CONTINUOUS CUTTING
looking at four or five cameras to operate the cutting machine . “ That is the natural progression .” While the current focus is on Garson and Canada , the MC51 currently in Australia ( a second machine ) is already engaged in another trial at Hillgrove Resources ’ Kanmantoo copper operation in South Australia .
This Komatsu MC51 trial is being used to develop the Kavanagh portal , approximately 500 m of decline , and a number of drill platforms which facilitate underground drilling to infill and expand the resource , and , subject to Final Investment Decision , will later serve as part of the broader underground mine infrastructure at Kanmantoo , according to Hillgrove .
The trial will focus on demonstrating the commercial viability of the machine and new materials handling and ground support processes , the company added .
Styles expects the rock hardness – in terms of MPa UCS – to be slightly lower than Cadia ( which was around 200 MPa ).
“ We know we can cut the material ; it is going to be about how well we can cut the material in a single heading decline ,” Styles said . “ This means the machine will have to be supported well with the ground support .”
Such an application is likely to see the MC51 progress through the rock as part of a ‘ batch process ’ whereby the machine is moved in and out of the heading in rotation with the ground support teams .
“ The goal will be to get high levels of utilisation of the machine and stress test the machine in that environment ,” Styles explained . Such a trial stands out in this market – one that , until this point , has typically seen TBM-type cutting machines applied on declines and undercutting technology trialled on level developments .
Styles sees the new breed of hard rock cutting technologies having the potential to upend this dynamic .
“ If you divide it up , you see TBMs more in the decline-style applications and undercutting in the level developments where more intricate , complex tunnels are required or where the material type may change as you progress ,” he said . “ That is how it has been for years .
“ I think , in the future , you may see some overlap . It could be a more flexible TBM technology on level development and , like what we are doing with Hillgrove , undercutting technology on declines .
“ A lot of this is going to depend on the application – the size of excavation , length of tunnel , ground support for strata , haulage strategy for material , etc .
“ It is all going to factor into the future cutting dynamic in the industry .”
Tailored treatment
While much of the continuous cutting market awaits news on the latest plans for Sandvik Mining and Rock Solutions ’ MX650 machine , 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 OEM says it has succeeded in developing a new method for continuous hard-rock mining with its Sandvik MN330 narrow reef production system .
Anglo American has placed the first order for the MN330 , which is due to be shipped to the Anglo American Platinum-owned Mototolo platinum mine in the Bushveld Complex of South Africa before the end of 2021 .
“ This is the result of a long-term collaboration , where we have developed not only a new system but a whole new method of mining ,” Arne Nicolaas Lewis , Vice President , Hard Rock Continuous Mining , Sandvik Mining and Rock Solutions , said . “ Even the mine ’ s layout has been designed specifically for this system .”
The solution consists of the hard-rock cutter Sandvik MN330 and a Hencon system that extracts the cut material from the mine and sends it through a series of filters and separators . Since it can be operated remotely , it greatly reduces the need for personnel to be inside the mine and drastically reduces employee risk exposure . Compared with the traditional drill-and-blast method used by Anglo American , CO 2 emissions are reduced by half , Sandvik said .
Sandvik has previously worked on the application of a Sandvik MN200 Reef Miner at the Twickenham mine , owned by Anglo American Platinum . This remotely-operated machine incorporates cutting , materials handling and roof bolting and was designed for mining narrow mineral reefs in hard rock .
Anglo American Platinum is working on productivity improvements at Mototolo – the company has said it is looking to expand production from 240,000 t / mth to 320,000 t / mth through technology deployment , aiming for a circa-20 % productivity improvement by 2025 , relative to 2020 . It is also looking at the development of the Der Brochen orebody to extend Mototolo ’ s life of mine . This includes development of a decline and required infrastructure to access Der Brochen and help replace declining production from Mototolo .
Meanwhile , in Canada , Sandvik has added to its roadheader customer reference list , having deployed a new Sandvik MT720 continuous
Sandvik says it has succeeded in developing a new method for continuous hard-rock mining with its MN330 narrow reef production system
miner to Osisko Development Corp ’ s flagship Cariboo gold project in British Columbia .
Delivered in January , the MT720 is an electrically powered and crawler-mounted boomtype roadheader engineered to cut hard and abrasive rock mass of up to 140 MPa UCS . It is being used by Osisko for drift development at the existing Bonanza Ledge Phase II mine and the planned Cariboo mine , which are both part of the overall Cariboo plan . The former has an estimated production of 62,000 oz over an initial two years , which started production in the March quarter of this year . Cariboo production is expected to start in 2023 .
The asset is expected to produce over 200,000 oz / y when both are in production , with ore processed at the permitted and scalable 1,000 t / d existing QR Mill .
The Sandvik MT720 roadheader was assembled in February 2021 and has been commissioned in drift development at Bonanza Ledge Phase II . It is cutting drift with 5.8 m wide x 5.3 m high dimensions , with up to 7 m of advancement achieved during a 12-hour shift including rock support , services installation and mucking . Translated on a monthly basis , this would provide about 200 m / mth of development , according to François Vézina , Vice President of
The Sandvik MT720 is an electrically powered and crawler-mounted boom-type roadheader engineered to cut hard and abrasive rock mass of up to 140 MPa UCS
70 International Mining | NOVEMBER / DECEMBER 2021