Patent ID: 8381654
Filing Date: 2013-02-26
Classification: F42D

Abstract:
1. A method of charging explosives in a substantially vertical blast borehole, with a loading density reduced in relation to that corresponding to the complete fill up of the borehole diameter, the method including the steps of: (i) introducing a charging hose in fluid connection with a nozzle into an end opening of the vertical blast borehole; (ii) moving the charging hose and nozzle along the blast borehole along a travel direction at a controlled rate; (iii) as the nozzle is being moved, forcing an explosive emulsion though the nozzle at a controlled pumping rate such that the emulsion is sprayed by the nozzle laterally relative to the travel direction, in an arc formation extending around an axis of the nozzle, which axis is parallel to the travel direction, and onto an inner wall of the blast hole; and (iv) adjusting the pumping rate and the controlled moving rate so as to form a coherent string of the explosive emulsion exiting from the nozzle, whereby the string only partially fills up the blast borehole diameter.