The paper presents new theoretical and experimental results about mechanisms of disintegration of mineral complexes and structural transformations of the sulfide surface under high-power nanosecond electromagnetic pulses (HPEMP). The heated gas outflow from nanosecond breakdown channels of sulfide minerals under HPEMP is considered. It is shown that the gas outflow from channels can be an additional destructive factor in the processes of the electric pulse discharge disintegration of mineral complexes. It is shown that the effect of HPEMP changes chemical surface composition and, respectively, technological properties of pyrrhotite and pentlandite. Morphology and elementary composition of new micro- and nanoformations on mineral surface of pentlandite and pyrrhotite have been investigated using up-to-date methods of SEM/EDX and Scanning Probe Microscopy. Preliminary electropulse effect on mineral products before flotation allows producing optimal conditions for flotation separation of pentlandite and pyrrhotite owing to forming the new nanophases and defects on the surface of sulfides.
The effectiveness of High-Power Nanosecond Pulses in the disintegration and liberation of fine-disseminated mineral complexes and the recovery of micro- and nanoparticles of precious metals from refractory ores was demonstrated in (Bunin et al., 2001; Chanturiya et al., 2001, 2003, 2005; Chanturiya and Bunin, 2005, 2007). Possible mechanisms of selective disintegration were considered in (Bunin et al., 2001; Chanturiya et al., 2003, 2006; Chanturiya and Bunin, 2005, 2007). It has been shown both theoretically and experimentally that electric breakdowns can play an important role in the nanosecond pulsed treatment of milled minerals that are carriers of finely disseminated gold and other valuable components. Electric discharges in such minerals are accompanied by a destruction of integrity in the form of breakdown channels and the formation of a system of cracks around these channels (Chanturiya et al., 2006; Chanturiya and Bunin, 2007).
