The Mt Wright Project is located near the town of Ravenswood in North
Queensland and is operated by Carpentaria Gold – a wholly owned subsidiary of
Resolute Mining Limited. Underground Development of the current Mt Wright
orebody commenced in June 2006 and the first production ore was brought to
surface in June 2007. The orebody is a rhyolite pipe containing fine-grained
disseminated gold in a granite host rock. Ground conditions tend to be good to
excellent throughout development, with some minor deformation experienced when
stope-sized excavations are formed.
The mine commenced as a sublevel
open stoping (SLOS) operation with the intent to utilise development waste to
back fill isolated upper level stopes while developing to the bottom of the
known orebody. The mine plan intended to commence production with a bottom-up
primary/secondary stoping retreat through the main orebody utilising cemented
fill. Some challenges were faced during the initial production phase that
•Ongoing underground diamond drilling and updating of the block
model resulted in some issues reconciling the grade control results to the
resource model. This was primarily due to the high variability of grade which in
turn caused difficulties in accurately identifying areas of low and
•The cost of establishing and operating a cemented fill plant
to achieve the planned extraction sequence of the orebody had increased
significantly beyond initial estimations.
•Geotechnical conditions such
as stress orientations, ground behavior and response to the forming of
excavations learned through the mining of the upper level stopes were different
to the assumptions made during the initial design.
A number of in-house and external
reviews of the mining method were completed which has resulted in a revised
mining plan. This paper will summarise the challenges faced and the
implementation of the mine plan to date.
Mackay, D, 2011.
Implementing and improving the mine plan at the Mt Wright Project, in Proceedings 11th AusIMM Underground Operators’
pp 135-142 (The Australasian Institute of
Mining and Metallurgy: Melbourne).