Emulsion explosive sensitising

Abstract

An emulsion explosive, formulated with a basic surfactant, which is sensitised by gassing with active sodium hypochlorite.

1 . A method of sensitising an emulsion explosive by means of gassing which includes the steps of:
 a) preparing an emulsion which includes a continuous phase, a discontinuous phase which contains ammonium nitrate as a nitrogen source, and a surfactant;   b) maintaining the pH of the continuous phase at a value above 5; and   c) adding active sodium hypochlorite to the emulsion,   
       wherein the surfactant is a basic surfactant. 
     
     
         2 . A method according to  claim 1  wherein the surfactant is SC75 DL. 
     
     
         3 . A method according to  claim 1  wherein the continuous phase comprises from 5.5% to 7.5% of the emulsion and the surfactant is present in the continuous phase in a range of from 15% to 25%. 
     
     
         4 . A method according to  claim 1  wherein the continuous phase includes up to 80% of a carbonaceous fuel. 
     
     
         5 . A method according to  claim 1  wherein the pH of the discontinuous phase is maintained at a value above 5.5 by the addition of at least one of the following: sodium hydroxide and sodium acetate. 
     
     
         6 . A method according to  claim 1  wherein in step c) the active concentration of the sodium hypochlorite, added to the emulsion, is in a range of from 8% to 14%. 
     
     
         7 . A method according to  claim 1  wherein the ratio of the emulsion to the sodium hypochlorite is 97:3 percentage.