Haver & Boecker Niagara processing equipment technology manager, Duncan High, discusses how technology can optimise a quarry’s efficiency and productivity.
Global demand for aggregates and mining materials is expected to continue rising, with the construction aggregates market projected to grow from US$444.7 billion in 2024 to $796.3 billion by 2034. That’s a lot of material, which means producers need efficient equipment to meet specifications and turn a meaningful profit.
Every tonne of material must go over at least one vibrating screen, so ensuring the equipment’s efficiency is critical to an operation’s success.
The good news is that there are technologies available today that can help increase or improve screening productivity. Integrating cutting-edge systems, such as eccentric screening technology, state-of-the-art screen media, and diagnostic tools, can prevent blinding, pegging, carry over, or contamination, thereby improving screening performance, productivity, and profits.
Heighten screening action
Vibrating screens engineered with a double eccentric shaft assembly maintain a constant stroke to prevent g-force fluctuations during material surging. The double eccentric shaft design forces the screen body to follow the movement of the shaft. While the shaft travels up, the counterbalance weights move in the opposite direction and create a force equal to what is generated by the body.
As a result, the forces cancel each other out, maintaining a consistent positive stroke that handles material volume spikes without losing momentum.
One producer in Western Canada quickly saw the benefits of switching to double eccentric screening technology when they replaced two horizontal vibrating screens with one double eccentrically driven, four-bearing, inclined portable screening plant.
Changing their equipment helped eliminate surging, blinding, pegging, and material contamination challenges, while increasing production by 25 per cent.
Reduce damaging vibrations
A vibrating screen’s operation can have a significant impact on the surrounding environment of a machine. The metal springs on a traditional concentric vibrating screen, for example, can be noisy to operate.
This metal-to-metal movement, whether up and down or side to side, can cause excessive noise and vibration. To resolve this problem, double eccentric technology utilises shear rubber mounts that are strategically designed to minimise lateral movement.
The rubber mounts reduce noise while maintaining smoother operation, even in extreme circumstances such as overloading, surging and starting or stopping under load.
The use of eccentric technology virtually eliminates vibration in the structure, or chassis, when used with portable equipment, which protects the integrity of the machine.
This means producers can potentially utilise multiple eccentric vibrating screens within a single structure, thereby boosting productivity. Attempting to operate multiple concentric machines in a structure, however, could create vibrations that are damaging enough not only to affect the quality of production negatively but also to open the door to safety risks and possible downtime.
A leading phosphate producer in North America — producing nearly 8 million tonnes per year — increased screening area by 60 per cent by transitioning to double eccentric equipment. The mine features a six-story screening plant that houses multiple vibrating screens, which operate continuously. Multi-story screen houses are common in the industry, but they can pose structural concerns due to the vibrating screens’ size, capacity, and force. Opting for double eccentric technology eliminated those concerns.
Expanding screening capabilities
As the demand for flexible processing solutions grows, portable screening plants have become increasingly important in mining and aggregates operations. These mobile systems allow producers to bring screening capabilities directly to the source, reducing material handling and setup time. When paired with eccentric drive technology, portable plants can maintain high screening efficiency while minimising structural vibration.
This combination supports safer operation and enables the use of multiple vibrating screens on a single chassis, even in challenging environments. The result is a more adaptable screening solution that meets production goals without compromising performance or safety.
Improve stratification
Combining the use of advanced eccentric screening technology with the best screen media for the application is a recipe for success. Specifically, polyurethane screen media can be a valuable asset to any operation seeking to prevent blinding and pegging while enhancing material stratification and extending wear life.
Polyurethane media offers the best combination of open area and wear life for both wet and dry applications. In particular, polyurethane screen media that is poured open cast can result in a wear life that is one-and-a-half to two times longer than that of injection-moulded products. Open-cast polyurethane permanently hardens when cured, maintaining its chemical properties and improving wear life.
Alternatively, injection-moulded screen media can soften when temperatures rise, resulting in shorter wear life. Polyurethane screen media also features tapered openings to reduce the risk of blinding and pegging.
The solution to improving material stratification lies in finding the ideal mix of screen media types to ensure all phases of screening work correctly. A screen media company that offers a variety of screen media types can help evaluate how material moves through the three stages of screening, from layered to basic to sharp, to provide recommendations on the best screen media for a specific application. Producers can customise the screen deck by choosing screen media that maximises productivity for each phase by blending the best combination of open area and wear life.
Prevent Equipment Damage
A vibrating screen requires regular maintenance checks to operate optimally. Vibration analysis and diagnostic systems designed specifically for vibrating screens by original equipment manufacturers (OEM) are reliable tools for maintaining the continued efficiency and longevity of screening machines. To ensure optimal productivity, operations can partner with an OEM that specialises not only in manufacturing equipment but also offers additional diagnostic tools, product-specific knowledge, and years of engineering experience.
Utilising vibration analysis software, for example, enables mining and aggregates operations to monitor a vibrating screen’s performance in real-time, detecting problems before they lead to diminished performance, decreased efficiency, and increased operating costs. The most robust systems incorporate eight wireless sensors that magnetically fasten to key areas of a vibrating screen, measuring orbit, acceleration, deviations, and other important data points that indicate the machine’s condition. The sensors send real-time information wirelessly to be analysed, ideally by an OEM-certified service technician who can provide a detailed summary and recommendations. Some manufacturers utilise vibration analysis technology to provide impact testing, also known as a bump test, which ensures proper machine calibration and promotes efficient operation. Impact testing involves striking the machine at key points with a dead blow hammer while the machine is off. Vibration analysis sensors are placed at key locations on the vibrating screen while a technician tests the natural frequency of a machine. Based on the results, engineers can adjust machine parameters to prevent operating in resonance, which can reduce productivity, cause damage to vibrating screens, and pose safety risks. It is essential to note that the natural frequency can shift over time as components are repaired or replaced; therefore, the impact test should be conducted regularly. By incorporating impact testing into an operation’s regular maintenance routine, producers can ensure optimum screening performance and equipment reliability.
Another advanced diagnostic tool is condition monitoring, which is designed to monitor the health of vibrating screens using modern algorithms and artificial intelligence. The system utilises permanent sensors that monitor the equipment 24/7 to capture real-time information and provide alerts via e-mail immediately upon the first sign of a potential problem. By constantly monitoring the accelerations of the vibrating screen, certain systems can even forecast the equipment’s dynamic condition in regular intervals of 48 hours, five days and four weeks. With consistent use, condition monitoring software will accurately identify and predict critical issues, advising when to schedule maintenance and what to focus on during that planned downtime. By using diagnostic programs to conduct regular analysis and engaging in predictive and preventive maintenance, operations will experience minimised downtime through faster problem-solving, lower repair costs, and increased peace of mind.
The development of the double eccentric screen and other screening technologies provides operations with innovative and cost-effective ways to increase their profits and efficiency. By integrating the right equipment, screen media, and vibration analysis systems, producers can achieve more uptime, higher-quality results, increased productivity, and greater profits. AB
