Miners invest in Sudbury Basin: Copper Cliff and Onaping Depth projects underway.

• Author: Tollinsky, Norm
• Position: MINING

Vale and Glencore's Sudbury Integrated Nickel Operations have received board approval for major mine projects in the Sudbury Basin.

Following several delays attributable to low commodity prices, Vale is proceeding with a C$760-million phase one development of its Copper Cliff Deep project, while Glencore is moving ahead with a US$700-million development of Onaping Depth.

Both projects are being undertaken to replace declining production from established mines.

"I don't think it's a surprise to anyone that most of our mines are facing declining production profiles," said Vale's Dave Stefanuto, vice-president, capital projects for the North Atlantic. "We need to find replacement volumes of ore, so we're starting to focus more on what we can do to start supplementing these declining orebodies. In the last few years, we spent a lot of time focusing on our surface plants, including the $1-billion Clean AER project. We've invested enough in our surface facilities. Now we have to feed them because they're no good if they're running empty."

The work includes the complete refurbishment of the Copper Cliff Complex South Shaft, which was shut down in 2008.

The steel in the shaft is being replaced. The headframe, loading pocket and dumping systems are being reconfigured and both hoists are being replaced. In addition, the coarse ore handling system and crusher station at the 4,000-foot level are being rehabilitated and the ore and waste handling systems, including all conveyances, bins and ore passes are being refurbished.

Glencore began developing drifts at Onaping Depth in 2017 in order to stay on the critical path as defined in the project's feasibility study, but only received approval for the full project in January 2018. The US$700-million project includes the construction of a winze from the 1,200-metre level laterally off the workings of Craig Mine to access some 14 million tonnes of ore 2,500 metres from surface.

The first 700 metres of the winze will be raisebored down to the 1,900-metre level and then slashed and extended beyond that to the 2,650-metre level using conventional shaft sinking technology. The project also includes all off-shaft development and associated ore handling systems.

First production from Onaping Depth occurs in 2023 with full production by 2025.

The new ore replaces declining reserves at the Nickel Rim South and Fraser Mines.

"Mining at Nickel Rim South is scheduled to cease in 2022," said Peter Xavier, vice-president...