THERMAL FRAGMENTATION: REDUCING MINING WIDTH WHEN EXTRACTING NARROW PRECIOUS METAL VEINS

CIM Vancouver 2010
Donald Brisebois, Jean-Philippe Brisebois,
Abstract The mining of high-grade, narrow vein deposits is an
important field of activity in the precious metal mining sector.
The principle factor that has undermined the profitability and
effectiveness of mining such ore zones is the substantial dilution
that occurs when blasting with explosives during extraction.
In order to minimise dilution, the Thermal Fragmentation
Mining Method enables the operator to extract a narrow
mineralised corridor, 50 cm to 1 metre wide (according to the
width of the vein), between two sub-level drifts. By inserting a
strong burner powered by diesel fuel and compressed air into a
pilot hole previously drilled directly into the vein, a thermal
reaction is created, spalling the rock and enlarging the hole to
80 cm in diameter. The remaining ore between the thermal holes
is broken loose using low powered explosives, leaving the waste
walls intact. This patented method produces highly concentrated
ore, resulting in 400% - 500% less dilution when compared to
conventional mining methods.
The mining method, reduces the environmental affects of
mining operations since much smaller quantities of rock are
displaced, stockpiled, and treated using chemical agents. The
fully mechanised equipment operated by a 2-person team,
maximises the effectiveness of skilled personnel, and increases
productivity and safety.
The Thermal Fragmentation is currently employed in 3
mining operations in North America.
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