RARE EARTH ELEMENTS FROM HEAVY MINERAL SANDS: REALIZING THE POTENTIAL OF A FORGOTTEN RESOURCE?

Although recent research has highlighted numerous potential sources of the rare earth elements (REE; e.g. Weng et al., 2013, 2015), a significant and well-known source of these vital elements (and other critical metals) is often neglected. Heavy mineral sands (HMS) deposits are placer deposits generated by the sedimentological concentration of dense minerals such as ilmenite, rutile, magnetite and REE-bearing minerals like zircon, monazite and xenotime.

Globally, the HMS industry is the world’s most important sources of titanium minerals and is dominated by Australia, which until the mid-1990s also exported monazite concentrates for REE extraction, generating 15-30% of world REE production before the advent of the present-day carbonatite-dominated REE mining industry (e.g. Mudd and Jowitt, 2016). This decline in REE production from HMS resources does not indicate that these critical metals resources have disappeared; in fact the opposite is true, with this lack of recognition of HMS as a potential source of the REE adding to confusion over future sourcing of these elements. Here, we present a comprehensive overview of the REE potential for current Australian HMS resources, including an assessment of the likely amount of contained monazite (the most common source of the REE within these deposits.

Our data indicate that REE extraction could potentially double the value of individual HMS projects, indicating significant opportunities in terms of ensuring secure future supplies of the REE and value addition by extracting monazite and xenotime for REE production. However, further research is needed to assess both the potential extraction of other by- and co-product elements as well as assessing any environmental and radioactivity issues posed by the extraction of these elements.

Mudd, G. M., & Jowitt, S. M., Rare Earths From Heavy Mineral Sands: Assessing the Potential of a Forgotten Resource. App. Earth Sci. (Trans. IMM B), DOI 10.1080/03717453.2016.1194955.

Weng, Z., Jowitt, S. M., Mudd, G. M. & Haque, N. (2015) A Detailed Assessment of Global Rare Earth Element Resources: Opportunities and Challenges. Econ. Geol., 110, 1925–1952.

Weng, Z., Jowitt, S. M., Mudd, G. M. & Haque, N. (2013) Assessing Rare Earth Element Mineral Deposit Types and Links to Environmental Impacts. App. Earth Sci. (Trans. IMM B), 122, 83–96.