HIGH PROFILE
Sandvik Mining has an extensive rock test library in Zeltweg( Photo: Adam Lach)
for tonnes per hour, according to Sandvik. Improvements were identified and designed to further increase the system’ s productivity and reliability, including installing ground support roof bolting while cutting and loading, reducing turnaround and relocation time and exploring remote operation potential.
This integrated system is notable for being much larger than other mining machines in the Saskatchewan Potash basin. The MF460-led system also requires less workers, equating to a lower labour cost per tonne, but also a lower overall equipment cost per tonne of potash produced, which BHP believes will give it an operating cost advantage over other Saskatchewan potash majors.
The delivery of these units will, alongside other machines going to the salt, gypsum and potash markets, see industrial mineralsbased revenues increase at the division in future years.
Vallant, sensing another market opportunity, sees the potential for commercialisation of other conveyorbased solutions that leverage the experience gained from the Jansen product development exercise.
“ When you look at the status quo in these types of soft rock room & pillar operations – many of which are located in Saskatchewan – a variant of our system would offer significant flexibility and productivity benefits,” he said.“ It is early days for these developments, but we think there will be other products following the system we have devised for Jansen.”
Cutting constraints
When it comes to hard-rock cutting, the dynamic is different with a sustained showcase of Sandvik’ s capabilities not yet in existence.
This is down to the complexity of cutting / boring in these variable environments, plus the need to ensure downstream bolting and material handling operations can keep up with progress at the face.
Anyone involved in this sector will admit that Uniaxial Compressive Strength( UCS) measured in MPa is only one part of the puzzle when it comes to assessing if rock formations or orebodies can be economically cut or bored through.
The team at Zeltweg are aware of this, with Restner telling IM about the Rock Mass C R model Sandvik has devised to better analyse which rocks are suited to its machines.
“ When we consider rock cuttability, we have traditionally looked at applications with rock that has a UCS of less than 140 MPa,” Restner said. This is especially so for roadheaders.
The continued development of the MX650 – the‘ X’ standing for extra hard rock in this case – is an exception to this, having been tested in rocks boasting a UCS of 300 MPa at the Mittersill mine in Austria, owned by Sandvik Group. The company’ s ongoing testing of polycrystalline diamond( PCD) bits on the cutting heads of machines could also push some of the company’ s existing commercial offering beyond the 140 MPa threshold.
“ The reality is, though, that we have cut rock with a UCS up to 180 MPa in some applications with our roadheaders where the rock is in shear-like structures,” Restner said.“ We can no longer analyse cuttability by UCS alone.”
A tour of Zeltweg’ s rock samples close to its high-load, hard-rock cutting test rig, part of the mechanical cutting competence centre established there 10 years ago, reinforces Restner’ s words, with cut rock formations over 140 MPa featured in an extensive line-up.
One would assume the physical rock test library Zeltweg has assembled would soon be replaced by digital simulations or even digital twins, but Restner saw no digital alternative on the horizon that was able to accurately reflect rock variability for cutting analysis.
“ There are no digital twins currently reflecting the conditions that a roadheader, for instance, will be cutting in,” he said.“ This is why we continue to encourage interested companies to send us representative samples of material to cut on our test rig.”
Some companies go even further than this – Anglo American, for instance, invested in a huge block of representative stone that the team at Zeltweg could steer the MN330 hard-rock continuous miner through to get an accurate reading of its ability to cut in the Merensky Reef of South Africa.
There are also cuttability tests on show from the cutting system developed for the first generation MX650, with a sample from the Musselwhite mine( formerly owned by Goldcorp, then Newmont and now Orla Mining) catching IM’ s eye.
These issues are widely acknowledged by the hard-rock mine development community.
This same community is also aware of the different avenues that vendors are pursuing to compete with the drill and blast process – undercutting technology and a variation of the traditional tunnel boring method among them.
Restner detailed numerous options the company has considered in looking to make a breakthrough in hard-rock mine development – microwave technology among these – yet he said the undercutting solution offered by the MX650, which could cut as well as bolt simultaneously, was by the far the best option explored.
“ The MX650 is not going to work in every application when it is benchmarked against drill and blast, but, if we prove out that it can effectively cut, mesh and bolt, and do so with development rates of 10 m / d or more, the wider industry will soon start to take note,” he said.
International Mining | JANUARY 2026 53