Speciation of naturally occurring radionuclides (Ra, Th, U) in the context of Rare Earth mining

14 Dec 2023
Job Information

Organisation/Company

Université Côte d’Azur

Research Field

Chemistry
Environmental science » Ecology

Researcher Profile

Recognised Researcher (R2)
Established Researcher (R3)

Country

France

Application Deadline

12 Jan 2024 – 22:00 (UTC)

Type of Contract

Temporary

Job Status

Full-time

Offer Starting Date

15 Jan 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

Post Doctorate position

 

The ubiquity of Rare Earth (RE) elements in all technological spheres has led to an explosion in demand, making their supply a political and strategic issue on a global scale. Due to its geological features, Northern Canada is an untamed land for many critical and strategical minerals and could rapidly become an asset to secure mineral resources independence. Several world-class RE deposits are known in Canada and could supply the majority of the Western world’s RE needs. 

 

But RE processing can yield approximately 1.4 tons of radioactive wastes in the form of solid, liquid, or gas for one ton of rare earth oxide. Uranium and Thorium and their descents (Radium for instance), called NORM (Naturally Occurring Radioactive Materials) are those radioactive materials of natural origin. To investigate the sustainable development of the mining sector, particularly in the Nordic environment, data on the radiological and environmental behaviour of NORMs are therefore necessary. Since no deposits are currently in operation in Quebec, characterization and prediction work is required to determine the fate of this component of RE ores.

 

The chemistry of Ra, Th and U are radically different. Therefore, the speciation (ie. the chemical molecular form) of these elements is suspected to be radically different in the environment.

The project will address two main questions:

            i) Assess the mobility of Ra, Th and U in a laboratory tailing model and understand the role of organic matter

            ii) Assess the speciation of U and Th in the laboratory tailing model.

We propose here to tackle this question with a combination of analytical and speciation tools in a perspective of environmental radiochemistry. Based on small bench top columns, a tailing model can be designed with ad hoc artificial weathering conditions. Soils collected from the vicinity of the Whapmagoostui-Kuujjuarapik research station of the Center for Northern Studies (CEN), in Nunavik (Qc), will be used as proxies to study the mobility of U, Th and Ra from RE tailings.

 

The methodology developed in this project is largely based on the skills of the consortium in radioecology and radiochemistry. Two types of spectroscopic measurements will be performed with the bench top columns : X-ray imaging using micro fluorescence spectroscopy (m-XRF) and X-ray spectroscopy using Extended X-ray Absorption Fine Structure (EXAFS). Analysis of metals (ICP-MS) in water outputs enables us to measure breakthrough curves of the system. A full picture of the ion mobility can thus be obtained, with expected differences between U and Ra on the one hand, Th and Ra on the other hand

Requirements
Specific Requirements

PhD in Inorganic chemistry or environmental chemistry

This project is a collaboration between the Takuvik International Research Laboratory of the CNRS and the Lariviere’s radioecology team, both at Université Laval (Quebec, Ca) and Institut de Chimie de Nice of Université Côte d’Azur (Nice, Fr). The post Doc position includes travels between Université Côte d’Azur and Université Laval.

 

English or French speaking.

 

Additional Information
Work Location(s)

Number of offers available

1

Company/Institute

Université Côte d’Azur

Country

France

City

Nice

Geofield

Where to apply

Website

https://www.abg.asso.fr/fr/candidatOffres/show/id_offre/118930

Contact

Website

https://univ-cotedazur.fr

STATUS: EXPIRED