Abstract: In order to achieve“more crushing and less grinding”and reduce the energy consump⁃ tion of beneficiation crushing and grinding, the -2 mm and -1 mm products under the ultra-fine crushing undersize of high-pressure roller mill in Meishan Iron Mine are taken as the objects, and the wet magnetic separation tests with different magnetic field strengths are carried out. The high-pressure roller mill + tow⁃ er mill process and the high-pressure roller mill + wet magnetic separation pre-concentration + tower mill process are used to carry out the comparison test of unit power consumption of tower mill.The test results show that according to the unit energy consumption of the products under the sieve, the products of -2 mm and -1 mm are ground directly into the tower mill to -0.074 mm content 65%, 70% and 75% respectively, which are 1.39~1.75 (kW·h)/t and 0.34~0.76 (kW·h)/t higher than the wet high-intensity magnetic separa⁃ tion of -2 mm and -1 mm products and then into the tower mill to the same fineness.The high-pressure roll⁃ er mill + tower mill process is adopted. The crushing and grinding unit total energy consumption of -2 mm product is 1.0~1.09 (kW·h)/t higher than that of -1 mm product tower grinding -0.074 mm content of 65%, 70% and 75% at the same fineness.The process of high pressure roller mill + wet magnetic separation pre�selection + tower mill is adopted. The crushing and grinding process is calculated according to the products under the sieve. The total energy consumption per unit of -2 mm products and -1 mm products is similar when they are ground to the same fineness, and the difference between the two is only 0.02~0.1 (kW·h)/t. Taking into account the life of the roller surface of the high-pressure roller mill and the energy consump⁃tion of crushing and grinding, the particle size distribution limit of the high-pressure roller mill and the tow⁃ er mill should be 1~2 mm.

Key words: crushing and grinding process, high pressure roller mill, ultra-fine crushing, tower mill, unit energy consumption