BOTTOMHOLE WAD OF BLASTHOLE CHARGE Russian patent published in 2015 - IPC F42D1/08 

FIELD: oil and gas industry.

SUBSTANCE: bottomhole wad of blasthole charge comprises a cylindrical solid body on the side surface of which in the plane, perpendicular to wad, circular grooves are made. The bottomhole wad is made from carbon fibre-reinforced plastic. The solid body of wad is made in the form of uniform monolithic structure from the material containing 74.8 weight fractions of small coal - small coal, slime, hardened by the cold hardening formaldehyde resin SFZh-3032 amounting 20.6 weight fractions and a hardener amounting 4.6 weight fractions of water solution of technical petrolsulphonic acid. The invention allows to increase efficiency of drilling-and-blasting works in coal mines due to reduction of labour input of processes of fabrication of wads and respectively their prime cost.

EFFECT: invention allows to improve quality of produced coal due to decrease of his impoverishment, the simplified bottomhole wad is suitable for charging of blastholes in automatic mode by respective robots.

4 dwg