A Modified Schimazek’s F-abrasiveness Factor for Evaluating Abrasiveness of Andesite Rocks in Rock Sawing Process

One of the most crucial factors involved in the optimum design and cost estimation of rock sawing process is the rock abrasivity that could result in a significant cost increase. Various methods including direct and indirect tests have been introduced in order to measure rock abrasivity. The Schimazek’s F-abrasiveness factor (𝑆𝐹_𝑎) is one of the most common indices to assess rock abrasivity. 𝑆𝐹_𝑎 is the function of three rock parameters including the Brazilian tensile strength (𝐵𝑇𝑆 ), median grain size (𝜙), and equivalent quartz content (𝐸𝑞𝑄𝑡𝑧). By considering its formulation, it has been revealed that the coefficient of each parameter is equal, which is not correct because each parameter plays a different role in the rock abrasion process. This work aims to modify the original form of 𝑆𝐹_𝑎 by introducing three correction factors. To calculate these correction factors, an integrated method based on a combination of the statistical analysis and probabilistic simulation is applied to a dataset of 15 different andesite rocks. Based on the results obtained, the values of -0.36, 0.3, and -0.89 are suggested as the correction factors of 𝐵𝑇𝑆, 𝐸𝑞𝑄𝑡𝑧 and 𝜙, respectively. The performance of the modified Schimazek’s Fabrasiveness factor (𝑀𝑆𝐹_𝑎) is checked not only by the wear rate of diamond wire but also by the cutting rate of the wire sawing process of Andesite rocks. The results obtained indicate that the wear rate and cutting rate of andesite rocks can be reliably predicted using 𝑀𝑆𝐹_𝑎. However, it should be noted that this work is a preliminary one on the limited rock types and further studies are required by incorporating different rock types.