Jan Nyqvist product manager from Automation Underground Mining at ABB explores new ventilation techniques.
Creating a safe working environment in underground mines is the primary concern for mining organisations, it is part of their license to operate before a vehicle moves or a person starts their shift. Management must ensure that personnel are not exposed to excessive levels of CO2, nitrous oxide, dust, humidity, temperature, toxic blasting, and strata gases. A constant supply of fresh air is essential throughout the mine. Therefore, ventilation systems are a critical and high-demand part of the underground mining process.
The need to constantly cycle clean air into mines, remove contaminated air, and regulate temperature has led to these systems becoming significant energy consumers, accounting for as much as 50% of resource use and operational expenditure. With increasing pressure on mining organisations to reduce their energy consumption, a new approach to ventilation has gained popularity: ventilation on demand (VoD).
VoD systems work by utilising sensors placed around the mine that transmit real-time data on key parameters such as vehicle use, personnel, and information from gas, flow, and temperature sensors to a central control system. This setup enables mine-side control of fans and air regulators. Over time, these systems learn and adapt as more data is collected, maximising air quality and evacuating blast gases faster, allowing workers to return to the face in less time.
For instance, ABB’s VoD system, ABB Ability Ventilation Optimizer, operates equipment according to actual demands. Using a positional tracking system, the technology identifies where people and vehicles are in the mine and their ventilation needs. An algorithm then calculates the optimal set points of the fans and implements this across the mine. The VoD optimiser recalculates airflow every 15 seconds, 24/7, ensuring appropriate levels of airflow are always running. This approach can save large mines up to US$3 million per year and reduce energy consumption by 50%.
Currently, ventilation systems are heavily relied upon to remove diesel fumes emitted from trucks running underground. Diesel engines typically waste 60-70% of energy in the form of heat, necessitating additional ventilation to clear continuous tailpipe emissions.
This application is coming into focus as miners plan for, trial, and buy new battery-electric operated vehicles to reduce their emissions. As mining fleets become electrified, the amount of diesel particles that need to be removed will decrease significantly, eventually reaching zero. However, this will only happen once every truck in every mine is electric, and this is some way off yet.
In the interim, sophisticated VoD systems will play a crucial role in ventilating hybrid mines. Many mines will operate mixed fleets for the foreseeable future with both diesel and electric trucks running. Ventilation will need to be distributed based on where different trucks are in the mines. VoD systems will provide the flexibility to adjust the ventilation to supply more air to areas with diesel machinery in operation. Even when the all-electric mine of the future is realised, ventilation will still be crucial. As mines go deeper, cooling and refrigeration become more of an issue, with some mines operating at temperatures of 35 degrees Celsius. Regulating temperature is vital to the efficient operation of electric fleets, ensuring battery charge, health, and capacity are preserved.
The evolution of ventilation systems in underground mining is a testament to the industry’s commitment to safety, efficiency, and sustainability. As mining operations transition to electric fleets, VoD systems will continue to play a vital role, adapting to new challenges and ensuring optimal working conditions. This integration of automation and innovative technologies promises a future where mines are safer, more efficient and sustainable.
Innovation has revolutionised many processes in underground mining today, not only ventilation. Robotics are changing the way workers complete vital tasks, such as blasting, while automation is reducing energy and water consumption in mines and improving waste management.
The next frontier of innovation is integrating these functions under one planning schedule and production control. Within this system, an automated layer connects daily processes, including ventilation, dewatering, conveying systems, in-pit crushers, and mobile machines to give the operator a comprehensive view of the process.
This holistic overview will enable key activities to be linked. For instance, after blasting, the space needs thorough ventilation to remove the remaining gases and dust before it can be mucked out. Automated production control would enable ventilation to automatically focus on the blasting location as soon as the process is complete, removing the gases as quickly as possible.
