Ventilation is responsible for a large part of the energy costs in a mine. For this reason, in collaboration with ABB, Boliden has installed an automation system for ventilation that is governed by needs in the mines in Kristineberg and Garpenberg.
Why ventilation governed by needs at Boliden?
In the breaking rooms in a subterranean mine, air is polluted by diesel vehicles and blasting. Creating the ventilation required to remove the pollutants is an energy consuming as well as a complicated business. There is a large potential to save energy in this area.
ABB solution
Kristineberg is one of Sweden's deepest mines operating at a depth of more than 1100 meters. The ventilation system has a capacity of all of 55000 m3 per hour and the first generation of systems for ventilation governed by needs was installed in 1997. However the system is limited to three positions, off, half speed and full speed. In 2007 Boliden selected ABB's 800xA automation system as the new platform, where all automation would be handled in one and the same control system environment.
The world's most modern ventilation plants for subterranean work
ABB's control technology has made sure that the air flow of the plant is automatically adapted to activities in the rock shelter in question. The fans are programmed to only operate in those rooms where an activity is in progress. On vehicles used in the mine, there are transmitters with unique identity numbers. When the transmitter starts, ventilation is increased according to a pre-programmed volume to the vehicles in the breaking room. The fan operates for approx. 14 minutes after the last vehicle has left the room in order to vent residual exhaust gases.
Return of investment within three years
Garpenberg, another Boliden owned mine, has a similar control system for a part of a new major mineral deposit, Lappberget, which will subtantially extend operations in the area. The system consists of twelve fans in Lappberget between a level of 985 and 1080 meters. After the installation, current consumption for these fans fell by approximately 200 kW, signifying a reduction of around 40 percent. At Garpenberg, approximately 50 fans will be connected to the control system in the initial phase.
"Energy savings will be so extensive that within a period of three years we will have recovered the investment," says Fredrik Ekenstedt, project manager for the Technical Staff at Boliden.