Crushing and liberation of materials by electrical disintegration

T. Fujita1*, I. Yoshimi2, A. Shibayama1, T. Miyazaki1, K. Abe1, M. Sato1,
W.T. Yen3, J. Svoboda4

1 Faculty of Engineering and Resource Science, Akita University, Akita 010-8502, Japan
2 Nittetsu Mining Co. Ltd., Hinodemachi, Nishitama-gun, Tokyo 1990-01, Japan
3 Mining Department Queen's University, Kingston, Ontario, Canada
4 Advanced Technologies (Pty.) Ltd., Johannesburg, South Africa

Received 31 August 2001; accepted 30 November 2001


Liberation by crushing is very important for separation of different materials in mineral beneficiation and for the recycling of the components. The mechanical crushing and grinding usually liberate minerals from rocks. However, it is difficult to crush the materials along the boundaries of different components. In this study, the voltage, electric current and energy used in several applications have been measured for the dielectric breakdown in liquid phase. The crushing of mortar, granite and concrete in water or oil by the impulse high voltage supply (a lightning discharge impulse) has been investigated. It is important for the large energy supply on the sample to decrease the duration of the wave front to reach the maximum voltage. The energy consumption by the electrical disintegration is greatly reduced as compared with the conventional compression test. The liberation along the boundaries of materials is possible by electrical crushing (disintegration).

Keywords: liberation; recycling; electrical crushing; electrical disintegration; lightning discharge impulse; high voltage; electric current; energy consumption

 * Corresponding author
   E-mail : fujita@ipc.akita-u.ac.jp