Ventilation Strategy Related to Battery Equipment at Macassa Mine
Mike Mayhew, Kirkland Lake Gold
Kirkland Lake Gold introduced battery equipped vehicles (BEV) at the Macassa Mine in 2011. The fleet of underground BEV haulage trucks and loaders has grown over the years to over 30 units, the worlds largest, currently handling approximately 80% of the daily production tonnage. The underground ventilation infrastructure at Macassa was designed and built for compressed air and electrical (i.e. tethered) equipment. The inflow and outflow of air occur through a limited number of relatively small openings, which further limit the air volume delivered to the underground workings. In addition to improving air quality, the reduced heat load generated by the BEV (when compared to diesel equipment) had a significant positive impact in the workplace. The use of BEV for material handling has enabled increases in production that would not have been possible using diesel equipment because the volume of air required to dilute diesel emissions would exceed the volume of air currently ventilating the mine. This paper outlines the evolution of BEV in use at the Macassa Mine, measurements of the heat loads generated by the BEV and principles guiding current and long-term ventilation design.