Performance analysis of rotary blast-hole drills through machine vibration and coarseness index mapping – A novel approach

Abstract

• A novel performance evaluation technique for rotary blast-hole drills performance. • Correlation of drill performance with machine-vibration and drill cuttings. • Drill cuttings collection and analysis as per ASTM standard. • Determination of mean particle size using Rosin-Rammler Diagram. • Obtaining Drill Vibration Index and the optimal drill operating regime. The performance of rotary drill machines commonly used in open-pit mines is measured based on the rate of penetration (ROP) and the bit wear. This paper develops a novel performance evaluation technique to obtain optimal drill operating regime through machine vibration and coarseness index mapping. The vibration levels of blast-hole drilling machines in axial and lateral directions were determined using accelerometers placed at the mast. The mean particle size (d) and characteristic particle size distribution curves for the drilled hole were plotted using sieve analysis and Rosin Rammler diagram. ROP showed an increasing trend with Mean particle size (d) with a correlation of R 2 = 0.61 and a decreasing trend with vibration for varied pulldown force and torque at a different rotational speed. A drill vibration index (DVI) is introduced as an indicator of vibration severity of the drill machine, and its relationship was studied with ROP and average mean particle size.