Explosive compositions

Abstract

A pumpable watergel explosive composition comprises 10 to 40 wt %, based on the total weight of the pumpable explosive composition, of a continuous liquid phase comprising a solvent, a solubilized chemical sensitizer and a gelling agent and 60 to 90 wt %, based on the total weight of the pumpable explosive composition, of a discontinuous solid phase comprising particulate oxidizer salt particles having interstitial spaces between the salt particles. The watergel explosive composition has a density of 1.05-1.4 g/cc and, a shear thinning rheology such that, when subjected to an external force, the explosive composition has a viscosity sufficiently low to render the watergel explosive composition pumpable. The combination of density and low water content provides energy numbers normally associated with more expensive aluminized formulations.

1 . A pumpable watergel explosive composition comprising: 
 a) 10 to 40 wt %, based on the total weight of the pumpable explosive composition, of a continuous liquid phase comprising a solvent, a solubilized chemical sensitizer and a gelling agent: and,    b) 90 to 60 wt %, based on the total weight of the pumpable explosive composition, of a discontinuous solid phase comprising particulate oxidizer salt particles having interstitial spaces between the salt particles wherein the liquid phase fills the interstitial spaces, the watergel explosive composition has a density of 1.05-1.4 g/cc and, when subjected to an external force, has a viscosity sufficiently low to render the watergel explosive composition pumpable.    
   
   
       2 . The pumpable watergel explosive composition of  claim 1  wherein the particulate oxidizer salt comprises particles having a tapped bulk density of 0.9-1.05 g/cc.  
   
   
       3 . The pumpable watergel explosive composition of  claim 1  wherein the particulate oxidizer salt consists essentially of particles having a tapped bulk density of 0.9-1.05 g/cc.  
   
   
       4 . The pumpable watergel explosive composition of  claim 2  wherein the solubilized chemical sensitizer comprises an organic nitrogen based salt of an inorganic oxidizing acid.  
   
   
       5 . The pumpable watergel explosive composition of  claim 4  wherein the nitrogen based salt comprises an amine salt.  
   
   
       6 . The pumpable watergel explosive composition of  claim 5  wherein the solubilized chemical sensitizer further comprises ammonium nitrate.  
   
   
       7 . The pumpable watergel explosive composition of  claim 4  wherein the solvent is selected from the group consisting of water, an alcohol, a glycol and mixtures thereof.  
   
   
       8 . The pumpable watergel explosive composition of  claim 6  wherein the solvent comprises water.  
   
   
       9 . The pumpable watergel explosive composition of  claim 3  wherein the particulate oxidizer salt is selected from the group consisting of alkali metal nitrates and perchlorates, alkaline-earth metal nitrates and perchlorates and mixtures thereof.  
   
   
       10 . The pumpable watergel explosive composition of  claim 9  wherein the particulate oxidizer salt further comprises at least one additional alkali metal nitrates and perchlorates, alkaline-earth metal nitrates and perchlorates and mixtures thereof.  
   
   
       11 . The pumpable watergel explosive composition of  claim 1  wherein the liquid phase comprises from 30 to 85 wt % solubilized chemical sensitizer, from 15 to 40 wt % solvent and up to 30 wt % solubilized oxidizer salt, based on the total weight of the liquid phase.  
   
   
       12 . The pumpable watergel explosive composition of  claim 1  wherein the liquid phase comprises from 50 to 80 wt % solubilized chemical sensitizer, from 18 to 27 wt % solvent and up to 30 wt % solubilized oxidizer salt, based on the total weight of the liquid phase.  
   
   
       13 . The pumpable watergel explosive composition of  claim 12  wherein the liquid phase comprises an aqueous MMAN solution and the oxidizer salt comprises ammonium nitrate.  
   
   
       14 . The pumpable watergel explosive composition of  claim 1  wherein the liquid phase comprises 15 to 25 wt % of the solublilized chemical sensitizer and from 7-12 wt % solvent, based on the total weight of the liquid phase.  
   
   
       15 . The pumpable watergel explosive composition of  claim 14  wherein the solublilized chemical sensitizer consists essentially of nitric or perchloric acid salts derived from organic amines.  
   
   
       16 . The pumpable watergel explosive composition of  claim 1  wherein the pumpable watergel explosive composition comprises from 5 to 15 wt % solvent, based on the total weight of the pumpable explosive composition.  
   
   
       17 . The pumpable watergel explosive composition of  claim 1  wherein the pumpable watergel explosive composition comprises from 7 to 10 wt % solvent, based on the total weight of the pumpable explosive composition.  
   
   
       18 . The pumpable watergel explosive composition of  claim 15  wherein the solvent comprises water.  
   
   
       19 . The pumpable watergel explosive composition of  claim 1  further comprising an insoluble sensitizer.  
   
   
       20 . The pumpable watergel explosive composition of  claim 19  wherein the insoluble sensitizer comprises perlite, microspheres, a gassing agent and mixtures thereof.  
   
   
       21 . The pumpable watergel explosive composition of  claim 1  wherein the gelling agent comprises guar gum, xanthan gum, locust bean gum, polyvinyl acetate, polyethylene oxides, polyacrylamide, starch and mixtures thereof.  
   
   
       22 . The pumpable watergel explosive composition of  claim 1  further comprising a cross linking agent.  
   
   
       23 . The pumpable watergel explosive composition of  claim 1  wherein the gelling agent comprises a guar gum which, 60 minutes after 9.00±0.01 g of the guar gum is added to a solution of 702 g of AN, 240 g of sodium nitrate and 258 g of distilled water at 43° C. and stirred for 2 minutes, has a viscosity of 7000-17,000 cps at 25° C.  
   
   
       24 . The pumpable watergel explosive composition of  claim 1  comprising from 0.3 to 1 wt % of the gelling agent, based on the total weight of the pumpable explosive composition.  
   
   
       25 . The pumpable watergel explosive composition of  claim 1  comprising from 0.3 to 0.6 wt % of the gelling agent, based on the total weight of the pumpable explosive composition.  
   
   
       26 . The pumpable watergel explosive composition of claim i wherein watergel explosive composition has a viscosity of 10,000-35,000 cps at 20 rpm and 21° C.  
   
   
       27 . The pumpable watergel explosive composition of  claim 13  wherein watergel explosive composition has a viscosity of from 50,000 to 300,000 cps at 2 rpm and 21° C.  
   
   
       28 . The pumpable watergel explosive composition of  claim 1  wherein the particulate oxidizer salt is associated with an organic combustible fuel.  
   
   
       29 . The pumpable watergel explosive composition of  claim 28  wherein the particulate oxidizer salt is combined with the organic combustible fuel to form a mixture prior to mixing the liquid phase with the mixture.  
   
   
       30 . The pumpable watergel explosive composition of  claim 29  wherein the particulate oxidizer salt comprises an ANFO blend.  
   
   
       31 . The pumpable watergel explosive composition of  claim 1  wherein the watergel explosive composition comprises less than 15 wt. % aluminum.  
   
   
       32 . The pumpable watergel explosive composition of  claim 1  wherein the watergel explosive composition comprises essentially no aluminum.  
   
   
       33 . The pumpable watergel explosive composition of  claim 1  wherein the watergel explosive composition comprises 15 to 35 wt % of the continuous liquid phase and 85 to 65 wt %, of the discontinuous solid phase, based on the total weight of the pumpable explosive composition.  
   
   
       34 . The pumpable watergel explosive composition of  claim 1  wherein the watergel explosive composition comprises 20 to 30 wt % of the continuous liquid phase and 80 to 70 wt %, of the discontinuous solid phase, based on the total weight of the pumpable explosive composition.  
   
   
       35 . The pumpable watergel explosive composition of  claim 2  wherein the particles comprise ammonium nitrate particles.  
   
   
       36 . A method of manufacturing a pumpable watergel explosive composition comprising: 
 a) preparing a liquid chemical sensitizer solution comprising a solvent a solubilized chemical sensitizer and a gelling agent at a first location;    b) transporting the liquid chemical sensitizer solution to a second location;    c) combining 10 to 40 wt % of the liquid chemical sensitizer solution, based on the total weight of the pumpable explosive composition, with 90-60 wt % of a solid phase comprising particulate oxidizer salt particles having a tapped bulk density of 0.9-1.05 g/cc and having interstitial spaces between the salt particles, based on the total weight of the pumpable explosive composition, to form the pumpable explosive composition wherein a gelling agent is added either to the liquid chemical sensitizer prior to combining the liquid chemical sensitizer with the solid phase, or during step (c), the liquid chemical sensitizer solution fills the interstitial spaces, the watergel explosive composition has a density of 1.05-1.4 g/cc and, when subjected to an external force, has a viscosity sufficiently low to render the watergel explosive composition pumpable.    
   
   
       37 . The method of  claim 36  wherein the pumpable watergel explosive composition also comprises an insoluble sensitizer, the liquid chemical sensitizer solution is a booster sensitive explosive and the method further comprises transporting the liquid chemical sensitizer solution as a booster sensitive explosive to the second location and transporting the solid phase as a non-explosive to the second location.  
   
   
       38 . The method of  claim 37  wherein the second location is a location at which the watergel explosive composition will be used and the method further comprises adding a cross linking agent to the explosive composition contemporaneous with loading the watergel explosive composition into a bore hole.  
   
   
       39 . The method of  claim 36  further comprising selecting as the gelling agent a guar gum which, 60 minutes after 9.00±0.01 g of the guar gum is added to a solution of 702 g of AN, 240 g of sodium nitrate and 258 g of distilled water at 43° C. and stirred for 2 minutes, has a viscosity of 7,000-12,000 cps at 25° C.  
   
   
       40 . The method of  claim 39  wherein the second location is a location at which the watergel explosive composition will be used and the method further comprises adding a cross linking agent to the explosive composition contemporaneous with loading the watergel explosive composition into a bore hole.  
   
   
       41 . The method of  claim 36  further comprising adding at least one of 
 a) an organic combustible fuel,    b) at least one additional alkali metal nitrates and perchlorates, alkaline-earth metal nitrates and perchlorates and mixtures thereof; and,    c) and mixtures of (a) and (b).    
   
   
       42 . A pumpable watergel explosive composition comprising: 
 a) 10 to 40 wt %, based on the total weight of the pumpable explosive composition, of a continuous liquid phase comprising a solvent, a solubilized chemical sensitizer, and a gelling agent: and,    b) 90 to 60 wt %, based on the total weight of the pumpable explosive composition, of a discontinuous solid phase comprising particulate oxidizer salt particles    wherein, the gelling agent comprises a guar gum which, 60 minutes after 9.00±0.01 g of the guar gum is added to a solution of 702 g of AN, 240 g of sodium nitrate and 258 g of distilled water at 43° C. and stirred for 2 minutes, has a viscosity of 9000-12,000 cps at 25° C., the watergel explosive composition has a density of 1.05-1.4 g/cc and, when subjected to an external force, has a viscosity sufficiently low to render the watergel explosive composition pumpable.    
   
   
       43 . The pumpable watergel explosive composition of  claim 42  wherein the particulate oxidizer salt is selected from the group consisting of alkali metal nitrates and perchlorates, alkaline-earth metal nitrates and perchlorates and mixtures thereof.  
   
   
       44 . The pumpable watergel explosive composition of  claim 43  wherein the particulate oxidizer salt comprises ammonium nitrate particles having a tapped bulk density of 0.9-1.05 g/cc.  
   
   
       45 . The pumpable watergel explosive composition of  claim 43  wherein the particulate oxidizer salt consists essentially of ammonium nitrate particles having a tapped bulk density of 0.9-1.05 g/cc.  
   
   
       46 . The pumpable watergel explosive composition of  claim 44  wherein the particulate oxidizer salt further comprises at least one additional alkali metal nitrates and perchlorates, alkaline-earth metal nitrates and perchlorates and mixtures thereof.  
   
   
       47 . The pumpable watergel explosive composition of  claim 42  wherein the solubilized chemical sensitizer comprises an organic nitrogen based salt of an inorganic oxidizing acid.  
   
   
       48 . The pumpable watergel explosive composition of  claim 47  wherein the nitrogen based salt comprises an amine salt.  
   
   
       49 . The pumpable watergel explosive composition of  claim 42  wherein the solvent is selected from the group consisting of water, an alcohol, a glycol and mixtures thereof.  
   
   
       50 . The pumpable watergel explosive composition of  claim 48  wherein the solvent comprises water.  
   
   
       51 . The pumpable watergel explosive composition of  claim 50  wherein the liquid phase comprises from 30 to 85 wt %. solubilized chemical sensitizer, from 15-40 wt % solvent and up to 30 wt % solubilized oxidizer salt, based on the total weight of the liquid phase.  
   
   
       52 . The pumpable watergel explosive composition of  claim 51  wherein the liquid phase comprises from 50 to 80 wt % solubilized chemical sensitizer, from 18 to 27 wt % solvent and up to 30 wt % solubilized oxidizer salt, based on the total weight of the liquid phase.  
   
   
       53 . The pumpable watergel explosive composition of  claim 42  wherein the liquid phase comprises an aqueous MMAN solution and the oxidizer salt comprises ammonium nitrate particles having a tapped bulk density of 0.9-1.05 g.  
   
   
       54 . The pumpable watergel explosive composition of  claim 42  wherein the liquid phase comprises 15 to 25 wt % of the solublilized chemical sensitizer and from 7-12 wt % solvent, based on the total weight of the liquid phase.  
   
   
       55 . The pumpable watergel explosive composition of  claim 54  wherein the solublilized chemical sensitizer consists essentially of nitric or perchloric acid salts derived from organic amines.  
   
   
       56 . The pumpable watergel explosive composition of  claim 42  wherein the pumpable watergel explosive composition comprises from 5 to 15 wt % solvent, based on the total weight of the pumpable explosive composition.  
   
   
       57 . The pumpable watergel explosive composition of  claim 42  wherein the pumpable watergel explosive composition comprises from 7 to 10 wt % solvent, based on the total weight of the pumpable explosive composition.  
   
   
       58 . The pumpable watergel explosive composition of  claim 56  wherein the solvent comprises water.  
   
   
       59 . The pumpable watergel explosive composition of  claim 42  further comprising an insoluble sensitizer.  
   
   
       60 . The pumpable watergel explosive composition of  claim 42  wherein the gelling agent comprises guar gum, xanthan gum, locust bean gum, polyvinyl acetate, polyethylene oxides, polyacrylamide, starch and mixtures thereof.  
   
   
       61 . The pumpable watergel explosive composition of  claim 42  further comprising a cross linking agent.  
   
   
       62 . The pumpable watergel explosive composition of  claim 42  wherein the gelling agent comprises a guar gum which, 60 minutes after 9.00±0.01 g of the guar gum is added to a solution of 702 g of AN, 240 g of sodium nitrate and 258 g of distilled water at 43° C. and stirred for 2 minutes, has a viscosity of 7000-17,000 cps at 25° C.  
   
   
       63 . The pumpable watergel explosive composition of  claim 42  wherein the gelling agent comprises a guar gum which, 60 minutes after 9.00±0.01 g of the guar gum is added to a solution of 702 g of AN, 240 g of sodium nitrate and 258 g of distilled water at 43° C. and stirred for 2 minutes, has a viscosity of 7,000-12,000 cps at 25° C.  
   
   
       64 . The pumpable watergel explosive composition of  claim 42  comprising from 0.3 to 1 wt % of the gelling agent, based on the total weight of the pumpable explosive composition.  
   
   
       65 . The pumpable Watergel explosive composition of  claim 42  comprising from 0.3 to 0.6 wt % of the gelling agent, based on the total weight of the pumpable explosive composition.  
   
   
       66 . The pumpable watergel explosive composition of  claim 42  wherein watergel explosive composition has a viscosity of 10,000-35,000 cps at 20 rpm and 21° C.  
   
   
       67 . The pumpable watergel explosive composition of  claim 53  wherein watergel explosive composition has a viscosity of from 50,000 to 300,000 cps at 2 rpm and 21° C.  
   
   
       68 . The pumpable watergel explosive composition of  claim 42  wherein the particulate oxidizer salt is associated with an organic combustible fuel.  
   
   
       69 . The pumpable watergel explosive composition of  claim 42  wherein the particulate oxidizer salt comprises an ANFO blend.  
   
   
       70 . The pumpable watergel explosive composition of  claim 42  wherein the watergel explosive composition comprises less than 15 wt. % aluminum.  
   
   
       71 . The pumpable watergel explosive composition of  claim 42  wherein the watergel explosive composition comprises essentially no aluminum.  
   
   
       72 . The pumpable watergel explosive composition of  claim 42  wherein the watergel explosive composition comprises 15 to 35 wt % of the continuous liquid phase and 85 to 65 wt %, of the discontinuous solid phase, based on the total weight of the pumpable explosive composition.  
   
   
       73 . The pumpable watergel explosive composition of  claim 42  wherein the watergel explosive composition comprises 20 to 30 wt % of the continuous liquid phase and 80 to 70 wt %, of the discontinuous solid phase, based on the total weight of the pumpable explosive composition.