As Australia transitions towards a net zero future, there’s increasing pressure on the mining industry to move towards sustainable methods of mineral processing. Stantec’s solutions provide a viable way forward.
There’s a commonly held perception in the community that Australia’s reliance on mining is holding us back from transitioning towards a clean energy future.
But mining needs to form part of the solution going forward, says Marius Phillips, Senior Principal Consultant Minerals Processing at Stantec.
“To meet a lot of the targets for various metals – for example, demand for copper is set to double by 2035 – the mining industry will inevitably need to be part of the solution.”
Stantec’s solutions play a critical role in helping companies move towards more sustainable methods of processing minerals. This can be achieved in four primary ways: energy optimisation, reducing water consumption, reprocessing waste materials, and transitioning to alternative sources of energy.
Driving down energy use
In the mineral processing space, Stantec’s key focus is finding solutions to maximise output while minimising waste.
Stantec recently completed a project for a tier one mining company to reduce its overall energy expenditure.
“We expanded the throughput of the existing assets from 5.2 million tonnes per annum to about 6.5 million tonnes per annum. That equates a 25 per cent increase in throughput for a system that has the same energy input,” says Phillips.
“We achieved this by coarsening the primary grind and putting a corresponding flotation unit on the tail end of it. It’s worked really successfully for this project and we’re now considering similar solutions for other projects as well.”
Reducing water consumption
Mining was a very different space in the mid 1980s when Stephen Beamond, Business Leader, Energy & Resources at Stantec, first entered the industry.
He remembers knowing when the plane he was travelling on was approaching a mine site because he’d spot a green tail of trees fed by water running from the mine site.
“There’s no way that would happen today,” says Beamond. “Water is such a precious asset and an expensive part of the mining process. Nowadays there is a huge emphasis on minimising products, including water, that go into running your mine site.”
With mineral production being a water-intensive process, Stantec focuses on water conservation by reusing or recycling water, or returning more water to the circuit, as part of a focus on sustainable processing.
Stantec’s solutions can help companies transition from traditional tailings disposal methodologies to coarser methodologies and filtration.
“That can result in consumption reducing from 0.5 cubic metres per tonne to 0.2 cubic metres per tonne,” says Phillips. “That’s a significant saving in the water space.”
Recycling waste products
A few decades ago, mining companies weren’t interested in reprocessing waste materials into another product, says Phillips.
But times have changed and many of Stantec’s clients with existing tailing dams are now looking into the possibility of reprocessing tailings into another product.
“There are a lot of tailings around the world with potential reuse value,” says Phillips. “They could be used for recovery of nickel, cobalt, gold, copper or even silica sand.”
“Could these tailings be reclassified and sold into the sand industry? Many companies are looking for sustainable sources of sand, given the current sand shortage, so reprocessed tailings could be sold into the sand industry,” says Phillips.
Watch the video to find out more about the sand crisis and how repurposing tailings could address the shortage.
Moving to alternate sources of energy
Powering mineral processing using alternative sources of energy, such as solar or hydrogen, has become a major focal point for Stantec in recent years.
“The biggest generator of greenhouse gas emissions on a mine site is typically diesel-powered mining equipment and power generation,” says Beamond.
“In the past there’s been heavy reliance on diesel, but a number of projects nowadays are gas. Diesel is becoming much rarer. You can still find diesel power in some really remote sites where it’s the only fuel source that’s available to get to site, but there’s a definite trend of moving away from diesel towards greener energy sources.”
In collaboration with a clean energy solution company, Stantec has developed hybrid power stations in Western Australia using a combination of gas, solar and energy storage for remote mine sites.
Stantec is also assisting one of its customers in NSW to develop a 15-30 megawatt solar farm.
“This will power their operations during the day so they’re not reliant on grid power. It will provide them with a substantial energy saving.”
Making the transition to a net zero future possible
Transitioning successfully to more sustainable methods of processing will require companies to embrace some fundamental principles.
“Companies need to take a cautious approach because if the process is rushed, critical steps and considerations can get missed,” says Beamond.
“If these methods are going to get real traction in the industry, then we need to have successful examples to draw on.”
Success stories need to be shared through a collaborative approach that encourages the exchange of best-practice approaches.
“There used to be a lot of secrecy in the industry. That’s fair enough if there’s something that gives you a competitive advantage, but I think we can work together as a community to bring mining into the next phase,” says Beamond.
“Organisations now share best-practice when it comes to safety which wasn’t previously the case in the industry. I think we need to be doing that with sustainability now too.”
Learn more about sustainable mineral processing and waste reduction from the recent Engineers Australia webinar, in collaboration with Stantec. Watch here