FILL STEMMING OF BLAST HOLES WITH ELEMENTS OF STONE MATERIAL Russian patent published in 2014 - IPC F42D1/08 

FIELD: blasting operations.

SUBSTANCE: fill stemming of blast holes with elements of stone material comprises the lower fill part of inert bulk materials over the air gap and the upper combined part. The upper combined part of the stemming is divided into two sections: the lower section with length of up to three diameters of the well, filled with elements of stone material with size of 0.2-0.6 diameter of the well, interstratified with the inert bulk material with the size less than 5 mm, and the upper, filled to the top of the well with the same inert bulk material.

EFFECT: invention enables to improve the efficiency of locking the detonation products in the charging cavity by the combined shortened stemming and to reduce costs for its formation.

1 dwg