Mining companies are working towards carbon neutrality, which requires lowering carbon monoxide emissions. One method of reducing emissions is by replacing internal-combustion engines (ICE) with battery electric vehicles (BEVs).
The drive for vehicle electrification will have significant impact on the metals required to produce BEVs, particularly nickel, copper, lithium, cobalt and molybdenum. Some estimates suggest that copper demand may be upwards of 3.7 Mt (4.1 million st) just for BEVs in the next 20 years. Combined with needs for renewable energy, BEV charging stations and energy storage facilities to feed power grids, the quantity of metals required for implementing BEVs at a large scale could easily outstrip current production.
The mining industry first investigated BEVs to help with ventilation and heat control in underground mines. A large impact on underground mines is diesel equipment’s generated heat and emissions, such as carbon monoxide, nitrogen oxide and diesel particulate matter. Converting to BEVs eliminates exhaust, reduces heat, and reduces ventilation demand.
Numerous engineering studies have compared the benefits and disadvantages of swapping diesel equipment to BEVs. Risks include not meeting airflow requirements, less flexible operation, BEV fires and limits to haulage distances.
One significant risk is a BEV fire. Over 100 toxic gases can be released by lithium-ion batteries. Battery fires can be difficult to extinguish as the fire may be enclosed in the battery pack. CO2 or chemical extinguishers may suppress the fire, but may not cool the battery pack, while water sprays are effective at cooling but may trigger electrical faults or react with lithium to release hydrogen gas. To lower fire risk, BEV charging stations, parking stations and battery storage facilities will ideally be located near an exhaust and include gas sensors, fire doors and fire suppression systems. Mine operations will need to ensure proper handling and removal of excess batteries. A full understanding of the ventilation system is required so that in the event of a fire, mine rescue teams can access the area.
The risks need to be analyzed in a study that considers the types of BEVs on site, a vehicle tracking system, the location of charging stations and battery storage locations and the quantity stored at each location and proper training on BEV operation and firefighting. The risk study also must consider if the ventilation system will meet airflow requirements if the mine reverts to using some diesel machines.
It is projected that the use of BEVs for mining applications will continue to increase as more companies seek carbon neutrality. However, careful planning and risk assessment is required with BEVs to ensure operational flexibility, intentional placement of charging stations, and training of personnel in operating BEVs, BEV firefighting, and emergency planning.
