If you operate an underground mine and rely on electric submersible pumps for dewatering, you’ve probably dealt with repeated seal failures, sometimes several times a year. If that sounds familiar, keep reading. And if you’re a fellow professional with insights or experiences to share, e’d love to hear from you.
Many mine operators spend significant time and resources replacing seals, repairing motors, or rewinding units, all triggered by a single root cause: seal failure. Most breakdowns in electric submersible pumps can be traced back to this issue.
Ask your maintenance team one simple question:
How many submersible pumps have we repaired in the past two years?
You’ll likely find that most of them were pulled out of service because of seal-related performance concerns. Now, imagine if your car required a complete engine rebuild two or three times a year. You wouldn’t accept it. Yet in mining, that level of failure often goes unquestioned, even though some of these pumps cost more than a family car.
So, is it really the seal’s fault? In most cases, no. The issue comes from using the wrong seal and the wrong pump for the job.
A Common Situation in Underground Mines
Earlier this year, we visited an underground mine operating close to 120 submersible dewatering pumps. By mid-2025, they had already spent around $900,000 on pump repairs and replacements.
The site setup was typical: pumping run-off sump water and slimes through 4 -inch pipework along the ramps. The maintenance team worked hard to keep the operation running, while the local pump supplier replaced failed pumps as quickly as possible. But that kind of arrangement simply keeps the failure cycle going.
In this case, standard dewatering pumps were being asked to handle slurries with up to 30% concentration by weight (cw), even though they were designed for clean water or light slurries only.
The outcome was predictable:
Understanding the Real Challenge
Most dewatering pumps aren’t built to handle Class 2 or Class 3 slurries, as defined by the Hydraulic Institute. Once the water level drops, they end up surrounded by dense solids and slimes, which quickly destroy seals and motors.
The real challenge is not only finding a more durable pump, but also managing the heavier, more abrasive materials that need to be pumped through existing pipelines designed for water. This leads to:
- Higher friction losses
- Greater pressure and power demand
- Accelerated wear
These are issues that can be solved, but only with the right pumping solution.
The ORCA Solution
At All-Pumps, we’ve developed the ORCA submersible slurry pump range to meet the demands of mine dewatering. The ORCA pump is built to handle high solids concentration and abrasive media while tolerating dry running conditions that would destroy standard submersibles.
Its agitated slurry pump design produces a homogenised mix of water and solids that can be efficiently moved through existing pipelines without the need for costly upgrades. When applied correctly, this approach can eliminate the need for manual “mucking out”, saving both time and labour while improving safety in sump areas.
The trade-off may include replacing pipework periodically, but the long-term savings in maintenance, downtime, and equipment life make it well worth it.
Why Seals Still Matter
Even the best pump will fail if fitted with the wrong seal for slurry conditions. If your submersible pumps are not equipped with heavy-duty slurry seals, they won’t last long underground. Any pump installed in a mine sump will eventually encounter abrasive particles. The question to ask is:
- “Is this seal designed to handle slurry?”
- With the ORCA range, the answer is yes.
Let’s Find the Right Fit for Your Mine
The All-Pumps team can carry out a full audit of your pumping setup to identify where upgrading to ORCA submersible slurry pumps will deliver the most value. We also perform hydraulic design checks to ensure each system operates close to the best efficiency point (BEP).
Our goal is not just to supply pumps but to help you:
If you’re ready to move beyond repeated seal failures, our experts are here to help.
Learn more about our ORCA range and other heavy-duty pumping solutions: