Miners increasingly seek pumps that can move more water further. Suppliers are eager to oblige.
(Photo: ITT Goulds Pumps)
Deepening Mines Demand Advanced Pumps
Suppliers announce solutions with automation options and that move more water further
By Jesse Morton, Technical Writer
“While solids-handling pumps are already used in a multi-stage format, the increased depth at which they now need to operate necessitates designs to be upgraded for much higher-pressure capability,” he said. “Even so, staged pumping is sometimes required when a single multi-stage pump station still cannot handle the total discharge head.” As pump complexity increases, suppliers are developing automation and advanced controls to simplify operation. “Smart sensors are used to monitor water levels, flow rates, and water quality, feeding data to centralized systems,” Bhabra said.
“At the same time better pump monitoring and control is becoming imperative,” he said. “Pumps with variable speed drives and automated controls help optimize energy use and reduce human intervention, while sensors monitoring pump health can predict when dewatering equipment will need maintenance, reducing downtime and costs.”
To answer tightening environmental regulations, “pump designs are being enhanced to have increased efficiency to reduce power consumption, while maintaining and increasing wear life to reduce the mean time between failures,” Bhabra said. The top suppliers in the space say their pumps help miners efficiently address these common trending challenges as well as others that are more site specific.
PD Pumps for Deeper
Mines
An expert at Weir said replacing multistage
centrifugal dewatering systems
with a single-lift GEHO PD (positive
displacement) pumping system helps
deepening mines cuts costs and increase
efficiencies.
“Assuming the life of mine is more than, say, five years, based on the work Weir has done in the past, at roughly 700 m it begins to make economic sense to consider replacing multistage centrifugal dewatering systems with a single-lift GEHO PD pumping system,” said Job Kruyswijk, manager, integrated slurry solutions.
A multistage system based on centrifugal pumps theoretically seems ideal during prefeasibility stages and is viable to a certain depth and age. “Because they’re built up out of many low-cost items, it is rare that the operator reviews the system and looks to optimize it,” Kruyswijk said.
As the mine deepens, multistage centrifugal pump system complexity increases. Pumping stations and piping is added, and maintenance requirements increase. “This means that the capital costs increase incrementally, while the operational costs accumulate over the life of mine,” he said. “Moreover, as the mine goes deeper, there is an increase in solids entering the system, which, depending on the pumps being used, can increase wear, often leading to premature failure.”
Increased wear and failures incur costs associated with maintenance, inspections, and parts replacement, Kruyswijk said. “These low-cost items and service orders continue to accumulate to the point at which they become needlessly expensive to operate.”
Eventually the point of diminishing returns, which is different for each site, is reached and breached. “Weir has observed that cost overruns are typical when expanding multistage pumping systems, particularly when operating at significant depths,” he said. The overruns can surpass 30% to 45%. “In most instances, this is the result of higher repair and maintenance costs,” Kruyswijk said. Those costs “may at first seem incidental compared to the cost of replacing the entire system with a single-lift system.” Ultimately, however, when combined with the costs of both planned and unplanned downtime they “undermine the economic viability of the multistage centrifugal dewatering system.”
A single-lift system designed around GEHO PD pumps offers a range of benefits, including cost savings and efficiency gains. “A single-lift system basically replaces the core of the multistage system,” Kruyswijk said. “Water is then collected in a central sump, and a single, high-head PD pump pumps it out of the mine in a single lift.” A single-lift system can use the decline used by the multistage system. “However, the best results are achieved if existing vertical access to the surface is available,” he said. The single-lift system could use existing blind shafts, ventilation shafts, hoisting or manway shafts, or boreholes. “Compared with decline access, which is essentially a system of ramps and crosscuts that connect the access points, shaft access means less piping length is needed to reach the surface, reducing costs and potentially determining the project’s feasibility.”
Using a vertical access, as opposed to a decline access, lowers the head requirements significantly, Kruyswijk said. “Power consumption and carbon emissions are around 30% lower for a single- lift system,” he said. “The higher the flow and the deeper the mine goes, the greater these savings become.” Single-lift systems require less maintenance. That reduces “the traffic underground and minimizes the amount of time personnel are required to perform potentially risky tasks, like pump rebuilds, in confined spaces,” he said. It also reduces maintenance costs.
Further, GEHO PD pumps offer key advantages over centrifugal pumps. “Firstly, high-head centrifugal dewatering pumps are typically designed to handle clean water, which means that, as the mine gets deeper and there’s an influx of coarse particles, the pump’s wear life is radically reduced and there’s an increased likelihood of pump failure,” Kruyswijk said. “GEHO PD pumps can handle significantly higher solid concentrates than it encounters in dewatering applications, ensuring greater reliability and pump efficiency,” he said. “GEHO PD pumps can handle slurry concentrations up to 85%, which far exceeds the requirements for dewatering applications.”
GEHO PD pumps are “efficient throughout the entire operating envelope,” Kruyswijk said. “From a sustainability perspective, the required head, combined with the efficiency of the pumping system, dictates the power consumption.” Results vary, but installing a PD pump typically offers “around 20% instant energy cost reductions at the nominal flowrate,” he said. “And during seasonal ingress, these savings can increase to more than 30%.” Thus, as a mine deepens, it is often “cost-effective” to replace complex multistage systems “with a single- lift system, whereby a single PD pump can replace many centrifugal pumps.”
High-volume Pumps Pass
Abrasives
Tsurumi reported mining-class GSZ
pumps are designed for maximum availability.
A mechanical engineer at the company
said the pumps readily handle abrasives
and require minimal maintenance.
“The GSZ Series is designed for demanding
dewatering applications and
features a side discharge to allow easy
passage of abrasives,” Pat Donahue said.
The high-volume dewatering pumps have “discharge sizes ranging from 6 to 10 in. (150 to 250 mm) and from 30 to 200 hp (22 to 150 kw),” he said. “They are equipped with 4-pole, 1,800-rpm motors; or 6-pole, 1,200-rpm motors.” The pumps are made of cast iron and feature “dual silicon carbide mechanical seals,” the company said. Series models also feature “internal thermal motor protection, an anti-wicking cable entrance, and Tsurumi’s exclusive oil filter,” Donahue said.
The impellers are made “of highchrome cast iron to provide the wear resistance needed in abrasive pumping applications,” he said. The 4-pole and 6-pole motors reduce impeller tip speed. “Reducing the impeller speed greatly reduces the wear caused by abrasives in the pumpage,” he said. “The wear plate is designed for simple in-field adjustment to allow for maintaining impeller clearance even after abrasive wear.”
Company literature reports a big gold-silver project in Chihuahua, Mexico, runs its dewatering system entirely on GSZ pumps. The miner switched to the pumps because they offer superior flow and comparatively reduced maintenance. “The Chihuahua plant has about 80 Tsurumi pumps in operation,” Tsurumi said. “In addition to the six GSZ-150- 4 models, the facility employs dozens of pumps from the LH (medium to high flows at high head) and LHW Series (extremely high-head capabilities), including the LH411, LH422, LH6110, LH645, LH25.5W and LH430W.
The pumps were adopted over the course of a decade, as the GSZ pumps simply outperformed competitor units. The GSZ pumps “move large amounts of mud, slurry and gravel continuously, 24 hours a day,” the company said. “The GSZ series is one of the most formidable high-volume submersible pumps available, with capabilities to pump up to 5,000 gpm,” Tsurumi said. “With impeller materials of high chrome and stainless steel, the GSZ series tackles the most aggressive dewatering applications.”
MIP Technology Simplifies
Maintenance
In a prepared statement, PCM highlighted
increasing demand for its Eco-
Moineau MX progressive cavity pump
(PCP) series.
“The MX series is engineered to
handle challenging conditions, particularly
in handling abrasive fluids with
high solid content,” PCM said. Key
design features and future real-time
monitoring capabilities “position the
MX series as a cutting-edge solution
for improving operational efficiency and
reducing both maintenance and energy
costs in mining dewatering.”
The MX pump features a helical rotor-stator configuration that ensures smooth, non-pulsating fluid transfer in tailings removal or closed-pit dewatering applications. With cast-iron body design, the pump also supports high-pressure operation up to 48 bar (696 psi) and a flow rate of up to 2,200 gpm (8,300 lpm) with the ability to clear particles up to 1.6 in. (40 mm). Its Maintenance in Place (MIP) technology “allows operators to replace critical components, like the rotor and stator, without fully dismantling the pump,” PCM said. “This minimizes downtime and operational costs, making it an ideal solution for mining operations that require continuous performance.” Improved uptime can translate to increased production and revenue. “In a recent open-pit dewatering project in Australia, the MX series reduced downtime by 20% due to its easy-to-maintain MIP design, resulting in a significant increase in productivity,” PCM said.
Other benefits offered include energy efficiency gains that translate to improved sustainability. “Unlike centrifugal pumps, which rely on high-speed rotations, PCPs operate at lower speeds while maintaining a steady, consistent flow,” PCM said. “This results in significantly lower energy consumption, especially when handling high-viscosity fluids or abrasive materials.” Reduced energy consumption “helps mining operators reduce operational costs while maintaining high performance,” the supplier said. “The MX series is positioned as a smart choice for customers seeking to reduce environmental impact.”
PCM’s PCP technology traces its history back to 1932, when René Moineau, co-founder of PCM, developed the initial designs. “Over the years, PCM has refined these designs, setting new standards for handling abrasive and viscous fluids, with innovations in elastomers, rotor designs, and pump construction,” the supplier said. Currently, the company “is heavily focused on digital integration and smart monitoring systems for its pumps,” PCM said.
“This will allow real-time monitoring of pump performance, enabling predictive maintenance and reducing the risk of unexpected failures,” the supplier said. PCM is also researching how to further improve the energy efficiency of its pumps, as well as ways “to create even more durable elastomers that can handle extreme temperatures and chemical exposure, thereby extending pump lifespans in the toughest environments.”
The approach reflects “PCM’s commitment to providing customized solutions that meet the unique challenges of its clients,” PCM said. “With decades of experience across various industries, PCM understands that each operation has distinct needs,” it said. “This drives dedication to engineering pumps tailored precisely to the requirements of every customer.”
Portable Pumps Move
Water 1.6 KM
Thompson Pump reported a coal miner
in the Midwest U.S. used 8JSCE and
12JSCG model heavy-duty portable
diesel-powered dewatering pumps to move high volumes of water up to a
mile (1.6 km).
The miner is one of the largest in
the U.S. and the site is believed to
contain 1.3 billion tons of coal. “The
site faces challenges, with ponds and
other materials overlaying the mineral
deposits, making a reliable dewatering
system a critical requirement,” Thompson
Pump said.
Multiple ponds required dewatering. And areas currently under excavation would need to be filled. “This process had to be repeated across multiple ponds throughout the entire complex, as the water was also being used to support the entire mining operation,” Thompson Pump said. “This required high-head and high-volume dewatering pumps,” it said. “They were moving the water over distances of a half mile to a mile (0.8 km to 1.6 km).” The existing pumps “were failing, likely due to the high volume of water,” Thompson Pump said. “And using these lower-volume pumps meant crews were spending a lot of unnecessary time trying to move the water, which slowed down the entire operation.”
The pumps feature Thompson Pump’s Enviroprime compressor-assisted priming system that eliminates product blow-by. The 8-in. (203-mm) pump features flows up to 3,200 gallons per minute (gpm) (12,100 liters per minute [lpm]), high heads up to 300 feet (91 m), and solids handling up to 3 in. (76 mm). The 12-in. (305-mm) pump has flows up to 5,200 gpm (20,000 lpm), high heads up to 350 feet (107 m), and solids handling up to 3.38 inches (86 mm).
“With two of each pump, water soon began flowing more efficiently and quickly,” Thompson Pump said. “To increase capacity even more and cut down on the dewatering time, the team added more pumps, a total of five of each model, and with the system running across the entire mining property.”
The mine site used the system for three years with substantial success, the supplier said. “The pumps’ ability to handle high-head and high-volume dewatering along with their low maintenance and automatic priming, which enabled the pumps to run dry unattended, helped to keep the project on track, on time, and on budget.”