Dust suppression is vital to maintaining site workers’ health and wellbeing, and meeting increasingly tight environmental licensing conditions.
Helping prevent haul road overwatering and underwatering, the new Cat 789D autonomous water truck (AWT) enhances productivity by enabling mine operations to digitally track water consumption and reduce waste.
Fully integrating into a site’s Cat Command autonomous haulage fleet to control haul road dust, the market’s first commercially available AWT is built on the field-proven 789D mining truck chassis and integrates the truck, tank and Cat water delivery system, WDS, connected with Cat MineStar technology.
Featuring Command for hauling, the new 789D AWT offers the same potential for greater utilisation than staffed equipment. The fully autonomous truck reduces shift changes, meal breaks and other operational delays to help improve efficiency. Complying with watering plans, the truck seamlessly interacts with other autonomous equipment and integrates with customer processes and systems managed by MineStar.
The 789D is the largest Cat water truck product offering, accommodating up to 165,000L, depending on tank configuration. The AWT senses when the water tank is running low and can be programmed to integrate with the refill station to fully automate the process. The auto-shutoff feature prevents tank overfilling.
“To meet customer requirements for dust control, Caterpillar implemented a MineStar-integrated watering model based on many years of site watering studies and Cat WDS performance data,” Caterpillar, general manager and vice president, technology and global sales support Corey Wurtzbacher said.
“This model allows the truck to monitor traffic, weather and road conditions, prioritise what areas need to be watered, when the areas need to be watered, and how many passes it should take to apply the correct amount of water saturation for the given conditions.
“The integration of Caterpillar’s many years of autonomous truck operations and water delivery development have been combined to make a high-performing autonomous watering solution.”
When Caterpillar set out to develop an autonomous water truck, integration with Cat MineStar Command for hauling and the Cat WDS was key to the integration process. The team began building communication between the truck’s on-board systems and the office control console to work with the Cat WDS interface.
To ensure seamless operation and proper communication between the WDS and MineStar, a compatibility check has been implemented in Cat WDS to confirm all truck control systems were running compatible software and reporting any on-board failures to the MineStar system for appropriate corrective action. Fully integrated into the truck’s design, the exclusive Cat WDS varies waterflow based on speed and automatically determines the correct amount of water needed to control dust. Knowing where, when and how much water to dispense, the 789D AWT helps customers conserve water, a scarce resource at many quarrying and mine locations.
When truck speed drops below the minimum watering speed setting, which determined by site operations, the system halts water delivery to help prevent overwatering, poor traction and damage to haul road intersections and other stopping areas. When the minimum watering speed setting is exceeded, the system begins depositing the specified amount of water commanded by MineStar.
Cat WDS actively monitors the water level and automatically turns off watering once the tank is empty. To reduce potential damage, the system has multiple safeguards to prevent the pump from running dry, which helps prolong water pump life and extends service intervals.
The automated system’s flat, controlled spray pattern delivers optimal litres-per-square-metre (gallons-per-square-foot) coverage across the haul road. Larger, heavier droplets designed to reach the ground help reduce spray loss to wind and evaporation.
Reducing health hazards associated with airborne particles, automated water delivery supports the reduction of dust that limits operator visibility for staffed equipment to enhance overall site safety. Remote tank-fill control, complete with auto shut-off to prevent overfilling, eliminates the need for a worker to be involved in refilling, reducing the potential of slips and falls.
Mines can quickly switch the flexible 789D AWT from autonomous to staffed mode for tasks like front water cannon operation. The cannon can distribute up to 2839L/min (759gal/min) and has a spray distance of 60m (200 ft). Even with the staffed operation, auto mode water delivery automates the process to leverage variable water flow and automatically determine the correct amount of water needed to control dust.
Cat Water Solutions integrates the 789D truck chassis with the proven Cat WDS and innovative MineStar technology.
In the event a site is not yet ready for a fully autonomous water truck, MineStar has cloud-based solutions that will work in the interim and allow customers to utilise, track and measure the productivity of the 789D before it is put into autonomous operation.
Basic and premium packages are available.
The basic package allows sites to track their asset and see when, where and how it is performing in terms of location of truck, water level, fuel level, watering mode, truck speed, truck refills, water dispersed, and truck utilisation per shift.
Premium will allow sites to track how their water trucks are tending to the site’s watering needs:
Watering heat map to show the age of water currently put down by all trucks in a shift
Watering heat map by truck to show where each truck watered and what mode was used
Utilisation of fill spots by each truck
Replay of truck watering activity for up to eight previous weeks of data, depending on how many assets are tracked
Suggested area to water based on age of water and traffic utilisation
When the site is ready for full autonomous mode, the water truck can be integrated into the MineStar ecosystem to work alongside the rest of the mining fleet.
The Cat dealer and parts network fully support this integrated autonomous water solution. Covered by a Caterpillar factory-standard warranty, the 789D AWT is eligible for Cat equipment protection plans) and customer value agreements. Retrofit kits are also available for existing Cat 789D truck platforms in the field.
A holistic approach
RST Solutions is an Australian business that operates around the world. It has three decades of experience developing tailored solutions for various fine particle challenges across numerous industries, processes and material types.
The company notes that sediment control in quarry and mining operations is a critical challenge, particularly in regions that experience high levels of rainfall. Uncontrolled sediment runoff can lead to significant long-term dust challenges, as well as initial operational inefficiencies, increased costs, and environmental compliance issues.
A holistic approach to sediment management is needed to prevent fine particulate movement from all open ground areas, reducing the need for costly remediation efforts.
Sediment build-up at quarry and mine sites typically results in several issues:
Sediment runoff from open ground areas – fine particles erode from all open surfaces, including benches, stockpiles, waste dumps, roads and exposed working areas, contributing to significant sediment loads
Roads as major sediment pathways – roads are a major source of sediment generation and act as large drains, channeling turbid water across the site and accelerating sediment transport
Pit floor sediment build-up – fines washed down from open ground areas accumulate at the pit floor, forming material that is too thick to pump and too sloppy to excavate and haul
Dust emissions – once dried, these fines become a major source of airborne dust, posing environmental and health risks
Drainage issues – channels and drains act as pathways for sediment transport, contributing to further sedimentation problems downstream
Treatment with flocculant-based dust suppressants prevents fine particles from becoming airborne dust when dry and from washing out as sediment when wet.
A three-tiered approach tailored to treat the key areas of a quarry or mine site is recommended to obtain a long-term solution while achieving immediate results. These three high-trafficked areas need to be treated simultaneously.
Open ground areas
Flocculant-based sediment binders/crusting agents can be sprayed on open ground areas – including faces, benches, stockpiles and waste dumps – to prevent fine particulate movement.
Strategic drainage design to effectively direct water flow is achieved through excavation of controlled drainage channels. Flocculant blocks placed within these drains settle sediment in runoff water before it reaches sediment ponds or other water collection points.
Roads (major sediment pathways and drains)
The type of treatment can vary depending on application methods. It is highly recommended to implement two or more approaches for enhanced sediment control:
Liquid additives compatible with dosing/injection pumps for automated application
Water cart application (or additional protection, a wider spray pattern to cover spoon drains along roadsides is recommended)
Flocculant blocks placed in spoon drains to capture additional sediment levels along road drainage pathways
Effervescent powder in a dissolvable bag is an easy and cost-effective alternative treatment for up to 20,000L of water per bag, simplifying application without bulk liquid storage or pumps
Channels and drains
A simple method of strategically placing flocculant blocks in secondary channels and drains to further reduce sediment loading in water before it reaches sediment ponds or final discharge points.
Despite best efforts, some sediment will inevitably reach collection dams. To meet approved discharge levels, a range of liquid flocculants and coagulants are used to clarify water by rapidly dropping turbidity and separating fines.
When sediment fines aggregate in a wet form after treatment, they become larger, more stable particles that are easier to control rather than stay as fine particles that turn into dust when dry and silt and sediment when wet.
Using a flocculant treatment reduces future dust emissions by binding fines together more effectively. This results in enhanced material stability and a reduction in the likelihood of recurring sediment issues. It also improves overall site management, streamlines operations, and reduces ongoing maintenance costs.
RST Solutions takes a comprehensive approach to fine particle management, designing cutting-edge solutions that can be applied using standard mining equipment. Strategies are designed to integrate advanced technologies and systems to address challenges across the entire supply chain, from quarry and mining operations to material transportation.
Innovative approaches designed by fine particle specialists such as RST Solutions treat the causes, not just the problem. Dust control, soil stabilisation and erosion control all come into play when designing a solution, with regular site visits an integral part of their service. This enables the team to customise solutions to a site’s specific attributes – topography, earthworks, materials and weather conditions – and think outside the box to deliver solutions for unique problems.
A holistic approach to sediment control addresses many aspects of fine particle management. It helps to prevent problems in other areas of an operation by stopping fines from moving, stabilising roads, clarifying runoff, and ensuring long-term dust control. Implementing this multi-tiered strategy can help operations achieve significant cost savings, improve environmental compliance, and streamline sediment management processes. AB
