Key points
- Desktop study reveals algal technologies have the potential to mitigate some of the environmental impacts of mining.
- Algae can be used in mine wastewater treatment, mine site revegetation and as a source of biomass for new industries.
- Now seeking partners to develop these technologies for mine-specific applications.
Algae might seem an unlikely candidate to help transform Australia’s post-mining landscapes, but a new CSIRO-led project suggests these tiny aquatic organisms could provide sustainable futures for mine sites, surrounding ecosystems, and local communities.
With support from the Cooperative Research Centre for Transformations in Mining Economies (CRC TiME), a research team led by CSIRO, in collaboration with the University of Queensland and Murdoch University, has completed a study exploring the environmental and economic potential of algae-based technologies in mining – during the operational phase and after closure.
The project brought together expertise from multiple industry and government partners, including South32, Fortescue, Rio Tinto, Heidelberg Materials, Energy Australia, the Queensland Mine Rehabilitation Commissioner and the Minerals Research Institute of Western Australia (MRIWA), to assess whether algae could help reduce the environmental footprint of mining, while also creating pathways for regional economic development.
CSIRO Senior Principal Research Scientist Dr Anna Kaksonen led a desktop project mapping the potential of algal technologies in mine rehabilitation.
“Algae can be cultivated on non-arable land, making them suitable for remote mine sites where agricultural activities may not be viable,” said Anna.
“They grow relatively quickly, fix carbon dioxide through photosynthesis and produce organic biomass that can be used directly on site or processed into valuable products. This offers environmental benefits while also reducing the need to transport materials from elsewhere – often a significant cost for mining operations in remote areas.”
Environmental solutions rooted in algae
Mining is a key driver for Australia’s economy, but its environmental impacts are sometimes significant. These can include greenhouse gas emissions, ecosystem degradation from wastes and effluents, dust from vehicles and ore processing, and the loss of topsoil during operations. But Anna said she believes algae may offer practical, scalable solutions across several of these problem areas.
One promising application is mine water treatment. Depending on the quality and chemistry of mine water at a given site, algae can either directly remove contaminants while growing or be used as a source of carbon and electrons to drive other biological treatment processes - such as sulfate reduction - to reduce acidity and remove metals.
“Many Australian mine sites have poor water quality, often with high levels of sulfate or metals,” said Anna.
“If algae can help improve the water quality, it can be an important tool for water treatment.”
Algal biomass may also assist with revegetation and mine site rehabilitation by acting as a bio-stimulant, increasing soil organic carbon content and supporting the establishment of plants in areas where topsoil is limited or depleted.
“In Australia, topsoil is often stripped away when mines are established and stockpiled for rehabilitation, but the quality of the topsoil degrades during storage,” she added.
“Using algae as a soil amendment would help support plant establishment and site rehabilitation when operations have finished.”
Identifying economic co-benefits
Beyond the clear environmental benefits, the project identified a range of economic and social opportunities tied to algae cultivation and processing.
Depending on the algal species and the site conditions, biomass could be used to produce pigments, bioplastics, biofuels, or even animal feed, opening up new post-mining industries.
This creates potential for local job creation, economic diversification, and supply chains that are less reliant on fossil fuels or long-distance transport.
“There are already large-scale algae operations in Australia, just not yet in mining context,” said Anna.
“This project is about improving our understanding of what would be technically, environmentally, and economically feasible based on what algae are present at Australian mining sites.”
Collaboration at the core
The stage one study was primarily desktop-based, drawing on existing literature and international case studies.
The interdisciplinary project partners explored topics including:
- Mine water chemistries and potential pre-treatment needs.
- Types of algae detected at mine sites.
- Cultivation and harvesting technologies.
- Potential uses and market value of algal products.
- Regulatory and environmental considerations.
An important component of the project was development of a First Nations Engagement Framework by Regional Economic Solution (RES), an Indigenous owned and operated company.
This framework provides tools for evaluating partnership potential of mining companies within the context of CRC-TiME First Nations Inclusion Principles, and subsequent engagement with First Nations communities.
“We want to understand how these technologies could benefit Indigenous communities who live near or care for the land around mine sites,” said Anna.
“In Stage Two, we hope to work closely with Indigenous businesses and leaders to explore opportunities for First Nations participation and ownership.”
Bench-scale trials to test technologies
With the desktop study complete, the team is now seeking partners and funding to progress to Stage Two: bench-scale experiments and testing of the most promising algae-based technologies with samples sourced from mine sites.
Plans for the next phase include:
- Investigating regulatory requirements and biosecurity issues
- Engaging with First Nations communities
- Identifying native algae species in mine water using DNA analysis
- Assessing the growth potential of these algae in mine water with and without supplements
- Evaluating water treatment performance and soil creation potential in bench-scale experiments
- Performing techno-economic and life-cycle analyses for selected applications.
While the project team is optimistic, Anna emphasised the importance of tailoring solutions to specific mine sites, climates and community needs.
"Australia’s mining regions are incredibly diverse – from rainfall and temperature to water quality and remediation priorities,” she said.
“We’ll need a range of algae types and technologies to match those different conditions.”
A big opportunity from something very small
For Anna, the most exciting part of the project is the sheer versatility and potential of algae for beneficial applications.
“There are so many types of algae with different properties: different temperature tolerances, salinity ranges, and biochemical compositions,” she said.
“That diversity gives us a toolbox of options, and the opportunity to match the right solution to the right site. The key will be finding applications that align with what mine operators need and what communities value.”
As mining companies and regulators increasingly seek sustainable, socially beneficial closure options, algae-based technologies may offer a new and exciting pathway forward.
You can download the full Stage 1 report for Project 3.15: Algae-based technologies for improved environmental outcomes
and sustainable post-mining futures, from the CRC TiME website.