METHOD FOR PREPARATION OF ROCKS BY EXPLOSION IN A PIT USING CYCLIC-FLOW TECHNOLOGY (CFT) Russian patent published in 2019 - IPC F42D3/04 E21C41/26 

FIELD: mining.

SUBSTANCE: invention relates to method of rock preparation by explosion. Method involves drilling of vertical and backward out-of-flow wells with formation of ledge slope at angle of 60–75° and oversized output of 4–6 % at solid charge or with air gaps. According to the established regularity and feature of change of natural and technogenic fracture of solid mass of rocks with depth at development of the above layer, working vertical or inclined wells are drilled according to the specified grid with underdrilling at 1.2–1.5 m and backward out-of-flow wells by 2–3 m in comparison with working for smooth separation at angle of 80–85° and dividing array by height of ledge according to required energy for uniform crushing into two or three parts and redistributing explosive charge in wells using air gaps, for example, one or two, made of two expandable halves of "tube" length in accordance with height of air gap, for example, from polyethylene or cardboard material in such a way that values of explosive charges in the middle zone increase in 1.3–1.5 times, in the lower one by 2–3 times in comparison with the value of the upper charge, at completion of unit preparation to explosion there used is tamping of crushed stone material in "tubes" with tides for bringing wires of blasting and explosions of charges are performed with 5–10 ms deceleration for explosion energy locking first of upper, then middle and lower charges in wells of unit.

EFFECT: higher efficiency of rock preparation by explosion in systems with cyclic-flow technology.

1 cl, 6 dwg