Increased liberation and flotation performance of bulk copper flotation concentrate following its regrinding in a stirred media mill

Published in Proceedings of the IMPC2020 Congress, SAIMM


Flotation concentrate originating from the Asarel-Medet porphyry copper mining and processing complex in Bulgaria has been subjected to regrinding using a Ro-Star mill; the effects of which on the downstream metallurgical behaviour are discussed. Particularly the effect on the liberation degree was studied through an optical microscopy and MLA-SEM automated mineralogy.

On the other hand, copper selective flotation of the reground bulk concentrate was realised to evaluate the anticipated metallurgical improvement. Process parameters such as involvement of prior hydrocycloning and variation of collector dosage have been evaluated.Within a two-minute residence time inside the Ro-Star mill, an improved liberation degree of the copper bearing minerals has been observed.

As a consequence, enhanced copper recovery and selectivity against pyrite was noted. It has been found that in order to guarantee efficient flotation of the resulting ultrafine particles, a modified flotation regime (i.e. changing collector suite and dosages) should be followed.


RoStar Mill,liberation, flotation recovery, ultrafine particles


The financial support from the EIT-KIC Raw Materials within the project ‘Upscaling of the RoStar ultra fine grinding mill for liberation of high valued ores” is gratefully acknowledged. The authors would like to thank to Maelgwyn Mineral Services and Assarel-Medet mine for their support and the permission to present the results.


A. Stefanova, K. Grossmanb, V. Stoilovc, A. Angelovc, U. Peukerd, and S. Gaydardzhieve*

aAurubis Bulgaria AD, 2070 Pirdop, Bulgaria

bUVR-FIA Freiberg Chemnitzer Str. 40, 09599 Freiberg, Germany

cAsarel-Medet AD, 4500 Panagyurishte, Bulgaria

dMVTAT, TUBAF, Agricolastraße 1, 09599 Freiberg, GermanyeGeMM

e -Minerals Engineering and Recycling, University of Liege, B52, 4000 Liège, Belgium

*Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

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