BLASTING METHOD OF DESTRUCTION OF IRREGULAR BLOCKS Russian patent published in 2016 - IPC F42D3/04 F42D1/08 C06B31/28 

FIELD: blasting operations.

SUBSTANCE: invention relates to explosive works for destruction of irregular blocks of rocks of the medium and lower than medium strength. Before the explosive works brand A ammonium nitrate (AN) is prepared: by processing with a surfactant - black neutralized contact (BNC) in the amount of 0.8-1.2 % of the AN weight and stirring until all granules are covered with a thin layer of the surfactant. To obtain dispersed AN the ammonium nitrate treated with the surfactant is milled. In an irregular block a shortened blast hole is drilled at the depth of 0.2-0.25 of the irregular block height. Into the drilled blast hole a linear initiator (type DC - detonation cord) and granulated AN processed with the surfactant are placed all the way down the blast hole. Above the blast hole charge a pressure charge is placed with processed ground AN with the particle size of 0.1-1 mm. Weight of the pressure charge is 1-5 wt% of the blast hole part of the charge, height of the pressure part of the charge is not less than 0.4 of its diameter. Charge can be formed both in a plastic bag and a paper shell or in bulk. Charge explosion is carried out. As the result of the DC detonation an explosion occurs in the blas hole part of the charge, and from the blast hole one - the pressure part of the charge is exploded. Detonation products of the pressure charge close detonation products of the blast hole charge, thereby prolonging the time of pulse loading the irregular block, thus helping its efficient destruction.

EFFECT: invention increases efficiency of explosion and reduces power losses.

7 cl, 4 dwg