Crushing operations have traditionally been associated with noise and the creation of dust – disadvantages that persist despite evolution in the array of available plants. Consequently, some of the further development the industry would like to see pertains to these aspects. “The generation of dust is the biggest problem of a crushing plant; plants should have automatic water sprinkling systems to control the dust generated and this applies to every step of the operations, the jaw crusher, cone crusher and vertical shaft impactor,” says Anup Kumar Jaiswal, Deputy General Manager P&M, Assam & North East, Reliance. “Also, plant components such as the screens and conveyors should be made more environment-friendly by having covers.” Crusher producers focus only on production and crusher performance; they don’t consider dust control and environmental problems, believes Anup Mishra, Manager, P&M, Madhucon Projects Ltd. “Dust is a huge problem with crushers and screens using material from the riverbed as feed; those using blasted materials create less dust. Water sprinklers can help mitigate the environmental damage but dampen the performance of the crusher. If Pollution Control Boards hadn’t laid down rules for dust control, crusher manufacturers wouldn’t realise their responsibility to the environment. We’d like to see more environment-friendly models with mist control systems.” Not all crushing plants incorporate sufficient measures for environmental protection, such as water conservation and recycling systems for dust control, avers Nachimuthu Krishnamurthy, Vice President - Operations, Transworld Garnet India. “Dust and noise pollution continue to be significant challenges in crushing plants, especially in urban or environmentally sensitive areas.” “The vacuum suctioning of ultrafine dust would help mitigate air pollution,” adds G Boopathi, Director, Uniqcore Constructions India. “More energy-efficient designs and ways to use recycled materials and minimise waste would help reduce the environment impact of crushers.” Krishnamurthy points out that implementing water recycling systems, more efficient dust capture and wastewater treatment would minimise the environmental impact of plants. Enhanced dust suppression systems, such as misting or vacuum-based systems, could reduce particulate emissions. Noise protection Krishnamurthy proposes noise-reducing enclosures around crushers and screens, as well as sound-dampening materials, to minimise noise pollution. Jaiswal sees automation as the answer to protecting manpower from the harmful impact of noise. “We need more automation in crushing plants so that less manpower is required to run them. Exposing staff to dust and high decibel sound is a health hazard; many operators develop hearing problems so the fewer people involved, the better. Also, crushing units should be mechanically designed to minimise the operational noise level.” Centralised control Automation would serve other purposes too. “Many plants still lack advanced automation and full integration with Industry 4.0 technologies, such as real-time data monitoring, predictive maintenance and centralised control systems,” notes Krishnamurthy. “Sophisticated sensors, IoT devices and AI-driven analytics would help optimise plant performances. Full integration with remote advanced condition-monitoring systems like vibration analysis or thermal imaging, and the use of machine learning, would help predict wear and tear and avoid situations when critical wear parts fail without adequate warning, leading to unscheduled downtime. Integration would also help adjust settings and optimise production.” “Improving remote diagnostics and automatic shutdown protocols, and introducing advanced safety features such as automated safety barriers could further reduce the risk of accidents,” he adds. “Existing safety systems don’t cover human interventions during maintenance or repairs. Implementing robotics for dangerous tasks would also enhance safety.” Boopathi proposes the application of machine learning and AI to implement predictive maintenance, quality control and real-time monitoring and optimise plant performance. Flexibility issues Changing demands require many users to expand their crushing and screening capacity, something many rigid plants don’t allow, says Krishnamurthy. “Modular plant designs would allow for easy scalability and reconfiguration, depending on the material being processed or changing production volumes. Modular designs would also be amenable to speedy installation and reduce downtime during maintenance or upgrades.” Another aspect concerning flexibility is the fact that many plants are designed for a specific type of material or throughput, making them less adaptable for varying materials or production requirements, he adds. “Designing crushers and screens that can easily switch between different materials (such as hard rock, sand, gravel, etc) or adjusting their settings based on material hardness would increase adaptability without significant downtime.” “Crushing and screening plants should be able to accommodate a greater variety of screens,” says Burhaan, CEO, SMB Environmental Projects. “At present, most plants are manufactured with grooves to accommodate only two to three different sizes of screens, which restricts the kind of output that can be obtained from the plant. We need plants with grooves that can be fitted with five to seven different types of screens.” Krishnamurthy points out that hybrid screening solutions could improve the handling of difficult materials while maintaining high throughput. Efficiency optimisation A significant amount of energy is lost in inefficient machinery that hasn’t been optimised for energy consumption, says Krishnamurthy. Correcting this would involve implementing energy-efficient motors and conveyors. Renewable energy sources or recovering waste energy could also contribute to energy savings. Reducing carbon dioxide emissions through fuel-efficient engines and electric-powered crushers would improve sustainability. He also proposes the use of self-cleaning screens and advanced vibration technologies to ensure screening plants continue to work efficiently despite high moisture content, stickiness or fine materials that clog screens. Boopathi proposes a self-locking system for fixing meshes to overcome the time delays in changing the second and third deck meshes to attend to faults. Every crushing plant has a grizzly to remove waste from the crusher feed and such overburden/rejection is more when feeding the plant directly from the quarry, observes Jaiswal. “These grizzlies need to be designed to function more efficiently.” Incorporating sensors “A sensor monitoring the automatic flow of grease would help control a jaw crusher, ensure non-stop operations and improve productivity,” says Boopathi. “Provisioning an automatic jam cleaning starter in the jaw crusher (external torque mode starter) would help avoid labour injuries and improve productivity.” Further, he points out that heating and vibrating sensors would help keep a continuous check on the rotor balancing and increase the productivity of VSI crushers. “Sensors monitoring the inward flow of the material would help adjust the crushing controls,” continues Boopathi. “In screening plants as well, sensors to monitor the inward flow of material would help adjust the vibration settings so as to enhance productivity while ensuring optimal power.” Conveyor enhancements Existing material handling systems, such as conveyors, are often not optimised for speed, efficiency or space utilisation, observes Krishnamurthy. “Smarter, automated material handling systems with adjustable speed drives, better route management and reduced bottlenecks would improve productivity. Conveyors with variable speeds and better chute designs can reduce blockages and wear.” Increasing the thickness of belt conveyor stingers would help the conveyor stay stable, align better and run more smoothly, especially in the instance of lengthy conveyors, adds Boopathi. “Heavy gearbox back stopper bearings would increase belt life and eliminate the need to periodically clean the belt.” Compact, mobile units While mobile crushers exist, developing more lightweight, compact and fully automated mobile crushing units that are easier to transport, set up and relocate would improve flexibility, especially in remote or difficult-to-access mining or construction sites, believes Krishnamurthy. Jaiswal envisages a place for crushing plants that occupy less space. “We need more compact plants so that less area is taken up for operations.” Implementing these features would take crushing and screening to a new level of efficiency as well as environment-friendliness. - CHARu Bahri