Howden was invited to design and implement a ventilation control system that would optimise the supply of fresh air to underground workers while reducing energy consumption and operating costs.
In Canada, the Eleonore gold mine is owned and operated by Newmont Corporation (formerly Newmont Goldcorp Corporation). They worked in partnership with Howden to introduce radically new Ventsim™ CONTROL technologies that brought impressive cost and energy savings while also raising productivity.
In most underground mines, the largest energy consumer is the ventilation system. Vital for providing essential fresh air to miners, ventilation systems have traditionally been very static; fans are set to run continuously 24 hours a day, 7 days a week. As well as preventing the build-up of dangerous levels of diesel equipment gases (CO, NOx) and diesel particulate matters (DPM) underground, they also evacuate respirable dust and the noxious gases associated with extracting ore and other waste chemicals.
The Eleonore gold mine has a fresh air capacity of more than 900 kcfm (425 m3/s). The principal ventilation system consists of two Howden Alphair 12300-AMF-6600 axial exhaust fans with a nominal power of 2,000 HP (1,471 KWh) each, configured in parallel. An exploration shaft has two Howden Alphair 11200-AMF-6600 main intake fans with a nominal power of 750 HP (551.62 KWh), again configured in parallel. The mine also has over 140 auxiliary and booster fans operated in conjunction with seven dampers and air regulators and a heating system fuelled by propane.
Newmont commissioned us to provide a control system that would provide safe, efficient ventilation optimization while reducing energy demands and costs.
We set out to create an automated system covering all the ventilation equipment in the Eleonore mine, including the main fans, underground auxiliary fans, and airflow regulators. 30 Ventilation Monitoring Stations (VMS) were installed to determine the quantity and quality of fresh air at various points underground. Each VMS includes one flow sensor and three gas sensors to detect CO, NOx, and C3H8, and is an integral part of the Ventsim CONTROL system.
A mine-wide tracking system was installed to detect the presence of vehicles and personnel underground. Each of the 144 vehicles was fitted with a Radio Frequency Identification (RFID) tag that indicates its position in the mine and whether the engine is operating. Everyone working underground was also given a unique RFID tag that connects to one of 254 zone-based Access Points.
The tracking data is transmitted from these Access Points to the control room on the surface through a hybrid fiber-optic network. There is currently between 60% and 70% wifi coverage in the mine, with plans for 100% coverage during full production. The data from the RFID tags provides enhanced safety and management of the movement of vehicles and personnel and Ventilation on Demand (VOD).
The data from the tracking system allows ventilation requirements for each zone to be calculated by the VOD logic software. This information is then used to automatically modify each of 140 underground auxiliary fans' speeds to ensure that each zone of the mine receives enough fresh air.
The control system in the Eleonore mine can be easily expanded as the mine grows in size to maintain adequate, safe ventilation in every part of the workings as new areas and levels are opened up.
The installation of the Ventsim CONTROL system, with its Ventilation Monitoring Stations and automation of all ventilation equipment, means that the supply of fresh air to individual work zones is maintained with complete safety, ensuring all underground personnel has a comfortable working environment. At the same time, the waste associated with continual ventilation of the whole mine has been eliminated.
As a result, there have been significant benefits in production and sustainability as well as safety. To quantify some of these benefits, an energy-saving analysis was carried out.
The investigation covered energy consumption in the underground auxiliary fans, the main intake, exhaust fans, and the propane volume used to heat the mine.
To date, there has been a 43% reduction in mine heating costs, a drop of 56% in underground ventilation electricity costs, and a remarkable 73% decrease in the cost of surface ventilation electricity, as detailed in the case study available. While these figures are impressive, the maximum potential savings will grow even more remarkable when the mine reaches total capacity.
Newmont – Eleonore won the Eureka Prize from Écotech Québec. The award was received to recognize the proven benefits of Energy Efficiency and Air treatment from the Ventilation on Demand (VOD) system implemented by Howden.
For its 10th anniversary, Écotech Québec celebrated the pioneers in Quebec who chose to adopt clean technologies. Nearly 250 stakeholders in the cleantech ecosystem were present. Great projects and many adopters have distinguished themselves by their contribution to the rise of Quebec's clean technologies.
We congratulate Newmont and are glad to collaborate with our client's objectives.
Newmont Corporation - Eleonore is proud to recognize the teamwork that has enabled a project such as Ventilation On Demand to continually improve our energy efficiency performance while maintaining the health and safety of our workers.