Finding alternative sources of sand – mine tailings

February 2021

The sand challenge

After water, sand is the second most exploited natural resource in the world. The demand for this material is growing exponentially around the world with urbanisation, development, population growth and sea-level rise. Yet, extraction of sand and gravel from rivers and the nearshore environment is already an environmental and resource problem. Despite increased recognition of sand as a strategic resource for sustainable development, the issue remains largely unaddressed and unresolved in many places around the world. With the coming post-COVID recovery investment in infrastructure construction – the largest demand sector for sand by volume – this situation needs to change urgently.

The ‘Finding alternative sources of sand’ project

This project investigates whether currently unused mining residues, with favourable mineralogical and physicochemical characteristics, can be transformed into a viable and sustainable substitute aggregate material for the construction industry, displacing the need for sand extracted from the natural environment.

Why now?

Attempts to give mining residues a second life have been made in the past, and suitability for certain applications has been proven. However, serious uptake has been impeded because these residues must be technically and economically competitive with conventional materials. Now, awareness of the growing sand sustainability challenge is generating clear calls for alternatives at scale. At the same time, changes in mining, environmental and waste policy means large volumes of mine tailings now need to be treated differently in many places in the world. The rising value of sand and the costs of storing mining residues may give new impetus to a circular economy synergy with a strong contribution to sustainable development.

Approach

This 12-month pilot is a collaboration between The University of Queensland and The University of Geneva. Over the course of 2021 our team will sample, test and evaluate co-products of iron ore tailings, develop potential resource substitution strategies, and interview different stakeholders in the mining and construction sectors. As we work through technical testing, we will engage in constructive dialogue with major stakeholders including artisanal, large- and small-scale miners, construction and manufacturing industries, standard setting institutions and regulatory bodies.   

Expected impact

Our research and dialogues will explore if co-products of iron ore can provide a just and responsible alternative sources of sand, which is a timely contribution to processes like the implementation of the UNEA-4 Resolution on Mineral Resource Governance. In the medium to long term, this pilot demonstration is expected to contribute to fundamental knowledge on methods and assessment procedures for testing the viability of sand alternatives. If iron ore tailings emerges as a viable source to meet demand for sand, the project may also produce new applied knowledge about a convincing circular economy response to the degradation of our natural environment from uncontrolled sand extraction.

Acknowledgment

This pilot project has been made possible through financial contribution from Vale International SA.

 

Figure 1. Tailings generation by mined commodities versus demand for natural sand by applications. Note: authors estimate.

 

 

 

 

 

 

 

 

 

 

Figure 2. Examples of tailings and recovered sand by-products.

 

Project Members

Professor Daniel Franks
Dr Artem Golev
Dr Martin Stringer