The Super Pit rock falls, which included two hits within less than 12 hours, have caused joint venture partner Newmont Mining to reduce its Australian gold production guidance for 2018.
Newmont, which owns the Super Pit as part of the KCGM JV with Barrick Gold, has lowered its 2018 guidance to between 1.4–1.6 million ounces (Moz) in 2018 from a previous target of 1.5–1.7Moz.
Prior to the Fimiston wall slips, the Goldfields mine was expected to produce 700,000-800,000oz at a production cost of $750-800 an ounce.
Now the slips have destroyed a ramp and blocked access to part of the pit, cutting its expected production to a range of 550,000-600,000oz at $825-875 this year.
Likewise, Barrick’s gold production was also impacted in the second quarter of this year. Both Newmont and Barrick have lowered their expected mining rates for the remainder of this year and in coming years.
KCGM general manager Cecile Thaxter previously said, “The rock falls and subsequent safety measures put in place have limited the availability of mining areas within the pit, resulting in lower mining rates.”
But Newmont chief operating officer Tom Palmer during a conference call last week said KCGM was expanding its processing rates at the Fimiston plant to cushion the impact of the rock falls.
Newmont’s gold cost for the quarter also rose to $757 compared to $748 per ounce last quarter due to the Kalgoorlie rock falls and other cost drivers.
This increased Newmont’s gold cost guidance to between $695 and $745 per ounce for the remainder of this year.
The Super Pit’s mine life is now under assessment. An approved extension, the Morrison cutback, is hoped to extend mining in the pit until 2026. However, its scope would be smaller than initially planned due to the rock falls.
“As we work through our longer term plans, a lot of the work to date was about safely understanding the impact of that slip and understanding the impact for this year, so work’s still under way in terms of the longer term impact and the various scenarios around that,” Palmer said.
“So that’s going to take a little bit of time for us to work through and then understand the longer term impacts beyond 2018, and then how we access the greater Morrison resource.”
KCGM cut 36 positions at the Super Pit last month.