Tag Archives: Kwatani

KWATANI SCREENS SUPPORT GOLDEN OPPORTUNITY IN NAMIBIA

Namibia’s bustling 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 (EPC) 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,” says Schoepflin. “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,” she 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,” says Schoepflin. “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 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,” she 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.”

NEW IRON ORE MINE ADDED TO KWATANI’S N CAPE FOOTPRINT

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 greenfields expansion of 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,” says Jan Schoepflin, Kwatani’s general manager: sales and service. “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.”

Kwatani’s scope of work on the 700 tonne-per-hour dry processing plant includes a1,5 metre wide grizzly screen to remove fines from the run-of-mine material before it reports to secondary crushing and a 1.5 metre single deck scalping screen. The company will also install two 2,4 metre 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,” says Mabotja. “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. With 47 years in the vibrating screen and feeder business, the company can bring its myriad lessons in the field to bear on each project. 

“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 says. “The customer was also able to visit our 17,000 square metre local manufacturing operation in Kempton Park regularly to see how we work, to check on fabrication progress and to witness the testing process.”

This level of engagement with customers builds their confidence in Kwatani’s ability, as they can experience first-hand the systematic, quality-controlled approach to design and manufacturing. The company’s extensive facility is ISO 9001:2015 certified. 

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

“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,” says Mabotja. “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. 

BUSINESS AS USUAL AS KWATANI/SANDVIK TRANSACTION CLOSES

Business as usual is how Kim Schoepflin CEO of Kwatani describes the news of the closing date of the transaction whereby Sandvik Rock Processing Solutions and Kwatani signed an agreement for the multi-national Sandvik Group to acquire the shares of this 45-year-old leading vibrating screen and feeder Original Equipment Manufacturer (OEM). 

Schoepflin says when the exciting transaction, which was subject to regulatory approvals and customary conditions, was made known to the mining and materials handling industries earlier this year it was exceptionally well received by the markets, from both potential and existing customers. 

“Kwatani has operated its world class production facility in South Africa for more than 45 years, and both Sandvik and Kwatani are technology leaders so bringing our combined resources to customers will be of enormous benefit,” she says. 

“What is most significant for the South African industry is that the collaboration is aligned with our government’s industrialization strategy. Furthermore, Kwatani is known for its commitment to compliance with the South African Mining Charter and we are a proudly Level 2 B-BBEE company.” 

Add to this, and a game changing move for the South African economy is that the Kwatani facility is set to become the global engineering and manufacturing base for vibrating screens and feeders for both local and international customers. The internationally recognised Kwatani brand, with its promise of being engineered for tonnage, will remain unchanged and the Kwatani brand will continue to be used across Africa while products sold internationally will be sold through the Sandvik sales channels under the Kwatani product name.

Schoepflin says that also exciting for the market is that Sandvik will further develop the Kwatani vibrating equipment brand globally. “This will see increased access to the Kwatani product through Sandvik’s global distribution network and customers will benefit by having access to a vastly increased customer service network.”

“Sandvik will also, through its global technology resources, provide access to monitoring and automation processes as well as access to its extensive R&D facilities which include simulators.” 

This, Schoepflin says, will provide opportunities for driving efficiency arising from the advance of artificial intelligence in the Fourth Industrial Revolution and will significantly empower the process of cost effective customisation. 

About Sandvik Rock Processing Solutions 

Sandvik Rock Processing Solutions, one of four different business areas in the Sandvik Group, is a leading global supplier of equipment, service and technical solutions for the mining and construction industries. Its products and solutions are specifically used in crushing and screening, quarrying and breaking and demolition application. 

About Kwatani 

Kwatani is Africa’s leading Original Equipment Manufacturer (OEM) of custom-engineers vibrating equipment including screens and feeders to both local and international customers. This South African based company, with a proven track record of 45 years, operates a world class production facility in Johannesburg. 

KWATANI DEVELOPS SPECIALISED SPIRAL ELEVATOR IN-HOUSE

Demonstrating its depth of local engineering expertise and technical capability, local vibrating screen specialist Kwatani has designed and fabricated a specialised spiral elevator for a mobile containerised sorting plant for a diamond mine in Australia.

Although not the first spiral elevator be produced by the company, this particular one was the first of its particular design to be engineered from scratch and manufactured by Kwatani.

Better known for its large, robust vibrating screens and feeders, the Kwatani 450 kg custom spiral elevator was an interesting contrast for the engineering team – but the results reflected the company’s usual standards of excellence. 

Within a timeline of just 10 weeks, the project combined first principles of physics with Kwatani’s decades of experience in custom design and manufacture.

“The client had very specific functional and dimensional requirements for this design, with the available space for installation being very constrained,” said Kwatani senior mechanical engineer Gideon de Villiers, who led the team in developing the two metre high spiral elevator. “We were also pleased to be able to meet the client’s throughput needs first time around with this specific design and build.”

The unit will convey up to 3.5 tonnes per hour of diamondiferous ore between sorters in a mobile containerised sorting plant, which is destined for a diamond mine in Australia. The material to be moved up the spiral elevator ranges in size from 5 mm to 30 mm. 

De Villiers highlights that Kwatani already has an established reputation with the sorter OEM, creating the necessary trust in Kwatani’s custom-engineering capability. 

“Our extensive knowledge on feeders and vibration dynamics placed us well to successfully tackle this innovation,” he says. “We started with the basic engineering calculations to clarify what dynamic movement we required, working through factors like planned tonnages, isolation of dynamic forces, friction value of ore, and motor orientation and direction.”

Designs were simulated using specialised software before Kwatani’s skilled team of artisan welders tackled the task of construction and platework. This included finite element analysis to identify areas of potential ‘hot spot’ stresses. 

Working with relatively light plates of 3 mm to 4,5 mm thickness, the elevator comprises S355 structural steel to cater for dynamic vibrations. The footprint was kept to around 700 mm, with two unbalanced motors at the base. 

“Due to the high value of the diamonds in the material, the structure also had to include static covers welded to the body, as well as maintenance doors with anti-tamper seals,” he says. 

Once fabrication was completed, the team embarked on a thorough testing programme lasting two weeks, conducted in Kwatani’s dedicated test laboratory. This allowed for the adjustment of various parameters, requiring close collaboration between the design and fabrication teams. 

ROBUST SCREENS CUSTOM-DESIGNED TO SUIT THE NEED

Kwatani’s success in developing custom vibrating screens for a range of scalping, sizing, dewatering, drain and rinse and desliming applications is built on decades of experience and practical research, according to CEO Kim Schoepflin.

“We focus on the detail of every project, so that the screen performance suits the customer’s mined product and expected output,” says Schoepflin. “This means working with all screen operating parameters like velocity,  stroke,  angle of stroke and deck inclination – as well as the appropriate screen media – to deliver results.”

A vital aspect of the engineering process is the testing of material in Kwatani’s laboratory, using wet or dry test screens and other equipment to outline options for the customer. This allows a differentiated approach to each category of screening required in mining and other sectors. 

“Scalping is usually one of the first steps in the comminution process, which subjects screens to intense strain and wear,” she says. “We therefore design our scalping screens for high drop heights, large sizes of material and considerable throughput tonnages which can handle up to 7,000 tonnes of heavy run-of-mine material ore per hour.”

This means a very specific design and fabrication of deck beams, traverse beams and side plates, for instance, giving maximum uptime and reliability. Using its integrated engineering approach, Kwatani also designs the scalping panels in-house, so that they provide the best balance between impact resistance, durability and economy.

The company also has an enviable track record in custom grizzly feeders – for scalping run-of-mine material varying from fine particles to one-metre lump sizes – across heavy duty applications in commodities including gold, manganese and diamonds. 

“Our feeders efficiently remove fines from ROM prior to secondary crushing, with a strong impact deck that minimises structural shock,” she says. “The configuration must suit the application, with rubber or steel options available. Grizzly bars can also be fabricated or supplied in a cast manganese option for heavy duty applications.”

Sizing is a broad category of screening, with wet or dry applications, where mines aim to achieve their required cut-off while maximising process plant efficiency, product quality and production tonnage. For wet applications, Kwatani offers static or dynamic water spray options on single, double or triple deck configurations depending on material – with either unbalanced motors or exciter gearboxes for larger capacity applications. 

“To protect screens’ deck components and side plates against wear, our options include a comprehensive selection of rubber, polyurethane and ceramic for greater durability,” says Schoepflin. “The key is to ensure high load capacity, improved wear life and lower operating cost.”

Kwatani’s desliming screens effectively remove slimes (fine particles) from larger particles in mineral processing, and Schoepflin says large multi-slope screens are a fashionable choice in this application.

“Our research and development has improved the efficiency of these multi-slope designs. We not only adjust the operating speed, but also the stroke and angle of stroke to optimise efficiency. We also align the number of slopes as well as change the angles of each slope to achieve better performance and life e,” she says. “For instance, we can design a more continuous curvature profile along the screen, with a higher number of slopes ensuring a gradual change of direction for material and optimise the material velocity to improve the overall screening performance. 

She highlights Kwatani’s ability to reduce the transfer of a screen’s dynamic force into the building structure in which it is housed. This is a significant concern in any application, but especially where the infrastructure is aging. 

“We design specialised counter frames for each custom screen, to minimise the transmission of forces into the support structure,” she says. “We have a range of screen mounting options – such as rubber buffers and torsional springs – to optimise this isolation effect.”

RESEARCH STUDY LEADS KWATANI TO BETTER BANANA SCREEN DESIGN

Numerical simulation research that modelled the behaviour of particles on a conventional banana screen has been leveraged by local vibration screen specialist Kwatani to make fundamental improvements in the design.

So important were Kwatani’s adaptations that they were able to double the throughput of a competitor’s problematic dewatering screen on a customer’s mine, where excessive water carry-over was limiting production potential. 

According to Kwatani chief operating officer Kenny Mayhew-Ridgers, the company’s depth of mechanical and metallurgical expertise underpins its ability to apply what it learns from research and field testing. 

“This specific research, which was done by Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the University of Queensland, highlighted that the traditional feed-end slopes of banana screens were generally too steep,” says Mayhew-Ridgers. “At around 34°, these slopes create material velocity in excess of 3 m/s – too high for efficient screening.” 

He considers that a more suitable slope at the feed end is 25°, leading into five or six deck slopes in the screen and ending with a discharge slope of just 5° or even 0°. This would ensure that the material velocity was less than 0,5 m/s at the discharge end. The drive angle, operating speed and stroke are also significant factors, he says.

“Our analysis allowed us to address a challenge that a customer was experiencing with their degrit screens,” he says. “Water carry-over from the screen to the conveyor belt was limiting throughput to only 250 t/h, and the mine needed more than that.”

Kwatani’s changed the screen feed-end slopes and incorporated a long discharge-end decline slope of 3°. The drive angle was also increased to 50° to improve the dewatering performance of the screen. These adaptations were possible within the constraints of existing chute work, motor base position and support structure. The size of the screen – measuring 3,66 m wide – meant that a considerable load needed to be supported on the screen deck, so circular hollow sections provided improved strength in place of the H-profile deck beams usually employed.

“The modifications were successful,” he says. “The mine’s plant manager was able to confirm that  the feed rate had been increased to 500 t/h with very little water carry-over, and this performance was consistently maintained.”

The application of the new design was outlined in a peer-reviewed paper by Mayhew-Ridgers and Kwatani director Derrick Alston, which was presented at an international mineral processing conference. 

SANDVIK AND KWATANI ANNOUNCE GAME-CHANGER FOR VIBRATING EQUIPMENT INDUSTRY

In an exciting joint announcement, Sandvik Rock Processing Solutions and Kwatani have confirmed that an agreement has been signed for the multi-national Sandvik Group to acquire the shares of this leading African OEM of custom-engineered vibrating equipment. The transaction is expected to be finalised around the fourth quarter of 2021, subject to regulatory approvals and other customary conditions. 

Kim Schoepflin, CEO of Kwatani, says not only is this a complete game-changer for the vibrating equipment industry, but customers will benefit enormously from the combined resources of Sandvik and Kwatani. Both companies are technology leaders in their own rights with Kwatani having operated its world class production facility in Johannesburg, South Africa, for more than 45 years. 

“What is most significant and exciting for the South African economy is that our facility is set to become the global engineering and manufacturing base for vibrating screens and feeders for both local and international customers,” Schoepflin says. 

This collaboration is not only a major milestone for the South African engineering industry; it is also in line with the South African government’s industrialization strategy. Schoepflin is also quick to point out that Kwatani will continue with its commitment to transformation and compliance with the South African Mining Charter. 

Commenting further, Schoepflin says that the internationally recognised Kwatani brand will remain unchanged. “Known for our brand promise of being engineered for tonnage, we will continue to use the Kwatani brand across Africa and products sold internationally will be sold through the Sandvik sales channels under the Kwatani product name.”

Sandvik will further develop the Kwatani vibrating equipment brand globally with increased access to the product through its global distribution network. Schoepflin explains that customers will benefit further by having access to a vastly increased customer service network. 

Speaking about future developments, Schoepflin says that Sandvik, through its global technology resources, will provide access to monitoring and automation processes as well as access to its extensive R&D facilities which include simulators. 

“This will provide opportunities for driving efficiency arising from the advance of artificial intelligence in the Fourth Industrial Revolution and will significantly empower the process of cost effective customisation,” she says. 

KWATANI SCALPERS TREBLE PANEL WEAR LIFE

As mines move towards using one large scalping screen between primary and secondary crushers – rather than a modular approach using multiple smaller screens – Kwatani 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 could be replaced, many operations are not so lenient, says Mayhew-Ridgers.

“The message from these mines is clear: the longer the scalper can run between maintenance interventions, the better,” he says. “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,” he says. “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. 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,” he says. 

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. 

KWATANI GROWS ITS BASE OF CUSTOMISED SCREENING SOLUTIONS

As leading vibrating screens and feeders specialist Kwatani has transitioned from equipment supplier to solutions provider, it has attracted customers from well beyond South Africa and even outside Africa.

According to Kwatani general manager sales and service Jan Schoepflin, the company’s strong in-house expertise and design capability – combined with the world-class manufacturing quality it consistently achieves – ensures that 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 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 African orders have been mainly to gold mines, and there is growing potential for gold mining in East Africa, he 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.”

He highlights that 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. 

“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 to be 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.”

COAL MINES NEED LOWER COSTS, RAISED PRODUCTIVITY

Despite South Africa’s energy supply being heavily reliant on coal, weak prices and more demanding mining conditions are putting pressure on coal mines and their suppliers to do more with less.

“Coal prices are low and any recovery in the short term is very unlikely,” says Frengelina Mabotja, senior metallurgist and capital sales engineer at vibrating screen specialist Kwatani. “Going forward, as coal seams with more overburden have to be mined, surface mining will potentially become much more expensive.”

Adding to the coal industry’s challenges is the unwillingness of many lenders to fund new coal plants and expansions, leading to great uncertainty. The result is a strong drive for ongoing cost reduction and increased productivity across both majors and juniors in the sector, says Mabotja.

“While most of SA’s coal supply is produced by a handful of major mining houses, Eskom has in recent years sought to develop the junior market with black ownership,” she says. “Kwatani partners with majors and junior miners alike, offering two distinct equipment ranges tailored to each segment’s specific requirements and capital budget.”

With its 44 years of local and global experience, Kwatani provides customised, cost effective processing solutions for mines’ specific needs. She notes that vibrating equipment requirements can vary significantly between a smaller-scale junior miner and a long-life major. This is in terms of the equipment’s size, operating lifespan, tonnage throughput, efficiency and yield requirements.

“Apart from the initial capital expenditure, mines’ process equipment has an enormous influence on their production efficiency, tonnage and operating cost,” she says. “Our long-lasting, robust vibrating screen and feeders are designed for continuous tonnage throughput and high efficiency. This reduces the processing cost per ton and the overall cost of the machine over its lifetime.”

For the large mine segment, Kwatani’s designs have included high capacity and performance screens such as its 4,3 m wide banana screen. Its brute force grizzly feeders for run-of-mine (ROM) operations are capable of sizing and feeding material at up to 2 000 tph, even from high drop-heights.

“Our engineering team has optimised the structural integrity, weight distribution and lifespan of this equipment,” says Mabotja. “We have many of our 4.3m wide banana screens operating at the largest opencast coal complex in the world.”

At the same time, Kwatani supplies screening equipment below 2,4 m wide for smaller-scale, modular plants processing up to 250 tph. These units are tailored to budget and provided within short delivery times.