The challenge
Perhaps better known for its abundance of natural energy resources, Colombia is also home to significant nickel and gold deposits. With increasing explosive cost pressures in the country, mining operators and industry partners are seeking to unlock greater value from their current explosives. At an open-cut nickel mine,
Enaex Colombia
sought to deliver savings to its client by reducing the kilograms of explosives per hole through the introduction of an airdeck in each hole using MTi's inflatable blasthole plug, BLASTBAG
™
AERO. To assess the potential of BLASTBAG
™
AERO, a test blast was conducted with the primary objective of demonstrating the operational and economic efficiencies from airdecks on the blast outcome. The target of the test was a 14% reduction in explosives without negatively impacting fragmentation, vibration and airblast
The solution
To reduce the amount of explosives in the hole, BLASTBAG
™
AERO, was selected as the tool to create the airdeck using a small portable compressor. Using compressed air BLASTBAG
™
AERO, can be inated or deated easily allowing for the bags to be precisely positioned in the hole. This allows for better, more consistant airdecks, capable of supporting several hundreds of kilos of stemming. For the test, a standard 6 x 8 burden and spacing pattern was selected , consisting of 98 blastholes . BLASTBAGs
™
were installed in 50% of the holes removing 0.6m of explosives from the standard charge design and the other 50% without BLASTBAGs
™
with explosives loaded according to the orginal blast design. BLASTBAG
™
were installed on one side of the blast, while the other side did not have any airdecks. Installation was quick and easy with no substantial increase in time required to install the BLASTBAG
™
AERO(around 1 minute per hole). This type of installation can be done after charging as it is independent of gassing . A great advantage of the BLASTBAG
™
compared to mechanical plastic in-hole plugs is that they do not generate traction or friction on detonator downlinesconsiderably reducing the risk of misfires due to cut-offs. BLASTBAG
™
AERO is a flexible and versatile tool covering hole sizes from 64 mm to 311 mm. With the advances in Lithium-ion batteries and compressor technology, many options for compressed air sources are usually available on a mine site ranging from inexpensive battery powered portable compressors, to accumulators on MMUs to service air in underground mine environments.
The results
After completing the trial blasts, it became evident from the results that a reduction in explosives usage could be comfortably achieved: a decrease of 14% in explosives per hole, annualised to potential savings of up to 200 tonnes of explosives per year. These outcomes were attained without compromising operational productivity, and without experiencing increased vibration or airblasts. Instead, there was an improvement in fragmentation (Up by 19%.) The client, highly satisfied, is currently in discussions with
Enaex Colombia
| Metric | Result |
|---|---|
| Explosive per hole | −14% (target met) |
| Annual explosive saved | up to 200 tonnes |
| Fragmentation | +19% (improved) |
| Vibration & airblast | no increase |
| Productivity | no loss |
The outcome
and MTi Group regarding the implementation of this solution site-wide.
