Candidates should have an outstanding research record in the field of Minerals processing with
extensive knowledge in physical chemistry, process mineralogy, minerals and/or chemical
engineering. The selected candidate will join the “Georessources” research Laboratory, a major
international research center with about 60 academics for a total staff about 180 persons developing
research programs in all fields of applied geosciences including, mineral processing, minerals
engineering, ore genesis, 3D modeling and economic geology.
The research activity will be in the “Minerals Engineering” team on fragmentation techniques and
processing of ores by flotation. Innovative research on the beneficiation of non-conventional and lowgrade
resources can be developed.
The candidate will integrate a research group with three senior researchers and 2-3 PhD students and
will be involved in experimental research and academic tuition depending on candidate’s curricula.
Scope of the proposal
As part of its green energy transition and decarbonisation efforts, the European Union (EU) is aiming
to have at least 30 million electric vehicles (EVs) by 2030. EU is heavily reliant on lithium imports
from few dominated countries which forces supply security issues. To combat the supply risk of
lithium, 15 European partners gathered and advanced a new mining paradigm i.e. zero-waste, multimetal/
mineral mining called EXCEED which stands for “Cost-effective, sustainable and responsible
extraction routes for recovering distinct critical metals and industrial minerals as by-products from
key European hard-rock lithium projects“.
Particularly, this project is in close partnership between Imerys, Keliber and GeoRessourcces
(University of Lorraine) and aims to utilize all possible beneficiation routes for recovering critical raw
materials and industrial materials, as by-products from Li-bearing hard-rock ores.
Quartz and feldspars are commonly by-products of Li-bearing pegmatite and rare metal granite
deposits. These minerals are widely applied in the production of glass, ceramics, and as fillers and
extenders. Traditionally, there are two main flotation processes to separate quartz and feldspar. The
first one is fluorine-flotation, which uses hydrofluoric acid (HF) or sodium fluoride (NaF) as pH
regulator and feldspar activator. Then, feldspars are floated from quartz using amine collectors under
highly acidic conditions. This process provides excellent selectivity with high-grade feldspar and highquality
quartz. However, the toxicity and harmful environmental impacts of fluoride ions limit the use
of HF at industrial scale application. In addition, this process will also increase cost production due to
the treatment of flotation fluoride-containing tailwater. The second method is fluorine-free flotation,
which could be addressed the problem caused by HF flotation. Several studies comprising mixing of
cationic and anionic collectors in strong acidic conditions using H2SO4 and HCl as pH regulator have
been proposed. However, when compared to conventional HF flotation, the effectiveness of the
separation is still unsatisfactory. Thus, there is a strong need for more fundamental approach on the
selective separation of quartz and feldspar without the harmful effects of HF treatment.
Description and objectives of the proposal
This project aims to develop a safe and environment friendly (fluorine-free) flotation method and at
the same time improve feldspar flotation selectivity. The project focuses on the most fundamental
aspects of flotation which are mineral surface chemistry and reagents performance. The study will
begin with mineralogical study in which the sample feed will be analysed through its chemical and
mineral composition. Then the floatability of feldspar and quartz, both pure minerals and mineral
mixtures, will be comparatively studied with and without HF treatment and collect the experimental
data on the understanding of separation mechanisms. The detailed mechanisms will be experimentally
examined using various techniques such as zeta-potential, contact angle measurement, infrared and insitu
Raman spectroscopies, adsorption tests, etc to identify interesting surfactants (collectors,
activators and pH modifiers). The flotation separation using the combination of the surfactant of
different molecular structure will constitute the main scientific approach to develop environmentally
friendly reagents regime at neutral or slightly alkaline medium.
The most fundamental aspects of the work will focus on the understanding of the self-assembled
hydrophobic monolayer formation on the feldspar minerals surface to control the process selectivity
and coarse particles flotation. Then, the project will study the effectivity of determined surfactants and
its optimised usage on the separation characteristics of feldspar and quartz through flotation from the
rare metals granites and pegmatite ores. Finally, there is also a possibility to utilize further the physical
properties of quartz and feldspar to explore other beneficiation route to compare it to flotation
approach. In the other hand, to approach zero-waste concept, the research topic related with the
recovery by flotation of the other minor but critical elements (Be,...) will be examined. Thus the
flotation of Be phosphate minerals may be explored.
Funding: This postdoc position will be supported by the Horizon Europe EXCEED Project
Duration: 24 months (possible extension by 12 months)
- list of publications,
- experience in field, analytical, experimental or modeling approaches
- project in two-three pages summarizing the main trends in research that the candidate would like to develop based on the above mentionned work program ( or on the selected points of proposed program)
Applicants should send via email a Curriculum Vitae, Provided documents and the names and email
addresses of two references to:
Pr Lev FILIPPOV, firstname.lastname@example.org
Calendar for applying:
- March 5th 2023: Deadline for submitting your application
- March 15: Preliminary review, the candidates will be contacting after being preselected.
- For definitive selection, an audition of the candidate will be arranged either in Nancy or by video-conference
Starting expected from 13 March, 2023 but is depending on the instruction of the application by the
administration of the university.
Level of salary: minimum 3500 Euros brut/month depending on the post-doc experience and
according to the University’s “working experience/salary” scale after PhD thesis