Tag Archives: Multotec

Multotec expands Brazilian presence with new manufacturing facility

Multotec has recently expanded its operation in Brazil with the opening of a manufacturing facility that, it says, enables the company to bring its manufacturing capabilities closer to its customers in the country, increasing its speed to market and enabling it to better serve the local mining sector.

Located in the city of Contagem, in the south-eastern state of Minas Gerais, the manufacturing facility is within close proximity of a multitude of iron ore mines that require an extensive range of mineral processing equipment for their plants.

Multotec Brazil Country Manager, Anthony Artin, explains that with Brazil being the world’s second-largest iron ore producer, Multotec had identified the country as a potential area of growth many years ago.

Artin says that, initially, Multotec Chile was overseeing the full South American region, with the company deciding to open a sales office in Brazil in 2019, giving focused service to Multotec’s customers here.

“The dynamics of Brazil are very unique as it is the fifth biggest country in the world, with the sixth largest population,” Artin says. “It has strict and complex import regulations.”

The feedback from clients emphasised the importance of localised sales and manufacturing in Brazil, according to Artin. Commercial and legislative requirements prompted a shift in Multotec’s approach, transitioning from a sales office to establishing a manufacturing facility in the country.

He said: “Our clients highlighted the significance of Brazil for Brazilians, emphasising the need for local manufacturing facilities to cater to the Brazilian market.”

The new facility focuses strongly on screening media, using compression moulding for the production of rubber screen panels and also hand-casting polyurethane (PU) panels. However, customers are increasingly requesting other products too, such as samplers and spirals that are used in mineral processing and separation.

“There are currently two bays in the manufacturing facility,” Artin says. “One is used for stockholding, assemblies and shipping, while the other is used for fabrication. Fabrication is done in two areas, with presses used for compression moulding of rubber and hand-casting moulding PU tables, alongside a PU preparation section and ovens.”

Artin notes that the facility has the capacity to produce 15-20 t/mth of elastomers and employs trained people in manufacturing and in stores, shipping and receiving. Plans are in place to increase the factory’s manufacturing capability in terms of injection moulding and more compression moulding, he said, adding that more machines will be incorporated into the operations – resulting in more people being employed in the future.

In addition, the premises also contain an office currently staffed by commercial, sales and administrative people. Having the office and manufacturing facility in one location is an added advantage, according to Artin. “It is beneficial having the people who sell the products located in the same space production,” he says. “They can thus understand the intricacies of the product and the processes that are involved in the manufacturing of the equipment.

“The ultimate goal is to have a fully localised branch. We want to have an all-Brazilian team, working for Multotec Brazil. Local partners and suppliers are key to us as we rely on local raw materials to deliver completely locally manufactured products.”

While the company’s focus has been on establishing the manufacturing facility, Artin says it has already applied for an extension of its environmental licence to ramp up its monthly production as it takes advantage of Brazil’s current lithium boom, which presents considerable opportunities in dense medium circuits.

Multotec Brazil will receive support from Multotec’s global industry knowledge and expertise, leading to enhanced operational efficiencies and providing customers with comprehensive solutions over and above a quality product offering, the company says. Furthermore, Brazil will collaborate closely with Chile on the Multotec range of customised samplers. With input from Chile and local manufacturing in Brazil, this collaboration will create a seamless workflow that maximises efficiency, ensuring the delivery of high-quality samplers tailored to the specific requirements of customers, it concluded.

Multotec pulping chute advances at Ekapa open opportunities for fines scrubbing tech

The performance of Multotec’s pulping chutes at Ekapa’s diamond treatment operation in Kimberley, South Africa, over the past couple of years has, the company says, opened the door to quicker and more cost effective fines scrubbing.

According to John Britton, Technical Consultant at Multotec, the two pulping chutes have achieved outstanding results, helping the customer’s facility to cost effectively increase the throughput of its Combined Treatment Plant (CTP).

“At our recent two-year inspection of the plant, we found that the wear rate on the ceramic lining of the wave generator was only 20 mm over that 24-month period,” Britton says. “Each chute was processing 380 t/h of recrushed kimberlite product with 380 cu.m of water, rushing down a 28° incline.”

Multotec’s patented wave generators use gravity to create a constant turbulent mixing action in the slurry flow that releases the mud, clay and slime sticking to the kimberlite particles. The chutes are positioned to receive material from the high pressure grinding rolls’ interparticle tertiary crushing circuit. Multotec’s engineered alumina ceramic tiles give the chutes and wave generators high wear resistance, it says.

“The chutes exceeded our expectations in how well they separated the clay from the kimberlite ore and broke up clay balls in the material stream,” Britton says. “This has really demonstrated the long-term capacity of our design to deliver results with hardly any maintenance or operator intervention.”

He highlights that the chutes are stationery structures that rely on the kinetic energy being created by the in-rush of slurry flow over the wave generators. This makes the solution much simpler and less energy-intensive than traditional rotary scrubbers with motors, drives and gearboxes. The chute can also achieve its results much quicker, as the material flow passes through in just three to four seconds.

Ekapa CEO, Jahn Hohne, says he has been impressed by how well the chutes have performed as an alternative to a considerably more costly scrubber circuit, and having delivered a 20% increase in throughput through the plant and making a positive economic contribution to overall efficiency. Hohne says he admired Multotec’s innovation capability and looked forward to even further improvements in the design.

Britton notes that, after conducting the wear inspection of the chutes, there were modifications Multotec was planning. One of these related to the retarder bars, which slow down and divert the slurry flow.

“We believe we can achieve even better results if we remove some of the retarder bars and install another set of wave generators,” he says. “Our results suggest that this will get the ore material even cleaner, before it reports to the screen, the conveyor belt and finally the dense medium circuit.”

The success of the pulping chutes at Ekapa has led to considerable interest from other diamond producers in southern Africa, he added.

Mato ready to show off new primary, secondary conveyor belt cleaners at Electra Mining

Mato is set to unveil a range of new belt cleaners at Electra Mining Africa 2022, in Johannesburg, in September, using the platform to highlight plans to expand its supply footprint.

Having been founded with a specific mandate to manufacture and supply mechanical conveyor belt fastening systems, Mato Products, a Multotec Group company, says it has become a household name in belt lacing equipment and clip fasteners. The two product ranges remain the company’s bread and butter, confirms Managing Director Benjamin Sibanda.

However, when Sibanda took the reins at Mato, initially as General Manager back in 2015, one of his immediate tasks was to diversify the company’s offering, which prompted the move into belt cleaning systems. To mark its first foray into this market, the company displayed its first units at Electra Mining Africa 2016.

In 2019, Mato landed its first major contract to supply and maintain belt cleaners for a leading colliery in the South African coal region of Emalahleni. This was immediately followed by another major contract, this time at a Botswana colliery for both the plant and underground operations. Since then, the company’s belt cleaning range has gained significant momentum in the market, particularly in the coal sector.

Going forward, however, the focus is to further grow the supply footprint into other commodities beyond the mainstay market of coal. The plan has already been put into action with a recent contract to supply a gold mine in Gauteng, South Africa. Elsewhere, the company is due to sign a major belt cleaning contract with a Botswana-based diamond mine, which will represent its largest deal to date.

“We have traditionally enjoyed major success in the coal market, but we believe that now is the time to expand into other commodity areas such as gold, diamond, iron ore and platinum,” Sibanda says. “To achieve this, we will pivot Multotec’s existing footprint into areas we have never been before.”

The market expansion strategy will be buoyed by a range of new offerings to be displayed at Electra Mining, which is scheduled to take place at the Johannesburg Expo Centre from September 5-9.

“Our main focus this year will be nothing else but belt cleaners,” Sibanda says.

One of the new offerings on display will be the MDP & MTP primary belt cleaner, which replaces the locally made MCP3-S model. Initially, it will be imported from Mato Australia, the manufacturing hub for the Mato Group, but, following Mato Products SA’s recent appointment as the group’s second manufacturing hub, the new primary belt cleaner will be produced locally.

Unlike the old MCP3-S which used the spring tensioning system, the new MDP & MTP comes with a compression spring.

The downside of the spring tensioning system is that, over time, it gets fatigued, especially in tough ores with heavy vibrations. Once you lose the spring tensioning, Sibanda says, the belt cleaner is deemed ineffective.

“Instead of pulling in the blade onto the drive pulley system as the means of tensioning, the compression spring now allows us to compress the blade onto the drive pulley,” he said. “This approach offers a longer life, even in applications with heavy vibrations.”

Another new offering making its debut is the MUS3 secondary belt cleaner, designed to fit in small and restricted conveyor areas where limited space is available. It is also suitable for reversing conveyor belts such as feeder belts or belts which have roll back.

Completing the new line-up will be the MUS2 Duro, an upgraded version of the MUS2, which has a parallelogram designed into the cushion. This facilitates a constant blade angle attacking the material flow allowing automatic adjustability within the cleaner for when belt thickness varies.

“Previously, the MUS2 had a buffer and the tungsten blade separate from each other,” Sibanda says. “This presented major problems, especially in aggressive applications with high vibrations. As part of our own local design improvements, the tungsten tip is now moulded onto the buffer as one unit and has been implemented for the range globally as the best version, making the MUS2 Duro a more robust and long-lasting belt cleaner than the previous MUS2.”

FLSmidth, Kwatani, Multotec and Zest WEG set for Electra Mining Africa

Major domestic and international mining equipment suppliers are gearing up for Electra Mining Africa in Johannesburg, South Africa, with FLSmidth, Kwatani, Multotec and Zest WEG just some of the names set to show off their offerings from September 5-9.

MissionZero on show

FLSmidth will be using this year’s exhibition to demonstrate the progress it is making in realising its MissionZero strategy, an ambitious program that aims at allowing mines and process plants to achieve zero emissions, zero water waste and zero energy waste by 2030, it says.

One of the innovative products to be featured on the stand includes its REFLUX® Flotation Cell (RFC). “This draws on FLSmidth’s established REFLUX technology, which has been in the industry for many years now and has proved outstandingly successful, particularly in the coal industry,” Alistair McKay, FLSmidth Vice President for Mining in Sub-Saharan Africa, Middle East and South Asia, said. “The RFC brings together the REFLUX concept with flotation technology and will allow process plant operators to start recovering the smaller fractions in their ore feeds, as well as introducing coarse flotation into existing systems.”

McKay adds that the RFC is now at an advanced stage of development and that FLSmidth is hoping to have a pilot plant operating in South Africa before Electra Mining Africa.

FLSmidth has many existing products and technologies that are already contributing strongly to MissionZero. Among them are its SmartCyclone™ solution, which automates the monitoring and control of cyclones; LoadIQ, a product that uses a system of smart sensors and artificial intelligence-based software to determine the optimal load in SAG mills; and its EcoTails™ system, developed in collaboration with Goldcorp (now part of Newmont), which blends filtered tailings with waste rock to create a geotechnically stable product called GeoWaste, which can be used to fill excavated areas.

While FLSmidth is a global group, much of the equipment that will be featured on its stand is produced in South Africa, either in whole or in part, at its Delmas Super Center, which manufactures vibrating screens; feeders, breakers and sizers; and polyurethane screening media and flotation parts.

Kwatani’s new age of efficiency

Kwatani plans to come to the Johannesburg Expo Centre ready to cast the spotlight on its modern multi-slope screen design and its strides in digital innovation.

While multi-slope screens – generally known as ‘banana’ screens – have been available since the 1980s and are, therefore, not necessarily new to the market, Kwatani has, in recent years, ushered in a whole new approach to the design of these screens, according to CEO Kim Schoepflin.

“Traditionally, multi-slope screens have always been renowned for their high velocity,” she says. “While the high velocity translates into high capacity, the downside is the resultant screening inefficiency and the high wear rate of the panels, which in turn translates into high maintenance costs.”

Kwatani can design its screens to perform efficiently at a lower building height and fit into existing screen infrastructure. The lower physical height of the screen also impacts the capital cost of complementary equipment such as pumps.

Apart from its leading-edge multi-slope screen design, Kwatani will also showcase its advances in the digital space. Digital technologies, says Schoepflin, have the potential to unlock new ways of managing variability and enhancing productivity. The miniature version of the Kwatani multi-slope screen to be displayed at Electra Mining Africa will, therefore, be digitally-enabled.

Kwatani COO, Kenny Mayhew-Ridgers, added: “We approach digitalisation in two ways. We believe that sensors are the starting point, as they are where data is created. Embedding sensors in plants, which in turn churn out large volumes of data for analysis, is increasingly attainable.”

Schoepflin continued: “The second scenario is the cloud environment, which is gaining strong momentum across the industry. As mining companies digitally transform, they simultaneously expect greater control over their data with all the benefits of a cloud experience. At Electra Mining Africa, we will, therefore, showcase these two scenarios – sensors with a PLC/SCADA and control room environment, as well as a cloud solution.”

The company also plans to highlight how the recent acquisition of Kwatani by Sandvik further advances its innovation drive, Schoepflin says.

“Leveraging Sandvik’s substantial experience in this field, Kwatani will further drive its digital offering, thus ushering in a new age of efficiency and winning the productivity and cost-control battle for our customers,” she concluded.

Multotec to showcase ESG-focused offering

Multotec has exhibited at every Electra Mining Africa exhibition since the show was launched in the 1970s. As usual, it will have a strong presence at this year’s event, with its in-house experts on hand to brief visitors to the stand on the company’s line-up of minerals processing equipment.

“Given that the Electra Mining 2020 was cancelled due to COVID, we see this year’s show as an excellent opportunity to reconnect with our customer base,” Rikus Immink, Multotec’s CEO – South African Operations, said. “The overall theme will be how our equipment and systems can assist customers in realising their environmental, social and governance (ESG) goals. We will also be emphasising our strong commitment to South Africa. We are a global group now, but we started in South Africa and the country still accounts for about half our revenues.”

Virtually all Multotec’s products can, to an extent, reduce consumption of resources such as water and energy and allow for more efficient operations, the company says. A prime example is provided by the pulping chute, a highly innovative concept in fines scrubbing first installed at Ekapa Minerals’ Combined Treatment Plant (CTP) in Kimberley in late 2019. More recently it has been successfully trialled at a diamond mine in Botswana. “We are very proud of this innovation and it will feature very strongly on our Electra Mining stand,” Immink says.

Other Multotec products to be highlighted at the show and which are able to contribute to energy and water saving include the company’s classification cyclones, which provide efficient solutions for desliming and dewatering; its ultra-fines spirals, which offer a non-chemical process for fines recovery and allow easy water recovery; its centrifuges and filter presses, which deliver effective solid liquid separation and dewatering solutions; and its screening media, whose many benefits include the recovery of non-chemical water.

Immink also notes that Mato belt cleaners, which will also feature on the Multotec stand, prevent spillage and reduce clean-up requirements. “This is not a product that gets much attention and yet it can play an absolutely crucial role in cutting wastage and in maintaining a clean environment,” he said.

The Multotec products that will be showcased at Electra Mining Africa 2022 are manufactured in South Africa, primarily at Multotec’s extensive facilities in Spartan, Johannesburg, with an accredited local content certificate from SABS.

Zest WEG focuses on efficiency, sustainability

After a decade-long expansion of its manufacturing capabilities in South Africa, Zest WEG, the South Africa-based subsidiary of Brazil’s WEG Group, says it is well placed to extend its already extensive footprint in the African market.

“We now have six manufacturing facilities in Gauteng and Cape Town, producing a wide range of equipment including gensets, transformers, electrical panels, E-Houses, MCCs and mini sub-stations,” Zest WEG’s outgoing CEO, Juliano Vargas, says. “This ability to manufacture locally gives us a huge advantage in the African market, as we can produce economically and deliver promptly to countries throughout the sub-Saharan region.”

Most of Zest WEG’s product offering will be on display at the Electra Mining Africa 2022 exhibition.

Vargas’s successor as CEO of Zest WEG, Eduardo Werninghaus, said: “Our theme, as always, will be how to change energy into solutions. There will, however, be a particular emphasis on efficiency and sustainability.

“One of the products that we’ll be highlighting is our range of WEG IE4-rated super-premium efficiency electric motors which were launched locally last year and which cost no more than their IE3 predecessors. These are the most energy efficient motors in the market and offer major operating cost advantages to users.”

Werninghaus says that the WEG IE4 motors have already received a warm reception from the mining industry, which is struggling with constantly rising electricity costs. “A medium-sized mine typically has between 2,000 and 3,000 electric motors on site – powering everything from fans and pumps to conveyor belts and screens – so the potential for very significant energy and cost savings is huge.”

Werninghaus adds that Zest WEG will also be showcasing many high-tech products and systems at the show. These include the already available WEG Motor Scan, which allows the continuous monitoring of electric motors and other rotating machines; and Pump Genius, a software package that enables a standard VSD to be dedicated to specific pumping systems with various motor and pump combinations, thereby providing improved control and monitoring capability.

Also on show will be WEG’s new Motion Fleet Management system, which uses artificial intelligence and machine learning to diagnose and monitor rotating equipment such as motors, VSDs, gearboxes and compressors. Based on cloud computing technology, the performance of assets can be monitored at any time from any part of the world. This approach reduces unplanned downtime and optimises repair actions.

“Keeping abreast of digital developments is a priority for us and Electra Mining Africa will give us an opportunity to show just how far we’ve come on our digital journey,” Werninghaus concludes.

Multotec spirals helping assess heavy minerals potential in Cameroon

Exploring for heavy minerals in Cameroon, a multinational mining company is gaining valuable results and insights through the use of an on-site pilot plant from South Africa-based process equipment leader Multotec.

The pilot plant was designed and assembled at Multotec’s extensive design, manufacturing and testing facilities at Spartan near Johannesburg, South Africa, and shipped to the remote site in central Africa last year. The containerised plant includes a range of Multotec’s own equipment including screen panels, cyclone rig and spiral rig.

According to Faan Bornman, Technology Manager: Research and Development at Multotec’s Technology Division, drill samples from the prospect area are passed over the screen to remove oversized material, with undersize going into a sump to be mixed with water to the correct density. The undersize material reports to the cyclone for desliming – the removal of very fine particles – delivering an underflow with an optimal size range of between 38 microns and 1 mm. This is fed to the spiral rig for concentration, with the spiral delivering a concentrate, middlings and tailings. The process allows the project to assess its economic heavy minerals portion, which is concentrated towards the inner section of the spiral.

“Multotec’s HX5 and 117HM spirals were employed to suit the customer’s requirement, with the new 117HM spiral showing great recovery in mineral sands,” Bornman says. “With the HX5 handling up to 5.5 t/h and the 117HM 2.3 t/h, these spirals also offer different recoveries and grade in the various heavy minerals.”

The equipment in this pilot plant is vital to achieving an accurate assessment of the deposit’s viability, but the results also give the customer important insights into how the full-scale plant should be designed if exploration proves results provide positive, according to Multotec.

“To ensure that the customer receives optimal value from the pilot plant, we sent a process engineer to site to commission the system,” Bornman says. “During the several weeks that he spent there, he also conducted training with local staff on how to run and maintain the plant.”

Multotec supplies 38 slurry pumps to Kazakh chrome project

Mineral process equipment specialist Multotec’s global reach has recently been highlighted with the supply of slurry pumps to a chrome project in Kazakhstan.

According to Gerhard Hendriksz, General Manager, responsible for slurry pumps at Multotec, an order of 38 slurry pumps was delivered in mid-December 2021 through a collaboration of Multotec’s international business team and the company’s distributor in Kazakhstan.

“The pumps were produced according to the specifications provided by Multotec’s distributor, ensuring the units will deliver the required duty for the end customer,” Hendriksz said. “This includes being designed to withstand highly abrasive operating conditions.”

Certain chrome deposits in Kazakhstan boast some of the world’s highest concentrations of chrome oxide (Cr₂O₃) – up to 62% content – making the slurry particularly abrasive. The pump range Multotec delivered includes models from the HD25 to the MD300, in metal- and rubber-lined configurations to suit their respective duties.

A turnaround time of just 10 weeks was achieved, with Multotec leveraging its local supply chain that included foundry work, machining and other suppliers, as well as collaboration with Multotec’s technical partner, 7D, based in Perth, Australia.

Andre Burger, Production Manager, responsible for pumps at Multotec, emphasised that a close working relationship with the end user and Multotec’s Russian-speaking business team ensured smooth preparation and delivery.

“Our distributor has in-depth knowledge of the customer’s applications and has the engineering expertise to ensure optimal product specification and performance,” Burger said. “Multotec will support the products with aftersales and support services, including availability of spare parts.”

Despite the trade disruptions related to the COVID-19 pandemic, Multotec has continued to perform strongly on the export front. Last year, it earned a place in the Exporter of the Year Awards – presented by the South African Capital Equipment Export Council.

Multotec supplies a complete range of pumps for medium- and heavy-duty slurry applications, including cyclone feed, spirals feed, mill discharge, tailings disposal, filter feed, effluent discharge and spillage. The range caters for flow rates from around 15 cu.m/h up to 2,000 cu.m/h.

Multotec addresses grade control, recovery issues with RAMA sampling system

With its latest sampling system that aligns with metallurgical accounting standards, minerals processing equipment company Multotec says it now offers unprecedented levels of accuracy for effective plant optimisation.

The company’s Realtime Automated Metallurgical Accounting (RAMA™) system promises to deliver significant value by unlocking higher mineral content through improved grade control and recovery, as well as by optimising the consumption of reagents. The system brings together three sampling disciplines – metallurgical accounting slurry sampling, sub-sampling, preparation and analysis – into one solution, it says.

“By integrating our advanced samplers with a sample preparation system that meets metallurgical accounting standards, we can feed online analysers with a fully representative and accurate sample,” Modisaotsile Nyokong, Process Manager at Multotec, says. “While analysers can be accurate instruments, they cannot provide meaningful results if they are fed with inaccurate samples.”

Nyokong highlights that the RAMA online analysis feed preparation system extracts regular and full sample increments from slurry flow streams according to AMIRA P754 metal accounting standards, best practice standard and Theory of Sampling (TOS). This eliminates more than 80% of the total sampling error and allows real time process control to be conducted to the highest standard, according to the company.

“Samples are extracted from the production flow using automated mechanical samplers which are TOS compliant,” he says. “This is achieved by taking full cross-cut samples that are representative of the flow stream.”

The analysed slurry is therefore unbiased, presenting an accurate reflection of all the key parameters such as particle size, slurry density, settling velocity and mineral grade, Multotec claims. Nyokong explains that process control samplers – including pressure pipe, poppet and shark fin type samplers – have traditionally been used to feed online analysers. However, these primary samplers do not comply with the TOS, with the result that poorly represented samples are analysed with high levels of precision – a futile exercise.

“Our advantage with the RAMA system lies with feeding representative samples to online analysers, using correct sampler designs,” Nyokong says. “This produces real-time results that represent the flow stream and are free of error or statistically significant bias.”

Multotec’s slurry sample preparation solution prepares and treats each analysis stream in its own line, making it ideally suited to analysers that deal with streams individually. This avoids cross-contamination. Where multiple streams are analysed through the same analyser source and detectors, some cross contamination of streams can occur with different grades or mineral properties – undermining the accuracy of the result.

Over an analyser multi-stream cycle, the RAMA system can collect composite samples for each stream, according to Willem Slabbert, Sampling and Magnetics Product Specialist at Multotec. This means the analyser does not measure the instantaneous off-take stream ‘sample’ from the traditional in-line continuous discharge like process control samplers – which is only done about 30 minutes apart.

“Rather, it measures the performance of each stream through multiple composite samples taken over the 30-minute interval,” Slabbert says “This reduces the grade or quality variability per flow stream, and gives the plant manager a more representative monitoring of minimum and maximum process conditions – with precise values.”

The problem with ‘snapshot’ sampling of process control samplers is that stream properties can fluctuate before and after the analysis., meaning the fluctuation is not captured in the results. By contrast, the RAMA system’s composite sample accounts for all process variations over the analysis period, according to Multotec.

Slabbert reiterates that sample analysis results are only as good as the sample presented for analysis, pointing out that this applies as much to online analysers for process control as it does to conventional laboratory analysis for metallurgical accounting.

“RAMA is also a cost saving solution, as separate process control samplers are no longer required,” he says. “The samplers’ purpose in our system is doubled up for both metal accounting and for process control – without the need for any compromise.”

Configured in a containerised and modular design, RAMA is a compact and mobile system. This allows for easy installation and retrofitting into any plant operation, where it can feed any type of online analyser. It can also be readily transported and commissioned, with flexibility for expansion where necessary. Layout options are available for plants that have primary and secondary sampling with a subsequent containerised sample preparation stations, as well as for those with primary sampling only and separate secondary sampling preparation.

The RAMA system allows analysers, for the first time, to be fed with representative samples taken from the production flow stream, according to the company.

Multotec added: “The innovative combination of existing equipment with proven track record into a modular, containerised solution will bridge the gap between metallurgical accounting accuracy and accurate process control.”

Slabbert concluded: “The advantages of this novel combination of sampling global best practices into process control applications will unlock value for both analyser calibration as well as optimal, dynamic process performance.”

WEC Projects, Multotec combine for Mali gold mine modular wastewater treatment plant

WEC Projects, in conjunction with its partner, Multotec, has designed and custom engineered a wastewater treatment plant for a gold mine in Mali, West Africa.

The plant, used to remove arsenic from the mine’s wastewater stream, incorporates a modular design which simplifies the logistics and reduces the costs of transport and installation, according to WEC Projects.

The international mine operator is a client of Multotec, an engineering company specialising in mineral processing plant design and installation. The company approached WEC Projects, a local EPC contractor in the water and wastewater treatment industry, to jointly develop a customised solution to remove toxic arsenic from the mine’s wastewater. A multi-stage removal system was required to meet the strict standards for the mine’s discharge. However, the system also required a modular design which would facilitate the transportation, installation and commissioning of the plant.

Wayne Taljaard, Managing Director of WEC Projects, said: “The mining industry in Africa presents some very unique challenges, not the least of which are the remote locations of many of the mines and the difficulties experienced in getting staff and equipment to sites where road, power and water infrastructure is often lacking, hence the requirement by Multotec for a modular solution that would allow for rapid transport to site and to simplify its installation and commissioning.

“The COVID-19 pandemic added to the difficulties for us and the client, causing delays that reduced the time frame for delivery.”

In the treatment process, the mine’s wastewater undergoes primary solid/water separation using coagulation and flocculation and the primary clarifier. From there it enters a two-stage chemical precipitation and secondary clarification process to reduce the arsenic levels. The final stage sees the sludge undergo dewatering before disposal. The treated water, although not potable, is then reused by the mine for process applications.

The plant has a processing capacity of 150 cu.m/h and is capable of reducing the arsenic levels from around 13 mg per litre to less than 0.1 mg per litre.

Taljaard added: “The project, incorporates a number of unique features in addition to its modular design, including nine custom-designed, proprietary lamella clarifiers and a multi-stage arsenic removal process capable of treating the wastewater to the mine’s discharge standards. WEC Projects has completed a number of water and wastewater treatment projects throughout Africa. Our ability to provide a customised and modular solution for Multotec underscores our ability as a major player in the industry both in South Africa as well as across the continent.”

Multotec looks to optimise SAG mill liner performance, milling efficiency and liner life

As the mining industry moves to larger semi-autogenous grinding (SAG) mills for higher productivity, Multotec says it is developing and applying innovative liner designs to optimise liner performance, mill efficiency and liner wear life.

“Our strong analysis capabilities in the design process – including discrete element analysis (DEM) and finite element analysis (FEA) – allow us to continuously evolve the application of our composite liners,” Sam Hearn, Global Sales and Business Development Manager at Multotec, says.

Hearn highlights how Multotec uses DEM software to simulate the interaction between the mill charge and the liners, and to evaluate liner profile over the life of the liner.

“The DEM analysis considers a range of variables such as the ore’s bond work index, its specific gravity, the size of the grinding media, the mill speed and the slurry density,” he says. “Sophisticated simulation capability allows us to accurately model the performance and wear of our mill liners. This includes predicting the liners’ wear life, to avoid unscheduled downtime and to extend the time between replacements.”

Emphasising that no two mill liner applications are identical, Hearn says this simulation can guide very specific refinements in the liner design for each customer. A detailed understanding of the operating conditions is vital to ensure that the final solution delivers optimal results.

He notes that the traditional use of steel liners in large SAG mills presents a number of challenges. For instance, there may be bending stress inside the steel liner due to inexact fitting on the mill’s curved surface, and the higher rigidity of steel, compared with rubber, makes it less than optimal for absorbing the energy of rock material inside the mill.

“This is where our composite liners come into their own,” he says. “These innovative liners combine the impact resistance of Hardox 500 steel inserts and the absorption capacity of our specially formulated wear-resistant rubber compound. Through the simulation, the structural integrity of the liners can be verified, while the geometric layout of the liners can be optimised.”

The composite liners are locally manufactured at Multotec’s extensive facility in Spartan, Gauteng, South Africa, in an advanced process that includes its unique submerged cutting technique to preserve the surface hardness of the liners.

“We combine our innovative design capacity with the latest tooling capability and production technology for large-scale manufacture,” Hearn says. Following the design and manufacturing process, Multotec conducts field trials to compare with the relative performance of composite liners and steel liners.

“We are confident that, given our product improvement processes and simulation ability, the wear life of our liners will achieve and often exceed expectations,” he says.

Multotec looks for increased resistance, longer wear life from new ceramic-based solution

A new ceramic-based solution from Multotec has opened the door for a range of componentry to be shaped using pressed alumina ceramics for high wear resistance and longer wear life, the South Africa based company reports.

According to Boyd Butterworth, Sales Engineer at Multotec Wear Linings, the opportunity arose when a chrome smelter in the Steelpoort area of South Africa’s Limpopo province was searching for a more cost-effective solution for certain wear parts in their rotary dryer multi-cyclone arrangement.

“The customer initially required the fabrication and ceramic lining of steel components in the multi-dryer cyclones,” Butterworth says. “The units are employed in the process of drying chromite ore particles and other feed material on its way to the pelletising section of the plant.”

The units are essentially dust cyclones – rather than the process or separation cyclones Multotec supplies – and are subject to aggressive wear. The feed to these multi-dryer cyclones typically consists of chromite ore, reductants such as anthracite, char, coke and coal, and fluxes like quartzite, dolomite and lime.

“The multi-dryer cyclone has four main components, made initially of steel and later lined with ceramics in response to the rapid replacement rate,” Butterworth says. “The wear rate is exacerbated by the high velocity of the material, which is required in order for it to remain in suspension while passing through the system.”

The customer’s eagerness to find a more effective solution allowed Multotec to present an unusual – perhaps unique – concept: solid ceramic components custom-shaped for this specific purpose, the company said.

Butterworth noted that the previous installation of standard ceramic tiles by a competitor did not adequately protect the components from the highly abrasive material which, moving at about 18 m/s, was still leading to frequent component replacements.

“Our proposal was to produce a solid ceramic blade and dome arrangement, as well as to provide the rest of the tube and inlet sections with engineered ceramics, installed at a very high standard,” he says.

Paving the way for this solution was a highly specialised and innovative new fabrication technique that saw the ceramics shaped into various complex and intricate designs while they are in the ‘green phase’ of production, using state-of-the art CNC technology.

“Thanks to this technique, we can produce solid alumina ceramic machine components,” Butterworth says.

The company’s research to date suggests that this might be the first time components like these have been produced from pressed alumina ceramics – making them a pioneering achievement.