Hydromulching and dust suppression are vital parts of rehabilitating a mine. Australian Mining looks at how companies are making these products more sustainable.
Revegetation and rehabilitation are essential parts of the mining life cycle.
But in order for a mine’s rehabilitation to be truly effective, the products used in the process must be environmentally friendly.
Australian Mining sat down with Global Soil Systems, its parent company B & K Revegetation & Landscaping, and rehabilitation product manufacturer Vital Chemical to discuss the sustainability of two vital products used in mine rehabilitation: dust suppression and hydromulching.
Dust suppression
A key process in the mining industry, dust suppression is used to reduce negative environmental impacts and improve air, water and soil quality.
Miners can use a variety of methods from water spray systems to chemical suppressants to keep the air healthy.
But with so many types of dust suppression methods available, it can be hard to know where to start. Vital Chemical breaks it down.
“At our core, we are scientists,” Vital Chemical director Paul McMullen told Australian Mining. “We substantiate everything we do with science, and we make clean chemicals for the environment and for sustainable purposes.”
While many may not automatically think of sustainability when hearing the word ‘chemical’, Vital Chemical is keen to change that narrative.
“We’ve had a direct shift in the last 20 years and now 90 per cent of our raw materials are sourced in Australia,” McMullen said.
“By domestically sourcing the raw materials for dust suppression, we are automatically decreasing carbon emissions while maintaining a higher standard of quality control.”
Dust suppression methods that meet site obligations and productivity constraints while being environmentally friendly can be hard to deliver, but Vital Chemical is up for the challenge.
“Governments have set net-zero targets for 2050, and dust suppression is a way of helping to meet those targets,” McMullen said.
“The mines we rehabilitate cover large areas, which means the carbon farming opportunities are great. Mines are really starting to see this, and they’re turning to more sustainable dust suppression methods as a result.”
Hydromulching
Perhaps less well-known than dust suppression (but no less important), hydromulching involves spraying a mixture of water, seed, fertiliser and mulch to revegetate damaged soil.
Having specialised in hydromulching since 1983, B & K have worked hard to ensure this crucial rehabilitation process is as sustainable as possible.
“Made from a by-product of forestry materials, our hydromulch is a mix of wood fibres, fertilisers and seed which is mixed in a tank and then sprayed onto the surface,” B & K general manager James Nebauer told Australian Mining.
“It gives a site both erosion control, and a bed for the new seed to grow on.”
Instead of planting and growing a whole forest just to cut it down for mulch, B & K makes hydromulch out of waste product.
Image: Global Soil Systems
“It could be timber that doesn’t meet housing or building specifications,” Nebauer said.
“Instead of that being thrown away or discarded, it’s made into a valuable resource.”
This process creates a continuous lifecycle with no end date.
“We’re growing trees from wood fibres that can then be used to produce more wood fibre that can then be used to produce more trees,” Nebauer said.
“The decarbonisation outcome from that process is really important in the effort to cut emissions.”
As the implications of climate change make themselves more known, mines are looking to cut down emissions as much as possible. KPMG’s ‘Mining Risk Forecast 2024’ report identified climate change as the top reported risk for ASX-listed mining companies.
KPMG partner risk consulting Caron Sugars said the finding represented an opportunity for the mining industry to set strong climate-related goals.
“There is opportunity ahead for Australian miners to focus not on extraction but also processing, with Federal Government support being provided for critical minerals,” Sugars said.
“This is a key part of the response to climate change risk and reflects the positive outlook for the sector longer term in both traditional mining and critical minerals.”
McMullen and Nebauer agree.
“When you think about what the sector can do next to keep up with its decarbonisation goals, the answer is pretty simple: use more products that are sustainable,” McMullen said.
“There has been a lot of improvement in the last two to three years, but there can always be more.”
Nebauer said this can be as simple as ensuring products used in rehabilitation are sourced domestically.
“It really is that simple,” he said. “It doesn’t make sense to source something that we can get here from the other side of the world.
“Start small, start with making sure your products are locally sourced and made, and then watch your goals fall into place.”
This feature appeared in the May 2024 issue of Australian Mining.
