DEM Dual-Energy X-ray Transmission (DE-XRT) HPGR History of engineering & technology JKR model OpenCV Technology: general issues aggregates approximation of particle size belt ore measurement brittle materials comminution contour detection convolutional neural network copper ore diagnostics enrichment flotation flotation agents image processing jig beneficiation kinetic energy lithology mineral processing movement characteristics particle size particle size distribution particle velocity polymetallic predictive maintenance