Delay compositions and detonation delay devices utilizing same

Abstract

A delay composition for a detonator or delay device. The composition comprising a mixture of silicon and barium sulfate, and an amount of red lead in the range of about 3 to 15%, and preferably 6 to 12%, by weight of the mixture. The invention also relates to a delay element comprising a rigid metal tube containing the delay composition, and a delay device incorporating the delay element.

1 . A delay composition comprising mixed particles of silicon, barium sulfate and red lead, the red lead being present in an amount of about 3 to 15% by weight of the composition. 
     
     
         2 . The composition of  claim 1  wherein the red lead is present in an amount of about 6 to 12% by weight of the composition. 
     
     
         3 . The composition of  claim 1  wherein the red lead is present in an amount of about 9 to 12% by weight of the composition. 
     
     
         4 . The composition of  claim 1  wherein the composition contains about 40 to 60% by weight of said barium sulfate and about 25 to 50% by weight of said silicon. 
     
     
         5 . The composition of  claim 1  further containing a binder causing collections of said particles to bind together in the form of free-flowing granules. 
     
     
         6 . The composition of  claim 5  wherein said binder is selected from the group consisting of solvent-soluble polymers, silica and swelling clays. 
     
     
         7 . The composition of  claim 5  wherein said binder is a water-soluble derivative of cellulose. 
     
     
         8 . The composition of  claim 5  wherein the binder is carboxymethyl cellulose. 
     
     
         9 . The composition of  claim 8  wherein said binder is present in an amount of 0.2 to 0.6% by weight of the composition. 
     
     
         10 . The composition of  claim 1  wherein the particles of barium sulfate have a specific surface area of about 0.8 m 2 /g, the particles of silicon have a specific surface area of 6 to 8 m 2 /g, and the red lead has a particle size of about 1 to 3 microns. 
     
     
         11 . A delay composition in the form of free flowing granules each consisting essentially of mixed particles of silicon, barium sulfate and red lead, together with a binder, the red lead being present in an amount of about 3 to 15% by weight of the composition. 
     
     
         12 .- 29 . (canceled)