Tag Archives: Warman

Weir Minerals addresses pump impeller and throatbush wear life

Equipment maintenance, Mineral processing, Mining equipment, Mining maintenance, Precious metals, Water management, , , , , , , , ,

Weir Minerals says its Warman® Wear Reduction Technology (WRT®) impellers and throatbushes for slurry pumps can help miners reduce operating expenses through improved efficiency, reliability and wear life.

An upgrade compatible with all Warman AH®, M and L series slurry pumps, the streamlined parts offer total ownership cost reductions, according to the company.

Warman WRT technology is the culmination of decades of research into the wear patterns and hydraulic performance of the Warman AH pump’s impeller and throatbush, the company explained. Together with a unique vanelet on the back shroud, replacing the five-vane impeller with a modern four-vaned design improves fluid guidance through the pump and represents a step change in impeller design, it said.

This technology has already proven its worth in the field, such as at Blackham Resources’ Matilda gold mine in Western Australia. Here, the installation of Warman WRT technology more than doubled impeller wear life in a demanding application involving abrasive, highly viscous slurry, Weir Minerals said. The new impeller and throatbush reduced total ownership costs for the pump by A$27,000/y ($19,117/y) due to the parts’ higher efficiency and longer wear life.

Marcus Lane, Global Product Manager, Centrifugal Pumps, said: “What I love about our Wear Reduction Technology is how it improves on everything our customers expect from the iconic Warman AH pump range.

“It uses best-practice design techniques leveraged by the world’s top slurry pump engineers to maximise hydraulic efficiency and reduce operating costs without increasing the pump’s complexity. Its advanced wear materials improve reliability and reduce time spent maintaining the pump.

“It simply makes the world’s most famous slurry pumps even better.”

Not only do the hydraulic refinements lower the pump’s lifetime consumption, but they reduce the net positive suction head requirements of the pump, making the upgrade an ideal way to compensate for process or feed changes which have left a Warman AH pump overtaxed, the company said.

“I’m so proud of the way Warman constantly innovates for existing customers,” Lane said. “Retrofitting WRT technology into an installed pump couldn’t be easier – next time you need to replace your impeller and throatbush, simply install the Warman WRT parts instead. Nothing changes in your setup, fitment, or general maintenance practices. The pump doesn’t need a speed change and the entire process uses existing maintenance tools.

“Really, the only thing that changes is that your pump is now a lot better at its job.”

New Weir Minerals Sand Wash Plant to boost recoveries

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Weir Minerals has released a complete sand wash solution that draws on its long experience in the sand and aggregate industry.

The Weir Minerals Sand Wash Plant comes with Linatex® lining, produces more saleable product than conventional sand screw plants, with fewer moving parts, and has an optimised process that produces a drier, higher-quality product with less fines, according to the company.

The solution has already proven effective at sites like Coimbatore Minerals in Tamil Nadu, India, Weir says, where a custom-built wash plant reduced its total cost of ownership by 51%, while offering a 23% reduction in fines that helped the company consistently meet the industry’s high standards for a saleable product.

Bruce Cooke, Global Product Manager – Sand Wash Plants for Weir, said: “We know the most important thing for quarry operators in washing is recovering as much sand as possible to maximise their sales, which is why we’ve designed an integrated solution for washing their product, with a hydrocyclone which can deliver greater recovery than sand screws. In addition, every component has been selected by our expert engineers for its long-service life, interoperability and ease of maintenance.”

The compact solution features a range of Weir Minerals equipment designed for high efficiency in sand and aggregate applications, including Warman® WGR pumps, Cavex® hydrocyclones, Enduron® dewatering screens, Linatex hoses and Isogate® knife gate valves.

The Warman WGR is a popular pump in the sand extraction industry, according to Weir, combining top of the line hydraulic design with an adjustable impeller, long bearing life and a simplified wet end, making replacement predictable and cost effective.

Precision moulded and lined, Linatex premium rubber is used for wear zones throughout the plant due to its proven wear performance in wet sand applications in operations around the world, Weir said.

Cavex hydrocyclones provide “exceptional classification efficiency” thanks to their unique 360° laminar spiral, delivering more saleable product than a sand screw solution would, the company said. Enduron dewatering screens, meanwhile, reliably separate product with a high degree of efficiency. And, finally, Isogate knife gate valves contribute to the plant’s straightforward maintenance.

Surendra Menon, President, Weir Minerals India, said: “For the new sand wash plant, we focused on making it quick and easy for quarry operators to get up and running. Its straightforward design means it can be assembled in just two days while its compact skids make it easy to drag into any operation.

“Efficient, reliable and easily integrated into flowsheets, we think the plant is a game changer for quarry owners.”

Weir Minerals looks to keep slurry moving with new lubrication system

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Weir Minerals has announced the global launch of a new lubrication system that, it says, can prevent bearing assembly failures, reduce maintenance downtime and promote safety.

The launch of Accumin™ lubricators follows international demand for the grease lubrication that has been ensuring optimal performance for equipment such as Warman® slurry pumps in Asia Pacific since 2014, Weir said.

Across more than 100 sites, the Accumin lubrication system has proven itself an efficient way of preventing expensive bearing assembly failures, reducing maintenance downtime and promoting safety by decreasing the amount of manual interface to keep equipment performing, the company said.

Making the move to Accumin lubricators helped one Australia iron ore mine save almost A$120,000/y ($73,705/y) in downtime reduction, pump rebuilds and bearing assembly replacements, Weir explained.

Michael Roinich, Accumin Specialist, Weir Minerals, said: “At Weir Minerals, we make the market-leading slurry pump for mining applications, but we can’t always control what happens when it gets to site. Between dust, overflow and gland seal leaks, lubrication is a vital tool in the constant battle to keep machinery going. Having an Accumin lubrication system fitted prevents over and under greasing, protects equipment from bearing failures and frees up man hours for more critical tasks.

“When we offer Weir Minerals equipment with an Accumin lubrication system installed, what we’re really doing is giving that equipment its best shot at a long and productive working life.”

Made in Germany, Accumin canisters are produced in 125 cm³ gas driven; 120 cm³, 250 cm³ and 500 cm³ electro-mechanically driven configurations, and can be deployed up to five metres away from the lubrication point, allowing easy and efficient access to the mount, Weir says. The electro-mechanical driven lubricator dispenses a consistent dosage of lubricant, regardless of ambient temperature. The system delivers 6 bar of operating pressure and can be monitored via an LCD display, flashing LED alert system and a transparent grease cartridge.

Roinich added: “Designed to meet the arduous demands of the mining industry, Accumin single-point lubricators set the global standard for lubricating Warman pumps and other grease-lubricated, mission-critical mining equipment supplied by Weir Minerals.

“We’re excited to share our market-leading, best-practice system with mines around the world who are embracing new technologies to simplify their operations.”

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

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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 Pumped Up by new dewatering game for miners

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Weir Minerals says it has created a “fun and simple game” to educate its customers on the OEM’s dewatering capabilities.

Pumped Up! uses a variety of Weir Minerals dewatering equipment to move water around a fictional mine site, according to Ian Ross, Global Product Manager for Dewatering at Weir Minerals.

Each of the 10 levels present players with a different dewatering obstacle to overcome, from recycling, to flooding, to underground mines and long distance pump requirements. Levels increase in difficulty, and the number of points awarded is determined by how long each level takes to complete.

Products included as part of Weir Minerals’ dewatering solution in Pumped Up! include Warman®, Geho®, Floway®, and Multiflo® pumps as well as Isogate® and Delta® valves, and Linatex® hoses.

The game was released as part of Weir Minerals’ 2019 Take Control Of Your Water dewatering solutions campaign. Through articles, expert profiles, and case studies, the campaign demonstrates how Weir Minerals use its engineering and project management capabilities, together with a wide range of equipment, to deliver an optimised dewatering solution unique to every customer site, the company said.

Head to www.dewateringsolutions.weir to play the game.

Weir Minerals confronts froth pumping problems

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As miners look to reclaim more minerals from the flotation process through froth pumping they are potentially exacerbating existing problems in their circuit design, according to Les Harvey, Regional Product Manager for Slurry Pumps at Weir Minerals.

Mining companies are making these moves to counteract declining ore grades, but, occasionally these techniques are deployed without making allowances for the design of the mine’s froth pumping equipment.

Froth pumping remains one of the most complex engineering challenges in minerals processing, as air management issues in the hopper, sump and pump itself lead to inefficient pumping, increased maintenance and even lost product, according to Weir.

“We’ve started to notice a pattern among our customers who are having trouble with their froth pumps,” says Harvey. “By using more flocculants and other chemicals designed to improve mineral recovery, they’re exacerbating existing problems in circuit design and reducing the returns they’re looking for.”

Close examination of the froth’s makeup and physical qualities is often needed to resolve issues. Ensuring operators’ froth handling equipment adheres to best design practices is an important first step in resolving problems, according to Weir.

Maintaining pressure in the pump

The key challenge in froth pumping is dealing with air in the pump itself, as it tends to naturally centrifuge into the impeller’s eye where it builds up into an ‘air lock’ which impedes the movement of slurry through the pump, Weir said.

In addition to reducing the pump’s efficiency, the air build up in the pump will reduce the flow through the pump and increase the slurry level in the suction hopper. The increased slurry level may push the pocket of air through the pump, causing surging and excessive vibration which can damage the pump bearings, impeller and shaft.

“The best way to manage air in a froth pump is to invest in a froth pump with a Continuous Air Removal System (CARS), which we have in our Warman AHF, MF and LF pumps,” Harvey says.

CARS allows air to move from the pump’s impeller eye to an air collection chamber in the back through a vent hole in the impeller. From that chamber, a flow inducer removes the air from the pump through a vent pipe.

Harvey said: “It’s also important to position the pump’s discharge pipe at the top of the pump, or at a 45° angle as this will give air trapped at the top of the casing a way to escape the pump.”

Solving problems in the sump and hopper

A persistent problem Weir sees is when hoppers designed to meet the demands of slurry pumping are used in a froth pumping application, Harvey said. “Slurry hoppers require turbulence to prevent the mineral content from settling, while turbulence in a froth pump prevents the air from escaping and leads to blockages.”

Tanks designed for froth pumping promote continuous circular movement, where solids and liquids are sent to the outside of the sump for further transport while air centrifuges into the centre where it can be removed. This ‘whirlpool’ movement can be encouraged by introducing the slurry from the top of the tank at a tangential angle, according to Weir.

Conical designs, rather than those with a flat or rounded floor, further improve the flow of minerals and froth into the pump, the company added.

Smooth sailing from the tank to the pump

To prevent blockages, the intake pipe which links the tank to the pump should be large diameter and slope downwards towards the pump, according to Weir. This design allows escaped air to separate and travel back up the pipe where it can escape from the sump, rather than build up into blockages.

Harvey said: “The shorter your intake pipe, the harder it is for blockages to build up. However, in addition to a maintenance spool and isolation valve, it’s a good idea to leave enough space for a water injection port, which is useful for flushing out any solids build up.

“To make maintenance easier, a dump valve can be included on the suction side of the pump, between the pump and the isolation valve. This will allow you to drain slurry from the pump and discharge pipe system when stopping the pump for maintenance.”

Understanding tenacious froths

Froths are often classified as either brittle – with large air bubbles that break easily – or tenacious – where air forms tight bubbles around minerals and is difficult to separate. Froth being more tenacious than was accounted for is a frequent cause of blockages as air cannot effectively be removed, Weir says.

Harvey said two things are happening in the market today: One, mine operators are grinding the product much finer than before to liberate more from the waste rock. Two, they’re using flocculants that produce much smaller bubbles which lock up the air a lot more than brittle froths.

“We’re working together with customers to find ways to manage these more tenacious froths, by looking at their circuit design and dealing with areas where the air could accumulate and block the system, paying particular attention to their pumps, pipes and sumps,” he said.

Weir Minerals takes a load off slurry pump maintenance

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An often-overlooked component, lifting tools help keep workers safe, maximise equipment life and can reduce pump rebuild times, according to Weir Minerals.

These tools have become increasingly important for handling slurry pump parts during maintenance as processing equipment has become larger and larger.

David Russell, Trials Manager for Weir Minerals Australia, says: “We have a duty of care to our customers to ensure they remain safe when operating and maintaining our equipment. Adopting our uniquely engineered lifting tools for our slurry pumps mean that when the correct procedures are followed, it’s very safe.”

It was only in the 1990s when a Warman® AH® 20/18 pump, was one of the largest available on the market. Now, it is regarded as a medium-sized model, outdone by the likes of the Warman® MCR® 760 pump.

Weir said: “As equipment has rapidly increased in scale over the past couple of decades, Weir Minerals has developed specially engineered tools to safely disassemble and reassemble machinery, reducing the risks associated with lifting components.”

In the case of slurry pumps, Weir Minerals’ range of lifting tools are designed for use when performing wet-end overhauls. Specific lifting tools are used for impellers, throatbushes, suction covers, frame plate liner inserts, stuffing boxes, casings and volutes.

These tools have also been designed to lift multiple components together to make rebuilds easier and quicker. For example, a lifting beam has been developed that lifts a suction cover squarely with the throatbush still attached to it.
“Using purpose designed assembly equipment in accordance with OEM lifting procedures can reduce rebuild time, in some cases by up to 50%, leading to increased plant uptime and availability,” the company said.

Russell said: “When lifting pump parts weighing more than two tonnes in restricted areas, there is little room for error. Often, the components will be worn and it is crucial they can still be secured and lifted safely in accordance with the strict global standards that Weir Minerals adheres to.”

When designing lifting equipment, Weir Minerals says it also carefully considers the mechanical strength and the stresses placed on the components being lifted, since worn parts are likely to be weaker and more brittle than new parts.

When it comes to impeller lifting tools, some competitors may employ a simple hook design, increasing the risk of the impeller falling off. Weir Minerals has developed a tool with a fixed locking jaw so that the impeller eye is locked in position and the component is properly secured prior to being lifted, the company says. “This positive engagement across two points of contact ensures that components are lifted evenly and securely with minimal risk of injury,” it said.

Independently certified in each region, the tools are manufactured and sold to meet local health and safety requirements, according to the company.

Joel Goodwin, Weir Minerals’ Aftermarket Manager for Warman pumps, said: “Safety is central in everything we do at Weir Minerals.

“We are an OEM supplier who complies with global safety standards and we adopt a stage-gated development process incorporating risk assessments and product stewardship best practice for equipment design and lifting.”

Weir’s Warman AHF slurry pumps cut through the froth in South Africa

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Weir Minerals’ Warman® AHF pumps have been put to the test at two mines in South Africa’s Limpopo Province, the company said.

The pumps were tasked with pumping frothy, high density and viscous slurries at the platinum and phosphate mines.

Weir said: “Handling froth in some process circuits can be very challenging, as froth will air-bind a conventional slurry pump. In froth applications, the Warman AHF inducer impeller solves this problem, producing far less surging. The inducer impeller and oversized inlet enhance the movement of the froth, high density or viscous slurries into the impeller, facilitating effective transportation.

“In addition, its higher efficiencies mean a smaller pump will deliver the required results.”

At the platinum operation, a Warman AHF 2 pump was commissioned in early 2016. It has met the specified flow rate of 40 m3/h with no pump-related stoppages, repairs or replacements, according to Weir.

A 12-month trial period showed the unit saved the mine over R200,000 ($14,153) when compared with the cost of the competitor pump installed previously. Based on this, the mine replaced another eight competitor products with Warman AHF pumps, Weir said. It has approved the Warman AHF 3 pumps as standard for all frothy applications at the plant’s first flotation section, and Warman AHF 2 pumps for the second flotation section, the company added.

The Warman AHF pumps – with Hi Seal® expeller (dry gland) design – were also tested in a viscous slurry application at the phosphate mine in Limpopo for six months. According to Weir, they demonstrated they could continuously pump the high-density viscous underflow slurry at relative densities above 1.9. “As a result, the customer purchased the pump and began upgrading all the remaining concentrate thickener underflow pumps to the Warman AHF pump technology,” Weir said.

This reduced the plant’s operational costs significantly, decreased dewatering and concentrate moisture extraction operations, improved filtration efficiency and increased concentrate throughput to the dryers, according to Weir. The Warman AHF pump also extended the underflow pumping boundaries and the overall reliability of the thickener underflow pumping system.

“Other field and laboratory tests have proven that the Warman AHF pump has largely overcome the problem of high-density viscous underflow slurries, with negligible effects on head at slurry yield stresses up to 200 Pa,” the company said.

Jacques Pretorius, Weir Minerals Africa’s Pump Product Development Specialist, said the approach to solving any thickener underflow pumping problem must be based on a thorough understanding of the entire application, the mineralogy and rheological behaviour of the slurry.

“Successful thickener underflow pumping projects are only achievable through involving a team of thickener engineers, pumping engineers and rheological consultants,” he said. “Weir Minerals’ pump trial campaigns confirm the successful operability of the Warman AHF pumps in viscous slurry applications.”

Weir Minerals Africa’s expertise pays off for Rio mineral sands mine in Madagascar

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Weir Minerals Africa has come to the rescue of Rio Tinto’s QIT Madagascar Minerals (QMM) operation, providing the mineral sands miner with a solution to its recurring process pond challenge.

According to Weir Minerals Africa’s Dewatering Product Specialist Neil Matthews, the mine was experiencing continual collapse of the 20 m suction hose to the Warman® AH® 12/10 pump mounted on a skid at the back of the process pond. This resulted in the need to keep priming the pump and, therefore, regular downtime.

“Unpacking the issues facing the customer was the first part of upgrading the mine’s process water utilisation,” said Matthews. “We discussed several options with the customer after which our dewatering and engineering teams collaborated closely to design a solution. It was vital to carefully consider the problem in the context of the geographic and site conditions, as well as the local fauna and flora.”

To provide the most suitable Weir Minerals products and solutions, the team specified a Warman® AH® 10/8 pump mounted on a Multiflo® pontoon (pictured) with the pump coupled to a variable frequency drive facilitating greater flexibility in dealing with varying site conditions. A second pontoon was fitted with a Warman® AH® 6/4 pump with motor and fixed speed drive as design conditions should remain constant throughout the life of mine.

Both pontoons are connected to a floating docking station which is, in turn, connected to a 20 m walkway fixed to the bank-side landing.

“It is standard practice in most of our pontoon designs to mount the pump sets at 30° to submerge the suction eye of the impeller, thereby ensuring consistent priming,” Matthews says.

One of the most important factors affecting the solution was Madagascar’s weather conditions, according to Weir. This includes regular tropical storms and high wind speeds, which have the effect of creating wave action and wind loading on the pond during storms. The pontoon solution had to accommodate this.

To address the wave action and minimise possible structural damage, the fixed walkway was designed to incorporate a pivot system on the bank landing structure. This allowed the entire assembly, including the docking station, to rotate 90° and still be tied down to the shore during these storms.

Matthews said: “Madagascar is also known for its varied wildlife, including crocodiles, so the design of the handrails and other structures needed to prevent crocodiles from gaining access to the deck space.”

These reptiles would tend to climb onto the deck to bask in the sun, making it almost impossible for staff to conduct routine maintenance. Restricting this access was achieved by closing all the gaps between the handrails and the separate structures.

“Our design took all the site conditions into account, making for better and more predictable operational reliability,” Matthews said. “Both the pontoons and the pumps can now be easily moved for servicing or for securing during bad weather.”

He highlights that Weir Minerals Africa’s team’s experience with mounting pump sets onto pontoons and its extensive process-related knowledge played a significant role in developing the product offering for the customer.

“It was also important for the design engineers to be present during the commissioning process to ensure support,” Matthews concluded.