How an Underground Gold Mine Stopped Losing Emulsion to Groundwater | MTi GROUP
Site Profile
| Location | Sefwi-Bibiani Belt, Ghana |
| Material | Gold |
| Process | Open Stoping (Underground) |
| Explosives | Emulsion |
| Hole Length | Up to 85 ft (26 m) |
| Conditions | Heavy groundwater ingress, monsoon flooding |
Water Was Wrecking Their Emulsion in Upholes
This underground gold mine in Ghana's Sefwi-Bibiani belt was fighting a losing battle with groundwater. Every time they charged an uphole, water would flush the emulsion right back out. It slumped, and seeped. Crews would often have to go back and reload holes just to hit the designed powder column.
They tried retention plugs. That didn't work. The water volume was too much for a mechanical fix. Plugs can't hold back excessive amounts of water.
During monsoon season, it got worse. Water literally poured out of the boreholes. The loading process slowed to a crawl and blast results drifted away from design. It was costing them money — time, explosives, and recovery.
What They Tested
The mine brought MTi GROUP in to look at the problem. After a site visit, the answer was obvious — trying to hold emulsion in place after loading wasn't going to cut it. They needed to keep the water away from the emulsion altogether.
The approach: line the uphole before charging. Use a BLASTSHIELD™ liner to create a physical barrier between the emulsion and the groundwater. But how do you hold it in position?
Our team decided to think outside the box. What if we could use a BLASTBAG™ AERO at the toe of the hole to lock the whole thing in place? When tested, it worked.
The liner was pre-cut to length. One end was inserted into the folds of the BLASTBAG™, securing it to the outside of the liner. An air hose was attached for inflation.
The emulsion hose was inserted inside the liner and pushed uphole along with the BLASTBAG™ and air hose. When the liner reached the toe, the BLASTBAG™ was inflated to lock everything in place and the air hose was removed.
Explosives were loaded inside the liner as the emulsion hose was retrieved — the same way you'd load any other uphole. Crews used the same charging hose and mine air they already had. No new gear. No complicated training.
| BLASTSHIELD™ Plus Liner | Multi-composite woven sleeve with gusseted design and rip-stop properties. Lines the full length of the hole. |
| BLASTBAG™ AERO | Inflated at the top of the hole using mine air. Holds the liner in place so it doesn't shift during charging. |
| Charging Hose | Standard mine charging hose. Emulsion is pumped through the liner into the hole as normal. |
How They Made Sure the Data Was Solid
Lined holes were tested alongside non-lined control holes in the same conditions. All test holes had visible water dripping from the boreholes before lining. Emulsion behaviour was monitored immediately after charging and over time. Control holes showed ongoing emulsion loss. Lined holes showed none.
The Results
The difference was immediate.
In the lined holes, there was zero emulsion slumping or leaking from the hole, and it stayed that way. One pass. No going back and reloading.
| Metric | Lined Holes (BLASTSHIELD PLUS™) | Control Holes (No Liner) |
|---|---|---|
| Emulsion Slumping | Zero | Ongoing slumping observed |
| Passes to Charge | 1 pass | Multiple passes required |
| Drippage After Charging | None | Emulsion seepage over time |
| Crew Efficiency | Faster — no rework | Slow — revisiting holes |
With emulsion staying where it was supposed to, blast results came back closer to design. The mine saw higher material recovery during the trial, and crews could move faster because they weren't doubling back to fix holes that had lost their charge.
So What Does This Mean?
The problem was never about holding emulsion in place after the fact. It was about keeping water away from the emulsion in the first place. That's what BLASTSHIELD™ liner does — it creates a barrier between the product and the groundwater so the charge stays intact.
For this mine, that meant no more wasted emulsion, no more reloading holes, and blast performance that matched design. Crews worked faster, less explosive was wasted, and recovery improved because the energy went where it was supposed to go.
If you're loading upholes in wet ground and fighting the same battle with slumping, this is worth looking at. It's not a plug. It's not a workaround. It's a liner that keeps the water out of the equation entirely.
What Happened Next
The mine was satisfied with the results. They adopted the BLASTSHIELD™ and BLASTBAG™ AERO solution in all areas with significant water flows.
It's now part of their standard procedure for wet upholes, and the results speak for themselves — consistent charging, less waste, and blast outcomes that actually match what was designed.
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BLASTSHIELD™ Plus Blasthole Liner
Ultra-high strength liner for waterlogged blast holes.
Ultra-high strength liner for waterlogged blast holes.
Vendor:MTi USA -
BLASTBAG™ AERO
Air-operated BLASTBAG™ for efficient, safe mining operations.
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Dropline Inflation Hose
Durable, rigid dropline for BLASTBAG™ AERO and BLASTBALL™ deployment.
Durable, rigid dropline for BLASTBAG™ AERO and BLASTBALL™ deployment.
Vendor:MTi USA -
Inflation Assemblies
Dropline + Handheld Inflator + Weighted Coupling
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Underground Inflation Hose Reel
Complete air service unit for underground hose deployment with BLASTBAG Aero™ and BLASTBALL™.
Complete air service unit for underground hose deployment with BLASTBAG Aero™ and BLASTBALL™.
Vendor:MTi USA -
Handheld Inflator
Handheld inflation tool with gauge - for use with BLASTBAG™ Aero and BLASTBALL™.
Handheld inflation tool with gauge - for use with BLASTBAG™ Aero and BLASTBALL™.
Vendor:MTi USA -
Inflation Coupling
Patented coupling for secure inflation of BLASTBAG™ Aero and BLASTBALL™.
Patented coupling for secure inflation of BLASTBAG™ Aero and BLASTBALL™.
Vendor:MTi USA
