Tag Archives: Kwatani

Kwatani customers set to benefit from Sandvik Rock Processing integration

Both local and foreign customers – as well as mineral processing OEMs looking for specialised solutions – are set to benefit from the recent acquisition of vibrating screen specialist Kwatani by global multinational Sandvik, according to the South Africa-based company.

The closing the transaction occurred late last year with Kwatani becoming part of Sandvik Rock Processing Solutions. 

The deal highlights South Africa’s world class nodes of excellence in the engineering sector, according to Kim Schoepflin, CEO of Kwatani, who says the Sandvik collaboration is a milestone for local industry. It also contributes significantly to the government’s industrialisation strategy, to foster world-class industries that can compete globally and promote job creation locally.

“The acquisition will allow Kwatani greater access into foreign markets through Sandvik’s extensive distribution network,” she says. “Our modern Kwatani facilities in Kempton Park, accredited in terms of ISO 9001:2015, is now the global engineering and manufacturing base for vibrating screens and feeders for customers.”

She adds that an added benefit for customers is the support they will receive through the Sandvik service network of engineers and technicians in the field. The proven interface between Kwatani and Sandvik equipment – for instance, a Kwatani screen feeding into a Sandvik crusher – will, the company says, add considerable value to customer’s purchasing choices.

“Customers get the best of both worlds, and can feel confident of the efficient dovetailing of our product ranges,” Schoepflin says.

Sandvik brings state-of-the-art resources which further leverage the benefits to Kwatani customers, the company says. This includes access to monitoring and automation processes as well as a depth of research and development into the application of technology like simulators.

Kwatani continues to invest heavily in its resources at its Kempton Park facilities, Schoepflin says, which employ and develop local expertise while sustaining a strong supply chain of local players. Sandvik supports this model, and shares the vision that business sustainability must be based on effective engagement, investment and commitment to the local economy. Kwatani’s local empowerment strategy supports transformation and is compliant with the South African Mining Charter.

“We work closely with local supply partners in our value chain – many of them being small businesses – to embed quality systems and manufacturing capacity,” Schoepflin says. “Customers can therefore be assured of quality throughout our products’ construction, with a reliable, sustainable and cost effective local production base.”

With its cost base rooted largely in the South African economy, Kwatani can offer customers a consistent pricing regime that is not vulnerable to frequent exchange rate fluctuations, it says. This has added to the popularity of Kwatani’s products at home and abroad, with the company twice being recognised in the Exporter of the Year awards hosted by the South African Capital Equipment Export Council (SACEEC).

“Our growth has allowed us to build our complement of competent staff, who are continuously upskilled to stay a step ahead of industry needs – with the help of our in-house training centre,” Schoepflin says.

An important indication of Kwatani’s depth of expertise and field experience is its ability to precision-engineer specific solutions for other OEMs in mineral processing. This extends to highly specialised equipment like sorters, which demand very precise feed characteristics and other protection.

“We are a partner of choice to OEMs whose equipment must operate within tight specifications, and which may have other specific requirements that a standard range of screens would not accommodate,” Schoepflin says.

Kwatani’s approach addresses the three key elements of vibrating screen performance: ore properties, screen design parameters and screening media. Its engineering solutions address all these priorities, Schoepflin says, giving customers optimal results at the lowest cost of ownership.

Kwatani’s mill discharge screen expertise to pay off at Namibia gold mine

Namibia’s mining scene is seeing an exciting expansion and technological innovation at a leading gold mining operation, with Kwatani supplying five mill discharge screens – all custom designed and manufactured at its Gauteng facilities.

Kim Schoepflin, CEO of Kwatani, says her company has a long history in Namibia and a strong footprint across various commodities there – including an established presence at this gold mine. It has worked with the engineering, procurement and construction contractor and the end-customer for two to three years on conceptualising the optimal solution.

“The mine is gearing up to increase its production by 50%, to take advantage of the strong gold price,” Schoepflin says. “Our role was to ensure that our discharge screens meet their exact process requirements – with our efficiencies of up to 95% – while delivering mechanical integrity for minimal maintenance downtime.”

The expansion includes the installation of two latest-technology mills – a high-pressure grinding roll (HPGR) and a vertical mill – which will boost production while reducing energy demand. Kwatani’s mill discharge screens, each measuring 3-m wide by 8-m long, will handle the coarse and fine material from the HPGR and the vertical mill. The company will also supply three silo feeders of 1.2 m by 2.5 m in size, to feed material from the silo to conveyors.

“Our screen design optimises the retention time on the deck, allowing for better screening and stratification,” Schoepflin says. “Due to the volume of slurry and water sprayed onto the screens, the added retention time assists with better drainage at lower cut points.”

The coarse screens were designed at a decline, and feature a larger screening media aperture with higher amplitude and stroke. Together with lower speed, this achieves better screening efficiency for the coarser particles. The fine horizontal screens, with smaller aperture screening media for the finer feed, were designed with a higher speed and lower amplitude and stroke; this will optimise the screening efficiency of the finer feed to these screens.

She also highlights the attention paid to the isolation of the vibrating screens. In this case, Kwatani engineers selected rubber buffers, which have higher dynamic loads but are more suited to wet applications and screens with a heavier mass.

“The number and type of buffers were defined according to the mass of the screens,” Schoepflin says. “The selection of rubber buffers for larger screens also assists with start-up and shutdown time, allowing the screens to come to rest more effectively.”

For these five screens, Kwatani, now part of Sandvik Rock Processing Solutions,  designed and supplied custom counter-balance frames to minimise the dynamic load to the plant infrastructure. The company’s screen technology includes designing its exciters in-house. This ensures that screens receive the necessary G-forces for optimal material stratification and screening, matching customers’ process requirements with the best possible efficiencies.

“To make sure our screens cope with the high capacity demands of modern processing plants, we rigorously test all units in our in-house testing facility before dispatch,” Schoepflin said. “These units began their journey to Namibia at the end of November 2021, and our team will support the commissioning when the customer requires.”

Kwatani adds to Northern Cape iron ore reference list with latest screening installation

South Africa-based vibrating screen and feeder specialist Kwatani will soon add another installation to its extensive footprint in the Northern Cape, this time for a new customer in the iron ore mining segment.

“We have over 1,000 screens, grizzlies and feeders in this important mining region, giving us a market share of about 95% of heavy-duty screening applications there,” Jan Schoepflin, Kwatani’s General Manager: Sales and Service, said. “With our well-established branch in Kathu, we are also able to assure our new customer of quick and highly competent service levels.”

The ore characteristics of iron ore demands mechanically robust screening equipment and Kwatani has built a name for itself in these applications, according to metallurgist Frengelina Mabotja, Kwatani’s, Head of Sales for SADC. “Our equipment is engineered for tonnage and continuous throughput, without compromising efficiencies,” Mabotja said.

Kwatani’s scope of work on the 700 t/h dry processing plant includes a 1.5-m-wide grizzly screen to remove fines from the run-of-mine material before it reports to secondary crushing and a 1.5-m-single deck scalping screen. The company will also install two 2.4-m-wide, double-deck sizing screens to separate material after secondary crushing, and five feeders to draw material from bins and stockpiles onto conveyor belts for feeding onto the downstream process.

“Our niche expertise allowed us to, once again, offer high performance sizing screens customised for this unique dry sizing application and optimise material separation by achieving the required cut size for the customer’s desired product size,” Mabotja said. “Our solution optimises the material separation while maximising efficiency and ensuring mechanical reliability for continuous and economical production.”

She highlights the depth of in-house experience – from both a metallurgical and mechanical approach– which allows Kwatani to assist the decision making of customers on equipment choice and specifications.

“Through the work of our design team, supported by our manufacturing and testing facilities, we have ensured that the solution will be fit for purpose and reliable,” she said. “The customer was also able to visit our 17,000 sq.m local manufacturing operation in Kempton Park regularly to see how we work, to check on fabrication progress and to witness the testing process.”

The equipment was completed on a tight deadline of 8-12 weeks, for delivery by year-end in line with the customer’s timeframe, according to the company.

“Our fully-equipped branch in the Northern Cape, staffed by specialists with decades of mining experience, will oversee the installation and commissioning of the equipment,” Mabotja said. “Our team will also schedule regular site visits to monitor on the equipment’s performance and condition, and advise on maintenance requirements.”

To underpin the reliable operation of all equipment supplied, Kwatani will also provide training for the customer’s maintenance personnel in the basic maintenance routines required.

Kwatani became a part of Sandvik Rock Processing Solutions late last year.

Kwatani large vibrating screen customisation pays off

Process plant designers often underestimate the movement of large vibrating screens when these machines start and stop, a challenge for which Kwatani says it has found an innovative and cost effective solution.

According to Kwatani’s Chief Operating Officer, Kenny Mayhew-Ridgers, the company has achieved considerable improvements in many screening applications by selectively fitting torsional springs alongside coil springs.

“It is well known that the vibrating motion of a screen impacts on the building and structural accessories around it,” Mayhew-Ridgers says. “This vibration is addressed by fitting isolators between the screen and the plant floor, and by constructing the plant building to certain minimum structural specifications.”

However, the focus is often on the frequencies that the screen generates in its steady-state phase – or the normal running phase – rather than during the transient phases when the screen is starting up or slowing down to a stop, Kwatni says.

Mayhew-Ridgers highlights that it is during these transient phases that the screen’s movement becomes amplified and potentially most destructive. Isolators between the screen and the floor – common among which are coil springs and rubber buffers – are meant to absorb vibrations and prevent damage to surrounding infrastructure. However, the transient phases, especially when stopping, can generate considerable sideways movement of the screen, which must be avoided.

“Traditional isolators like coil springs usually perform well in controlling the up-and-down movement of the screen,” he says. “Our experience is that the sideways movement, which is induced most strongly when the machine stops, can be better controlled by torsional springs.”

However, he notes that coil springs retain the advantages of being cost effective and providing a good linear isolation of the screen from the building structure. In this respect, their isolation characteristics are generally better than rubber buffers which excel in terms of their damping qualities.

“The torsional spring provides the best of both worlds, giving a good linear range for compression during operation while also becoming non-linear like the rubber buffer during stopping,” Mayhew-Ridgers says.

Using its experience observing screens operating in the field, Kwatani has developed and trialled various solutions in its dedicated testing centre at its headquarters in Kempton Park, South Africa. By optimising the best combination of coil springs and torsional springs, the company says it has succeeded in achieving the best results for customers.

“It’s not that torsional springs are better than coil springs,” Mayhew-Ridgers says. “It is about finding the right combination – through intensive testing and adaptation – for the customer’s particular requirements; we have both the expertise and the equipment to do this.”

Kwatani breathes new life into scalping screens with rubber, polyurethane wear panels

As mines move towards using one large scalping screen between primary and secondary crushers – rather than a modular approach using multiple smaller screens – Kwatani says it has found ways to triple the panel life in these single mission-critical units.

According to Kenny Mayhew-Ridgers, Chief Operating Officer of Kwatani, any downtime in this single-line stream would require the mine to store several hours of production. While some mines schedule regular weekly production halts during which an exciter or worn screen panels can be replaced, many operations are not so lenient, he said.

“The message from these mines is clear: the longer the scalper can run between maintenance interventions, the better,” Mayhew-Ridgers said. “Our research and development efforts, together with extensive testing in the field, have allowed us to extend the life of screen panels from eight weeks to over six months.”

While smaller screens use wire mesh screening media, Kwatani has evolved larger screens that use rubber or polyurethane screen panels. Although these panels present less open area, they deliver important advantages.

“Key to the success of our design is our integrated approach – which matches the panel design with that of the scalping screen itself,” Mayhew-Ridgers said. “This allows us to achieve a balance between screening area, aperture layout and screen panel life – a result based on a sound understanding of screen dynamics.”

Whereas wire mesh undergoes rapid wear from abrasive materials, the rubber or polyurethane panels are more wear resistant and deliver longer life, according to the company. The latter require gentler declines for effective stratification, but a key factor is the stiffness of the screen bed.

“The stiffness of the supporting structure must go hand-in-hand with the screen panel design to achieve our required results,” Mayhew-Ridgers said.

Polyurethane panels, while strong and lightweight, have screening apertures that tend to be too stiff for heavy-duty scalping applications. This leads to blinding. Rubber overcomes this problem, however, and also delivers improved wear life.

Kwatani has also developed a panel replacement system – with a fastening mechanism on the underframe – that improves safety and saves time, it says.

Kwatani branching out from South Africa roots

Vibrating screen and feeder specialist Kwatani says it is transitioning from equipment supplier to solutions provider, as it attracts customers from well beyond its South Africa headquarters.

According to Kwatani General Manager Sales and Service, Jan Schoepflin, the company’s strong in-house expertise and design capability – combined with the manufacturing quality it consistently achieves – ensures its customised solutions deliver optimal performance at the lowest possible lifecycle costs.

“Our recent orders show that our customer base in Southern Africa remains strong, while there is growing recognition of our cost-effective offerings in West Africa, East Africa and North Africa,” says Schoepflin. “At the same time, orders from countries like Canada and Russia indicate that our markets abroad continue to grow.”

Kwatani says it remains the market leader in the supply and servicing of vibrating screens and feeders on iron ore and manganese mines in South Africa’s Northern Cape province. It also counts platinum, coal, diamond and gold mines in its customer base. Its West Africa orders have been mainly to gold mines, and there is growing potential for gold mining in East Africa, Schoepflin says.

Over its four decades of operation, Kwatani has produced about 16,000 custom-designed screens, and is building, on average, 30 to 40 units a month in its ISO 9001:2015 certified facility close to OR Tambo International Airport in Johannesburg.

“Our reputation has been built on prioritising what our customers need, and doing business with integrity and trust,” Schoepflin says. “This means delivering on what we promise and making sure that customers achieve the expected value from our products.”

The company’s solution focus is underpinned by its significant and ongoing investment in local skills, ensuring that its designs leverage strong mechanical and metallurgical engineering expertise, according to Schoepflin.

“This confidence in our products allows us to offer a process guarantee to customers, to deliver the tonnage, throughput and fractions that they expect,” he says. “Depending on which country our customers operate in, they may also have different industry and quality standards/certification expectations and we work closely with them to understand these clearly and meet their requirements.”

Schoepflin also emphasises the company’s service capabilities, which include its local service centres closer to customers, and its support partners in other countries.

“The careful selection of these partners is vital to meet customers’ stringent technical expectations,” Schoepflin says. “In some countries, our partners can also manufacture components according to our drawings and specifications, should there be an urgent requirement from a customer.”

Kwatani collaborating with EPCMs, miners on bespoke screening options

Mineral process plant designs are favouring higher-capacity vibrating screens and a more holistic approach to plant optimisation, according to screen specialist Kwatani.

“These trends hold great potential for the mining sector, and Kwatani has been at the forefront of technologies driving this direction,” Annelize van der Walt, Kwatani’s Business Development Manager for Mining and Minerals, says.

Vibrating screens are essentially the “glue” that integrates various unit processes, from bulk materials handling to optimally liberated comminution and pre-concentration, according to the company.

“Larger, engineered-for-tonnage screens are growing in popularity, as they reduce the number of processing modules and hence the level of infrastructure required, especially on mega-projects,” van der Walt says. “Higher capacity is becoming the new design standard for greenfields projects.”

There is also an ever-greater demand for reliability and uptime in these mission-critical machines, as well as an expectation of longer lifespans. All this requires bespoke solutions that address site-specific conditions, van der Walt says, while leveraging digital technology for real-time monitoring and control.

“Kwatani’s metallurgists and engineers use their extensive on-site experience and in-house laboratory facilities to innovate from our proven technologies,” she says. “A cornerstone of our philosophy is close collaboration with engineering, procurement and construction management contractors and end-customers to customise solutions, from concept to construction, commissioning and operation.”

Annelize van der Walt, Kwatani’s Business Development Manager for Mining and Minerals

Specific conditions include waterless beneficiation in arid Mauritania, where Kwatani’s screens operate completely dry in an iron ore plant. In South Africa and Botswana, meanwhile, the company has retrofitted dewatering screens to reduce water consumption, while increasing output by 40% with the same footprint.

“We also recently designed screens for exceptional ore characteristics in a precious metal beneficiation facility in Canada,” she said. “This required a high level of customisation, not only in the screening media but in the mechanical design.”

Remote mine locations – which are difficult to access for maintenance and replacement purposes – also guide the design parameters. In a recent project, Kwatani innovated by selecting special hard-wearing materials for the construction of the screening equipment. The design included components that would provide early warning of wear.

Embracing a more holistic plant design approach, customers often invite Kwatani to participate in optimising the screening side of their chosen beneficiation technology, van der Walt says. A different screening approach would be taken, for instance, in a dry pre-concentration application than in wet dense medium separation.

“This holistic approach is also facilitating greater synergy between original equipment manufacturers,” she says. “This is a very positive trend, allowing us to consider the impact of different equipment on the performance of each – from mineral processing apparatus to transfer chutes.”

Underpinning Kwatani’s responsiveness to customer’s specific needs is its ongoing research and development.

“Our R&D unit is currently working on projects to suit our designs to novel crushing and grinding technologies, which are changing the whole approach to the process flow of future plants,” van der Walt says. “These are significant innovations for the mining sector, and we are excited to be at the forefront with our evolving screen designs.”

Kwatani is incorporating digital technologies to facilitate remote monitoring and control of its vibrating screens. It is also piloting a service app for mobile phones, which helps operations predict their maintenance needs more accurately. The app also helps to drive down the total cost of ownership by gathering data that can be used in future design improvements.

Kwatani problem solving doubles diamond mine’s screening feed rate

Kwatani says it has helped a South Africa diamond operation double the feed rate of its degrit screen through the use of one of its customised solutions.

The customer was operating several multi-slope screens to dewater product between 0.8 mm and 5 mm in size, before it was treated by dense medium separation (DMS). However, the screens were causing a severe carry-over of water onto the conveyor belt to the DMS, according to the South Africa-based OEM.

“The feed rate on each screen was being limited to about 250 t/h,” Kwatani CEO, Kim Schoepflin, said. “We tackled this by designing and manufacturing a customised multi-slope screening machine to fit the customer’s existing footprint.”

Schoepflin said Kwatani’s replacement was able to double the feed rate to about 500 t/h, with minimal water carry-over.

As a result of the success of this unit, the customer requested Kwatani to replace the whole bank of screens, it said.

In another contract, a customer asked for assistance with underperforming screens that could not deliver the original design parameters. They also wanted to increase the tonnage throughput by 17%, according to the company.

“We conducted a careful evaluation in collaboration with the customer, and came up with an innovative and economical solution,” Schoepflin said. “Simply replacing the existing screens with Kwatani’s new larger screens would have been costly and time consuming, so we decided instead to replace the screen’s existing gearboxes.”

The replacement gearboxes delivered greater vibration, but without exceeding the output torque the existing motors driving the gearboxes could provide.

“Drawing from our portfolio of locally designed and manufactured exciter gearboxes, we were able to implement this solution very quickly,” she said. “The two new exciter gearboxes were delivered to site and were in operation within two weeks – successfully and immediately increasing the screen’s throughput.”

The benefits to the customer did not stop there, according to Schoepflin. The newly optimised operating parameters meant the material bed depth was lower, so the drive motors drew a lower amperage and reduced the cost of power consumed.

“Our customised screening and feeding solutions – developed by our in-house team of experienced mechanical engineers and metallurgists – are based on consultation with each customer,” she explained. “The result is a design that delivers the optimal processing performance and tonnage at the lowest cost of ownership.”

Kwatani solves the screening equation at South Africa coal processing plant

Kwatani has once again shown its mineral processing expertise in a retrofit project that saw one of the largest coal processing plants in South Africa boost screening throughput.

The South Africa-based company was brought in to consult on possible solutions to assist the plant in not only returning its screening throughput performance to the original design parameters but increasing it further.

Kwatani Chief Operating Officer, Kenny Mayhew-Ridgers, said: “Having evaluated the challenges on site and consulted extensively with the plant personnel, we determined that the suggestion to incorporate a bigger gearbox onto the screen would fail.”

The screen lifespan was in excess of six years and Kwatani determined it would not be able to accommodate substantially larger gearboxes offering 50% more output than the currently installed exciter gearboxes. “This would have resulted in irreplaceable damage to the screens,” Mayhew-Ridgers stated.

Because the customer was also looking for a quick and cost-effective solution, purchasing new screens with larger vibration capabilities was not an option, according to the company.

Kwatani came up with a simple solution, according to Mayhew-Ridgers.

“The plant was achieving 450 t/h on 480 t/h screens and was looking to increase this to about 525 t/h. This equated to roughly a 17% increase in performance. Replacing the screen’s existing gearboxes with those that could deliver greater vibration but would not exceed the output torque that the 37 kW drive motor could provide was the answer,” he said.

With a range of locally designed and manufactured exciters gearboxes in its portfolio, Kwatani was quickly able to provide the customer with two new exciter gearboxes delivered to site, installed and operational in the two-week timeframe the customer was looking for. “The increase in screen throughput was immediate,” Mayhew-Ridgers said.

The success of the retrofit saw Kwatani secure the order to replace three additional screens for the customer with new exciter gearboxes now currently operating at 550 t/h – 22% more than the original requirement. “Our success has proven our capabilities and screening knowledge and we have further secured all the screen repair work as well,” Mayhew-Ridgers added.

“We have positioned this business to offer expertise that extends beyond the supply of screening equipment. Our product knowledge enables us to correctly specify the right equipment and components for the application – in a case-by-case scenario,” he concluded.

Kwatani screens and feeders tackle manganese ore in South Africa

As a vital aspect of a plant expansion at a manganese mine in the Northern Cape of South Africa, Kwatani says it is supplying four heavy duty vibrating screens and 10 feeders to help boost throughput.

According to Kwatani CEO, Kim Schoepflin, this large-scale equipment is custom-designed and engineered for tonnage to meet the mine’s challenging operational requirements.

“Manganese ore is very demanding on vibrating screens as it has a high specific gravity and is also very abrasive,” Schoepflin says. “Our machines are engineered to perform the application’s duty requirement while being robust enough to deliver maximum uptime.”

The units being supplied include a 3.6 m double-deck scalping screen, a 3 m double-deck screen, a 2.4 m screen and a 1.8 m dewatering screen. A local OEM that has designed and engineered vibrating screens for over four decades, Kwatani has built a reputation for world-class expertise and capability, it says.

“Customers choose us for our engineering track record – developing technology that can manage the tonnages they require,” Schoepflin says. “This means understanding each mine’s specific conditions, and then building a design to meet a range of complex mechanical and metallurgical factors.”

The order to the mine is being rolled out on time and on specification to the customer’s satisfaction, according to Kwatani COO, Kenny Mayhew-Ridgers.

“The efficiency and quality of our work process allows us to design, manufacture and deliver custom-designed screens in the same timeframes that other OEMs deliver standard models,” Mayhew-Ridgers said.

This is particularly demanding as custom-designed equipment undergo an intensive design process after being verified by rigorous finite element analysis in-house, Kwatani says. Prior to dispatch, all units endure intensive testing before being commissioned on a customer’s site. For this reason, Kwatani boasts its own in-house advanced testing facilities at its Kempton Park facility, in South Africa. Aligned to ISO 9001 standards, the testing protocols have been developed in-house with decades of experience. This allows full testing similar to cold commissioning, even before delivery to site.