment for the development phase.
DavyMarkham was awarded the turnkey contract for the manufacture, supply and installation of a 16.5ft double drum production hoist.
ABB provided the power and automation system for the mine. A subcontract was also awarded by DavyMarkham for producing the drives and controls for the production hoist.
Golder Associates were engaged to design the hydraulic backfill plant. OCL Trucking and Custom Crushing is the supplier of sand for the mine, while Lafarge is the supplier of powdered cement. AMEC was engaged to construct the water treatment plant for the dewatering process. Simsmart Technologies provided the ventilation system for the underground mine.