Skip to main content



The objective is to improve salt type minerals flotation installation outputs (better quality of concentrate, higher recovery of fine fraction) at lower cost.
In the course of this work 3 new technologies have been assessed with the aim of improving the performance and control of fluorine flotation. These are: column flotation; dielectric measurement to monitor oleate adsorption on pure fluorine; development of a continuous analysis system.

It has been found that flotation columns allow the appreciable reduction of stages involved in the production of the concentrated fluorine. These can be reduced from 6 to 3 and may be reduced further if the efficacy of the early stages is monitored.

Dielectric measurement is capable of very neatly characterizing the interactions between collector and fluorine. However, there always remain a great many uncertainties concerning interactions in a complex environment.

A continuous analysis system was developed using neutron activation and this has been defined. Simulated measurements using the system have been promising.
All the studies will be realized on 2 specific cases : the fluospar mineral of Mineraria Silius situated in Sardinia (treatment capacity 350000 tons/year on mineral grading 35 percent calcium fluoride, 3 percent lead sulphide and 5 to 7 percent barium sulphate) and the fluorine mineral of Olette (Sogeren Company) in the Eastern Pyrenees (treatment capacity 100000 tons/year of a mineral grading 60 percent calcium fluoride). The conclusions obtained will be transposable to numerous other flotation installations of salt type minerals existing within the EEC.

Work to be carried out, milestones and targets are described below.
Synthesis of existing mineralogical data and acquisition of new data on nature of impurities, intergrowth and liberation size for the ores, the concentrates and the tailings.
Neutron activation analysis, completion of a prototype detector for pulp, neutron activation methodology.
Dielectric measurements of a decanted mineral pulp to find out the possibility of detecting and eventually modifying the absorption of sodium oleate and other reagents in the fluorite and calcite particles, in order to increase flotation selectivity between them.
Column flotation experimentation.
Modelling of column flotation based on the above experimental results and on the existing models (Dobby and Finch and/or other models developed for complex sulphide).
Optimization of column flotation design (selection of size and number of columns) through laboratory and semi industrial trials results measuring performance of different column designs, applicability of column cells to different flotation stages and definition of a process control system via an expert system.
Evaluation of the economic gains through enhanced control of the flotation process, particularly column flotation with an industrial neutron activation from both the technical and economic point of view of column flotation in the processing flowsheets of the 2 industrial installations.

Funding Scheme

CSC - Cost-sharing contracts


Nuova Mineraria Silius SpA
Viale Merello 14
09123 Cagliari

Participants (3)

Bureau de Recherches Géologiques et Minières (BRGM)
Avenue Du Concyr
45060 Orléans
Università degli Studi di Cagliari
Piazza D'armi
09123 Cagliari
Université de Nancy I (Université Henri Poincaré)
Domaine Scientifique Victor Grignard
54506 Vandoeuvre-les-nancy