Imperial formed a joint venture with Australian partner Newcrest Mining Ltd. [NCM-ASX] at Red Chris in March 2019, after agreeing to sell a 70% stake in the mine to Newcrest, which is now the operator. Imperial continues to hold a 30% stake in the joint venture, which aims to leverage the Australian company’s technical expertise in block caving operations.
In keeping with that plan, they are developing a plan to mine the deep resource beneath the current open pits in a bid to exploit high grades in the deep East Zone.
In an update on exploration, Imperial said there were up to eight diamond drill rigs in operation in Q4 2020. A further 18,063 metres of drilling were completed in 15 drill holes. All intersected mineralization, except for four which were dedicated geotechnical holes.
Since August 2019, a total of 104,435 metres have been drilled in 88 holes.
Drilling has confirmed the potential for additional high-grade mineralization south of the South Boundary Fault to the east of the East Zone pit. This is a significant discovery that has the potential to expand the known area of the Red Chris Porphyry system, as the South Boundary Fault has historically been assumed to define the southern extent of mineralization.
Imperial said Red Chris produced 88.3 million lbs copper and 73,787 oz gold in 2020. It said copper and gold production increased 22.9% and 102.9% respectively, compared to 71.9 million lbs copper and 36,371 oz gold in 2019.
The increased production was driven mainly by higher and better gold recoveries. However, production in Q4 2020 was significantly lower than Q3 2020 as a result of lower mill throughput rates. “Mill throughput in the period was impacted by continued unseasonal rain followed by cold weather causing material handling issues,” the company said in a press release. These impacts were partially offset by higher gold grade and recovery.
Red Chris production in Q4 2020 was 17.2 million lbs copper and 16,251 oz gold, compared to 22.2 million lbs copper and 18,052 oz gold in Q3 2020.
In its metal production guidance, Newcrest has said it expects Red Chris to produce 55.1 to 66.1 million lbs copper and 45,000 to 55,000 oz gold from July 1, 2020, to June 30, 2021.