抄録
Prilled ammonium nitrate manufactured in this country has been applicable for AN-FO blasting. This paper is the second report of fundamental studies on AN-FO blasting using the recently improved prilled AN. The studies were consisted of experimental AN-FO blasting tests in a mine formeasurements of the cap-sensitivity and the detonation valocity and laboratory tests of loading AN-FOto bore-holes by an ejector type AN-FO bore-hole charger.
AN-FO tested was more cap-sensitive in comparison with the AN-FO reported in the first report. Two bound No.6 blasting caps had a possibility to ignite 94 a 6 AN-FO charge in a sealed steel stube. Detonation velocities of AN-FO measured by Dautorich method were from 2, 0000 to 3, 000m/s.
By compressed air jet loading, AN prills were crushed and filled in a bore-hole at high density, 0.85-1.0, to the density of original AN-FO, 0.81.
The diameter and the length of loading hose, namely hose resistance, is very much effective on the loading speed of the compressed air loading system of AN-FO. The diameter of borehole is a major affecting factor for the state of AN-FO loaded in a bore-hole such as the density. While, the loading air pressure and the distance between the top of loading hose and the face of charge in a bore-hole are minor factors for the state.
Loading techniques of AN-FO by compressed air system is rather experimental and should be established by practical operation in each mine.
