ON THE POSSIBLE EFFICIENCY OF HORIZONTAL CUTTING BY THE LEDGE EXPLOSIVE BREACKING IN QUARRIES

Abstract

The article presents the results of changes analysis
in the indicators of drilling and blasting works in
some large enterprises for a significant period of
their work. The increase in the specific consumption
of explosives and the volume of drilling by year was
shown, the reasons for this increase were explained.
The article considers the prospects of development
of drilling and blasting operations in terms of reducing the cost of explosives.
A technological solution is proposed to improve the
energy efficiency and resource saving in the production of drilling and blasting operations, which consists in the use of a horizontal cut on the sole of the
ledge in the case of a ledge explosion. The distances
between the wells of the vertical series at which the
pressure from the explosion of a cylindrical charge
in the rock mass exceeds the stress of rock formation
are determined. In order to further implement the
method of breaking off the horizontal hole, the distances between the horizontal holes providing the
separation of the massif along the sole of the ledge are determined. Comparison of two methods of rock
mass breaking – traditional and method with the use
of horizontal cutting – showed that the use of horizontal cutting should be sufficiently effective in
terms of reducing the specific consumption of explosive by more than 2 times. In addition, due to the
increased distance between vertical cerves, the volume of block drilling is reduced.
To ensure the safe operation of drilling equipment
during horizontal drilling, additional requirements
of industrial safety to the design of the drilling machine are formulated. The schematic diagram of a
rig for horizontal drilling is given. The design of the
drill rig provides hydraulic protection against partial rock mass fall, a remote-control unit on the basis
of KAMAZ vehicle, the compressor and the oil-station.