A New Look at Hard Rock Abrasivity Evaluation Using Acoustic Emission Technique (AET)

Measurement while drilling (MWD) is one of the most important and useful tasks in mining operations. Access to a method for the accurate measurement of drill and rock-related operating parameters can greatly reduce the cost of drilling operations. Abrasivity is an important rock property with a direct impact on the wear rate and lifetime of drilling equipment as well as the rate of penetration. While many methods and standards have been developed for the measurement of rock abrasivity, these methods are often costly and time-consuming and require complex preparation. This study investigates the possibility of estimating the rock abrasivity by processing the acoustic and vibration signals generated while drilling. For this purpose, 13 samples of igneous rocks, which are classified as hard rocks, are used for drilling tests. Before the tests, the Schimazek abrasivity factor of the samples was obtained by measuring their strength and texture properties (from petrographic thin sections). Acoustic and vibration signals were analyzed in time, frequency and time–frequency domains, and a series of parameters related to the resulting spectra were extracted. After obtaining the acoustic and vibration parameters for drilling, the relationship between them and the abrasivity of the rock was investigated. Using a combination of PCA and MLR, the first seven principal independent components of input parameters were obtained. They were used to formulate an equation to predict the abrasivity of hard rocks with a correlation coefficient ( R 2 ) of 0.9574. The accuracy of the model in terms of RMSE and MAE are 1.87 and 1.49, respectively. The results of this study show the possibility of estimation of rock properties by processing the signals generated during the rock drilling operation. This approach can be used in real-scale operations in the industry simply by installing acoustic and vibration sensors on the drilling rig for a fast, accurate, and non-destructive determination of the abrasivity of rocks and the related operating parameters without the necessity to stop the drilling process for sampling and in laboratory measurements. Highlights Rock abrasivity is one of the most important geomechanical properties of rocks which has a direct impact on the choice of operating parameters and reducing the time and costs of projects. One of the most widely used indicators of the abrasivity of rocks is the Schimazek abrasivity factor. In recent years, acoustic waves have been in