A NEW SYSTEM OF DRILLING AND BLASTING OPERATIONS FOR STEEP ORE BODIES

Abstract

The tasks of finding ways to increase the efficiency of underground mining of extremely narrow and narrow rake veins have always been the focus of attention of a large number of researchers, since such ore bodies have complex or extremely complex mining-and-geological conditions, such as: poor ore reserves, often complex morphology, variable thickness, significant strike length and depth of dip, often soft or medium-soft ore and host rocks.

In Armenia, these include the Shahumyan, Azatek, Armanis, Lichkvaz-Tey gold and polymetallic deposits, etc. An increase of the efficiency of the operation of these mines depends on the development, improvement and creation of new underground mining systems.

In this regard, one of the ways in the development system of narrow ore bodies is to increase the qualitative and quantitative indicators of ore breaking with the help of the revealed rational interdependence between the width of the stope and the mounted wells geometry, their diameter, length, type of charge and the structure of explosives.

For the development system used in an underground mine of the mining and processing plant of Armenia, a new scheme of drilling-and-blasting of ore is proposed, according to which a row of 19 holes are suggested to be drilled in the stope along the strike of the ore body, with successive numbers from 5 to 23, where the diameter of the loading hole is 64 mm, and the diameter of the unloaded hole is 89 mm. The loading and unloaded holes are drilled in staggered rows.

The advantages of the new drilling-and-blasting scheme are: reducing the number of explosives, reducing the area of the stoping face and reducing the amount of commercial ore extraction, improving the safety of the faceworker, and as a result, increasing the efficiency of ore extraction due to reduced dilution.