Redesigning Stopes for Improved Recovery of Ore
Document type: Case Study
Categories: Case Study

the stope. It was also revealed during the site visit that there were PROPER VOID FOR PROPER ROCK
issues related to tight digging of the muckpile even though EXPANSION
the fragmentation was adequate. After the investigation, the DynoConsult representative
 sat down with the mining engineers and worked out a new
 Technology Used stope development plan that would produce the proper
 amount of void in the panel for proper rock expansion. LACK OF RELIEF FOR STOPE BLASTS WAS
 Two test blasts were conducted. Scans of the panels after
DETERMINED TO BE THE MAIN ISSUE the mucking of the test blasts indicated that the recovery in
A site visit was conducted by DynoConsult to investigate the panels had improved from 70-80% to over 90%. the situation at the mine. A top to bottom review of the
blast design and practices was carried out with the mine Next Steps
engineers. In addition, an underground tour of the mine
gave DynoConsult a first-hand account of the situation and
current results experienced.

n and practices was carried out with the mine Next Steps
engineers. In addition, an underground tour of the mine
gave DynoConsult a first-hand account of the situation and
current results experienced. EVOLVING BLAST DESIGNS
Although the customer had initially assumed the issues Refinements on the stope blast designs continue to evolve
they were experiencing could be resolved with different through discussions with the mining engineers at this
delay times, the investigation on site quickly revealed that operation and will lead to continued improvements in the
the issue was related to lack of relief for the stope blasts. blasting program at this operation. The void into which the rock from the stopes was designed
to expand was far too little to allow for proper rock
 20%
breakage. DynoConsult’s representative informed the increased
 recovery

Disclaimer This case study is provided for informational purposes only. No representation or warranty is made
 or intended by DYNO NOBEL INC. / DYNO NOBEL ASIA PACIFIC PTY LIMITED or its affiliates as to the
 applicability of any procedures to any particular situation or circumstance or as to the completeness or accuracy
 of any information contained herein. User assumes sole responsibility for all results and consequences.
 ©2017 Dyno Nobel

Project Summary
$1 MILLION OF UNRECOVERABLE ORE
This underground nickel mine in the Midwest United States
is relatively young with only a few years of production
blasting. The operation is employing a sublevel stope
mining technique. The operator purchases Dyno TITAN®
RU emulsion and electronic detonators for blasting. The customer was experiencing poor blast results over
a substantial period of time. When the customer first
contacted DynoConsult® for assistance, the concern was
the under-breaking of the ore which left valuable material
along the ribs. At that time the mine engineers were looking
for guidance on the delay times they should be using to
improve the recovery of ore mining engineers at that time that most, if not all, of their
During the site visit by DynoConsult, it was also discovered blasting issues could be resolved by redesigning their
that there were a few instances of benches and bridges stope panels to incorporate a greater void for relief. being left in the stope after mucking. In one stope it
was estimated that over $1 million worth of ore was left Results
unrecoverable in the stope. It was also revealed during the site visit that there were PROPER VOID FOR PROPER ROCK
issues related to tight digging of the muckpile even though EXPANSION
the fragmentation was adequate.

Redesigning Stopes for Improved Recovery
 of Ore