ON THE ISSUE OF SELECTING EXPRESSION TO CALCULATE THE SPEED OF DRILLING OF THE DOWN-TO-HOLE MACHINE FOR THE REGULATION PURPOSES OF DRILLING OPERATIONS

Abstract

To standardize drilling operations at the quarries, it is
important to have information about drilling efficiency,
which is mainly determined by the drilling speed in specific conditions. Application of «Uniform production
standards (timing) for open-pit mining operations for
mining enterprises. Drilling» developed in the USSR in
the purpose of regulating drilling operations at mining
enterprises is not sufficient, since they do not take into
account modern models of high-performance drilling
equipment. The solution of the problem can be achieved
during pilot drilling, which requires delivery of an experimental model of the drilling rig to the mining enterprise to the open pit, or as a result of express calculation, which is preferable due to the relatively low labor
intensity. The purpose of the research presented in the
article was to identify an acceptable analytical expression for calculating the drilling speed by down-to-hole
method. For this purposes, we have carried out the
analysis of previously obtained results by other researchers. As a result of the analysis, the formula of
professor G.M. Kryukov has been established that, unlike
other well-known expressions, takes into account only
the main factors of the drilling process – impact energy,
impact frequency, strength coefficient of rock on the
Protodyakonov scale, design parameters of the pin
crown, and it does not contain hardly-to-determine coefficients and parameters. The results of the calculation
speed of drilling down-to-hole machine. The results of
the calculation speed of drilling down-to-hole of blast
holes for specified conditions – diameter drill bits
(90÷165 mm), percussion power of the drilling rig
(20÷33 kW) and strength coefficient of rock on the professor M.M. Protodyakonov scale (6÷16). As a result of
regression analysis of calculated data obtained according to the formula of professor G.M. Kryukov, approximating exponential expressions are established. The use
of expressions provides significantly simplifying the determination of the speed of drilling down-to-hole of blast
holes for specific conditions when standardizing drilling
operations in quarries.