COAL AND SOFT-ROCK MINING
room and pillar coal operations for this unit, but, globally, it thinks there is an opening for salt and potash mines too.
Speaking of potash, Restner visited Saskatoon in April for an event, taking the
Sandvik recently marked significant milestones with the MB672 bolter miner( on the left) in China and the MC431 continuous miner( below) in Australia
opportunity to highlight a new concept as an alternative to the four-rotor borer miners that have proven successful in local potash operations.
“ We already offer the MF products to the market – so the MF420 at Nutrien and the MF460 that is set to soon start up at the Jansen project – with some of the mines in Saskatchewan looking for replacements for the four-rotor machines they have historically used,” Restner said.
These discussions have seen the company resurrect a cutter arm that it initially proposed to use for undersea / submerged mining as part of the Nautilus Project.
“ We are asking them,‘ Does it really make sense to create a four-rotor machine, or could a highly performant continuous miner achieve even more?’,” Restner said.
This could see the company combine its expertise in continuous miners with the cutter arm it developed for Nautilus for the“ Mega Miner” concept.
Restner explained:“ This cutter arm, which weighed more than 90 tonnes, could be merged with the frame and crawler track unit of the strongest borer miner we have, which is the MF460. If we install 1.2 MW of cutting power behind this, we have a high-capacity continuous miner on our hands that can bridge the gap between the bolter miners used in German salt applications and the borer miners we already have.”
Restner and the team are targeting a 2.5 Mt / y soft-rock cutting capacity for this concept, which is almost double the production rate achieved by Sandvik’ s most productive bolter miner, the MB770.
In the US, meanwhile, the company is refining its MC351 continuous miner and lining it up for a second trial in the local coal market.
Finally, when it comes to the automated bolting processes offered by the latest generation bolter miner, the MB672, Sandvik has progressed from demonstrations and is soon expected to start operating a rig able to bolt autonomously at a mine in China.
Earlier this year, a new highwall mining machine was formally inaugurated at the Sharda Open Cast Mine( Sharda OCM), in South Eastern Coalfields Ltd( SECL)’ s Sohagpur Area. SECL is part of state-owned coal mining giant Coal India and is already experienced with highwall mining having used the method since the early 2010s including a previous machine supplied by Gainwell Engineering in 2019.
This highwall miner was also supplied by Gainwell, which stated:“ With an expected production life of nearly nine years, this advanced solution is set to enhance coal output, improve operational efficiency and support safer, more streamlined mining practices. Built to unlock resources smarter and sustainably, the highwall miner shows our commitment to driving innovation on the ground.”
The machine is a GHWM300M, which, Gainwell says, can be tailored to mine coal seams as low as 762 mm or as high as 5,000 mm. Gainwell offers three electric cutter modules – low seam, mid seam and high seam. The cutter modules are interchangeable and quickly attached to the highwall mining system. The machine also offers fibreoptic, gyro-based navigation, enabling precise cutter module location data in real time, it says. Operators benefit from enhanced steering and control of pillar width.
Gainwell adds that the GHWM300M produces high volumes of coal at very low cost. It is safer than traditional underground mining, as it sends no one underground, and it works economically with a small crew and very little support equipment. The company explained:“ It’ s versatile in its mobility and application, and it produces large quantities of coal at inherent ash levels … the Gainwell highwall mining system offers an innovative and efficient method for extracting coal from exposed seams in a multitude of applications.”
The GHWM300M works on the pit floor or bench directly in front of the exposed seam. Up to 300-m-long parallel rectangular drives are cut into the coal seam by means of the cutter head module and push beams. These push beams transport the cut coal internally via two counter rotating spiral / screw conveyors( augers) back to the entry of the drive and then onto a stockpile. The whole mining cycle is completed by a crew of 5-6 with no personnel ever going underground.
The highwall miners are manufactured at Gainwell’ s Asansol factory in West Bengal where it has made a series of major investments in recent years.
14 International Mining | AUGUST 2026