E Baawuah, C Kelsey, J R Kelly, J Addai-Mensah and W Skinner
14thAusIMM Mill Operators’ Conference, 29-31 August 2018, Brisbane, Australia
ABSTRACT
Comminution continues to be the most capital-intensive unit operation in mineral processing. The fundamental purpose of comminution is to liberate the valuable minerals so that they can be economically concentrated into saleable products. Declining ore quality characterised by lower grade and increased complexity requires significant energy consumption for comminution. Low-grade magnetite ores are typically fine-grained and require fine to ultra-fine grinding (P80 ~ 30 - 40 µm) to enhance its liberation from the typically siliceous gangue matrix. Historically, this has been achieved using multi-stage crushing and grinding technologies, which require high energy consumption with low energy efficiency. This motivated innovations in energy efficient technologies for comminution. Such technology has been developed in the IMPTEC super-fine crusher. It is an innovative, dry (with the potential to be operated wet), media-free, energy efficient crusher that can to reduce 10 mm feed particles to 19 – 30 µm with very low recycle loads. In this study, the mineralogical and physicochemical characteristics of crushed magnetite ore using the IMPTEC super-fine crusher have been investigated in comparison with those of rod milling. The super-fine crusher generated higher liberated magnetite minerals in the – 300 + 212 µm and < 45 µm size fractions compared to rod mill. Both comminution devices generated large low-grade hematite and goethite middlings. However, the rod mill produced higher locked/unliberated hematite and goethite compared to that of the super-fine crusher. Quartz mineral had the highest liberation irrespective of the comminution device used. The super-fine crusher generated higher entrapment of other minerals within the silica matrix compared to the rod mill. The breakage mechanism of the super-fine crusher which is predominantly through high compression with shear, generated improved mineral liberation in the coarse size fractions compared to the predominant abrasion and attrition breakage mechanisms of rod milling. The higher mineral liberation generated by the rod mill is potentially due to the prolonged batch milling of the ore compared to the single-pass open circuit of the super-fine crusher.
AUTHOR DETAILS
E Baawuah (1), C Kelsey (2), J R Kelly (3), J Addai-Mensah (4) and W Skinner (5)
- PhD student, Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
- FAusIMM, Technical Director, IMP Technologies P/L, 83A Proctor Rd, Hope Forest, SA 5172. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
- Director – IMP Technologies P/L, Lower Templestowe, Vic 3107. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
- Adjunct Professor, Minerals and Resource Engineering, Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095; Department of Mining and Process Engineering, Namibia University of Science and Technology, Windhoek, Namibia. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
- Research Professor, Minerals and Resource Engineering, Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
ACKNOWLEDGEMENTS
CEEC acknowledges and thanks The Australian Institute of Mining and Metallurgy for organising the 14thAusIMM Mill Operators’ Conference (MillOps 2018).
Abstracts can be found at the MillOps 2018 website.