Extraction

DynaCut™

Hard rock cutting machine

Challenge

While drill-and-blast is typically the most cost-effective method to fracture and remove hard rock in surface and underground mining, a continuous hard rock cutting system would offer the potential for simplified scheduling, decreased stoppage times, safer and faster advance rates, and greater productivity.

Pick-based mechanical excavation machines have had limited success in higher-strength materials (generally those with a compressive strength above about 40MPa) due to inherent performance limitations of this cutting method. The challenge was developing an energy-efficient cutting system capable of rapidly excavating hard rock.

Solution

Mining3 developed the Oscillating Disc Cutter, which was licensed in 2006 by Joy Global (now Komatsu Mining Corp) and rebranded as DynaCut™. With relatively low input power, the DynaCut cutting technology – now incorporated into Komatsu’s DynaMiner machine – enables continuous, or semi-continuous mining of hard rock in both surface and underground applications.

How it Works

DynaCut combines an undercutting approach (exploiting tensile and shear failure mechanisms) with a high-frequency dynamic motion. The method requires much lower forces than those associated with conventional roller disc cutting, and can effectively cut rock well beyond the strength limits of pick-based tools.

The DynaMiner machine has two key parts: the DynaCut disc that oscillates, which is mounted to a smart boom and a compact, lightweight, mobile mining machine which together form part of a continuous cutting system. It can cut in any direction and is not limited by the availability of a free edge, allowing for the development of flexible, accurate tunnel profiles of any shape.

Benefits

  • High capacity and automation friendly
  • Energy efficient and requires a relatively small carrier
  • Provides a very smooth opening, reducing the requirement for tertiary work such as scaling and refinishing roadways
  • System disturbs less of the surrounding rock mass compared to drill and blast methods
  • Provides a cleaner and safer solution producing large chips and little dust
  • Eliminates drilling and blasting processes, and primary loading machines (large shovels)
  • Reduces ancillary loading and handling machine requirements (loaders and dozers)
  • Provides a relatively consistent product size range, suitable for continuous transport via conveyor systems
    i.e.reducing or eliminating the crushing/sizing component of typical in-pit crushing and conveying (IPCC) systems

  • Capable of continuous cutting across a very broad range of materials, with potentially minor configuration changes (e.g. cutter type) to optimise performance in various material classes

Status

Mining3 continues to work with Komatsu Mining to further develop the DynaMiner as part of a hard rock continuous mining system. Testing of a DynaMiner prototype machine was recently performed at Newcrest’s Cadia East mine in NSW, Australia.