Improving environmental and energy management on mine sites

The DeGrussa mine solar farm. Image: Sandfire Resources

As the mining industry is often scrutinised for its potential environmental impact, the need for companies to retain their social licence to operate should remain a key priority.

Deloitte national mining leader Nicki Ivory explained there was a growing sentiment from stakeholders questioning whether the mining industry is abiding by its social licences.

This is particularly the case after the news of mine failures that caused environmental damage, such as the tailings dam bursting at BHP and Vale’s Samarco operations in Brazil, which flooded the states of Minas Gerias and Espirito Santo and killed 19 people; the collapse of a tailings pond at the Mount Polley mine in Canada; and in Australia, the spillage of more than 2300 tonnes of coal slurry from the Clarence Colliery into the heritage-listed Blue Mountains area.

“The onus is on the mining companies to make sure those things don’t happen,” Ivory told Australian Mining.

Miners are also called on to be more aware of their pollution via greenhouse gas emissions as part of the broader efforts to reduce global warming worldwide.

Ivory noted that diesel has historically been the fuel of choice for mining companies, but this is beginning to change as some companies explore renewable energy sources.

She pointed to Sandfire Resources’ DeGrussa copper-gold operations in Western Australia, which installed a solar facility that integrates with its diesel fired power station. The solar facility is designed to supply around 20 per cent of the annual power requirements of the mine and is expected to slash emissions by around 12,000 tonnes of carbon dioxide a year.

“They [Sandfire] were some of the early adopters of using available incentives to build a renewables project next to their mine at relatively low cost to create a sustainable power source well beyond the life of the mine,” Ivory said.

Energy management

Energy management is becoming a bigger priority for mining companies. Ivory said they were beginning to look at it more strategically for their operations, especially since energy expenses accounted for nearly 30 per cent of operating costs.

Ivory added that energy costs were likely to increase over the years as mining became more energy intense, deposits got deeper and grades became smaller.

“We’re seeing more companies looking at energy strategically not just at the procurement process,” she said.

“The supply side has historically been the focus – where companies manage the cost of where they buy the energy from – rather than looking at it far more holistically across not just the financial but the environmental and social areas as well. We call it the triple bottom line of energy management.”

Ivory emphasised that companies should improve management of the demand side, for example if a company does most of its processing during the day, they may use solar power during the night rather than having a 24-hour processing cycle.

She said companies should consider how they could restructure on the demand side to make their operations more efficient.

“There is a lot companies can do that can help themselves financially and tick the good environmental and social responsibility boxes,” she added.

Ways to address energy management and environmental sustainability

The report said companies should optimise their energy usage, and take a ‘system level approach to energy management’.

This includes looking at all their processes to reduce energy consumption across the board; building internal capabilities around energy management; setting up a governance structure; clarifying goals and targets; and fostering an energy conscious culture.

Ivory also mentioned the importance of water management as a way to maintain environmental sustainability.

“Water is clearly scarce in parts of Australia, and we need to be thinking about how new technologies are playing a role here, so developing processing technology that can operate with less water or on a dry basis rather than a wet basis,” she said.

The report encouraged companies to continually explore strategies to reduce water consumption on site such as implementing a mine design that allows dry processing – using no water – and employing sensor-based ore sorting, which finds minerals and waste before extraction, thus reducing both water and energy usage.

It also suggested more environmentally sustainable ways mining companies could repurpose and rehabilitate their mine operations after closing, for example the Wheal Jane tin mine in the UK repurposed into a part with recreational trails or other dormant mines being transformed into solar and wind power installations.