Protected by diamonds

Hundreds of meters underground at a remote gold mine in the northern Canadian territory of Nunavut, Sylvain Desrosiers is completing the Sisyphean task of removing drill rods from an in-the-hole drill rig.

Under the manual control of another driller, the rig begins bringing up a series of 1.8-meter, almost 24-kilo drill rods. Desrosiers steps forward, lifts a rod from the frame of the drill, and carries it over to a storage area about three meters away before coming back for the next one. Five minutes pass, then 10 as he unloads them all. Desrosiers, the general foreman at underground mining contractor Machines Roger International, makes it look easy, but it’s physically demanding work that puts a driller in direct contact with heavy machinery.

Two years ago, the company’s drill operators had to perform this time-consuming task multiple times per shift. Machines Roger, one of the largest underground drilling contractors in Canada that is currently operating roughly 65 drills at mine sites across the country, is handling production drilling for the low-Arctic mine site. But when the company began working on the contract, its drill operators quickly learned that the mine’s location wasn’t the only unique thing about it. The region’s silica-rich rock had created ultra-abrasive ground conditions that forced them to change out or regrind their standard carbide drill bits every five to ten meters.

The stop-and-start of frequent bit changes was having a significant impact on productivity, recalled Christian St-Amour, Machines Roger’s Operations Manager. The company had targets of 75 meters per shift per drill, but with standard carbide bits it was seeing closer to 35 or 40 drilled meters per shift. “We’re responsible for 100 percent of the production drilling, so our problem was the mine’s problem as well,” St-Amour said.

A collaboration with Epiroc changed all that. Machines Roger turned to the company for help, and in July 2023 began trialing eight of Epiroc’s innovative Powerbit X drill bits. The bits are manufactured with a durable polycrystalline diamond layer over the carbide to better withstand harsh ground conditions. Powerbit X’s protective PCD layer is created from a sintered-together mass of randomly oriented diamonds that’s applied to each button of the bit and exposed to high pressure and temperature.

Quickly, the contractor saw results: the rugged diamond-protected drill bits had an average service life of 445 meters per bit during the trial – with some bits exceeding more than 700 meters of service life – allowing operators to work for multiple shifts without changing a bit. Today, St-Amour said, Machines Roger achieves roughly 85 meters per drill per shift – exceeding its daily, monthly and quarterly targets – and Powerbit X bits achieve an average service life of more than 700 meters.

Powerbit X bits have had many additional benefits for the company, St-Amour said during a separate site visit to the company’s headquarters and workshop in Val d’Or, Quebec. Strolling between bright-red inventory shelves stacked with drill components and machinery, he points out that, due to the Nunavut mine’s remote location – with no roads to other parts of the territory – and the region’s cold climate, an entire year’s worth of fuel, equipment and supplies must be shipped in by barge during a ten-week period in the summer. Machines Roger is in the midst of planning its own shipment for the 2025 barge, and Powerbit X has made the logistics far less complex, he said.

The company used to have to budget to send $500 000 worth of drill bits up to the site, to account for the frequent bit changes. Now, he said, the company only requires about 12 bits per month – well down from 70 standard carbide bits per month previously – and is able to transport them on regular flights with mine personnel, cutting down transportation and shipment costs.

Ryan Harrower, a Supervisor at Machines Roger who works at the northern site, said making the switch significantly improved his workday. In addition to his main supervisor duties, Harrower occasionally fills in as a mechanic, electrician, driller and nipper and says the bits freed him up to do necessary maintenance, organization and inventory work that he didn’t always have time for. Most importantly, the bits reduced the safety risks workers faced.

There are also sustainability benefits, said Shakeel Khalfan, Epiroc’s manager of business development and technical services. Using longer-lasting drill bits and eliminating the need for re-grinding altogether translates to an estimated 90 percent reduction in carbon emissions per drilled meter with Powerbit X bits compared to standard carbide bits.

The partnership with Machines Roger, a long-time client, presented Epiroc with the opportunity to further develop an innovative technology, Khalfan said. After working with Machines Roger to test several different carbide bit styles on the abrasive rock, Epiroc proposed Powerbit X. During the trial and long afterwards, the two companies have maintained an open dialogue and data sharing. The collaboration has led to incremental improvements to Powerbit X bits, Khalfan said.

Ryan Harrower says Epiroc has remained open and receptive to drillers’ feedback throughout the trial. “They hear what we’re saying. They try to help us improve, and they’re trying to improve their quality of bits,” he said. “It’s been good to work with them.”

That PCD technology has been around for roughly 50 years, but to date has been too cost-prohibitive to be widely adopted in the mining industry, said Jonas Falkeström, Manager of Global Innovation and Technology at Epiroc Rock Drilling Tools. That’s starting to change as companies see clear use cases for these ruggedized bits.

One powerful opportunity for the industry, Khalfan said, is enabling autonomous or remote-controlled drilling, which could fully remove workers from the face. “That is the future: trying to automate the drilling technology so you could actually work it from the surface, and you could run it for the whole shift, maybe multiple shifts, before having to go down there to do maintenance and change the bit,” he said.

Falkeström says he expects PCD drill bits to significantly replace traditional bits, and Epiroc aims to “lead this technology shift.” The company now has multiple customers across the globe using Powerbit X. At other customer sites where the bits were tested in mixed ground conditions for development drilling, Powerbit X bits averaged more than 1 000 meters of service life per bit.