Tag Archives: Weir Minerals Africa

WEIR MINERALS AFRICA BENEFITS AS MINING SURGES

Weir Minerals Africa, part of the LSE-listed Weir Group, is currently performing strongly, more than maintaining its share of the African market and also moving into new geographies on the continent such as Nigeria.

“Overall, we have a healthy order book,” says Rajen Govender, interim Regional Managing Director of Weir Minerals Africa. “The current surge in commodity prices has given a big boost to the mining industry, which has led not only to mine owners pushing up production from existing facilities but also to new projects being approved. As a supplier of a wide range of minerals processing equipment, we’re obviously benefitting from this upturn in activity.”

He adds that Weir Minerals Africa, like most suppliers, is susceptible to the current global shipping constraints which have arisen as a result of the COVID pandemic and other contributing factors but says the company is managing this problem in close association with its customers to ensure minimal impact on their operations.

“These constraints have also led us to look at a greater degree of local manufacture,” he states. “We already have a considerable local manufacturing capability at our Alrode and Isando premises in Johannesburg and our Heavy Bay Foundry in Gqeberha but there is scope for this to be expanded. We have a team looking at the options right now.”

Weir Minerals Africa provides products and systems for slurry transportation, mine dewatering, crushing and grinding, classification and separation, wear lining, corrosion protection and tailings management. Among its world-class brands are Warman®, GEHO®, Cavex®, Enduron®, Trio®, Linatex® and Isodry™. The broad range of equipment available enables Weir Minerals Africa to provide its customers with integrated solutions addressing every part of the minerals cycle.

While the South African market remains an integral part of the company’s business, the rest of Africa is becoming increasingly important and now accounts for over 50 % of the revenue. “We’re seeing good growth in the SADC region and in West Africa, and we can also report a significant turnaround in East Africa and Central Africa, notably Tanzania and the DRC respectively,” Govender notes. “We’re also excited to have secured our first major order in Nigeria.”

The Nigerian order – for an iron ore project – is substantial and has seen the supply of equipment for screening, washing, grinding and pumping. The order includes Trio® jaw and cone crushers and apron feeders, Enduron® vibrating screens, an Enduron® high pressure grinding roll (HPGR), Trio® coarse washers and a blade mill, as well as Warman® slurry pumps. The vibrating screens for the project, which is due to be commissioned shortly, include two massive 51-tonne double-deck banana screens manufactured in South Africa.

Govender says a major focus area for Weir Minerals Africa is sustainability. “When we talk about sustainability, we’re talking about reducing energy consumption, saving water and cutting emissions across every aspect of our operations, including our offices and manufacturing plants,” he explains. “We’re making good progress with this in South Africa and our foundry in Gqeberha, for example, has recently received a divisional award for its water harvesting initiative.

“We’re also, of course, prioritising energy savings in our products, allowing them to run more efficiently and with lower consumption without productivity being compromised.” He adds that the Enduron® HPGR technology can achieve energy savings of up to 40 % in crushing and grinding, which are traditionally amongst the most energy intensive processes in mining.

Govender also emphasises that Weir Minerals has a continuous programme of investment in digital technology and points to its Synertex® Industrial Internet of Things (IITT) platform as a major step forward for the company. It allows data from machines to be captured and analysed, with the major benefits being energy optimisation, reduced maintenance and enhanced productivity.

FULL WATER MANAGEMENT OFFERING FROM WEIR MINERALS AFRICA

Optimising water usage is a priority for Weir Minerals Africa – it is an area that can often be overlooked but contributes significantly to a mine’s Environmental Social and Governance (ESG) drive as well as its bottom line. “Our product and service offering aims to assist mines reduce their overall water consumption while optimising their usage requirements,” says Marnus Koorts, pumps general manager.

He says that when assisting a mine with its water requirements, Weir Minerals Africa’s starting point is to gain an understanding of the mine’s often unique challenges (for example, seepage in unknown areas and water accumulation), evaluate the site which often reveals unexpected outcomes and put together a tailor-made solution designed to integrate into existing infrastructure and resolve the problem areas.

Koorts’ colleague, Christian Stehle, who is head of engineering at Weir Minerals Africa, emphasises that the delivery of such solutions is generated in collaboration with the company’s in-house engineering team, an offering few OEMs provide. “When dealing with water it is important to understand that it is a dynamic situation where changes can be frequent. Our team understand this and know how to manage it with the support of our extensive product range.” 

So strong is Weir Minerals’ engineering capability that it has coined the term ‘engineered to order’ – a phrase that demonstrates its focus on delivering customised integrated solutions. 

The company designs and engineers a full range of dewatering pumps and equipment under well-known brands Multiflo®, Warman®, Envirotech® and GEHO® – suitable for any dewatering, drainage or water transfer application, providing optimum pumping performance in the most arduous conditions in applications all over the world. 

These dewatering pumps are part of Weir Minerals Africa’s extensive range of mine and dewatering products, including Cavex® hydrocyclones, Enduron® dewatering screens, speciality Linatex® hose, Isogate® valves, and tailored Multiflo® pontoons and barges. 

Following a partnership agreement with Andritz, the company also offers the Isodry® brand. This incorporates a range of equipment that has been specifically developed to deliver first class solid-liquid mechanical separation for the mining and aggregates industries including thickeners, filter presses, centrifuges, and vacuum belt filters.

Both Stehle and Koorts confirm that Weir Minerals Africa (together with all Weir Group companies) have, are and remain invested in technology – because this too assists with any sustainability drive, particularly when used in conjunction with water management solutions.

A prime example of the company’s dedication to providing technology-driven solutions is Synertrex® – an intelligent analytics platform that can easily be integrated into existing systems. It helps operations to understand wear rates, forecast replacement part timing and assists in making decisions to improve overall efficiency without unexpected downtime. 

WEIR MINERALS MARKS GREAT DECADE FOR WARMAN® DIRTY WATER PUMP

It has been 10 years since Weir Minerals Africa sold its first Warman® DWU (dirty water unit) pump, with the locally developed and manufactured innovation achieving success in Africa and abroad.

According to Weir Minerals Africa head of engineering Christian Stehle, the Warman® DWU pump was designed to fill a gap in the market between conventional slurry pumps and clear water pumps. It succeeded in combining the best of both pump categories, to create a product with the wear resistance and robustness of the slurry pump and the efficiency of a clear water pump.

“We wanted a solution that would meet the needs of customers who wanted to pump water with a specific gravity of up to 1.05,” says Stehle. “They usually needed to do this over long distances, and often with high heads.”

He notes that the Warman® DWU pump is able to deliver high performance along with energy efficiency and reliability, without being susceptible to high component wear rates and premature mechanical failure due to dirt levels in water.

The first unit was sold in September 2011 to a mining operation in the Limpopo province town of Phalaborwa, and delivered such good results that the customer went on to purchase more of them. As the Warman® DWU pump was marketed through the global Weir Minerals network, it has also established itself in markets as far afield as Canada. 

The range has been enhanced over the years on a number of fronts, including its materials of construction. It is now available in stainless steel and in other hard-wearing materials for acidic applications. Initially developed with the traditional gland seal arrangement, it now includes the mechanical seal and the centrifugal seal as options. 

Modern design tools have allowed a continuous improvement in the evolution of the Warman® DWU pump, he says. With the 3D modelling of complex shapes, as well as 3D printing technology, the application of Computational Fluid Dynamics (CFD) has enhanced progress.

“The success of this pump in as little as a decade is a testament to Weir Minerals Africa’s design and manufacturing capability, as well as our understanding of customer requirements,” he says. “We continue to work closely with customers, turning needs into solutions for a sustainable mining sector.”

ENVIROTECH® PUMPS POPULARITY CONTINUES IN AFRICA 

Underpinning the popularity of Envirotech® pumps is Weir Minerals Africa’s ongoing investment and support, as well as the pumps’ integration into various pumping solutions that the company offers.

According to Marnus Koorts, general manager pumps at Weir Minerals Africa, Envirotech® pumps are especially popular in the gold mining sector, where up to 200 of these pumps can be found on a single site. He says there are three ranges in the Envirotech® line-up, which Weir Minerals Africa acquired in 1994 and continues to develop and support. 

“The Envirotech C5 range of metal pumps has always been a favourite for dirty water applications, and is widely used in mine dewatering,” says Koorts. “Its high pressure capacity of 6900 kPa makes it ideal for high head applications.”

The Alpha range of Envirotech® pumps is rubber-lined to resist abrasion, while the Envirotech® ME pump with metal expeller and Envirotech® MG pump with metal gland are unlined. All the ranges benefit from ongoing research and development, and are available in the various materials of construction offered by Weir Minerals Africa. 

“When selecting and sizing their pumps, customers can choose from our range of metal alloys including our Ultrachrome and Hyperchrome alloys,” he says. “There is also a wide range of rubber linings on offer, from our R55 premium grade elastomer to butyl rubber formulations.”

The technology incorporated into Envirotech® pumps make them a valuable part of Weir Minerals Africa’s engineered-to-order solutions and pontoons, where they are integrated with other products like Linatex® hoses and Isogate® valves. Koorts also highlights that the company’s Synertrex® smart analytics platform can be applied to Envirotech® pumps, for remote monitoring of equipment health.

Among the most important aspects of its expertise that Weir Minerals Africa has applied to its Envirotech® pumps is its Wear Reduction Technology (WRT®), which gives them not only longer wear life but also higher operating efficiencies.

“Many of the Envirotech pumps are now coming out with WRT components as standard,” he says. “This delivers massive value to customers, as the energy saving from the high efficiency is substantial.”

In a recent highly abrasive application, the WRT® impeller in the Envirotech® pump delivered double the lifespan of a replicator’s impeller. More importantly, the Envirotech® pump consumed almost a fifth less electricity each year, saving the user many times more than the value of the component itself.

“We continue to evolve and upgrade the Envirotech pump range in the same way as all our products, giving customers a modern and responsive solution to their pumping needs,” he says. 

The Envirotech® pump range is cast and manufactured in South Africa, and supported through the company’s extensive branch footprint throughout Africa and the Middle East.

NEW 650 MODEL EXPANDS THE INNOVATIVE CAVEX® 2 HYDROCYCLONE RANGE

When the Cavex® hydrocyclone was introduced to the industry over 20 years ago it set the benchmark for the rest of the market. The recently launched Cavex® 2 took this product range a step further with enhanced performance and design. It marked a new era in separation technology, with its LIG+™ advanced laminar spiral inlet and size of the feed chamber, delivering performance unlike any other cyclone on the market.

Now Weir Minerals has expanded the Cavex® 2 product line with the introduction of the Cavex® 2 650, which addresses the continual demand for increased operational and circuit capacity. It is the second in a range of standard sizes that Weir Minerals is planning to release.

Lerato Ramanala, product manager hydrocyclones at Weir Minerals Africa, says the Cavex® 2 650 hydrocyclone offers excellent separation efficiency and is ideal for both brownfields and greenfields projects, delivering operational flexibility and great recoveries.

She sees major demand for the new 650 model coming from customers with high throughput plants that require coarser cut points, a requirement typically found in gold, platinum and copper applications.

She adds that the new 650 model hydrocyclone – like the other sizes in the Cavex® 2 range – can easily be retrofitted at existing sites, replacing either the original Cavex® or competitor cyclones. “This allows increased throughput while using the same footprint, and customers are very enthusiastic about this feature,” she says. 

It is important to note that enhancements of the hydrocyclone performance go hand in hand with improving the environmental footprint of the equipment. 

By reducing bypass returning to the mill, fewer fines are returned to the mill in a closed-circuit milling process, thus reducing the need for energy to be used to further process particles that are already small enough to move on to the next stage. 

As a hydrocyclone that can make a finer separation, the Cavex® 2 650 model can operate at a lower pressure for further energy savings or a higher feed density for water savings while maintaining the existing cut size from the hydrocyclone. 

The Cavex® 2 650 hydrocyclone delivers significant benefits to mining customers including an increase in operational and circuit capacity of up to 30%. It can be equipped with Synertrex®-enabled monitoring system which can detect roping or blockage conditions in advance for continuous, efficient operation of the hydrocyclone.

RUBBER LINING PROTECTS EQUIPMENT AGAINST WEAR, BUT CHOOSE CAREFULLY

Mines are well aware of the significant cost savings that can be achieved by using rubber to increase the wear life of equipment, however selecting the right product for the application is vital.

Perhaps the first issue to clarify is that there is no single lab test to provide a definitive answer, according to Yatheen Budhu, product manager rubber products, hoses and spools at Weir Minerals Africa. 

“The industry standard test for rubber materials is the ISO 4649 dry abrasion test, however most wearing materials on a mine exist in a wet environment,” says Budhu. 

“For this reason, our Weir Minerals specialists developed a modified version of the ISO 4649 test, the Wet Abrasion Resistance Index (Wet ARI) test which can be used for wet abrasion testing and is better matched to what actually happens on the mine. The test was developed specifically to replicate wet slurry wear conditions for elastomers and over many years of testing has become the standard by which we can predict the wear of not only our rubber, but that of our competitors and then rank these side by side,” he explains. 

He makes the point that the same wear material – such as slurries, sand or aggregate – will behave differently in varying conditions. For this reason, Weir Minerals’ Wear Testing Programme includes unique tests such as the Weir Coriolis test, which is particularly suited for mill pumps, as well as the Wet ARI test. 

“The range of options can seem overwhelming, but it is vital to select the right material for the job,” he emphasises. “Getting this wrong means shorter wear life and raises the risk of premature failures that could lead to unplanned stoppages for maintenance.”

Budhu highlights the proven ability of natural rubber to withstand abrasion, especially when its composition is close to the natural latex found in the rubber tree. This is where Weir Mineral’s innovative manufacturing process makes all the difference.

“Each additional step in the production of rubber can damage its molecular chains and compromise the raw natural rubber’s excellent abrasion resistance,” he explains. “Through our unique liquid phase compounding process, we ensure that our premium rubber retains the essential properties of raw natural rubber and this allows it to deliver excellent wear life.”

After almost a century of successful operation in both industrial and mining applications, Linatex® rubber is renowned for reducing long term wear caused by fine particles, including the wet and abrasive conditions in mining. It is especially suitable for low angle applications, and its use includes the lining of pumps, piping, hoses, chutes, valves and tanks.

Where coarser materials are involved, Weir Minerals offers its Linard® range of natural rubber compounds. This material combines high flexibility with excellent resistance to cutting, says Budhu. Linard® compounds also resist deformation while providing anti-stick properties. 

“The choice of liner solutions goes beyond natural rubber to include synthetic rubbers,” he says. “The latter are formulated to be used where corrosive chemicals and high temperatures become a factor.”

For these applications, Weir Minerals developed its Linagard® range of synthetic rubbers. These withstand the effects of leaching acids and hydrocarbons, as well as slurries which are hotter than 70⁰C. 

“Rubber lining is a highly skilled process which – when done correctly with the correct type and thickness of rubber – can contribute considerably to the life and profitability of a plant,” Budhu concludes.

WEIR MINERALS’ MILL CIRCUIT UNIVERSITY TRAINS FOR SUSTAINABLE SOLUTIONS

By giving its personnel the ‘big picture’ of minerals processing, the Weir Minerals Mill Circuit University ensures that customers benefit from a broader, solution-focused approach.

“Offering sustainable solutions to the minerals processing sector – rather than just products – needs insight and understanding of the operational context,” says Teddy Malunga, Principal Process Engineer at Weir Minerals Africa. “The Mill Circuit University gives our customer-facing staff knowledge of the full circuit, as well as where our various products make their specific contributions.”

This has become a vital aspect of the modern mining industry, as customers look increasingly for technology partners who can offer and support integrated solutions, says Malunga. He highlights that Weir Minerals Africa’s comprehensive offering covers processing stages from crushing, grinding, classification, separation and rubber lining to slurry transportation, mine dewatering systems and tailings management.

“The Mill Circuit University ensures that we all grasp the full range of minerals processing fundamentals in addition to our particular product specialisations,” he says. “This allows us to understand the client’s processes better, and collaborate more easily across our own process, CIP, engineering, supply chain and projects departments.”

Holding five-day courses three times a year, the Weir Minerals Mill Circuit University in the Africa and Middle East region enrols about 25 candidates per course. They learn from both internal and external presenters, and are familiarised with plant processes and Weir Minerals products. 

The involvement of the University of Pretoria in the minerals processing component of the course adds a special value, including the award of continuous professional development (CPD) points. Course attendees also benefit from a visit to the university’s Department of Material Science and Metallurgical Engineering, which provides more practical insights. 

“We also see the value in sharing a range of ‘soft skills’ in our courses,” he says. “This includes communication skills, neuro-linguistic programming and relationship building.”

An important aspect of the course is to empower Weir Minerals Africa personnel to understand the needs of customers more clearly and focus on their key performance indicators (KPI) like plant availability, throughput and recoveries. These factors are then included in the process of identifying the appropriate products and designing solutions that meet the sustainability needs of our clients.

QUALITY, CUSTOM RUBBER HOSES FROM WEIR MINERALS AFRICA’S ALRODE FACILITY

As a leading South African producer of high-quality rubber hoses, Weir Minerals Africa designs and builds mining hoses for customers from 50 mm to 1,000 mm nominal bore up to 10 metres in length and up to 1,100 mm bends.

“Our state-of-the-art manufacturing facility in Alrode, Gauteng, comprises advanced semi-automated processes to produce both hard wall hoses, soft wall hoses and bends,” says Yatheen Budhu, product manager rubber products, hoses and spools at Weir Minerals Africa. “With a decade of investment in semi-automated building equipment and training, we can ensure high levels of safety, manufacturing consistency and quality in our custom-engineered products.” 

“The safety of our people is our number one priority, and the investment included system improvements in the hose building process protecting our employees from harm at all times,” he says. 

These hoses are designed to the specifications of customers around the world, using an option of Linatex®, Linard®, Linagard® and Linacure® abrasion-resistant internal wear liners. The hard wall mining hose is built for suction and discharge applications, with a heavy spring steel wire helix to cater for high dynamic loads. For discharge applications with no vacuum or suction that could collapse the hose, the soft wall mining hose is usually used as it allows for ease of movement and flexibility.

“Among the innovations we have introduced is a wear-indicator system, for critical applications where unexpected hose failure carries an unacceptable level of risk,” says Budhu. “The wear-indicator system gives operators early warning of wear on the liner, and allows proactive replacement to be planned and conducted.”

Weir Minerals Africa’s world class local manufacturing capability gives a number of benefits to mining companies, he says. These include a quicker lead time and a valuable contribution to Mining Charter compliance.

“Having our manufacturing facilities relatively close to our customers also facilitates our engineered-to-order approach,” he says. “We spend time with customers whenever possible – through our comprehensive branch network – to understand their conditions and requirements.”

For mines across the commodity spectrum, Weir Minerals’ rubber hoses deliver long wear life – from demanding conditions in mineral sands dredging operations to tailings, cyclone feed or thickener underflow.

“Our hoses must deal not only with abrasive materials, but also unexpected foreign objects in slurry, some of which may be sharp,” he says. “Nonetheless, as an example, we have seen our hoses in mineral sands applications last up to seven years – considerably longer than the customer is used to.”

The company also manufactures related equipment like flexible distance pieces – instead of normal bellows – to customer specifications, notes Budhu. With its Linatex® wear liner, these items last considerably longer. In addition, they can be used to connect pipework that is not well aligned. 

Weir Minerals Africa has an extensive footprint across the continent to deliver efficient technical support for its range of rubber lined hoses. This technical experience, coupled with the premium quality liners and the consistency achieved through using the semi-automated manufacturing process gives customers the assurance of a well-engineered product for the application.

DECADES OF INNOVATION ELEVATE WARMAN® MILL CIRCUIT PUMPS

Doing duty as an integral part of a mine’s minerals extraction circuit, Weir Minerals’ Warman® mill circuit (MC) slurry pumps withstand the harshest conditions while delivering their mission-critical function.

Marnus Koorts, Weir Minerals Africa’s product manager for pumps, emphasises that a mill circuit pump must deal with relatively large rock fragments from the primary mill, which can rapidly wear the pump’s throat bush, impeller and volute liner. 

“If this installation is not optimised, the abrasion could reduce the pump’s wear life to a matter of weeks,” says Koorts. “The significance of wear life is high, as the whole mill circuit comes to a halt when the primary mill’s circuit pump stops – potentially affecting minerals extraction for the whole mine.”

He highlights that the company’s Warman® MC pump range is regarded as a global flagship for the mining sector, evolving over more than eight decades of continual development and innovation. A considerable portion of Weir Minerals’ total R&D investment – which sees 1,3% of its total global sales being ploughed back into product improvement – is directed toward these pumps. 

“Over the years, we have developed many unique and ground-breaking innovations,” he says. “For instance, we developed the adjustable throatbush, a technology that we have advanced ahead of our competitors.”

This innovation optimises the efficiency of the pump, ensuring that the gap between the rotating impeller and the casing is kept at the minimum specified. This, in turn, reduces recirculation and ensures that the pump’s operating efficiency is routinely restored. 

The addition of deep expelling vanes on the high-pressure side of the throatbush diminishes the formation of eddies, which means less turbulence and better hydraulic efficiency. Minimising recirculation also cuts the pump motor’s energy consumption, generating savings on electricity costs that quickly justify the investment on a Warman® pump with this capability. 

“Ease of maintenance is another priority with the Warman MC pumps, allowing for quick and safe repair procedures,” he says. “The quick changeout system of the pump’s wet end is a key innovation, as the entire wet end can be unbolted and removed from the bearing and drive assembly shaft – taking hours off the time required to replace wear parts.” 

With respect to the materials used, Weir Minerals has developed a wide selection of materials for its throatbushes and for lining impellers and pump volutes. While most slurry pumps on the market use high chrome metal in these applications, the company also offers various rubber compounds and a hybrid Warman® MCR-M option – a metal-lined volute which is interchangeable with a rubber lined volute.

An in-house optimisation team – using 3D scans of the mine environment and computational fluid dynamic (CFD) analysis of the slurry flow – helps customers achieve the full benefits of Warman® MC pump innovations. In this way, performance improvements can be modelled even before installation takes place, says Koorts. 

LINATEX WEAR RESISTANT RUBBER LINING CUTS COSTS AT SENTINEL

Weir Minerals’ Linatex® Premium Rubber and Linard® 60 have significantly improved wear life at Kalumbila Minerals Limited’s Sentinel mine in Zambia, after the Weir Minerals Africa team was asked to provide a lining solution that would last longer than the incumbent product. 

To date, the Linatex® and Linard® solution has achieved six times the life of the product previously installed at Sentinel Mine. The competitor rubber product was no match for the high impact and abrasive nature of the 4,500 tph of slurry being fed to the mill discharge chute. 

The competitor rubber lining was failing after two months, resulting in downtime and added costs for equipment hire and specialised personnel. The remote location of the site also made obtaining materials for repairs a challenge. 

The Weir Minerals Africa team specified a double-layered rubber lining solution. A bottom layer of 30mm Linatex® Premium Rubber was selected to improve impact absorption, due to its resilient properties. Linard® 60 with a thickness of 25mm was selected for the top layer, due to its cutting and tearing resistance to the product reporting to the discharge chute. 

Weir Minerals Africa’s technical lining manager ensured the order was delivered to the customer site timeously. Together with a team from the Weir Minerals Zambia branch, the lining of the parts took place during a scheduled plant shutdown.

The combination of 30mm Linatex® Premium Rubber and Linard® 60 has lasted for one year with little to no signs of wear. This is a 250% wear life improvement when compared to the competitor product. As a result, Sentinel Mine has experienced reduced downtime and benefitted from the associated cost savings and with the increased plant availability maintenance personnel have been freed up to focus on other problematic areas in the plant.

Sentinel Mine has a longstanding relationship with Weir Minerals, with a range of Weir Minerals products installed and serviced over many years. With this in mind, the mine was confident that the team would provide an effective solution. 

Linatex® Premium Rubber is a proprietary vulcanised natural gum rubber, produced through a unique liquid-phase compounding process using high quality natural latex. It exhibits outstanding strength, resilience and resistance to cutting and tearing, giving superior performance in wet abrasion conditions.