Trials with all battery-electric underground equipment are ongoing with a number of major mining groups worldwide from Vale to Codelco and Barrick. At Sibanye-Stillwater’s US PGM mining complex in Montana, which includes the Stillwater and East Boulder mines, the company recently told IM it is currently trialling an Artisan Vehicles (part of Sandvik Mining and Rock Technology’s Load and Haul division) A4, 4 t payload (1.5 m3/2 cubic yard capacity) LHD. This is an updated version machine as an initial unit was trialled in 2018-2019.
Sibanye-Stillwater told IM: “As we engaged Artisan with this machine, we agreed to a 200 run-hour period where we were able to address minor defects and bugs while we also trained people. The next sequence of 300 run hours is actually a performance period wherein we are matching unit productivity performance, reliability, failure rates and repair rates. As well, we are wanting to confirm battery charge and re-charge cycle.”
The company adds: “We are presently at 296 total hours on the machine – so 96 hours into the formal performance period. Unit productivity has been good. Reliability issues have remained – largely small issues and parts flow due to COVID have been very problematic. The machine is solid – but small things are still causing uptime issues. We are pleased in that we are realising about 5.5 hours charge time and generally a 2 hour re-charge cycle. This works well for us. The machine is stealthy, quiet and has plenty of power.”
Artisan states on this model: “The A4 LHD is by far the smallest LHD capable of carrying 4 tonnes. Its compact stance allows for the best line of sight visibility – far better than any machine in its class. It is more manoeuvrable with a 20% tighter turning radius. It has 350% of the power and far more torque than its diesel rival while producing only 1/8th of the heat.” The A4 uses a powerful battery electric motor generating 150 kW and 800 Nm of torque. As with other Artisan machines, it uses LiFePO4 chemistry in the patented battery system.
Stillwater and East Boulder are shallow to intermediate level underground PGM mines mainly producing platinum and palladium located approximately 85 miles southwest of Billings and some 32 miles south of the town of Big Timber. Both mines extract PGM ore from the J-M Reef – Stillwater from the east and East Boulder from the west.
