Tag Archives: Lundin Mining

Martin Engineering air cannon tech keeps the fines flowing at Lundin’s Eagle mine

Martin Engineering, a leader in industrial bulk handling, has helped Lundin Mining’s Eagle Mine in Michigan’s Upper Peninsula with clogging and downtime issues, resolving these problems and improving material flow with powerful and compact air cannon technology.

Martin Engineering installed the cannons in a chute carrying damp fines through the refining process at Eagle, with the cannons mitigating blockages and facilitating the movement of material. The result was improved safety, reduced labour costs, greater production, less downtime and a calculated circa-1,000% saving to the cost of operation over existing solutions.

“Safety is a top priority for us,” Ted Lakomowski, Lead Reliability Technician at Eagle Mine, said. “When we experienced clogging and downtime at the processing mill, our crew naturally swung into action to resolve it, but we immediately sought a safer long-term solution.”

Eagle Mine is the only primary nickel mine in the USA, producing 1.5% of the world’s total nickel production. The company extracts approximately 2,000 t/d from the underground nickel-copper mine using a bench-and-fill stoping process. Ore from the mine is stored in a covered coarse stockpile facility prior to transport to the Humboldt Mill. A former iron ore processing plant, the Humboldt facility’s three-stage crushing circuit reduces the material to 3/8 in-minus (9.5 mm-minus), then a single stage ball mill grinds it further and it is mixed into a slurry.

To liberate the nickel and other minerals from the waste materials, a refining process of selective flotation is used. During the crushing process, a mesh screen separates the fines from the remaining aggregate, which are fed back through the process. Fines that pass through a screen fall into a wide-mouthed hopper, leading to a chute that narrows to approximately 2.5-m wide by 0.6-m high and – after a dead drop of several feet – slopes in a circa-45º of decline. This slope slowed the descent of the fine material for a low impact and centred discharge onto a conveyor belt leading to the ore bins. Material buildup began at the hopper and at the discharge slope, but could also occur at virtually any point, blocking the chute, according to Martin Engineering.

Such accumulation would stop the entire crushing process approximately three-to-four times per shift for as long as an hour, blocking input of material all the way back to the ore storage area. Workers attacked the clog with 4.5-m long air lances from the top of the hopper and bottom of the chute. The method used a tremendous amount of compressed air and diverted manpower from other essential duties. Moreover, air lances caused excessive splash-back of wet material, which was extremely messy and potentially hazardous.

Eagle first installed a polymer lining in the chute. Offering a low coefficient of friction, the lining was bolted to the chute wall and acted like a smooth slide for the material to ride down. Less effective against the adherent qualities of the material than hoped, Eagle next installed pneumatic vibrators onto the vessel wall, intended to agitate the adhered material and promote its descent down the chute slope. But the fact that the polymer lining was bolted to the vessel caused it to dampen the vibration of the units, limiting the force to only the impact zone and not much farther.

“We were forced to default back to air lances, but kept on looking for a better solution,” Lakomowski explained. “Having worked with Martin Engineering in the past, we asked them to come in, examine the issue and offer a safe, effective and affordable solution.”

Lakomowski advocated for the initial installation of five 35 litre Martin® Hurricane Air Cannons, followed by two more placed in essential spots in the chute. One unit was placed at the area where material discharged into the hopper, two others were positioned at the hopper slope where the most accumulation was observed and two more were placed along the drop chute. All of the tanks were accompanied by a 101 mm pipe assembly ending in fan jet nozzles.

Offering more force output than designs double their size with considerably less air consumption, the compact air cannon tanks measure only 406 mm in diameter 633-mm long, weighing 35 kg each, Martin Engineering says. The units fire a shot of air at up to 120 psi (8.27 bar) through the pipe assembly to a fan jet nozzle. The nozzle spreads the air stream 304 mm at the exit point, distributing the blast pattern across the surface of the wall.

Operating on a regular firing schedule of every 1-10 minutes – readjusted for production volume, time of year and moisture level – revealed the seven-cannon configuration reduced clogging issues and downtime, according to the company. This significantly lowered the risk to operators and reduced the cost of operation.

“When I did the cost assessment, I was surprised to discover that there was a 1,000% compressed air savings in using the air cannons over the air lances,” Lakomowski said. “It’s a significantly lower effect on our system than initially predicted, and managers are very happy about that.”

The project also improved safety, as workers spent less time diverted from other assignments to use air lances or create vibration by beating on the vessel walls, Martin Engineering said. By being able to perform maintenance on wear parts like valves from the outside of the cannon without tank removal, upkeep can be safely performed by a single technician with no heavy lifting involved, it added.

“Just from a safety aspect, this solution has paid for itself,” Lakomowski concluded. “The Martin Engineering team was easy to work with, and they were cognisant of our budget restrictions. Overall, this was a successful project.”

Zinkgruvan Mining and Epiroc collaborate on teleremote drilling trial backed by LTE

Zinkgruvan Mining is feeling the effects of teleremote drilling using a 4G LTE network and Epiroc’s Simba E7 rig at its underground base metal mine, according to a case study from the Sweden-based OEM*.

In early spring 2021, Zinkgruvan Mining, working in conjunction with Epiroc and IT, and telecom operator Telia, first connected its Simba E7 rig to an LTE (Long Term Evolution) network. Since then, remote production has taken off like a shot in the areas where the LTE network has been commissioned, according to Epiroc, while acknowledging this is still in trial mode.

The mine has a total of four Epiroc Simba rigs, with, at present, one of these connected via Simba Teleremote, some 350 m underground. In the future, operators may move to an office 800 m underground to get closer to the rig.

“So far, we’ve drilled seven pallets remotely,” Operator, Jocke Lindblad (pictured on the left), said. “It runs very smoothly, and as soon as we find something that doesn’t work, I can call the Epiroc service engineer who has been there from the start.”

Lindblad monitors the rig from a quiet above-ground office, next to a window where daylight flows in.

“I like being down in the mine too, but it’s certainly safer and better for the body to sit here,” he said. “It’s nice to be able to take a coffee break or get a breath of fresh air when I feel like it.”

The fact the operators do not need to drive down into the mine on a regular basis means they can drill an average of four hours more per day, according to Epiroc. In purely technical terms, Lindblad can operate the rig from an office in the same way as he would down in the mine. The screens and levers are the same as on the rig.

“The only difference is that I can’t hear the drill,” Lindblad said. “But you do have to keep a close watch on the measurement values on the display.”

An LTE future

Epiroc said: “Building a dedicated LTE network has been a challenge. It is much harder to bring together a design in a mine than above ground. However, the choice was easy.”

Craig Griffiths, Mining Manager at Zinkgruvan Mining, said the company, a Lundin Mining subsidiary, looked at running automation via Wi-Fi, but decided against this as it wanted the network to work for at least another 10 years and be able to handle the demands of the future.

He is convinced the investment puts the mine in a good position for years to come.

“This will give us better control over our production and reduce our costs,” he said. “It feels really good. But the greatest gain will be in respect of safety, with our employees having to spend less time in the mine.”

No-one to ask

While the Simba occasionally – under Lindblad’s supervision above ground – changes position for a new drill hole, Mattias Dömstedt, Technical Production Coordinator, and Håkan Mann, Project Manager, have time to explain how the technology works, and how the work of installing it has progressed.

“Once complete, the project will have seen about 70 remote radio units, ie transmitters and receivers of radio signals in the LTE network, installed in the mine, providing coverage of around 70 km,” Mann said. “The LTE network will then be extended as the mine expands. The portion of the LTE network currently in operation covers around 15 km.”

By then, hopefully some time in 2022, it will be possible to run another Simba rig by teleremote, provided that RCS4 can be used via LTE, Epiroc said. But Dömstedt, Mann and their colleagues on the project have already come a long way since the very first tests in December 2020, which were designed to show whether teleremote over the LTE network worked at all.

Dömstedt said: “We were in Epiroc’s workshop 800 m down in the mine. We had a remote station in the room next to the rig, and we looked out to see if it was moving around on the rig, and it was.”

The company sees LTE opening further possibilities. For example, Zinkgruvan has collaborated with Mobilaris to set up unique, full site coverage, communication and positioning infrastructure at the site, a project that led to the development of Mobilaris Virtual Tag™, which is running on LTE.

Mann said: “As we are the first to build something like this, we haven’t been able to ask anyone for help, we’ve had to solve all the problems ourselves along the way.”

According to Mann, the key to success lies in clear, short decision-making paths and a responsive way of working where everyone, including partners and suppliers, takes responsibility and is fully committed.

“This is exactly our approach to this project,” he said. “Everyone involved has had direct contact with each other. Even the operators have been able to talk directly to those building the network.”

The close cooperation with Epiroc has been crucial to the project, according to the OEM.

“Our development has gone hand-in-hand with that of Epiroc,” Mann said. “They’ve known that we were going to build an LTE network and then developed their teleremote system accordingly.”

Despite the fact Zinkgruvan is still a long way from bringing home the project, both Mann and Dömstedt are proud of what they have achieved. After completing 6,500 remotely drilled meters, they say the drilling is more efficient than ever, while the operators are satisfied and happy. The target is to reach 10,000 m, after which a thorough evaluation of the technology will be carried out.

Dömstedt said: “It’s been fantastic to work on this project. I’ve been working with automation in different ways for four years here in the mine and now have started drilling and see how it has developed – it’s been really fun! Of course, the fact that we’re getting such good feedback from the operators makes it even more exciting.”

*This story is an edited version of an Epiroc Customer Story here 

Lundin Mining enlists Ausenco for plant expansion optimisation study at Chapada

Less than a year after acquiring the Chapada copper-gold operation from Yamana Gold, Lundin Mining is eyeing up a plant expansion at the Brazil mine.

The company has enlisted Ausenco to carry out a feasibility study to evaluate the optimisation of the current copper-gold processing plant from 24 Mt/y to 26 Mt/y, Ausenco confirmed.

In addition, Ausenco is to undertake trade-off studies to determine optimum plant expansion scenarios for a future expansion.

Prior to Lundin Mining acquiring the mine in July 2019, previous owner Yamana had been studying plant expansion opportunities to increase the processing rate to a range from 28 Mt/y to 32 Mt/y, Lundin Mining says. The relocation of some plant infrastructure to allow the push-back of the pit wall for the development of the Sucupira orebody was also being studied.

The processing facility at Chapada comprises a single-line plant designed to treat sulphide ores at a current capacity of around 65,000 t/d, or 24 Mt/y, with the conventional crush, grind and flotation process producing a gold-rich copper concentrate.

Lundin Mining expects Chapada to produce 51,000-56,000 t of copper in concentrate in 2020, along with 85,000-90,000 oz of gold in concentrate.