Tag Archives: Marnus Koorts

Weir maps out role in mine dewatering

Environmental, Mining equipment, Water management, , , , , ,

In both open-pit and underground mines, unexpected water ingress can severely disrupt production unless an effective dewatering solution can be quickly applied; some forethought will go a long way in making this happen.

According to Marnus Koorts, General Manager Pump Products at Weir, one of the key challenges is that unplanned dewatering usually requires sizeable equipment to be retrofitted into locations where there is often no infrastructure to support it.

“In many open pits, for example, the voltage in the power network is different to normal motor voltages,” Koorts says. “This therefore calls for the application of transformers to achieve the right supply voltage.”

The underground environment may have its own restrictions, such as the need for any equipment and motors to be flameproofed. It quickly becomes apparent, he explains, that any solutions provider needs not only an in-depth knowledge of the pump duty requirement. They also need to understand the various peripheral equipment that will render the pump suitable for the application.

“Satisfying these elements will allow the challenge to be more effectively addressed, but what about similar incidents in the future?” he asks. “The next important step is to look ahead and ask what the mine will be doing – and where mining will be taking place – in a year from now.”

He highlights the risk that water might be pumped during an emergency to a nearby holding location, where it creates an obstacle for future operations on the mine. With a bit more planning, the dewatering process can ensure that water is removed further away at the outset. This, he suggests, could require the use of booster stations.

“There are not many pumps that can dewater a deep underground mine or open pit in a single lift,” Koorts says. “This means finding suitable places to install booster pumps, and ensuring that the appropriate power supply is available there. This may not always be easy, if certain levels of an operation have been mined out and no longer have active infrastructure.”

With a forward-looking approach, a mine can also identify the depths at which dewatering may be required in two to three years’ time, and when more booster pumps will need to be installed to cater for deeper operations.

“At this point, the situations can start becoming quite complex, and every site demands a highly customised solution,” he says. Among the more innovative solutions, he notes, is the use of pontoons for open-pit mines – with technology to automate their operation. A pump mounted on a pontoon can be positioned in an open pit, and can float if the area starts to flood. Fitted with the relevant sensors, the pump will pick up the rising water levels and begin dewatering.

“The pontoon solution is also useful for emptying holding dams, especially since it can draw water from the middle of a dam, where it is cleaner and easier to pump,” Koorts explains. “Of course, the quality of the water will determine the pump type to be employed, as clean and dirty water present very different demands for a dewatering pump.”

“In the SADC region, a diamond producer procured a bespoke dewatering solution to facilitate the removal of accumulated water in the pits,” Koorts says. “This was achieved through a series of diesel-powered booster pumps, enabling uninterrupted operations throughout the rainy season. Another example is a copper producer in Central Africa that procured a bespoke solution to aid in the dewatering of surplus water accumulated during their operations. This measure not only complied with their environmental commitments but also ensured the safe and sustainable relocation of water away from operational areas.”

He concludes that customers can save considerably on finding the right solution in advance. With pumps such as Multiflo®, Warman®, Envirotech® and GEHO®, Weir can contribute in-house design capacity and niche expertise, even in less familiar fields such as buoyancy, the company says.

Weir rubber linings excel in large particle abrasion pumping applications, Koorts says

Comminution of minerals, Equipment maintenance, Mining equipment, Mining services, Mining software, , ,

Weir says it has found that its customers dealing with large particle abrasion in their pumps can save significantly on components and maintenance downtime by using rubber linings.

According to Marnus Koorts, General Manager for Pump Products at Weir, these linings excel in applications where particles are being driven by a great deal of energy.

“Rubber is very good at absorbing and transferring the energy from moving particles , whereas metal liners are more readily worn away by those impacts,” Koorts says. “This makes rubber linings ideal on the larger mill pumps and similar applications, which is where our customers get optimal value from this solution.”

He notes that Weir has spent decades developing its elastomer technology and trialling it in the field, giving it considerable advantage over competitors – many of whom have only recently begun introducing rubber lining on their pumps.

“We have helped customers to deal with some of the most abrasive applications to be found in mining,” he says. “These conditions are commonly found where hard rock is mined, crushed and milled, and the coarse particles leave the mill to be pumped further. Among our case studies are installations where the pump’s wear life was improved significantly after it was lined with rubber.”

Another benefit of using rubber in these large pumps is that it is relatively lightweight compared with unlined metal pumps, enhancing safety and easing maintenance of rubber parts.

“A mill pump is a mission-critical item of equipment, so maintenance really needs to be as fast and infrequent as possible,” Koorts says. “The whole plant process often comes to a halt when the mill stops if there is no standby pump, what we call a Service Class 5 pump.”

Replacing a rubber lining on a pump can be done quickly, and less often – giving the plant optimal uptime. He points out that this also provides a higher level of safety against the risk of particle wear actually breaking through the shell of the pump. In cases where these incidents have occurred, the high pressure inside the pump can spray slurry up to a couple of hundred metres – presenting considerable safety and environmental hazards.

“Where the rubber lining is present, it is encapsulated by a metal shell for added support,” he says. “Maintenance planning can be enhanced by using Weir’s Synertrex wear monitoring technology, which would alert the operators to the need for parts replacement, avoiding failures.”

He highlights that many of Weir’s pump ranges are available with the option of either rubber or metal liners. This has allowed many customers to easily trial the rubber lined option, as this can be done through a simple swap-in process during the plant’s shutdown period.

“We’ve seen a definite shift in the mining industry towards rubber lining on pumps, as mines recognise their value in these applications,” he concludes. “This is also a time when mining companies are starting to consider their upstream and downstream carbon impact. They can gain from the lower carbon footprint associated with rubber linings compared with steel.”

Weir Minerals Africa provides tailings management flexibility with mobile pumphouses

Bulk handling, Mining equipment, Mining services, Water management, , , , ,

Weir Minerals Africa says its mobile pumphouse is ideally equipped for the needs of mine tailings operations.

As the company explains, pumping slurry to tailings facilities requires a solution that can move as the dam expands to allocate room for additional tailings.

Weir Minerals Africa Pumps Product Manager, Marnus Koorts, says a mobile pumphouse completely avoids the cost of any civil engineering for permanent on-site pump buildings. “Instead, it is designed to be moved as required across the site, using its own specifically engineered, skid and jack-and-roll elements,” he said.

Koorts says the offering is part of Weir Minerals Africa’s engineered-to-order solutions, which also reduces the long-term total cost of ownership. The three-point Warman® Multiflo® pump mounting system allows the base and skid to act independently. This minimises the risk of misalignment between the pump and motor shaft during operation and relocation. The unit incorporates an integral gland water supply system and a separate electronic house for power control and remote communication.

Koorts highlights that as a mine’s process plant matures, the tailings line grows with new tailings dams being created, often using Linatex hoses and Isogate valves. It is a significant advantage to be able to move the pumphouse, and to add pumps to the tailings line if the increased distance requires more pressure. It is also an important contributor to reducing initial capital costs.

The design of the mobile pumphouse, he emphasises, sets a new standard for tailings management applications, providing the customer with the tools and equipment to rapidly reconfigure their pumping network, with the ability to move it to other sections of the tailings pond.

Weir Minerals solutions include Multiflo pump barges and floating pontoons mounted with Warman SHW submersible slurry pumps for extracting the fluid tailings. Its Warman slurry pumps are ideal for boosting recovered tails from the pond, to drive the new tailings treatment process plant, the company says.

Koorts emphasises that, with increased scrutiny and pressure to improve the management of tailings, it is more important than ever to look at different methods that are innovative and fit-for-purpose.

Weir Minerals continues to go with the Multiflo in barge applications

Environmental, Mining equipment, Mining services, Sustainable mining, Water management, , , , , , , , , ,

Even with 40 years of custom barge solution expertise under its belt, Weir Minerals says it is continuing to innovate with new designs for applications in oil sands, tailings management and tropical and cold climates.

Developed over the decades, the Weir Minerals range of Multiflo® barges provides a solution for numerous applications, according to the company.

Water reclamation for oil sands market

Reclaim water barges are an integral part of tailings management solutions in oil sands applications, where tailings contain high percentages of water that can be recycled back through the process plant.

Upon identifying the need for reliable systems which were easy to manage and maintain, Weir Minerals developed its mega-barge exclusively for the oil sands market. This all in one package includes pumps, valves, hoses, and piping.

“This is where our turnkey value proposition really took off,” Kris Kielar, Product Manager for engineered-to-order dewatering products at Weir Minerals Canada, explains. “Our largest barge system includes a fully integrated electrical control houses that powers 9,000 hp (6,711 kW) worth of pumps, overhead cranes, remote monitoring and control, and the longest floated walkway we’ve ever provided, with ‘warm-up’ stations every 150 m for one kilometre.”

Mega-barges are the ideal solution for unique applications, such as the scale of water reclaim needed at some of the world’s largest oil sands operations, according to Weir Minerals.

“A typical oil sands operation requires nine barrels of water per barrel of bitumen produced,” continues Kielar, “so the more water that can be reclaimed, the better. The larger the operation, the bigger the water saving potential.”

In addition to the mega-barges for the oil sands market, Weir Minerals also developed modular barge packages as a fully customisable solution for ease of shipment, and a reduction in both capital costs and onsite installation costs. The introduction of both static and mobile, land-based, booster stations and pumphouses further expands the Multiflo barge solution capability while maintaining a single point of contact for customers, the company says.

Tailings management

The need for custom barge solutions for tailings management has increased in recent years. Where previously dewatering pumps in tailings applications were “set-and-forget”, the increased focus on tailings dam safety has shined a new spotlight on barge solutions that can provide heavy-duty, reliable pumping, Weir Minerals said.

Not only must sites revisit current arrangements to consider how their tailings will be handled in the future, they also need to empty the old dams decommissioned by environmental and mining authorities, the company said.

Ricardo Menezes, Barge Systems Specialist at Weir Minerals Brazil, said: “We are equipped to provide the entire solution. From initial consultation and design, to manufacturing, commission, and training and supervision of site operators. We work hard to bring our customers the best possible solution for their site, and we do it all under one roof.”

These all-in-one Multiflo packages eliminate the headache of integrating civil construction, electrical control rooms, control systems, pipes, cables, and mechanical and electrical works, according to the company. Weir Minerals engineer these dewatering barges in-house and employ naval engineering consultants to create tailored solutions for its customers.

Menezes continues: “Sites are being asked to transport tailings on a larger scale than before. An off-the-shelf solution might not work with their existing site infrastructure and that is where our fluid transport expertise comes in.”

Reliability in any situation

Applications in tropical environments, which experience heavy and sometimes unexpected rainfall, often require barge-mounted dewatering pumps to handle the rapidly rising water levels.

Multiflo land-based barges are built to float, protecting the pump unit from being flooded as often happens with a traditional skid pump unit, Weir Minerals says.

These land-based barges are fitted with integrated skid runners that allow them to be towed around mine sites and launched or retrieved with the use of dozers or excavators. The integrated skid runners also provide the added benefit of using the barge as a skid pump operating at the pond edge with easy land access for operators and servicing, the company says.

Marnus Koorts, Product Manager for dewatering pumps at Weir Minerals South Africa, says the company gets very specific requests for these land-based barges.

“We recently completed a project for a customer experiencing regular high wind speeds and tropical storms,” he said. “We needed to account for wave action and wind loading to ensure our solution would minimise risk of structural damage during these storms.”

Other considerations such as water quality, where pH can range from very low through to high, and water content, such as high percentages of suspended solids and floating debris, are also key to maintaining dewatering equipment on site, according to the company.

“Multiflo barges maximise reliability through innovative protection systems chosen specifically for the environment that the barge will operate in,” Weir Minerals says.

For one customer in South Africa, the Weir Minerals team needed to account for more than just water, according to Koorts.

“One of the design requirements for this particular installation was for the handrails and other structures to be engineered to prevent crocodiles from gaining access to the deck space.”

Dewatering in cold climates

In the last year, Weir Minerals barge specialists from Canada have been working with teams in Russia and Finland, to establish a European centre of expertise specifically for dewatering barges in cold-climate applications. Key environmental factors such as wind, snow and seismic loading can affect the buoyancy and stability of the barges, which they looked to address.

“We’re building on the work of the North and South American teams,” Artem Filippov, Dewatering Product Manager at Weir Minerals Russia, said. “Working together and using insights gained from their years of experience have allowed us to create unique barge dewatering systems for our European customers.”

Weir Minerals’ cold-climate expertise comes from experience in floating barge systems at temperatures below -45°C, de-icing systems and winter barge access systems. In addition, Multiflo barge systems are fully marine naval certified under all weather conditions and are marine architect certified, the company says.

Weir Minerals solves ‘dirty water’ fluid transfer problem with Warman DWU pump

Environmental, Mining equipment, Water management, , ,

As IM goes to press on its March print issue and a feature on dewatering, sector leader Weir Minerals is stressing the importance of using a fit-for-purpose pump that can handle “dirty water”.

While the market offers specialised slurry pumps to handle thick and abrasive slurries, as well as submersible and sump pumps for pumping clean water, neither of these options provide an effective solution for pumping dirty mine water, Weir Minerals says.

The company has leveraged its extensive knowledge of pumping slurries and developed the Warman® DWU (Dirty Water Unit) pump, designed to handle both increased suspended solids in dirty water while operating at high discharge head pressures.

“The introduction of, and subsequent clogging from, suspended solids is one of the most common causes of premature failure in a dewatering pump,” Weir Minerals says. “‘Upset’ conditions during the underground mining process are the general cause of increased suspended solids levels entering the mine’s dewatering discharge water.”

The Warman DWU pump combats both these challenges, transporting the dirty mine water to its designated discharge point via single (140 m), multi-stage (480 m) portable, or permanent pumping solutions, the company says.

‘Dirty water’ is the name given to water with too high a percentage of suspended solids to considered be ‘clean’, but too low of a percentage to be classed as slurry, Weir Minerals says. “Dirty water becomes a problem onsite when the solids concentrate inside a dewatering pump collects around the motor frame, overheating the pump and causing the motor to fail.”

The Warman DWU pump is, Weir Minerals says, specifically designed to handle dirty water from onsite ponds and open pits with specific gravity of up to 1.05. Where a pump built to handle clean water will fail once dirty particles are introduced, the DWU pump will not, according to Weir. “That is because the DWU was designed using computational fluid dynamics and utilises Weir Minerals’ advanced material technology, allowing the DWU pump to process the fluid efficiently and minimise pump maintenance in the long run,” the company said.

Marnus Koorts, Product Manager for Pumps at Weir Minerals Africa, said: “In most circumstances, high-head clean water pumps will fail when they are required to process even a minute amount of particles. Once you have greater than 1% of particles, a site’s only other option is to install slurry pumps.”

Slurry pumps are commonly used to address the dirty water problem, but this solution is costly and inefficient, according to Weir Minerals.

“Without a specialised dirty water pump like the Warman DWU, up to three slurry pumps need to be sourced, installed, and maintained just to pump the dirty water as far as a single Warman DWU pump can,” the company said. “The pump utilises a new high-pressure casing to withstand pressures up to 7,000 kPa, enabling it to pump operating at maximum speed and achieve a head of 140 m at the best efficiency point.”

Koorts summarises: “This results in a lower total ownership cost and reduced downtime for the customer while providing them with increased efficiency and energy savings over using slurry pumps in the same application.”

The Warman DWU pump provides a solution to a fluid transfer problem that can quickly affect an entire operation, according to Weir Minerals. “By making use of the latest Warman WBH® mechanical end design, customers benefit from 90% common component interchangeability, allowing them to reduce stockholding of spares,” the company said. “In addition, the Warman DWU pump is available with either an electric or diesel motor and can be mounted on either a pontoon, skid, or trailer, which provides sites with the flexibility to move the pump around to where it’s needed.”

Koorts said: “Pontoon mounting an electric DWU pump allows for series pumping at base level or stage pumping out of an open pit. With Weir Minerals’ dewatering expertise we’re able to engineer a complete solution that places the suction end of the pumps into the water, while the pump and motor are mounted at an angle above the water line. This keeps the suction end of the pump submerged and eliminates suction problems. With a diesel driven pump, we install a vacuum assisted priming system that reprimes the pump when needed.

“Essentially, customers can set and forget.”

The Warman DWU pump provides a flexible dewatering solution to sites, not only in the portability around site, but in the range of fluids the pump is built to handle, Weir Minerals says. “In the nine years the pump has been on the market, Weir Minerals engineers have continued to improve the DWU’s capabilities.”

Although designed to handle dirty water, the Warman DWU pump is also able to process clean water with 78% efficiency, and the addition of a stainless-steel casing means the DWU pump is now suitable for highly acidic applications (pH >2), according to Weir Minerals.

Weir Minerals Africa optimising pump performance for filter presses

Mineral processing, Mining equipment, Water management, , , , , ,

With mining companies focused on reducing and recycling as much water as possible while recovering valuable minerals and metals, filter presses are becoming a much more common sight in the concentration process.

Weir Minerals Africa says these “mission-critical” filter presses demand a carefully selected pump to ensure optimal performance and uptime.

Marnus Koorts, Product Manager for Slurry Pumps at Weir Minerals Africa, says the high pressures associated with operating a filter press often lead the pump to underperform.

“The operation of a filter press involves a wide spectrum of pressure and flow conditions within each cycle,” Koorts says. “This ranges from high-flow, low-pressure conditions when slurry is initially being pumped into the press, to low-flow and high pressure when full.”

He emphasises it is not enough to simply specify a pump for the average of this range of conditions. Rather, it is vital to establish the minimum and maximum values on the spectrum, and to specify accordingly.

“Filter presses in the market can demand pressures of up to 45 bar,” he says. “In many cases, therefore, the application requires high-pressure pumps such as the Warman AHPP high pressure range.” These pumps offer multi-stage high pressure operation to 1,000 psi and are used in slurry transportation and tailings management operations.

Koorts continued: “Where lower pressure requirements are present, the newer technology of the Warman WBH could be used as it is generally a more efficient pump with longer wear life of spare parts.” The Warman WBH pumps, also used in slurry transportation and tailings management applications, come with a wide variety of impellers and shaft seals and maintains efficiency through ‘one point adjustment’ during the wear cycle, according to Weir.

Failure of pumps to deliver enough pressure to a filter press results in the solid-liquid separation process being inefficient, according to Weir, with the selection of the right pump an important starting point in ensuring optimal operation.

The next key aspect of the customer’s selection, Koorts says, is the choice of sealing arrangement. This aspect of the pump can often lead to issues in the plant, when valuable product is lost through leakage.

“An expeller seal is not usually recommended, as the pressure it generates to seal the pump is generally not sufficient in a filter press application,” he said.

Weir said: “The stuffing box option can be used under certain conditions. However, the pressure of the surface water needs to be higher than the pressure inside the pump. This means that it would usually be suitable on a low-pressure pump for a low-pressure filter press.”

Koorts added: “When the filter press requires a higher pressure, then the plant will have to provide a water line with a higher pressure to feed the gland, or it will not seal properly.”

The preferred sealing option is a mechanical seal for these applications. While this is more costly, it offers substantial savings by preventing product being lost and downtime being incurred, according to Weir.

A further consideration is the level of corrosive aspects of trace elements in the slurry. This can lead to rapid corrosion of mild steel pumps. This is why many applications require stainless steel options.

Comprehensive technical backup needs to underpin each step in this process, Koorts said. For Weir Minerals Africa, this begins with its local manufacturing process, which includes foundries for casting components, through to local componentry manufacture and assembly capability.

“This quality control and capacity feeds into our spares availability and service exchanges for refurbished pumps,” he says. “The result is quick supply through our strategically located branch network with 12 offices in South Africa and eight through the rest of Africa.”