Canadian mines need to keep moving forward with the battery electric vehicle (BEV) technology but safety has to be involved in every step along the way, according to Mike Mayhew, the man who spent the last three years as mine superintendent at the Kirkland Lake Gold Macassa Mine and Integration Manager for Shaft 4 at that mine.
Mayhew, who is now the principal consultant for Mayhew Performance, was one of the key speakers at a symposium hosted by Workplace Safety North in Sudbury to assess the risks and manage the hazards of the new BEV technology.
“I don’t say safety is a priority. I say it’s a value. We live safety every day and then the next thing it has got to be part of your culture, part of your values. So safety for us is very valuable.”
Mayhew said 80 per cent of the mobile mining production fleet at Macassa has been switched over to battery electric in recent years. He said that decision was related to a ventilation concern at Macassa’s South Mine Complex in Kirkland Lake.
He said it was realized nearly eight years ago there was not enough airflow through the old mine workings to support continually mining with diesel equipment.
“So the bottom line here, mines get deeper and they get hotter. Either they were going to invest in a cooling system or they were going to do the battery technology.”
Mayhew outlined details from a case study involving the Artisan Z40 battery electric 40-ton haulage truck versus an MT2010 battery electric hauler. The study showed significantly less heat was generated using the Z40 battery vehicle that was first designed and created for the Macassa Mine.
Mayhew said despite the improved performance of BEVs, the mine had to take into account the actual chemical composition of the vehicle battery.
“We’re going to have to understand what’s inside the battery, because if we don’t understand, how do we manage it?” Mayhew asked the group. “What’s the risk? What’s the fire hazard? How do we manage it if there is a fire?”
As part of the learning experience at the mine, Mayhew recalled an incident where it was revealed that even when high-voltage and low-voltage connections were unplugged, there was still live current inside the battery. It was discovered that one of the hazards that could occur during maintenance was called arc flash.
He said a procedure was developed so that technicians working on the mobile electric equipment were required to wear a protective suit and a face mask.
Mayhew said any mining operation that has electric vehicles will have to do the research and establish procedures for the possibility of fire. He said that will become especially important for Mine Rescue and the people specifically assigned to fighting fires underground.
Mayhew recalled a mock fire scenario underground. He said in reality there was no fire, but it was still enough to make him sweat as he considered the possibilities of things going wrong.
“If you’re 4900 feet below surface and there’s people underground and there’s a fire, you know what, it’s all about saving people and making sure that you have the right procedures and process in place.
“I didn’t know if it was a diesel truck at that time. Or a battery truck. There was limited information. Anyway we went through the procedure. But what a learning experience,” he said.
Mayhew said the next step for the industry is to begin sharing information for safety purposes.
“We have to ensure that we in the mining industry have the right information when it comes to battery technology.”
He said this means sharing information on performance, on maintenance and safety and it will involve the mining companies, the maintenance teams and the original equipment manufacturers.
CORRECTION: Our original version of this story mis-identified the MT2010 haulage truck as a diesel, instead of correctly identifying it as a battery electric vehicle. Our apology for the misunderstanding.