Abstract:
HPGR (High pressure grinding rolls) plays an important role in energy-saving and consumption-reduction in metal mines owing to its unique advantages in the lamination crushing principle. Given the differences in mechanical properties, homogeneity and particle size of feed ores, different material layer thickness in a same equipment affects HPGR lamination crushing performance. In this study, taking Anshan-type hematite ores as the research object, suitable particle layer thickness for lamination crushing was characterized based on the macro-mechanical properties and the numerical simulation of real fracture (RFPA) of ores. The tests of compressive strength and tensile strength of standard ore samples were first carried out, and the homogeneity m of ore was characterized by numerical simulation. Then, numerical models of variable layer thicknesses with
Φ10 mm spherical hematite particles were configured, and the ballast tests were performed with horizontal constraint simulating the HPGR lamination comminuting process. Finally, an appropriate layer thickness was determined by analyzing the processes of stress transfer and three-dimensional crack penetration failure coupled with the relative energy consumption. It was shown that the fracture mode of configuration with a thickness of 8 layers was diagonal penetration, which was conducive to stress transfer promoting the comminution of particles in the whole bed with a high energy efficiency. Results provided a research basis for determining a suitable layer thickness of HPGR in industry.