CONTINUOUS CUTTING
Making the cut
COVID-19 has only strengthened the case for technologies able to cut hard rock in a continuous fashion , with the economic , safety and electrification benefits starting to hit home . Dan Gleeson speaks to the major players in the space to get the latest
The Komatsu MC51 trial now underway at Vale ’ s Garson mine will see the machine carry out 400 m of development over a 9-12 month period
There have been more than a few false dawns in the hard-rock mechanised cutting space – as IM has referenced on more than one occasion .
Yet , the industry appears to have returned to the office after the initial impacts of COVID-19 having re-evaluated their underground mine plans and the host of technologies on offer with renewed interest around mine site deployments .
Whether it is for orebody access , ore mining , or some other mine infrastructure , mechanised cutting looks set to be part of the global technology discussion for years to come .
Changing the cutting dynamic
Weeks before IM went to press , a major
milestone in the world of continuous cutting was achieved with the launch of the Komatsu MC51 at Vale ’ s Garson mine in Sudbury , Canada .
Featuring undercutting disc technology for mechanical cutting , the MC51 is the culmination of more than 10 years of research and development looking into how to break rock continuously and precisely through a fully electric system that outputs zero emissions . The machine can be operated remotely via line of sight , while the on-board DynaCut technology is billed as offering cutting accuracy to within 50 mm of plan .
The technology and partnership were discussed at the most recent MINExpo 2021 , five years after Joy Global ( since acquired by Komatsu ) introduced a prototype machine featuring DynaCut technology for continuous hard-rock mining at the previous edition of the Las Vegas show .
While this earlier machine was essentially a DynaCut cutterhead fitted on a medium-sized roadheader , the parallels between the two iterations of the mechanical cutting machine in terms of mine site trials are apparent .
Back in 2016 around the same time as the Las Vegas event , a trial of the DynaCut technology on this prototype machine at the Cadia mine , in New South Wales , Australia , was getting underway . “ This was a different machine – more of a proof of concept to validate the cutting system and cutting technology ,” Stephen Styles , Product Manager at Komatsu , told IM . “ It was all about the initial fundamentals : Can we break rock ? Can we cut rock ? What do the rates look like ? What size rock chips do we get ? What does the tunnel look like ?”
Five years later , an MC51 with that same DynaCut technology has not long finished another trial at Cadia where the full 5 x 5 m diameter “ tunnelling machine ” was successfully tested at the block cave mine ahead of the aforementioned Garson trial .
Styles expanded on the changes to the machine : “ We made some minor changes to the cutting system – mainly for packaging and efficiency – but it is very similar technology to what we did over that 2016 timeframe .
“ The major changes were to the machine itself . The machine is now able to , while we ’ re
cutting , continuously handle material . We ’ re able to bring the material into the front of the machine , through the centre conveyor and load behind the machine .
“ It is also able to hold itself stable in the heading while cutting and handling material , plus we have a set of Komatsu roller tracks on the machine to allow it to manoeuvre around the mine .”
He added : “ We have built the machine around the cutting system .”
That machine now measures in around 12 m in length – from the front of the gathering head / shovel to the back end of the conveyor – and is 3.5-4 m in width , according to Styles .
The cutting system , meanwhile , can cut in any direction thanks to a flexible single boom configuration . This allows it to develop tunnel profiles of any shape , according to the company .
There are no constraints on the haulage setup behind the machine – the on-board conveyor can dispatch material onto a variety of equipment or onto the gallery floor – but the latest Cadia trial involved an 18 t LHD .
“ An LHD is probably one of the most flexible underground material handling tools in the underground mining environment – it can , as the name suggests , load , haul and dump ,” Styles said .
Feedback from Cadia has led to the company selecting a 7 t Komatsu WX07 LHD to follow the MC51 for the Garson trial .
And , in the next year , Komatsu plans to roll out
68 International Mining | NOVEMBER / DECEMBER 2021