Improvements relating to blasting in mines and quarries

摘要

338,454. Tschenn, V. Feb. 11, 1929, [Convention date]. Blasting; hydraulic mining; jet apparatus. -Bore-holes are provided with spherical enlargements 11 to receive blasting charges by forcing hydrochloric &c. acid 'in fine jets through a longitudinally-displaceable nozzle 8 ; the acid is forced from a container 9 by compressed air supplied from a reservoir 10. A small preliminary charge may be exploded in the bore-hole to facilitate the action of the acid.