Comparative laboratory study of conventional and Electric Pulse Fragmentation (EPF) technologies on the performances of the comminution and concentration steps for the beneficiation of a scheelite skarn ore

Kathy Bru (1) , Mickael Beaulieu (1) , Rui Sousa (2) , Mário Machado Leite (2) , Ana Botleho de Sousa (2) , Erdogan Kol (3) , Jan Rosenkranz (3) , Daniel B. Parvaz (4)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
2 LNEG - Laboratório Nacional de Energia e Geologia
3 LUT - Luleå University of Technology = Luleå Tekniska Universitet
4 SELFRAG AG

Electric Pulse Fragmentation (EPF) is an innovative technology that uses High-Voltage Pulsed Power (HVPP) for the selective comminution of a material. This paper aims to compare a beneficiation flowsheet including an EPF treatment in the comminution circuit to a conventional pathway where the EPF step was replaced by a series of jaw crushers. Tests were performed on a skarn ore containing scheelite as the main mineral of interest. This ore is characterized by a fine-grained mineralogy and represents a challenge to conventional comminution processing, requiring fine grinding to liberate the valuable minerals. Fine grinding has high energy requirements and Kathy Bru Formal analysis Investigation Methodology Conceptualization a,⁎ [e-mail], Mickaël Beaulieu Investigation Methodology a , Rui Sousa Resources Formal analysis b , MárioMário Machado Machado LeiteLeite Resources Formal analysis b , Ana BotlehoAna de SousaBotleho de Sousa Resources b , Erdogan Kol Investigation c , Jan Rosenkranz Investigation c , Daniel B. Parvaz Investigation Formal analysis d,e a BRGM, ⁎ Corresponding author. i The corrections made in this section will be reviewed and approved by a journal production editor. generates large amounts of fines which can result in losses of the target mineral due to their removal before the concentration processes, especially in this case since scheelite is a brittle material.Comparison of EPF treatment to mechanical crushing with a similar product size P80 (i.e. 80% passing size) showed that the EPF treatment led to a significant increase in WO 3 content and distribution in the 0/250 µ m size fraction suggesting a pre-concentration aspect to EPF treatment. Moreover, a marked improvement of the grindability of the ore treated at a discharged energy of 9.1 kWh/t was observed with values of 10.6 kWh/t compared to 14.5 kWh/t when conventional treatment was used. Subsequent grinding and concentration steps confirmed the positive impacts of the fragmentation selectivity and pre-weakening effect of the EPF treatment. In particular, a reduction in fines production was observed after ball milling and a better concentrate grade was achieved for a similar recovery rate when an EPF treatment was included in the comminution pathway compared to the conventional one. These results confirm the potential of the EPF treatment for improving the performances of the beneficiation processes of this scheelite-bearing skarn ore.

Mots clés: Scheelite; High voltage pulse; Electric pulse fragmentation; Selective comminution; Concentration

Domaines: Sciences de l'environnement; Sciences de l'ingénieur [physics]

Kathy Bru, Mickael Beaulieu, Rui Sousa, Mário Machado Leite, Ana Botleho de Sousa, et al.. Comparative laboratory study of conventional and Electric Pulse Fragmentation (EPF) technologies on the performances of the comminution and concentration steps for the beneficiation of a scheelite skarn ore. Minerals Engineering, 2020. ⟨hal-02497971⟩