Explosive emulsion compositions and methods of making the same

Abstract

A detonator sensitive explosive emulsion composition includes an oxidizing phase including a supersaturated solution of ammonium nitrate and a fuel phase including sufficient emulsifying agent to permit dispersion of the oxidizing phase in the fuel phase. The detonator sensitive explosive emulsion composition further includes a crystallization temperature depressant consisting essentially of at least one of an amine and an amine nitrate.

1 . A detonator sensitive explosive emulsion composition comprising:
 an oxidizing phase including a supersaturated solution of ammonium nitrate;   a fuel phase including sufficient emulsifying agent to permit dispersion of the oxidizing phase in the fuel phase; and   a crystallization temperature depressant consisting essentially of at least one of an amine and an amine nitrate.   
     
     
         2 . The explosive emulsion composition of  claim 1 , wherein the crystallization temperature depressant includes one or more amines selected from X, Y, and Z, or their combination. 
     
     
         3 . The explosive emulsion composition of  claim 1 , wherein the crystallization temperature depressant includes one or more amine nitrates selected from A, B, and C, or their combination. 
     
     
         4 . The explosive emulsion composition of  claim 1 , wherein the crystallization temperature depressant is hexamine nitrate. 
     
     
         5 . The explosive emulsion composition of  claim 4 , wherein the hexamine nitrate added to the composition has a density between about 1.20 and about 1.30 g/cc at about 25° C. 
     
     
         6 . The explosive emulsion composition of  claim 1 , wherein the explosive emulsion composition has a crystallization temperature at which the emulsion composition begins to crystallize, and wherein sufficient crystallization temperature depressant is added to lower the crystallization temperature to below about 80° C. 
     
     
         7 . The explosive emulsion composition of  claim 1 , further comprising a crosslinking agent, and wherein the explosive emulsion has a density between about 1.0 g/cc and about 1.5 g/cc and a crystallization temperature of less than about 80° C. 
     
     
         8 . The explosive emulsion composition of  claim 1 , wherein the fuel phase comprises sufficient emulsifying agents to maintain the dispersion of the oxidizing phase in the fuel phase under shock/shear conditions (additional information needed from inventors on this; as mentioned in spec, trying to claim around this benefit will require something more specific than ‘maintain good resistance to crystallization with less emulsifier) 
     
     
         9 . The explosive emulsion composition of  claim 1 , wherein the emulsifying agent in the fuel phase amounts to between about 1% w/w and about 3% w/w of the explosive emulsion. 
     
     
         10 . The explosive emulsion composition of  claim 1 , wherein the oxidizing phase comprises a supersaturated solution of ammonium nitrate in water; wherein the fuel phase comprises mineral oil and sufficient emulsifying agent to permit dispersion of the oxidizing phase in the fuel phase; and wherein the ammonium nitrate constitutes between about 50 weight percent and about 80 weight percent of the explosive emulsion composition, wherein the water constitutes between about 5 weight percent and about 15 weight percent of the explosive emulsion composition, wherein the mineral oil constitutes between about 0.01 and about 5.0 weight percent of the explosive emulsion composition, and wherein the crystallization temperature depressant constitutes between about 0.1 weight percent and about 10 weight percent of the explosive emulsion composition. 
     
     
         11 . The explosive emulsion composition of  claim 1 , wherein the composition is detonator sensitive after being stored for at least one year. 
     
     
         12 . A method of producing a detonator sensitive explosive emulsion in a reactor, the method comprising:
 adding an ammonium nitrate solution in water to a reactor, wherein the ammonium nitrate solution is at a temperature of about 90° C. or greater;   adding an oil phase to the reactor;   adding a crystallization temperature depressant to the reactor; and   mixing the ammonium nitrate solution, the oil phase, and the crystallization temperature depressant; wherein the reactor is maintained at a temperature of about 90° C. or more for less than about 8 hours after the crystallization temperature depressant is added to the reactor.   
     
     
         13 . The method of  claim 12 , wherein the reactor temperature is maintained at about 90° C. or more for less than about 1 hours after the crystallization temperature depressant is added to the reactor. 
     
     
         14 . The method of  claim 12 , wherein the reactor temperature is maintained at about 90° C. or more for less than about 30 minutes after the crystallization temperature depressant is added to the reactor. 
     
     
         15 . The method of  claim 12 , wherein the crystallization temperature depressant consists essentially of at least one of an amine and an amine nitrate. 
     
     
         16 . The method of  claim 15 , wherein the crystallization temperature depressant consists essentially of hexamine nitrate solution. 
     
     
         17 . The method of  claim 16 , wherein the hexamine nitrate solution comprises hexamine nitrate in a water solution having a density at about 25° C. of between about 1.2 and about 1.3 g/cc. 
     
     
         18 . The method of  claim 16 , wherein the hexamine nitrate solution is added to the reactor at a temperature between about 10° C. and about 30° C. 
     
     
         19 . The method of  claim 12 , wherein the reactor comprises a batch process reactor. 
     
     
         20 . The method of  claim 19 , and wherein the ammonium nitrate solution in water and the oil phase are mixed to form an emulsion prior to adding the crystallization temperature depressant. 
     
     
         21 . The method of  claim 20 , wherein the reactor is maintained at a temperature of about 90° C. or more before the crystallization temperature depressant is added, and wherein the temperature is maintained above about 75° C. after the crystallization temperature depressant is added. 
     
     
         22 . The method of  claim 12 , wherein the reactor comprises a continuous process reactor including at least an emulsion mixer. 
     
     
         23 . The method of  claim 22 , wherein the ammonium nitrate solution, the oil phase, and the crystallization temperature depressant are stored separately and are combined to form a feed stream to the emulsion mixer. 
     
     
         24 . The method of  claim 23 , wherein the emulsion mixer comprises an inlet mixer, and wherein the crystallization temperature depressant is added to the feed stream in the inlet mixer. 
     
     
         25 . The method of  claim 22 , wherein the ammonium nitrate solution and the oil phase are combined in the emulsion mixer to form an intermediate emulsion, and wherein the crystallization temperature depressant is mixed with the intermediate emulsion in a secondary mixer downstream from the emulsion mixer. 
     
     
         26 . The method of  claim 25 , wherein the continuous process reactor further comprises an emulsion cooler downstream from the emulsion mixer, and wherein the crystallization temperature depressant is mixed with the intermediate emulsion downstream of the emulsion cooler.