Tag Archives: hydrocyclones

Weir Minerals expands the Cavex 2 hydrocyclone range with 650 model

Base metals, Comminution of minerals, Equipment maintenance, IoT, Mineral processing, Mining equipment, Water management, , , , , ,

Weir Minerals, building on over 20 years of Cavex® hydrocyclone experience, has added the Cavex 2 650 to its product line, with the cyclone set to deliver unparalleled results, the company says.

The release follows the recent launch of the Cavex 2 hydrocyclone, which brought with it the introduction of a LIG+™ inlet and chamber design that, the company says, produces a more stabilised flow pattern, further reduces turbulences and friction throughout the hydrocyclone and provides up to 30% additional capacity.

The latest 650 model has undergone years of research, lab testing and in-field testing to ensure it can withstand the rigours of heavy-duty industrial and abrasive applications. It also addresses the continual demand for increased operational and circuit capacity, and offers customers process improvements combined with digital technology, Weir Minerals said.

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

“By reducing bypass returning to the mill, fewer fines are returned back to the mill in a closed-circuit milling process, thus reducing the need for energy to be used to further process particles that are already small enough to move on to the next stage. This frees up mill capacity, previously used up with fine particles, for the size reduction of larger particles.”

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

And, finally, using equipment with a higher volumetric capacity requires fewer units to be installed upfront as well as fewer consumable spare parts used over the life of the hydrocyclone.

Significant benefits to mining customers include:

  • Increased operational and circuit capacity up to 30%;
  • Maximised plant recovery by reducing the quantity of misclassified particles with an average improvement of the alpha parameter of more than 10%;
  • Improvements in bypass with an average of over 15%;
  • Opportunity to retrofit Cavex 2 650 cyclone into existing cyclone cluster footprints;
  • Less turbulence during the separation process due to the LIG+ inlet and elongated chamber design;
  • Enhanced performance with a Synertrex®-enabled monitoring system, which can detect roping or blockage conditions in advance for continuous, efficient operation of the hydrocyclone; and
  • Improvement of environmental footprint.

To satisfy all process conditions and slurry types, the Cavex 2 650 hydrocyclone comes with a range of material technology options including Linatex® premium rubber, R55 rubber, neoprene for high levels of hydrocarbon and ceramic.

The Cavex 2 650 hydrocyclone can be customised to suit almost any application with a variety of spigots, vortex finders and cone angles, according to the company.

These new hydrocyclones have already been put to the test, with the latest Cavex 2 650 hydrocyclone trial taking place with a customer in Chile. The testing was conducted in a large copper ore mine which had a SAG mill in a closed circuit with the cyclone cluster. The trial tested one Cavex 2 650 in a six-place cluster of existing Cavex cyclones and saw an improvement of up to 48.5% in circulating load and 31.7% in water bypass versus the original cluster, according to Weir Minerals.

A lab water test with the same hydrocyclone fittings as above also yielded positive results: a 211 mm inlet and 260 mm vortex finder delivered 16% more capacity at 100 kPa, and 17% more capacity at 250 kPa.

“These improvements in efficiency and bypass translate to increased savings for brownfield sites where the existing hydrocyclones do not have enough capacity and are maxed out, while greenfield projects benefit from savings in capital expense,” the company said.

The Cavex 2 650 hydrocyclone is the second in a range of standard sizes that Weir Minerals is planning to release, with more sizes in development to expand the current product range.

Cedric Minería selects CDE EvoWash wet processing tech for Buin sand, gravel ops

Energy minerals, Mineral processing, Mining equipment, Mining services, , , , , , , , , , , , , , , , , , ,

Chilean mining and aggregates company, Cedric Minería, has announced a major overhaul of its aggregates business following a significant investment in advanced wet processing technology from CDE, the Belfast-based company says.

The family business, which expanded into aggregates production in 2003, has revealed plans for a new wet processing solution at its Buin operation.

Established in 1981, Cedric Minería specialised in the production of calcium carbonate and sulphur products before diversifying its interests and launching its silica operation, Mina Nancy, near the city of Calama in Antofagasta Region.

It soon secured listing as a strategic supplier of silica to state-owned copper mining company Codelco for its copper smelting plant in Chuquicamata, northern Chile.

Following the success of its silica business, Cedric Minería soon after commissioned its first aggregates processing plant in Buin which supplies the local market with a range of washed sand and gravel products for pre-cast concrete, asphalt, pipe bedding and more.

This summer, CDE will commission the EvoWash™ sand wash plant and an AquaCycle™ water management system at the company’s Buin site, replacing their existing washing screws.

Using CDE cyclone technology, the new plant will enable Cedric Minería to produce two grades of high quality, in-spec fine sands: 0-5 mm and 0-8 mm.

A compact, modular sand washing system, CDE’s EvoWash screens and separates the smaller sand and gravel fractions through an integrated high-frequency dewatering screen, sump and hydrocyclones which provide control of silt cut points and eliminates the loss of quality fines with significant commercial value.

An alternative to water extraction and the costly process of pumping water to the plant, CDE’s AquaCycle significantly reduces costly water consumption by ensuring up to 90% of process water is recycled for immediate recirculation, the company says. It helps to accelerate return on investment by maximising production efficiency, minimising the loss of valuable fines and reducing water and energy costs. A single, compact and user-friendly unit, it can be applied to high and low tonnages across many market sectors.

Cedric Minería owner, Cedric Fernández, says the investment in CDE technology is a significant step forward for the company.

“We’re making a huge technological leap forward with this new plant. Cedric Minería branched into the aggregates business almost two decades ago and throughout that time we have operated a traditional system,” Fernández said. “The existing plant has served us well, but we need a modern solution that is future-ready. Our latest investment in CDE wet processing technology represents the beginning of a new chapter for our company.”

Fernández says the COVID-19 pandemic had a significant impact on the construction industry but anticipates strong future demand for sand and aggregates to support the country’s public works investments.

CDE Business Development Executive, Gustavo Brasil, says older technology is very much under the spotlight for materials processors as they work to remedy inefficiencies.

“Recognising the limitations of the existing setup, the team at Cedric Minería are setting out on an ambitious transformation project to replace a traditional processing plant with a much more advanced and efficient technological solution,” he said.

The CDE solution engineered for Cedric Minería will revolutionise its current process, he added.

“CDE’s Evowash solution will enable Cedric Minería to produce superior fine sands with less moisture content while the AquaCycle water management system will deliver massive efficiency gains by recycling process water and driving down operational costs,” he said.

Weir releases new gate valve as it advances Terraflowing, ToolTek solutions

Comminution of minerals, Mineral processing, Mining equipment, Mining maintenance, Mining services, Water management, , , , , , , , , , , ,

Weir Minerals has released a new Isogate® WR knife gate valve to reduce cycling discharge while improving wear life.

The lightweight, long-lasting Isogate WR knife gate valve offers miners and aggregates operators alike a step change in valve performance, according to Weir Minerals.

The release came on the same week Weir Group announced its 2020 financial results, which saw the company report revenue and adjusted operating profit of £1.97 billion ($2.73 billion) and £305 million from continuing operations, respectively. These figures were down 4% and 3%, respectively, from 2019 totals.

On the new valve, Weir said: “Incorporating the latest advances in design and materials technology from Weir Minerals’ expert engineers, the range of Isogate WR knife gate valves are more reliable, while producing minimal fluid discharge and weighing considerably less than equivalent mining valves.”

John Abbott, Global Product Manager – Valves & Tailings, said: “Drawing on decades of wear analysis, we’ve optimised the Isogate WR knife gate valve’s body design, by reinforcing the areas subjected to the harshest wear and pressure. At the same time, we have reduced the weight elsewhere to produce a robust, long-lasting mining valve that’s significantly lighter than comparable products.

“The weight reduction can be especially significant in situations where a number of valves are used on a specific installation, such as in a hydrocyclone cluster, or where lightweight piping systems are used.”

The gate has also been redesigned, with stronger materials resulting in a thinner gate that can still withstand the pressure of mining slurries. This combines with the valve’s unique gate guide that, Weir says, reduces deflection by ensuring smooth gate movement and less strain on the sleeve elastomer during blade transition.

The Isogate WR knife gate valve uses Weir Minerals’ new Isogate WSL sleeve, which comes with proprietary Linard® HD 60 silica-reinforced natural rubber to solve the three most common problems with sleeved knife gate valves: leakage during cycling, tearing and load distribution ring (LDR) failure due to corrosion and erosion, the company explained.

Leveraging the Linard HD 60 rubber’s high resilience against cut, tear and abrasive wear to improve wear life, the new Isogate WSL sleeve fully encloses the LDR to prevent corrosion. By allowing the rubber to move with the blade cycles, the design reduces the chance of tearing while reducing slurry discharge by up to 75%, according to Weir.

The Isogate WSL sleeve can also be used in existing Isogate WS knife gate valves, improving wear life and decreasing discharge on cycling.

Abbott added: “When designing the Isogate WR knife gate valve, we focused on features that improve the everyday experience of working with our valves. This includes important things like improved grease distribution and improved body flushing when used on high solids concentration applications.

“In-depth finite element analysis enables us to ensure the product’s integrity, while making it lightweight. There are also a lot of smaller features to make life easier, such as a larger grease reservoir, ISO mount standardisation and an external visual indicator for the valve’s status.”

Other notable developments from Weir Group’s 2020 financial results included the first order for ESCO’s ToolTek™ system.

This collaborative effort with key mining customers provides enhanced safety for maintenance personnel during the replacement of worn Nemisys® points and adapters, according to ESCO. It features a hydraulic crane mounted tool that is remotely operated, well out of harm’s way during the replacement of worn components. New parts are pre-staged on racks  positioned on the flatbed truck outfitted with the hydraulic crane. The truck also features a recycle bin for safer disposal of worn parts.

Alongside this, Weir said in 2020 it installed the first pilot Terraflowing® plant at a customer’s mine site designed to cost-effectively reduce water in tailings, enabling this waste product to be safely stored or repurposed.

Terraflowing incorporates a two-stage cyclone dewatering process followed by centrifugation of the final stage of cycloning overflow. In the process, three dewatered tailings streams are produced: a primary cyclone underflow, a secondary cyclone underflow and a centrifuge pulp. These three streams can be combined or used in different configurations depending on the end use of the tailings stream, according to Weir Minerals.

This three-stage system offers the flexibility to make provision for variations in mineralogy and particle size distribution as well as the opportunity to recover ‘tailings as a resource’, it added.

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

Comminution of minerals, Equipment maintenance, Mineral processing, Mining consumables, Mining services, , , , ,

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.

Weir Minerals strives for unmatched hydrocyclone performance with release of Cavex 2

IoT, Mineral processing, Mining equipment, Mining services, Sustainable mining, Water management, , , , , , , , , , , , ,

Almost 25 years after the original Cavex® hydrocyclone came into the classification market, Cavex 2 is set to introduce a step-change in performance and sustainability, with water and energy savings, according to Weir Minerals.

The launch of Cavex 2 marks a new generation of hydrocyclones, Weir says. Like the original Cavex hydrocyclones did more than two decades ago, Cavex 2 introduces new geometric features to offer performance unmatched by any cyclone in operation today, the company claims.

Debra Switzer, Global Product Manager for Hydrocyclones at Weir Minerals, said: “Our Cavex 1 design set an industry benchmark over two decades ago with its unique 360° laminar spiral inlet geometry, which significantly reduced turbulence. This design was so successful and desired by the market that it was widely replicated by competitors.

“Following years of research, development and trials, we have improved upon this design with the creation of LIG+™ inlet and chamber design. This unique design produces a more stabilised flow pattern, further reduces turbulences and friction throughout the hydrocyclone and provides up to 30% additional capacity.”

The advanced LIG+ design (patent pending) enables the Cavex 2 hydrocyclones to classify up to 30% more feed slurry, while occupying the same footprint as competitor hydrocyclones, according to Weir. This allows operators to achieve more throughput with fewer operating hydrocyclones, reducing the upfront capital expenditure.

The new design has taken into consideration the shape and angle of the hydrocyclone to ensure particles report to the correct stream, Weir says. This reduces recirculation and misclassification, further improving separation efficiency.

“Cavex 2 allows our customers to do more,” Switzer says. “A more sustainable circuit, with lower energy and water requirements. Expand the capacity of their existing circuits, without increasing the footprint of the cyclones or clusters. It’s the kind of generational engineering leap that will change the way circuits are designed for decades to come.”

Cavex 2 takes advantage of Weir Minerals’ Synertrex® IIoT technology, which enhances the overall performance of the hydrocyclone. Armed with this technology, operators are automatically alerted to roping or blockage conditions ahead of time, ensuring the hydrocyclone runs under the most optimal operating conditions.

“To minimise the amount of bypass that is produced in any hydrocyclone, it is favourable for it to operate in the semi-roping condition,” Switzer said. “This is often difficult to do continuously because any upset in the hydrocyclone’s feed conditions could move it into the roping condition, but, with Synertrex, this balancing act can be closely managed.”

Cavex 2 hydrocyclones can be customised to suit almost any application, according to Weir, with a variety of spigots, vortex finders and liners. Liners are available in a range of material options, including Weir Minerals’ proprietary R55® rubber compound or Linatex® premium rubber, both of which have been proven to outlast competitors elastomers in similar applications, Weir says. Liners can be replaced via a ‘snap-in’ system requiring zero adhesive, while smaller models (400CVD and below) are available with moulded fibreglass housings, the company says.

Switzer concluded: “Every stage of the Cavex 2’s design has been guided by the needs of our customers. As a consequence, it has been tested in multiple mining applications throughout the globe. These tests revealed outstanding results of up to 30% additional capacity.

“Decreasing ore grades and increasing need to reduce both water and energy usage have created the need for a low maintenance, highly efficient hydrocyclone, which can be readily retrofitted into existing circuits to increase throughput and maximise returns.

“I can’t wait for our customers to see what this new range is capable of.”

FLSmidth’s digital R&D bearing fruit at the right time

Automation, Comminution of minerals, Communications in mining, Equipment maintenance, IoT, Mineral processing, Mining equipment, Mining services, Mining software, , , , , , , , , , ,

As miners look for more digital solutions to ensure they can cope with the challenges that come with operating through exceptional circumstances like COVID-19, FLSmidth is leveraging decades of research and development to help them make this transition.

Terence Osborn, FLSmidth’s Director of Product and Account Management for sub-Saharan Africa and the Middle East, highlights that R&D is the lifeblood of the company’s new technologies. So much so, that it has some 80 projects underway to improve its mining-related offerings.

“The power of digital technology is certainly a key element of these efforts,” Osborn says. “Together with our Blue Box digital concept, based on our ECS/ControlCenter™, which is a cybersecure interface between our equipment and cloud data storage, we use our SiteConnect™ mobile app to monitor the performance of equipment and process plants in real time. The ECS/ControlCenter V8 process control platform sits at the heart of our digital vision, a key component in our growing portfolio of digital solutions and services that we call ENABLR.”

An example of this applied capability is an FLSmidth REFLUX® Classifier modular plant operating on a South Africa mine. Using SiteConnect, operations managers can have real-time access to over a hundred operational parameters on the plant. Data analytics linked to the cloud data can also generate time-based trends for instant viewing on the app.

“We have also developed SmartCyclone™ technology for our hydrocyclones,” Osborn noted. “This innovation uses sensors to detect wear and roping, a condition that reduces separation efficiency. By sending an alert when certain operating parameters are breached, the system ensures optimal efficiency is maintained, even as slurry conditions in the circuit vary.”

He highlights that the company’s machine-level solutions are offered as part of plant and process packages. At both plant and process level, there is also FLSmidth’s advanced ECS/ProcessExpert® solutions, which facilitate not just monitoring and control, but advanced optimisation enabled by state-of-the-art artificial intelligence technologies.

“It is important to remember that control systems need to be flexible, so that they adapt to customers’ needs and to their existing systems,” Osborn says. “With FLSmidth’s depth of expertise in software engineering and machine control, we can ensure that our machine-level systems connect with all market leading control systems – to seamlessly deliver the data that mines need for effective decision making.”

The company’s R&D pushes the boundaries of performance in a range of mineral processing fields. These include advancing its lamella plate technology in mineral separation applications, adapting its vertical roller mill for dry grinding in mining, and extending wear life of pumps with new polymers.

Belzona’s new abrasion-resistant coating to help miners patch up equipment

Equipment maintenance, Mining consumables, Mining maintenance, Mining services, , , , , , , , , , , , , ,

Belzona Polymerics, a provider of high-performance polymeric repair composites and protective coatings, has launched a new product to add to its portfolio of solutions for industrial maintenance.

This new product, Belzona 1818, has been specially formulated for emergency patch repairs in highly abrasive environments typically found in industries such as mining, cement, pulp and paper, and biomass, among others, where equipment is commonly exposed to extensive erosion and abrasion from excavated or processed materials of varying type, size and shape.

What is easily identifiable about this new product is its distinctive blue colour. This vivid blue serves as a good mixing indicator and provides contrast where an application is carried out in poorly lit conditions or against dark background surfaces where the repair area should be easily identifiable, the company says. These conditions can be common in typical industrial applications where Belzona 1818 is likely to be used.

Based on initial research and feedback from engineers in the field, it is envisaged the product will be used on various types of equipment within abrasive environments such as slurry pumps, grinding mills, screw conveyors, chutes and hoppers, hydrocyclones, wear plates, dust extraction pipe work, agitator shafts, hubs and blades.

Belzona 1818 is the newest addition to the highly erosion resistant Belzona 1800 series product range and bridges the gap between surface tolerance, fast cure and high abrasion resistance, the company says. Its fast curing properties means minimal downtime for damaged equipment – so much so that the product can experience full mechanical loading and heavy abrasion just two hours after application, depending on cure temperatures.

“In these abrasive environments, surface preparation can also be an issue and contamination is common, therefore the equipment cannot always be fully cleaned or ideally profiled as required for many repair materials,” Belzona says. “The desire to deal with adverse application conditions creates a need for a not only fast-curing, but also a surface-tolerant material.”

As a result, Belzona 1818 has built-in surface tolerant technology, enabling it to bond onto steel substrates even when surface preparation is minimal or if the substrate is heavily contaminated with oil or water, the company says. The product can also be applied and cured underwater.

Kristine Savicka, Belzona R&D Technician, explains: “Belzona 1818 builds on our knowledge and experience of producing highly abrasion-resistant systems, and combines this technology with our know-how and expertise in producing fast-cure and surface-tolerant products for application in non-ideal conditions. Belzona 1818 offers the high erosion resistance expected of the Belzona 1800 series with added application benefits, offering ease of use and a fast return to service.”

This new product is supplied in 1 kg units where base and solidifier can be combined on a Belzona work surface. Belzona 1818 is easy to mix and apply and offers a good working life (16 minutes at 20°C) while still offering fast cure and a rapid return to service, according to the company. The product is suitable for emergency repairs where downtime must be kept to a minimum and optimal surface preparation cannot be achieved due to accessibility or environmental and application constraints.

Belzona 1818, as with all Belzona products, is made to the highest quality and safety standards and has undergone rigorous performance testing, the company says. Belzona 1818 is user friendly and can be applied without the need for hot work or specialist tools. In addition, it is formulated without solvents and is free from CMR classification and labelling, while maintaining cure speed and performance to give a durable and long-lasting repair.

New Weir Minerals Sand Wash Plant to boost recoveries

Industrial minerals, Mineral processing, Mining equipment, Water management, , , , , , , , , , , , ,

Weir Minerals has released a complete sand wash solution that draws on its long experience in the sand and aggregate industry.

The Weir Minerals Sand Wash Plant comes with Linatex® lining, produces more saleable product than conventional sand screw plants, with fewer moving parts, and has an optimised process that produces a drier, higher-quality product with less fines, according to the company.

The solution has already proven effective at sites like Coimbatore Minerals in Tamil Nadu, India, Weir says, where a custom-built wash plant reduced its total cost of ownership by 51%, while offering a 23% reduction in fines that helped the company consistently meet the industry’s high standards for a saleable product.

Bruce Cooke, Global Product Manager – Sand Wash Plants for Weir, said: “We know the most important thing for quarry operators in washing is recovering as much sand as possible to maximise their sales, which is why we’ve designed an integrated solution for washing their product, with a hydrocyclone which can deliver greater recovery than sand screws. In addition, every component has been selected by our expert engineers for its long-service life, interoperability and ease of maintenance.”

The compact solution features a range of Weir Minerals equipment designed for high efficiency in sand and aggregate applications, including Warman® WGR pumps, Cavex® hydrocyclones, Enduron® dewatering screens, Linatex hoses and Isogate® knife gate valves.

The Warman WGR is a popular pump in the sand extraction industry, according to Weir, combining top of the line hydraulic design with an adjustable impeller, long bearing life and a simplified wet end, making replacement predictable and cost effective.

Precision moulded and lined, Linatex premium rubber is used for wear zones throughout the plant due to its proven wear performance in wet sand applications in operations around the world, Weir said.

Cavex hydrocyclones provide “exceptional classification efficiency” thanks to their unique 360° laminar spiral, delivering more saleable product than a sand screw solution would, the company said. Enduron dewatering screens, meanwhile, reliably separate product with a high degree of efficiency. And, finally, Isogate knife gate valves contribute to the plant’s straightforward maintenance.

Surendra Menon, President, Weir Minerals India, said: “For the new sand wash plant, we focused on making it quick and easy for quarry operators to get up and running. Its straightforward design means it can be assembled in just two days while its compact skids make it easy to drag into any operation.

“Efficient, reliable and easily integrated into flowsheets, we think the plant is a game changer for quarry owners.”

Multotec builds integrity with hydrocyclone solution at Zambia tailings facility

Base metals, Comminution of minerals, Mine operation news, Mineral processing, Mining equipment, Mining services, Water management, , , , ,

An innovative hydrocyclone solution from Multotec is allowing a large Zambian copper mine to develop a safe and cost effective tailings storage facility (TSF), the South Africa based company says.

The TSF faced a number of specific challenges, according to Frikkie Enslin, Senior Applications Engineer responsible for cyclones at Multotec, including its extensive planned capacity and the area’s flat topography. The mine’s process plant pumps some 10,000 m³/h of tailings to the TSF, requiring its final circumference to reach about 19 km.

“The flat area around the mine meant there was no suitable topography to provide a natural dam,” Enslin says. “It was therefore vital to create strong walls to retain the slurry from the plant, so that the integrity of the TSF could be assured.”

Simple gravity separation and sun-drying had proved unable to create material firm enough to constitute walls, according to Multotec. In the early days of the plant’s operation, it was shown material being deposited by means of plain spigoting could still not be walked on even after a month of drying in the sun. By contrast, Multotec’s 250 mm GV hydrocyclones were able to deliver an underflow discharge that could be walked on in just two days, the company said. After a week, the material could withstand the weight of an excavator.

The sheer volume of slurry being pumped into the TSF, however, created its own challenge. The hydrocyclones had initially been mounted on metal cradles, which were inundated within a couple of hours. Extracting the cyclone and cradle from the mud for the next placement was difficult and very time consuming.

“The customer needed a solution that would keep the cyclone above the slurry level for longer, and would be easier to move,” he says. “To do this, we designed a cyclone cradle that could be attached to a long wooden pole, giving much greater height, allowing the customer to leave the cyclones in the same position for a much longer time.”

With Multotec’s experience and facilities for custom design and manufacture, the hydrocyclones were then modified to be lighter. This made them easier to handle and manoeuvre, it said.

“Constructed with a lighter metal, these tailor-made units are industry leaders in terms of being lightweight and are rubber-lined to ensure long wear life,” he said. “We also made some innovative improvements to the vortex finders and the cone sections, which are now metal spun.”

Other changes were made to speed up the changing of a spigot, and the moving of the hydrocyclones from one point on the TSF wall to the next. The design now includes a threaded spigot coupling and quick-release connections on the cyclone.

The solution has been so successful to date that over 250 of Multotec’s modified GV hydrocyclones have been installed.

“Just as we collaborated closely with the customer in developing this solution, so we continue our partnership in monitoring the performance of our hydrocyclones as the project goes on,” Enslin says. “An expert applications engineer from our Johannesburg head office visits the site regularly, while our Zambia office in Chingola offers solid technical and field service support. We don’t just sell process equipment, but rather process solutions.”

Weir Cavex hydrocyclones take a load off at OceanaGold Didipio mine

Base metals, Comminution of minerals, Equipment maintenance, Mine operation news, Mineral processing, Mining equipment, Mining maintenance, Mining services, Precious metals, , , , , , , , , ,

The installation of 19 Cavex® 400CVX10 hydrocyclones at OceanaGold’s Didipio gold and copper mine in the Philippines has led to savings of more than $800,000/y through a dramatic reduction in grinding circuit recirculation, according to Weir Minerals.

The Didipio mine, which employs more than 1,500 workers (drawn predominantly from the local community), has expanded throughput over the last few years in line with its transition from open pit to underground mining. This increased the incumbent cyclones’ feed density beyond what they could effectively manage, leading to a circulating load of up to 700%, according to Weir.

The Cavex 400CVX10 hydrocyclones significantly improved separation efficiency due to their finely tuned spigot liner diameter and the strength and corrosion resistance provided by its cast housing, according to Weir.

Thanks to these qualities, the introduction of the Cavex hydrocyclones reduced the circulating load from 620% to 374%, with the direct savings in power consumption, ball consumption, cyclone and pump maintenance costs exceeding $815,000/y.

Gary Webb, Processing Manager, OceanaGold Didipio project, said: “Having had good performance from Cavex hydrocyclones at our New Zealand sites (Macraes and Waihi), we were confident that retrofitting Cavex hydrocyclone cluster at Didipio, with an increased number of smaller cyclones than we had at the time, would help reduce our problematic circulating load and lever multiple benefits in doing so.

“The changeover to Cavex hydrocyclones has exceeded our expectations, enabling higher throughput and lower consumable costs without being penalised in grind size.”

The performance of Cavex hydrocyclones can be attributed to the 360° laminar spiral inlet geometry design, which provides a natural flow path into the hydrocyclone, Weir said. This shape allows the feed to blend smoothly with rotating slurry inside the chamber, reducing turbulence.

Mike Arakawa, Philippines Country Manager, Weir Minerals, said: “Working with customers across the globe, our expert engineers are constantly looking at how they can maximise separation efficiency, hydraulic capacity and extend the wear life of not just the hydrocyclone, but our customers’ overall processing plants.

“I’m proud of the results we’ve achieved together with OceanaGold. Reduced circulation means reduced power draw, fewer balls consumed and less equipment wear, creating a more sustainable mine.”

Didipio produced 114,985 oz of gold and 14,999 t of copper in 2018, with 120,000-130,000 oz and 14,000-15,000 t of copper slated for 2019.