CONTINUOUS CUTTING AND RAPID DEVELOPMENT
A view of the -9 °, 5.5 m diameter decline face at Eland . This was constructed in hard rock , norite , with the MTB cleared from the tunnel without constructing a typical TBM receiving chamber
Last year , IM also reported on progress of the Mobile Tunnel Borer ( MTB ).
Master Tunnelling , a division of Master Drilling known for its raiseboring expertise , was contracted for a performance validation project at Northam Platinum ’ s Eland mine in South Africa during the second half of 2019 .
A 130 m stretch of decline tunnelling was completed during a three-month period at Eland , with the best tunnel advances being 6 m / d in a typical seven hour a day boring time for a five-day consecutive period . The tunnelling operations started after moving the MTB some 1.3 km through an existing box cut , portal and central decline with an inclination of up to 15 ° in some places ; launching it from a reusable starter frame .
On the back of this work , a 1.5 km decline extension contract was awarded that was terminated in March 2020 after three weeks of operation and 30 m of tunnelling . This came as a result of Northam Platinum cutting capital to the Eland project following COVID-19-related market uncertainties at the time . The MTB is currently under maintenance and improvements at Master Drilling ’ s facilities in South Africa with the prospect of placing it on a project in early 2021 . A detailed root cause analysis was conducted from operational and technical data , with Master Tunnelling saying it is confident these changes and its experience will set it up for a step change in performance on the next project .
Facilitate , communicate , promote
Even though the Canada Mining Innovation Council ( CMIC ) and its ‘ Continuous Underground Mining ’ program have more than mechanical cutting in its remit , CMIC remains one of the key organisations pushing cutting developments forward .
Within its program , CMIC has projects focused on hard-rock mechanical cutting demonstrations , mechanical cutting continued learning , and conventional drill and blast transformation .
The Continuous Underground Mining : Mechanical Cutting project began in early 2017 and has been able to gain the support of Agnico Eagle Mines , Glencore and Vale as partners , all of whom have committed to learn and showcase the potential of new cutting technologies to the wider industry .
The upcoming trial with mining company Vale and industry OEM Komatsu might have everyone talking at the moment ( see Cutting collaboration boxout ), yet , according to Carl Weatherell , CMIC Executive Director and CEO , and Trevor Kelly , Innovation Manager of Mining at CMIC , this project momentum is just a snapshot of the activity CMIC has seen in the last year .
“ Our members are actually spending more time looking at these transformative technologies and , in some cases , pushing us to achieve innovation results faster ,” Weatherell said .
Kelly said COVID-19-related delays and a setback on another potential collaborative project has actually allowed members to recommit in terms of the project focus , with an increase in the desire to engage , learn and support the program ’ s project pipeline . This has seen the collaborators return to the work they carried out in phase two ( the project is currently in its third stage ) to learn from – and build relationships with – OEMs and service providers .
“ This process enabled us to maintain and build relationships with the likes of Komatsu , Sandvik , Master Drilling , Bergteamet , Robbins , and others ,” he said .
CMIC says it continues to evaluate the relationships it has in place with potential project partners to ensure all parties are aligned with CMIC ’ s aims , and OEM relationships and collaboration partnerships continue to revolutionise the mining sector .
“ We continue to engage companies at all levels of the organisation to facilitate , communicate and promote innovation activities taking place in all companies and the wider industry to develop a thread of interest at all levels , from site to senior executives ,” Kelly said . “ We are having conversations at multiple points of the business to maintain this interest across the board .”
This effort has certainly paid off with the Vale and Komatsu collaboration demonstration project , which Kelly is confident of having signed off and in place by the end of the year .
“ This new project with Vale and Komatsu is a good opportunity to bring people in , provide the opportunity to get up to speed on industry developments and participate in a major industry trial at a relatively low cost point in comparison to independent development ,” he said .
“ When I have the final collaboration agreements in place , I can raise the flag . That initial interest should then be converted into participation , allowing more and more parties to gain a better understanding of how this and other mechanised cutting technologies can play a role in transforming the underground mining industry .”
Hard-rock continuous mining
One of the presenters on CMIC ’ s ReThinkMining Webinar back in June was David Hickson , Sandvik Mining and Rock Technology ' s Regional Sales Manager , Mechanical Cutting , for Canada .
Hickson provided an update on the company ’ s MX650 , a cutting machine using roller disc undercutting technology for mine developments in excavations from 4 x 4 m to 5.1 x 7 m .
The Sandvik MX650 , in development since 2014 , is expected to graduate from test work at Sandvik ’ s Mittersill test mine , in Austria , to Petra Diamonds
Finsch mine , in South Africa . Having previously anticipated arrival of a
Sandvik says a 12-14 m / d advance is possible with the MX650 in a 4 x 4 m development in 150 MPa rock
International Mining | NOVEMBER / DECEMBER 2020