Continuously compressing crushing towards a dry processing method, a testing for graphite ore

• Published in: Minerals engineering Vol. 212; p. 108713
• Main Authors: Paasovaara, Niina, Hartikainen, Samuel, Peräniemi, Sirpa, Kuopanportti, Hannu, Yang, Shenghong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-07-2024
• Subjects: Continuously compressing crusher; Crystal size; Dry processing; EU critical material; Graphite flake; Hugger crusher; Liberation; Continuously compressing crusher; Dry processing; Hugger crusher; Graphite flake; Crystal size; EU critical material; Liberation
• ISSN: 0892-6875; 1872-9444
• DOI: 10.1016/j.mineng.2024.108713

•The new innovative continuously compressing crushing (CCC) was tested for the first time for natural ore samples.•The basic idea of the new CCC method has been to implement the principle of the ideal comminution method as accurately as possible.•The liberation of ultra-coarse-grained graphite flakes (+300 µm) was most observed in the crushing product of pilot-scale CCC.•CCC enables the enrichment of coarser and cleaner graphite.
In this study the comminution methods of graphite bearing ore were compared by using five different crushing methods, namely a jaw crusher, a roll crusher, uniaxial compression tests, and a new type of continuously compressing crushers. These new continuously compressing crushers were available in laboratory and pilot scales. The particles in the + 1700 µm size class produced by continuously compressing crushing were coarser and rougher in texture compared to the rounded particles produced traditionally by a jaw crusher. In the size class −100 µm, most of the graphite flakes were observed independently in the products of each of these crushing methods. The liberation of ultra-coarse-grained graphite flakes in size class + 300 µm was most observed after pilot-scale continuously compressing crusher. The shape and enrichment of the graphite flakes were very similar after both laboratory and pilot scale continuously compressing crushers. In contrast, the graphite flakes produced by jaw crusher appeared as broken particles in the form of accumulation of several layered and non-independent graphite flake structures. The results of this study demonstrate that the new innovative continuously compressing crushing method enables the enrichment of coarser and cleaner graphite, which has a much higher value and wider industrial applications compared to amorphous and fine-grained graphite.