Potential of pulsed water jets for cutting and fracturing of hard rock formations

ABSTRACT: Significant experimental results on cutting and fracturing of hard ore-bearing and non-ore-bearing rocks with pulsed (interrupted) water jets are presented. The main purpose of the experimental work was to investigate the potential of pulsed water jets for enhancing the productivity, safety and the operating environment of continuous mining, tunnel boring or any other type of mechanical cutting machines currently in use. For the purpose of this paper, the term “pulse” is used in a generic sense to describe any type of pulsed water jet, viz., large single pulse (water gun or cannon) or, high frequency (≫ 1 Hz) interrupted, percussive or droplet laden water jets. A search of the literature and practical considerations indicated that the water gun is not suitable, for instance, for incorporation into continuous mining machines. In order to assess the potential of the high frequency pulsed jets for fragmentation, attention was focused on the interrupted jets generated by a perforated rotating disc p...