Tag Archives: Weir Minerals Africa

LINATEX HOSE REDUCES DOWNTIME AND OPERATING COSTS AT NAMDEB

The installation by Weir Minerals Africa of a Linatex® 808 hard wall rubber hose with wear indicator system is reducing downtime and operating costs at Namdeb’s Sendelingsdrift treatment plant in Namibia.

The challenge facing Sendelingsdrift was that it was changing out the incumbent competitor’s rubber hoses every four weeks due to excessively high wear rates. In addition to the ongoing downtime, the plant also risked losing concentrate due to the hose failures. As the concentrate media contains diamonds, additional security was required when dealing with hose failures that result in concentrate leakage – adding to the costs. 

The Weir Minerals Africa service teams regularly visited Sendelingsdrift to engage with the plant manager, area engineers and other operational staff to get a better understanding of their requirements and problematic applications. After an audit of the site, the team considered all the parameters and proposed a trial of a Linatex® 808 rubber hose fitted with a wear indicator system. 

The proposed solution would be capable of withstanding the slurry flow rate of 84 l/s with a slurry density of 2,65 t/m³. The wear indicator system installed on the hose would indicate when the hose was nearing the end of its life; no physical inspections would be necessary. 

In addition, Sendelingsdrift would save the cost of additional security requirements by eliminating premature hose failures.

Sendelingsdrift agreed to the proposed trial, and the Weir Minerals Africa service team conducted weekly site visits to inspect the hose and the wear indicator system. While the competitor hose generally failed after delivering 32,000 tonnes of ore, the trial showed that the Linatex® 808 rubber hose surpassed 162,000 tonnes.

The hose lasted seven and a half months before being replaced, which was more than six times longer than the competitor’s hose – representing a significant cost saving for the customer. The Linatex® rubber hose processed over 2,5 million tonnes of concentrate and a similar volume of slurry during this time.

Designed for dual delivery and suction applications, Linatex® 808 rubber hose can be custom manufactured to any size and is available with a range of flange types.

AUTOMATIC LUBE SYSTEM FOR WARMAN PUMPS

Pump failure due to lack of regular lubrication can halt production in a process plant, but despite this risk many plants continue to use manual greasing procedures which are often unreliable. 

Lubricating of pumps is a time consuming and labour-intensive process that is often difficult to control and to conduct with the required level of precision, says Marnus Koorts, product manager – pumps at Weir Minerals Africa. 

“Many minerals processing plants around Africa may not have duty schedules that closely monitor and enforce regular lubrication of pumps with the exact volumes of lubricant,” says Koorts. “In our experience, pumps are frequently under-greased or over-greased, and this can severely undermine the lifespan and reliability of pumps.”

The answer, he says, is the Accumin™ range of lubrication systems from Weir Minerals, designed for use with Warman® pumps. The Accumin™ 250 Lubricator, for instance, includes a 250 ml replaceable lubricant cartridge fitted to a reusable drive unit. 

“The lubricator is driven electro-mechanically, dispensing a consistent dosage of lubricant at precise intervals ,regardless of ambient temperature and back pressure,” he says. “It can even be installed up to five metres away from the lubrication point, allowing operators to gain access to the mounting point more easily than to the pump itself.”

He notes that the lubricators are also simple to maintain. The status of some units can be determined by an LCD display, flashing LED alert system and an on-cartridge recording system. The clear cartridge shows how much lubricant remains.

“The accurate lubrication of pumps pays itself back in improved uptime by avoiding the disruption and consequences of unexpected pump failure, as well as in reduced maintenance costs and even energy consumption,” he says. 

As South Africa’s electricity costs climb and mines work towards energy efficiency as part of their efforts to combat climate change, a more effective lubrication regime makes pumps more economical to run. 

“Bearing wear is a ‘silent killer’ for a pump’s efficiency, demanding significantly more power as it progresses,” says Koorts.

The Accumin™ lubricator also adds to smooth plant operation by freeing up operators to focus on more demanding functions, he concludes. 

CAVEX RETROFITS BOOST RECOVERIES AT AFRICAN MINES

Following the retrofitting of two Cavex® 700CVX13 hydrocyclones by Weir Minerals Africa, one of Ghana’s lowest-cost surface gold miners reported an almost 70% improvement in classification efficiency.

There was also 50% longer wear life on the units’ liners compared to the competitor’s cyclones, and a 33% wear life improvement on the spigot. The mine had turned to Weir Minerals Africa after experiencing low recovery, with considerable coarse gold settling in the tanks. 

The mine required a solution that would achieve a P80 cut point of 120 microns or finer, while the incumbent hydrocyclones were achieving only 53% passing 106 microns. After analysing the situation and generating simulations, the Weir Minerals Africa team recommended two Cavex® 700CVX13 hydrocyclones and installed them into the mine’s existing infrastructure. The units were the first of this model to be installed in Africa. 

A range of vortex finders and spigots attached to the hydrocyclones further optimised their performance. Test results after six months confirmed that they were achieving 85,5% passing 106 microns in the overflow, compared to the 50,5% achieved by the mine previously. As a result of the Cavex® 700CVX13 hydrocyclones’ improved Total Ownership Cost (TOC), the mine intends to retrofit the balance of the cluster with these units. 

In another success story – this time in South Africa – Cavex® hydrocyclones have improved separation efficiency and provided a finer overflow product at a leading fluorspar producer in Limpopo province. The existing flat bottom competitor cyclones in the mine’s secondary mill circuit were found to be unsuitably sized and were achieving a coarser grind to the overflow for downstream processing. 

The Weir Minerals Africa team identified the Cavex® 400CVX10 hydrocyclone as the best equipment for the application. Not only are these hydrocyclones able to raise the efficiency of classification and separation, but improve overall wear life due to the reduced turbulence of the 360 degree laminar spiral inlet.

The Cavex® hydrocyclone cluster achieved a higher separation efficiency by reaching the required P90 cut point of 90 microns, reducing the stream of coarse particles to the overflow stream. The result was that the mine increased its mass recovery feed to the flotation circuit by 4,9%.

So satisfied was the mine with the performance of the Cavex® hydrocyclone that it ordered another four-way Cavex® 400CVX10 cluster for its new mill. It also ordered four Cavex® 250CVX10PU tailings hydrocyclones to replace the incumbent competitor product, as well as another for the product dewatering stream circuit.

ABRASIVE SOLIDS HANDLING MADE SIMPLE WITH THE NEW WARMAN SUBMERSIBLE PUMP

The new, high chrome Warman® SSB-A submersible pump from Weir Minerals presents a versatile pump and robust solution for slurry and sludge removal.

“Conceptualised and commercialised by Weir Minerals Africa, the Warman® SSB-A pump is well suited for duty in Africa,” says Marnus Koorts, Product Manager – Pumps at Weir Minerals Africa. 

Engineered for abrasive applications and for handling solid particles, the pump’s applications include mine dewatering, removing mill scale and cleaning up sumps as well as moving slurry, coal-pile run-off or dirty water with a solids content of up to 60% by volume. Koorts highlights that the pump can be moved easily between applications, so is ideal for dealing with temporary problems such as pipe bursts or leakage.

The hard-wearing design includes casting the casing, impeller and wear plates from Weir Minerals’ Ultrachrome® A05 high-chrome alloy, while the motor is designed for continuous and efficient operation though using the pumped media to assist in dissipating heat build-up in the motor windings.

“This durability enhances the range of applications in which the pump can be deployed, including even hardened slurry,” he says. “Customers will move the unit around extensively to wherever it is needed, so we designed the outer housing to avoid snagging by ensuring there are no points that could potentially hook or break as the pump is transported and operated.”

The impeller radial load is balanced out by the opposing forces created by the twin-volute discharge. This stabilises the pump during operation, allowing it to be placed in any position without the risk of oscillating, he says. The design also optimises the life of the cantilevered shaft and its components. 

“Users of the Warman SSB pump can also choose to run it in manual or the optional extra, in automatic mode,” Koorts says. “The automatic mode provides the convenience of self-monitoring water levels, switching on and off as required.” 

Electrical control philosophies can be adapted to suit site applications, such as over-current protection, an earth leakage circuit breaker, while the safety delay feature can reduce the number of starts per hour. 

“The robust, fit-for-purpose design makes this pump a reliable and cost effective solution in a wide range of duties,” says Koorts. “It represents the ideal combination of wear resistant materials and specialist hydraulic engineering.”

NEW GENERATION CAVEX® HYDROCYCLONE BOOSTS THROUGHPUT, WEAR LIFE

Weir Minerals has launched its Cavex® 2 hydrocyclone, which is an exciting improvement on the successful Cavex® hydrocyclone launched in the 1990s.

The design of the new generation model ensures a step-change in separation performance and reduced turbulence, says Lerato Ramanala, product manager hydrocyclones for Africa and the Middle East at Weir Minerals Africa. 

“The Cavex 2 hydrocyclone improves the design of the 360⁰ laminar spiral inlet, which delivered a step-change in separation performance and reduced turbulence,” says Ramanala. “The new design includes the LIG+ advanced laminar spiral inlet and a longer feed chamber, further reducing turbulence and classifying a higher volume of feed slurry.”

She highlights that the Cavex® 2 has the same footprint as the original Cavex® hydrocyclone – and competitor cyclones – so retrofitting is a simple process. Customers can benefit not only from the increased throughput capacity but through operational flexibility by being able to take hydrocyclones offline for maintenance without affecting process flow. 

Results from Cavex® 2 hydrocyclones installed across the globe have shown that it maximises plant recovery by reducing the quantity of misclassified particles; the alpha parameter improves by an average of 10% while the bypass improves by an average of over 15%. Fewer fines are returned to the mill, and mines can reduce their carbon footprint by consuming less energy for small particle reduction.

The Cavex® 2 accommodates the company’s in-house Synertrex® industrial internet of things (IIOT) technology, which detects sub-optimal operating conditions like roping in real time and improves overall performance. This aligns with mining industry efforts to leverage digital technology to create mines of the future. 

The shape of the liner has also been improved leading to longer life, less downtime for maintenance and lower total cost of ownership. Liners are available in a range of materials including industry‑leading Linatex® premium rubber and other robust Weir Minerals natural rubbers such as R55®.

HIGH FLEXIBILITY, LOWER COST WITH MOBILE PUMPHOUSE

Pumping slurry to tailings facilities requires a solution that can move as the dam expands to make room for additional tailings, making Weir Minerals Africa’s mobile pumphouse ideal for the purpose.

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

Koorts says the offering is part of Weir Minerals Africa’s engineered-to-order (ETO) 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 (E-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 capex 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 continually dedicates significant investment towards product improvement, aligning with an industry shift from fixed products to more mobile equipment options and solutions. 

The company’s 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. 

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.

EXCITING YEAR AHEAD FOR WEIR MINERALS IN AFRICA AND MIDDLE EAST

Weir Minerals Africa is focused on partnering with customers to drive efficiencies using its proven technology-driven solutions.  

According to Grant Ramsden, Regional Managing Director of Weir Minerals Africa and Middle East, the company’s successful evolution over a century and a half continues with a strong sustainability vision for the modern mining, minerals processing and the sand and aggregate industries.

“As our mining sector customers look to reduce their carbon footprint, we are engineering solutions for a future that prioritises energy efficiency and raises productivity,” says Ramsden, who stepped into his new role during the economic lockdown in 2020. “With leading brands all the way from ground-engaging tools to processing equipment across the mill circuit, we have an exciting year ahead with our continuously expanding equipment range.”

Among the solutions that will raise most interest, he says, are the company’s high pressure grinding rolls (HPGRs), which are more energy efficient than traditional ball mills and utilise dry processing. With most of the global mining sector having readily embraced this technology, there is still plenty of scope for its adoption in Africa. 

“Another exciting area of opportunity for us remains our GEHO positive displacement pump range, where we continue to see substantial interest,” he says. “These pumps represent the latest advances in hydro-transport, and will also add to the efficiencies that we can bring to mining across Africa.”

In the context of the Covid-19 pandemic, Ramsden says that Weir’s Synertrex® condition monitoring and smart analytics platform will also attract more attention in 2021. Developed by Weir Minerals to complement its portfolio of mining equipment, Synertrex® monitors product operation and feeds data automatically to the cloud and control systems. This also allows for remote monitoring where employees or management may not have regular physical access to plant operations.

“With our service-focused approach, we are able to become directly integrated into the customer’s operation, through having one of our own experts in the mine’s control room helping to monitor equipment and possibly even procuring the necessary spares,” he says. “Synertrex has already proved itself in South Africa’s minerals sands segment, and similar interest has been expressed from other commodity miners in our region. This system can also streamline procurement by alerting customers when new spares may be needed.”

Ramsden also emphasises the value in Weir Minerals’ wear resistant technology (WRT), which has demonstrated increases in the life of impellers and throat bushes of Warman® slurry pumps by up to 30%. These improvements significantly extend pump life and reduce total cost of ownership for our customers.

As an established original equipment manufacturer (OEM) in South Africa, Weir Minerals Africa is planning further investment in upgrades and process improvements at its Isando foundry. It will also be directing resources for a technology upgrade at its Isando rubber plant, one of two local facilities contributing to the company’s range of IP-protected rubber products.

“After a difficult 2020 for everyone, it will be exciting to be investing and expanding to assist our customers to meet their production targets,” he says. “We also look forward to continuing our investment in local skills, which includes supporting 22 graduates – 90% of whom are drawn into our business after qualifying from their university studies.”

Ramsden highlights the importance of the Weir Minerals’ Mill Circuit University in providing essential training to our staff – helping to keep the company and the broader mining industry operating at the highest levels of performance. 

“The technical experts in our business constantly leverage new technology, applying it to our products to the benefit of our customers,” he says. “The use of 3-D scanners, for instance, enhances the capability of our process engineers when they visit customer sites. This enables them to quickly generate the measurements they need to develop quality proposals for productivity solutions.”

He is also confident about the prospects for the Middle East, where comminution is the main focus of the company’s offerings – serving the considerable demand for infrastructure works in that region. Its local capacity has been further enhanced by the recent unveiling of a new world class service centre in Dubai in the United Arab Emirates. 

“This aligns with our mission to be available wherever and whenever our customers need us,” he concludes. 

LARGE SCREENS FOR NIGERIA SHOW WEIR MINERALS’ DESIGN DEPTH

Two of the largest screens built by Weir Minerals Africa are being designed and manufactured in South Africa as part of a process solution for an iron ore mine in Nigeria. 

According to Tiisetso Masekwameng, general manager comminution at Weir Minerals Africa, the flowsheet accepted by the customer includes equipment for screening, washing, and grinding supplied by Weir Minerals. 

“Within our scope of work are the two largest Enduron double-deck banana screens built by Weir Minerals,” says Masekwameng. “This is made possible by the depth of design expertise in our Separation Technology Group, an eight-strong team conducting research and development.”

Steven Hunter, separation technology group leader at Weir Minerals Africa, says the two 51-tonne Enduron® double-deck banana (DBHG 43/97) screens for this project were built upon the designs of the Weir Minerals existing screens range. These large machines measure 4,3 metre wide and 9,7 metre long and can process 1,750 tonnes per hour.

“The customer’s production requirements demanded this considerable size, so we optimised the design by minimising mass without compromising structural integrity,” says Hunter. “We conducted extensive finite element analysis (FEA) on the whole machine but focused on the main structural elements, ensuring that the units were fit-for-purpose while still being light enough to be driven by the exciters.”

Nonetheless, the size of the units still demanded the design and manufacture of Weir Minerals Africa’s largest exciter yet – the Enduron® LTX 10. With 120 tonnes of excitation force (at maximum setting), these units will drive the screens at a stroke of 9,4 mm and a gravitational force of 4,6 G. Hunter highlights the close collaboration between the Research & Development and manufacturing teams that contributed to the successful development and testing of the Enduron® LTX 10 exciters.

“The screens are also ready to be fitted with our IIoT (Industrial Internet-of-Things) platform, Synertrex,” he says. “This allows the machines to be monitored remotely; the system can measure the machine’s performance any deviations arising that may require proactive attention.”

The order for Nigeria also includes two Trio® jaw crushers, two Trio® cone crushers, two large 2- metre by 8- metre Trio® apron feeders, two Trio® pan feeders, eight Enduron® vibrating screens and an Enduron® HPGR (high-pressure grinding roll). 

For the clay washing circuit, Weir Minerals Africa will supply the mine with a Trio® twin-shaft blade mill and Trio® twin-shaft coarse washers as well as Warman® slurry pumps.

TRIO® CONE CRUSHERS BOOST PLANT CAPACITY IN OMAN

When one of the largest crushing operations in Oman needed to raise its production by 30%, Weir Minerals knew that a Trio® TP350 cone crusher was the answer.

It was a demanding application, involving the crushing of hard, coarse-grained gabbro for use as construction aggregate. Gabbro has a high compressive strength of 220 to 230 MPa and an abrasion index of 0,45. The existing crusher was running at 270 to 280 tonnes per hour with a closed side setting of 38 mm.

“The operators wanted to increase the crushing plant’s capacity to over 300 tonnes per hour,” says Tiisetso Masekwameng, general manager comminution at Weir Minerals Africa. “This could not be achieved without overloading the existing crusher, leading to machine trip-outs and excessive wear.”

Running for 10 hours a day seven days a week, the operation needed to be efficient. It could not afford excessive downtime caused by unexpected stoppages or frequent maintenance. Masekwameng highlights that the rugged Trio® TP range is specially designed for heavy duty crushing, and the Trio® TP350 model was ideal for this application.

“After detailed discussions with the plant’s general manager to understand their needs, we recommended this model,” she says. “With its capacity of 340 to 370 tonnes per hour at the same closed side setting of 38 mm, we were sure it would deliver the right result.”

Not only did it achieve the required output, but it also reduced downtime by 50%. Installation was straightforward, requiring only an adaptor motor base to accommodate the larger, 250 kW electric motor. Noting the crusher’s ease of maintenance, the customer was also pleased with its consistent performance and reliability.

“Our Trio TP cone crushers feature a steep crushing chamber angle and a large crushing stroke,” says Masekwameng. “They operate at an optimum speed to deliver a high-quality product through increased inter-particle comminution.”

She adds that these crushers are also designed to allow for maximum mobility without sacrificing versatility or crushing force. The Trio® crusher range is compatible with Weir’s Synertrex® technology for remote monitoring. Synertrex® is an industry-internet-of-things (IIoT) platform that monitors mining equipment for peak reliability and performance.

WEIR MINERALS AFRICA IN SOUTH AFRICAN EMPOWERMENT DEAL

In an important empowerment transaction for leading minerals solution provider Weir Minerals Africa, the company’s South African operation, Weir Minerals South Africa (Pty) Ltd, is now 25.1% owned by black empowerment partner Medu Capital.

According to Weir Minerals Africa Regional Managing Director Gavin Dyer the deal is another step in an ongoing transformation journey. The transaction was finalised in Johannesburg in May 2020.

“We have, over the years, made significant progress in terms of our employment equity, skills development, preferential procurement and socio-economic development,” says Dyer. “We are therefore very pleased to conclude this transaction, which creates an organisational ownership structure that is more representative of the demographics of South Africa.”

The deal has been facilitated by the creation of Weir Minerals South Africa (Pty) Ltd, whose assets include sales branches across the country, an assembly facility in Alrode, Gauteng, and a distributor network.

“This initiative also further enhances our value proposition to customers in the mining industry as they work to support the imperatives of Mining Charter 3,” he says.

Part of the global Weir Group PLC, Weir Minerals Africa serves primarily the mining sector around Africa and the Middle East. It also manufactures world-class mineral processing equipment for export to international group destinations. Listed on the London Stock Exchange, Weir’s engineering heritage dates back over 140 years.

“With its extensive local investment in skills, service capability and manufacturing capacity in South Africa, the Weir Group has always been supportive of our empowerment drive,” Dyer says. “This strengthens our position as a local technology leader serving global markets.”

Formed in 2003, Medu Capital is a 100% black-owned investment management company with a focus on private equity. Dyer highlights that Weir Minerals South Africa looks forward to Medu Capital becoming an active partner in guiding and fostering its future success.

Explaining the rationale behind Medu Capital taking up the shareholding in Weir Minerals South Africa, co-founder and director Ernest January says Weir Minerals has an outstanding reputation for high quality products.

“The company’s design, engineering and technical capabilities, combined with its high-quality standards and global reach, have led to impressive long-term customer relationships and a strong track record,” January says.

“We are proud to be associated with the Weir brand and support the company’s aim to achieve and maintain a competitive B-BBEE rating. We look forward to working with the management team to complement its value proposition to customers and are excited to participate in the company’s growth story.”