Identification of the oversized rock pieces in hydraulic hammer breaking process based on the scanner data geometry features analysis

Due to the harsh conditions in the mining environment, it is difficult to fully automate some of the tasks carried out by mining machines and devices. As part of the technological process of extracting copper ore from Polish mines, the material is broken with a hammer to fit through the screen of a 40×40 cm square shape slot, after which it is loaded and conveyed for further processing. Usually, most of the material remaining on the screen cannot be considered oversized, additionally smaller particles can form blockages or rest on larger blocks. In this case, the crushing is not necessary, and only its movement may be sufficient. The focus of the presented research is on the identification of the particles that would be considered oversized, as it is a crucial task in the breaking hammer automation process. The authors propose a method based on the analysis of initially extracted 3D data copper ore blocks obtained from laser scanning at one of the transfer stations in KGHM Polska Miedź S.A., Polkowice-Sieroszowice mine. The difficulties of measurement are multiplied by the necessity of performing the scan from a single point of view, which was forced by safety concerns. Segmented but incomplete 3D data are processed, which results in finding the geometric features that prevent the material from going through the screen in an automatic manner.