CONTINUOUS CUTTING the mine process – cost of operators , cost of equipment , keeping up with technology , overbreak , quality control , explosives , safety , etc – could potentially be solved with the Komatsu miner . For instance , no one has to be at the face in the optimal machine setup .”
The benefits go further than that though , according to Jardine – a man who has experience of mechanical cutting technology from his time at Pasminco when the mining company was trialling the first Robbins Mobile Miner at the Broken Hill mine in New South Wales .
“ In a world where I am using a mechanical rock excavator , I don ’ t have to buy A $ 2 million trucks , I can buy A $ 800,000 trucks because I am producing chips and have no overbreak to deal with . I don ’ t have to spend millions of dollars on the road because it is cut and smooth like a concrete floor . I don ’ t need loaders underground now as I am mining straight into a truck . The list goes on .
“ It is potentially a huge step change ; it changes everything we do and how we do it , all while providing a much better result .”
Cutting commitment
Epiroc ’ s Mobile Miner family has been spoken of in mechanical rock excavation circles for many years , with its steel disc cutting technology having undertaken tests in both Sweden – at the OEM ’ s own Kvarntorp facility – and South Africa –
at Anglo American Platinum ’ s Twickenham PGM mine .
The largest Mobile Miner still under Epiroc ownership is the 40V , which is typically used in small-to-medium-sized tunnels and cut-and-fill mining requiring 4 m x 4 m advances .
The V indicates that the cutter head is placed vertically – as opposed to the H of the 22H , placed horizontally – with the stated advance rate of the machine being 10-15 m / d depending on the rock type .
Reminiscent of a traditional TBM , the first 40V was expected to be deployed at Hecla Mining ’ s Lucky Friday mine in Idaho , with Epiroc and Hecla having partnered on a project for the Remote Vein Miner ( RVM ) – as Hecla refers to it – since 2017 .
Over that same five-year period , Hecla has also been working on a new mining method used to control the seismicity at the mine by blasting larger areas . Called Underhand Closed Bench ( UCB ), this method has proven successful at Lucky Friday , as the company ’ s 2021 annual report stated .
“ As we were completing de-stress blasting at Lucky Friday mine in preparation of receiving the RVM , we came to the conclusion that this drill and blast method could be optimised in a way that would be even more effective as an alternative – rather than an addition – to the RVM ,” Hecla said in the report .
During 2021 alone , 86 % of the tonnes mined at Lucky Friday came from use of the UCB method , which has been decreasing the risk of workers in headings that have the potential for a seismic event , making the mine a safer place for its workforce , Hecla said .
“ In addition , being able to utilise the headings more than 75 % of the time is a clear and obvious benefit , and we anticipate the production at the Lucky Friday mine for the super materials is in hard-rockincreasing as a result ,” the company said . “ What ’ s more , with the success we ’ re seeing from this new method , we can deploy the RVM at another Hecla operation .”
This operation has now been confirmed as Hecla ’ s Greens Creek mine in Alaska , USA , a mine that primarily uses cut and fill , and drift and fill techniques , supplemented by longhole stoping where orebody geometry permits .
This is different to the primary mining method of underhand stoping with paste backfill that Lucky Friday leverages .
According to Marcus Eklind , Epiroc Global Business Line Manager – Mechanical Rock Excavation , this has resulted in some changes to the planned deployment of the 40V .
“ The 40V , as has been discussed , was designed to accommodate the narrow veins and underhand stoping method used at Lucky Friday ,” he told IM . “ Greens Creek is a different proposition , offering different opportunities .”
machine for challenging conditions
The PTM 100 equipped with a transversal hydraulic cutter head is the perfect match when the production face has difficult geological conditions and drill and blast methods are not applicable .
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Tel .:+ 49 5903 707-0 info @ paus . de www . paus . de