Almost carbon neutral ventilation at Boliden’s Kankberg

Swedish mining major Boliden says it needs many solutions if it is to achieve its carbon intensity reduction goals. One example is the installation of a heat exchanger in Kankberg gold and tellurium mine, which will make a big difference locally. Andreas Markström, Mine Planning Manager at Kankberg, saw the potential of this technology early on and began to count its possible impacts. It is ready to begin operations at year-end. “Compared to other mining companies around the world, the Kankberg and Boliden Mines both have low energy consumption. But even though I think we’re best, we’re not satisfied. The heat exchanger let us take a giant step toward carbon neutral ventilation in Kankberg. The climate benefit arises in that all ore loading and haulage to the surface was going to be electrified,” explains Andreas.

Heat exchangers are already used in Garpenberg and in the zinc mine. After extending the mine ventilation system, Boliden also created the right conditions in Kankberg. Since this is the first time the technology has been used in such a cold climate, the Swedish EPA’s Climate Leap is subsidising 28% of the investment cost. The hope is that the technology will be implemented in more mines with similar conditions. “This is a clear example of how we make a difference wherever we can and collaborate with the authorities to improve. I would like to take this opportunity to highlight the employees who have driven and implemented this improvement,” says Daniel Bergius, Mining Manager Kankberg.

In the winter, ventilation has to be heated using LPG to prevent the shaft freezing.  The exhaust air from the mine is heated further, both by geothermal heat in the rock and the vehicles used in the mine. Using the heat exchanger, we lead the warmer exhaust air past the inlet air on either side of plates such that the heat is transferred. This technology allows the reduction of Kankberg’s LPG consumption by 85%. This is one activity among many that will help Boliden achieve the goal of reducing its carbon intensity by 40% by 2030.