Experimental Study On Impact Crushing Law And Energy Distribution Of Magnetite Ore

It requires huge energy for mining and processing hard ores in most of metallurgical mines, including crushing magnetite ores which wastes energy seriously with high cost,so consumption reducing is imminent. In the actual production of iron mines, impact crushing is the most important way of processing ores. Therefore, in order to explore the breaking way and energy consumption law of magnetite ores, magnetite ores are studied by using impact crushing test with SHPB system.1) Strain rate, compressive strength and stress-strain relationship are analysed in the test process, the crumbling method is observed and the mechanical properties are studied under impact loading of ores. The results showed that crack initiation stress increases first and then decreases as the increasing of strain rate. Crack strain, peak strain and compressive strength increases gradually as the incident energy increases. In addition, the breaking way of test blocks is tensile split along the axial direction.2) The data of incident energy, absorbed energy, transmission energy and reflection energy are studied in the test process, laws of energy distribution and consumption are revealed. It was found that most of incident energy become transmission energy, smaller part of incident energy become reflection energy and about 40 percent of incident energy become absorbed energy. What's more, crushing energy density increases as the incident energy increases.3) The debris of blocks which had been sieved are studied, fractal feature of debris is analyzed, and the law of debris distribution is revealed. The results showed that fractal dimension increases with the crushing energy density increases, average size and feature size decreases. Moreover, two mathematical models are established to predict average fragmentation and feature size in order to control the size of magnetite by regulating input energy, which provide reference for iron mines.