SAFETY ELECTRIC DETONATOR FOR BLASTING OPERATIONS Russian patent published in 2006 - IPC F42D1/45 F42C19/12 

FIELD: production of means of initiation, applicable in blasting operations for a short-delayed blasting of explosive charges, in mines and pits dangerous in gas and duct inclusive.

SUBSTANCE: constantan with a diameter of 40 μm at a ratio of the resistance bridge length to its diameter 1/d₁=25-50 is used as a resistance bridge in the electrical detonator, the interval between the series of delay of the electric detonator determined as (H_n+1-H_n)/U=30-50, where H_n+1 - the subsequent series of delay of the electric detonator, H_n - the previous series of delay, U - the rate of burning within 4 to 320 ms, the ratio of the length of the layer (Δ) of the flash absorber covering the outer surface of the case to the case diameter (d₂) should be Δ/d₂=0,01-0,042, and the ratio of the height of lead azide to its diameter H/d₃ should be at least 0.09. Trisodium phosphate hydrate or polyvinyl chloride chlorinated resin applied to the case outer surface is used as the flash-absorbing compound coating the case outer surface. Delaying compounds. Compound No.1, formulation, per cent by mass: ferrosilicochrome (FSC)-50-52; minium - 50-48, binder (0.4-2.5 per cent) - above 100 per cent, at a specific surface of FSC (Ssp) - 2200-3500 sq/g. Compound No.2, not containing lead compounds, formulation, per cent by mass: ferrosilicochrome - 55-65; barium peroxide processed by abietic resin - 35-45; binder (0.4-2.5 per cent) above 100 per cent.

EFFECT: enhanced efficiency and safety of blasting operations in mines and pits dangerous in gas and duct, provided reliable operation in the group of native blasting machines.

5 cl, 4 tbl