Conventional rock quarrying requires environmentally
disruptive drilling and blasting, especially where harder rock is
concerned. What is more, these operations mix better quality material
with other materials and produce stones with rough surfaces. Better
methods involving advanced cutting machines do currently exist,
but expert interpretation is invariably required to assess whether
they can be used in specific situations.
This project focused on the development
of a continuous surface mining machine adapted for use in hard rock
conditions, together with a system for classifying rock cuttability.
A prototype successfully cut through very hard weathered pegmatite,
demonstrating that such a machine could work reliably in commercial
operations. This is the first such machine to present a real economical
alternative to drill-and-blast techniques. Significant progress
was also made in formulating a rock cuttability index.
The project trials showed a 25% reduction
in operating costs for a surface miner operating under conditions
of intermediate rock hardness. The new system also gives a smooth
surface and allows selective quarrying, meaning different grades
of material can be easily separated and shipped to different customers,
maximising the value of the deposit. Partners say moves to launch
the new machines commercially began even before the end of the Brite