Stabilising tailings dam capping with plant-based enzymes

About the project 

Develop novel ways to stabilise tailings from mining operations

If you are primed to start your career in engineering and construction and ready to tackle sustainability in this industry, the University of South Australia – Australia’s University of Enterprise – is offering a hands-on project-based PhD within the Sustainable Infrastructure and Resource Management (SIRM), in partnership with BHP.

While mining operations contribute approximately 21% to Australia’s GDP and 1.2% to the world’s total GDP, they also generate significant quantities of tailings as a byproduct, which are stored in tailings storage facilities (TSFs). When mining operations are closed, TSFs are closed and decommissioned to prevent leaching into the ground and surface waters.

However, due to the legacy of tailings operations and the diverse and complex nature of available closure materials from mining operations, many TSF surface tailings require stabilisation to ensure their integrity and reduce costs.

Our project explores biostabilisation as an emerging alternative, using plant-based enzymes derived from Paddy melon to catalyse the reaction between carbonate and calcium ions from a natural calcium chloride solution.

This process promotes the precipitation of calcium carbonate (CaCO?) between particles, effectively binding and stabilising tailing particles. Our project involves a comprehensive geochemical study, examining factors such as soluble ion and salt concentrations, pH levels, temperature (T), and the presence of heavy metal inhibitors.

We will also assess challenges like clogging, flow restrictions, and the formation of CaCO? polymorphs due to rapid precipitation.

You will join SIRM, which is a multidisciplinary and highly collegial environment. You will benefit from mentorship and collaboration with experts across several fields. The research concentration will provide you with access to unique expertise, resources and equipment that will help you excel in your research.

What you’ll do

In this project-based research degree, you will develop kinetics models of powdered enzymes for optimising the concentration of ions and salts, pH, T and heavy metal inhibitors for adequate CaCO3 precipitation in a single treatment cycle.

You will also evaluate the behaviour of TSF surface tailings with a systematic increase of CaCO3 precipitation.

Our project gives you the opportunity to work alongside a number of influential industry consultants, many of them based in international institutions. Upon graduation, you will one of the leaders in the discipline and a pioneer in transferring knowledge in the discipline.

Where you’ll be based

You will be based in SIRM. Our future depends on the increased application of sustainable infrastructure and responsible use of our natural resources. SIRM facilitates this goal by conducting research in three main streams:  natural resources and environmental resilience,   innovative infrastructure and asset management and smart communities.

The construction industry is an essential part of our lives, but it is one of the highest contributors to climate emissions.  SIRM is committed to meaningful research that can help re-shape this industry into a leader in sustainable practices.  SIRM also works directly with the resource sector, particularly water and forestry, to inspire innovative management.

SIRM brings together diverse research expertise to address significant challenges for industries and the society at the interface of the natural and the built environments at both the macro and micro level to sustainably manage natural and built environments by applying innovative and efficient resource use.

We build resilient ecological and human systems through active engagement of diverse stakeholders and implement circular economy principles (rethink, reduce, re-use, and recycle) and innovative technologies for construction and other built environment sectors. We also promote smart resource recovery and the design and construction of efficient net-zero buildings and support liveable cities and regional communities, tourism and agri-food production. Financial Support 

This project is funded for reasonable research expenses. Additionally, a living allowance scholarship of $35,200 per annum is available to Australian and New Zealand citizens, and permanent residents of Australia, including permanent humanitarian visa holders. Australian Aboriginal and/or Torres Strait Islander applicants will be eligible to receive an increased stipend rate of $52,352 per annum (2025 rate). A fee-offset or waiver for the standard term of the program is also included. For full terms and benefits of the scholarship please refer to our scholarship information. International applicants are not invited to apply at this time.

Eligibility and Selection

This project is open to applications from Australian or New Zealand citizens, and Australian permanent residents or permanent humanitarian visa holders. International applicants are not invited to apply at this time.

Applicants must meet the eligibility criteria for entrance into a PhD. 

All applications that meet the eligibility and selection criteria will be considered for this project. A merit selection process will be used to determine the successful candidate.

The successful applicant is expected to study full-time and to be based at our Mawson Lakes campus in the north of Adelaide. 

Essential Dates 

Applicants are expected to start in a timely fashion upon receipt of an offer. Extended deferral periods are not available. Applications close on Wednesday, 4 June, 2025.