ENDURON® High Pressure Grinding Rolls (HPGR)

About this product

ENDURON® high pressure grinding rolls (HPGR) set the benchmark for sustainable comminution in high tonnage hard rock mining. Overview With low energy consumption, low maintenance requirements, excellent throughput capacity and high availability, ENDURON® high pressure grinding rolls (HPGR) are a proven way to improve the efficiency of mineral grinding circuits and industrial mineral applications. Setting the benchmark for energy efficient grinding, they use dynamic skewing to provide best-in-class size reduction and wear life, and are fast becoming the go-to technology for both brownfield and greenfield projects. Our innovative ENDURON® High Pressure Grinding Rolls (HPGR): • Consume up to 40% less energy/power than traditional tumbling mills (>200,000t CO2 saved*) • Contain a unique bearing arrangement that prevents bearing failure and enables the rollers to be quickly exchanged within a 24-hour shutdown • Require no grinding media (>700,000t CO2 saved*) or additional water for fine grinding • Maximise crushing pressure while allowing tramp and oversized material to pass through without incident • Result in less contamination and downtime in the recovery process • Have a low total cost of ownership (~ €0,09 – €0,20 cost per ton of ore processed - labour and wear parts) • Provide high availability (>95%) and prolonged wear life * annual saving from our 2021 installed base At Weir, we are specialised in high tonnage, hard rock HPGRs to satisfy the need in mining to process higher volumes of ore. Our ENDURON® HPGR portfolio ranges from pilot machines to large format production machines including the world’s largest operational roller surface, capable of processing over 118,000 tons of ore per day. For high availability and performance, despite changing feeding conditions, there’s no better choice than ENDURON® HPGR. For more information about HPGR technology and how it can be used in mining and industrial minerals applications, please contact our team. Frequently Asked Questions What does HPGR stand for? HPGR stands for high pressure grinding rolls. High pressure grinding rolls (HPGR) are a type of grinding machinery that have been used in mining and industrial minerals applications for the last 30 years. They work by using inter-particle grinding to reduce particle size and increase grinding efficiency by transferring pressure to particles from multiple directions. Can HPGR technology be used across a wide range of applications and product qualities? Given the HPGR’s operating parameters can be adjusted, it not only offers flexibility across applications but also allows for changing feeding conditions during life of mine production. Traditionally, and when compared to cone crushers, high pressure grinding rolls are known for effective fine particle generation. However, whilst deploying different flowsheet configurations combined with lower grinding pressure, HPGRs have proven to be maximise product yield even in applications where too many fines are undesirable. Moreover, HPGRs can deal with feed moisture content above 10%, as long as the saturation level and material properties allow for adequate “resistance” to compression. Can HPGR technology be used to crush pebbles? Regardless of whether they’re receiving feed directly from an upstream SAG mill or further reducing pebbles that have passed through a dedicated cone crusher, high pressure grinding rolls (HPGR) offer highly efficient reduction, generating substantial amounts of fines that reduce the energy required for downstream milling. For more information about how HPGR technology can be used to optimise pebble crushing, click here. Is HPGR technology difficult to operate compared to crushers? ENDURON® HPGRs do in fact include a sophisticated and dedicated control system enabling operators to conveniently change relevant parameters that define the preferred operating bandwidths. The programmable logic controller (PLC) assures that these set points are achieved to deliver stable and optimal grinding efficiency, even under changing feeding conditions. Additionally, we aim for seamless integration of the equipment into an applicable mine site's Distributed Control System (DCS), local human interface (HMI) and remote conditioning. What is dynamic skewing? In its simplest form, dynamic skewing relates to the ability of the HPGR to react to changing feed conditions where different particle sizes and ore hardness are being presented to the rolls. Skewing ensures that the material’s compressive strength is exceeded across the full width of the tyre. This requires a mechanical design and control philosophy to cater for a durable and effective roll skew. ENDURON® HPGR technology is centred around enabling durable roll skew which automatically adapts these changing feeding conditions applicable to hard-rock mining processing. What is air classification? Air classification uses airflow, generated by industrial fans to transport and classify the ground HPGR product through several separation stages, whereby product at target size is captured and oversized particles are recycled back to the HPGR for additional grinding. Depending on the targeted grind size, the system incorporates a combination of static and/or dynamic classification systems followed by a filtration system. The system is designed to be low maintenance whilst delivering high system availability and operates autonomously without manual adjustments to be required on a day-to-day basis. What are the major maintenance intervals of HPGRs and what is the anticipated availability compared to traditional crushers? ENDURON® HPGRs are well known for reaching machine availabilities of over 95%, whereas conventional crushers sit around an average of 85%. This is a testament to the: • Bearing arrangement design • Long-lasting wear life of ENDURON® grinding tyres / rollers • Safe and quick exchange of roller assemblies within 24 hours In hard-rock grinding applications, tyre wear life of 12,000-15,000 hours is readily achieved, however to maximise efficiency, we always aim to align tyre wear life with major scheduled shutdowns. As a result, OPEX costs are kept to a minimum and from a sustainability perspective, wear materials are fully consumed. What are typical throughput ranges and associated installed power for high pressure grinding rolls? The ENDURON® HPGR portfolio consists of machines that are suitable for typical production capacities ranging from 50tph up to 6500tph. The typical installed power per machine varies from 2*50kW up to 2*6800 kW. How do HPGR circuits compare to that of SAG / ball mills? How do you see both products operating in the future? The depletion of ore grades, increasingly hard ore bodies and the need for large volumes of ore to be processed at a finer grind to liberate minerals is becoming the new norm. SAG/ball mill combinations have proven to be effective in processing large volumes of ore with relatively minimal material handling requirement, however there is limited flexibility to cater for changing ore bodies across the life of a mine. As energy, water and grinding media consumption are becoming increasingly important, we see the market adopting HPGR circuits at an increasing pace. As a result of flexible operating conditions (i.e. pressure), the right amount of energy can be used for the specific ore being processed. Additionally, fluctuating throughput requirements can be readily compensated by the HPGRs roll speed, which is fully adjustable due to variable-frequency drives. Features and benefits Enhanced Roller Surface Technology The enhanced roller surface technology of the ENDURON® HPGR, combined with spring loaded lateral walls, delivers optimal product quality with minimal wear and power consumption. Additionally, this innovative HPGR technology provides exceptional tyre wear life. Our combination of hard-metal studs and the material embedded between these studs has gained wide recognition, enabling a superior autogenous wear layer protecting the roller's surface. As a further benefit of the studded roll, the nipping properties are significantly improved. Our patented roll surface system has been further developed to the stud-lined surface and is state-of-the-art HPGR technology. We also ensure repeatable quality, enhanced tyre performance and longer wear life through our automated stud installation process. Proven Performance and Quality Where HPGR technology has replaced traditional methods of crushing and grinding (i.e. SAG and/or ball mills), customers have seen energy savings of up to 40%, and substantially improved mineral liberation. The unique bearing arrangement of the ENDURON® HPGR delivers market-leading bearing life and is designed to protect against premature failure, with proven performance guarantees over 10 years (>100,000hrs). It also allows grinding rolls to be skewed outside the bearing, eliminating bearing peak loads without compromising crushing conditions, and tramp metal or oversized material present in the feed to pass through smoothly without damaging the rollers (or "tyres"). Additionally, its superior roll length to diameter (L:D) ratio delivers the highest product quality, minimising recirculation and reducing operational costs. It also enables smaller tyre diameters for a given tonnage relative to all competitors. This optimises the operating gap and ensures full pressure across the entire tyre length, exceeding the ore’s compressive strength. Automatically Adjusts to Changing Feed Conditions The ENDURON® HPGR can dynamically accommodate changing feed conditions through skewing increasing productivity and efficiency within the grinding circuit. Skewing ensures that pressure is evenly distributed across the full width of the roller (tyre), minimising recirculation. This is particularly applicable in segregated feed conditions within mineral grinding applications. It can also stabilise the product output despite changing feeding conditions, causing less fluctuations downstream. Overall, this results in enhanced process control and increased mineral recovery. High Machine Availability Compared to traditional crushers, ENDURON® high pressure grinding rolls (HPGR) provide higher machine availability (>95%) with low maintenance requirements. This means that they can process more material at the one time, compared to crushers that typically provide only circa 80% availability. Improved Sustainability When compared to other mineral grinding equipment, our advanced HPGR technology offers numerous sustainability benefits. Despite some improvements in the design of SAG (Semi-Autogenous Grinding) mills over the years, ENDURON® high pressure grinding rolls (HPGR) take sustainable mining to the next level, with significant energy savings and substantial reductions in water consumption. This makes the ENDURON® HPGR an ideal choice for mines in arid environments without significant or affordable access to groundwater. Moving away from traditional classification methods, we have developed a complete dry-air classification system which combines HPGR fine grinding and efficient classification without a single drop of water. When used in mining and aggregate applications ENDURON® high pressure grinding rolls: • Reduce energy/power consumption by up to 40% • Improve downstream capacity by up to 40% • Consume less grinding media helping to reduce operational costs • Save up to tens of thousands of tonnes of CO2 annually supporting future decarbonisation of the mine • Require little to no water during operation Most greenfield projects processing hard (competent) rock include HPGR technology as part of their standard comminution flow sheet. However, it is also a great solution for brownfield optimisation. Flexible and Dynamic ENDURON® high pressure grinding rolls (HPGR) provide a flexible comminution solution with the operational bandwidth to process different types of ore throughout the life of a mine. It produces optimal product quality via controlled roll skewing and self-adjusting lateral walls. Through dynamic skewing, it is able to respond to changing feeding conditions and adapt the machine to maximise grinding efficiency. This dedicated local control system seamlessly integrates with a plant’s DCS (Distributed Control System) and provides the operator with transparent feedback on the performance of the equipment. Enhanced Downstream Mineral Recovery ENDURON® high pressure grinding rolls (HPGR) offer enhanced downstream mineral recovery and improved downstream grindability. Reduced Grinding Media Consumption Compared to other grinding equipment (e.g. mills), ENDURON® high pressure grinding rolls (HPGR) provide substantial savings due to reduced grinding media consumption. This helps to reduce costs, contamination, overall carbon footprint and downtime in the recovery process. Lower Civil / Building Costs Compared to other HPGR technology, ENDURON® high pressure grinding rolls (HPGR) contain a shorter more compact frame design, unique length to diameter (L:D) ratio and compact cylindrical bearing arrangement. This allows users to enjoy significantly reduced infrastructure costs as the required civil structural height is kept to a minimum. Global Service Network Our ENDURON® HPGR technology is backed by our unrivalled Weir Minerals service centre network. Our team is always here to help, regardless of your location, and can also service machinery onsite for added convenience. Why Weir? At Weir, our reputation for quality engineering and exceptional service is second-to-none. With over 150 years of engineering expertise and decades of creating innovative designs from the highest quality materials, our range of ENDURON® grinding equipment is built to last. As a company, we are committed to helping the mining industry move towards a more sustainable future. This goal is at the very core of what we do and through innovation and advanced material technology, we aim to: • Create long-term value for our customers • Positively impact mining and aggregate operations and • Support environmental sustainability When compared to traditional mineral grinding circuits, ENDURON® HPGR technology can save up to 40% in power consumption. And, when combined with air classification, the use of grinding media for fine grinding (as used in grinding mills) can be diminished, as well as the embodied energy used to produce grinding media. All ENDURON® high pressure grinding rolls (HPGR) are backed by our global service centre network that spans across more than 60 countries world-wide. Our team are always there for you, no matter your location. We can also service machinery onsite for added convenience. Applications ENDURON® high pressure grinding rolls (HPGR) can handle a wide variety of ores and particle sizes, from fine pellet feed all the way up to coarse grinding of 75mm copper, gold or iron ore. When it comes to feed material characteristics, the specific ore type is not detected by an ENDURON® HPGR, however ore hardness, size and bed compressibility are important considerations. In addition to its high tolerance for ores of variable hardness, ENDURON® high pressure grinding rolls provide greater flexibility in feed conditions and circuit design compared to traditional mills, especially for hard rock and gold miners. Although, high pressure grinding rolls are generally thought to be most effective in controlled “dry” mineral grinding applications, they can readily process minerals above 10% moisture (depending on the material saturation level). This allows ENDURON® HPGR to fit into a wide array of mining and aggregate applications within both wet and dry classification. Suitable to be used with feed materials such as: • Aggregate • Aluminium • Bauxite / Alumina • Chrome • Copper • Diamonds • Glass • Gold • Graphite • Iron • Kimberlite • Lead • Limestone • Lithium • Mineral Concentrate • Mineral Sands • Molybdenum • Nickel • Palladium • Phosphate • Platinum • Potash • Rare Earths • Silica Sand • Silver • Slag • Soda Ash • Zinc Processes • Concentrate Regrinding • Pebble Crushing / Milling • Pre-Leaching • Primary Crushing • Secondary Crushing • Tertiary Crushing • Tertiary Grinding Product specifications The sizing parameters for an ENDURON® HPGR are initially determined by laboratory or pilot plant testing, as complemented by our extensive operational experience. This requires that the machinery is scalded up with correction factors for roll geometry, peripheral speed, press force, gap and moisture content to be present in the industrial sized installation. The dedicated scaleup procedures are validated by more than 30 years of actual field performance and form the basis of our wide ranging performance guarantees. Furthermore, the specific energy, measured in kWh/t is captured during the tests at different pressures. This allows our ENDURON® HPGR to achieve the best operating conditions for maximum mineral recovery at the least energy consumption. Replacement parts When it comes to the success and reliability of your ENDURON® HPGR grinding equipment, having a proactive servicing and spares strategy is critical. The highest-wearing parts of the ENDURON® HPGR include the rollers ("tyres") and cheek plates. These will need to be replaced throughout the lifetime of your ENDURON® HPGR, depending on the application. Services and maintenance ENDURON® high pressure grinding rolls (HPGR) are backed by our unrivalled Weir Minerals service centre network. This means that our on-the-ground staff and dedicated HPGR service facilities are here to support you, regardless of your site's location. We can assist at any time and understand both upstream and downstream conditions to deliver the greatest energy, water and ownership cost savings providing: • 24/7 support including in-house support (ranging from machining, manufacturing and assembly to factory acceptance testing) • Regional HPGR service technicians • Specialist HPGR project and site management • Full system installations • High quality wear and spare parts • Personalised advice and solutions • Servicing of machinery at our service centres or on site for added convenience • Ongoing support and training Our world-leading team of experts will work with you to maximise your up-time with comprehensive flow sheets and equipment reviews, while adhering to the strictest global quality standards.