Tough drilling conditions goes with the territory in Africa’s Copperbelt which straddles the border between the Democratic Republic of Congo and Zambia. No less than 70% of the world’s cobalt is also mined here, most of which is found in the Katanga Province of the DRC. As global demand for cobalt soars in tandem with the flourishing battery industry that it supports, one open pit mine in particular – Mutanda – has drawn more and more attention. This comes as no surprise given that it holds the world’s largest deposit of cobalt.
At the latest count, Mutanda produced some 27,300 t of cobalt and 199,000 t of copper. The mine is owned and operated by Glencore which relies only on the best teams and equipment to extract both these highly coveted metals with maximum efficiency. Operations at Mutanda mine were suspended in November 2019 for scheduled mine rehabilitation work and it will reopen in 2022.
From 2017, local contractor Blu Rock was tasked with blasthole drilling in a challenging section of the mine characterised by semi-hard to hard rock conditions as well as water ingress, friable formations and abrasive rock. “But this was no match for the powerful SmartROC 65 as Blu Rock unleashed its superior performance and exceeded productivity targets,” says Epiroc.
Ever since Blu Rock was founded in 2007 Epiroc has been the equipment supplier of choice and the company’s fleet consists of more than 20 Epiroc surface drill rigs including FlexiROC T40, SmartROC T40, the ROC L series as well as Christensen CS14 and Boyles C6C rigs for exploration drilling. “Epiroc has been our partner since day one and we pride ourselves on our proven track record of drilling above our monthly target” says Kris Jedrzejczyk, Managing Director, Blu Rock Mining Services.
When Glencore commissioned the job of drilling blastholes at Mutanda mine, Epiroc says it was the perfect opportunity to put Blu Rock’s latest acquisition to the test, the SmartROC 65, which is built to face the toughest of conditions.
Looking back, the debut of SmartROC 65 – the first SmartROC in the DRC – was a thriving success at Mutanda mine according to Jedrzejczyk at Blu Rock. “The SmartROC D65 did very well with our operations at Mutanda and the excellent performance in terms of productivity and safety was noted by our other clients. This led other mining companies to order eight more rigs.”
SmartROC D65 is loaded with intelligent features and gives operators a fully-automated drill cycle which includes automated drilling and rod handling. The rig comes equipped with a Hole Navigation System (HNS) which reduces non-drilling time and improves precision.
Drilling 140 mm diameter holes to a depth of 8-12 m, SmartROC D65 achieved a solid penetration rate at Mutanda of 0.62 to 0.97 m/min using Epiroc 140 mm flat front drill bits and 114 mm OD, 6 m long drill rods. Two operators manned one drill rig each working on two 12-hour shifts toward a productivity target of 12,000 m per month.
“We always want to give our clients good value for money,” Jedrzejczyk continues. “Using Epiroc equipment means that we can complete projects safely and deliver high quality workmanship on time.”
While producing high quality blastholes with consistency and speed, the SmartROC D65 also unlocked significant cost savings thanks to the Auto Drill function, low fuel consumption and long service life of drilling tools.
Blu Rock wants to bring a fresh and innovative approach to mining services in Zambia and the DRC with a focus on flexibility, and this includes offering exploration drilling capabilities which is a competitive field in the region.
“To remain competitive, we had to analyse and review the cost structure while maintaining high exploration drilling performance. The Boyles C6C was the best choice as they are very straightforward machines, easy to operate and service.”
Two Boyles rigs were deployed together with two Epiroc Christensen CS14 surface core rigs drilling horizontal holes for dewatering and angle holes for geotechnical assessment. Epiroc provided on-site training and depending on the ground conditions, this fleet drilled 12-30 m per shift (an average of 800 m per month).
The favourable results with quality cores delivered on time led to Blu Rock being awarded further exploration work at Mutanda. Jedrzejczyk concludes: “We have gained a lot of experience with Epiroc drill rigs over the years, they are treasured, and we consider them part of the Blu Rock family. Epiroc always backs us up with spare parts, maintenance support and prompt replies to requests from our logistics team.”
