Abstract: The ore of a copper concentrator in China has high hardness and low grade. In the produc⁃ tion process，the grinding operation capacity is insufficient，and the power consumption and ball consump⁃ tion indicators are high. In order to change the current situation of grinding operation and improve the grind⁃ ing efficiency，the high pressure roller mill ultra-fine crushing operation was added before the ball mill op⁃ eration，and the high pressure roller mill technical transformation was carried out on a grinding series on site. At the same time，another grinding series with the same configuration was used as a reference for com⁃ parison. On the basis of the initial pressure of 5.5 MPa，the ore throughput of not less than 80 t/h and the roller spacing of 16 mm determined by the high pressure roller mill condition test，the relative grindability and Bond work index test indexes of the ore before and after the roller pressure were compared. Finally， the effect of high pressure roller mill operation on the production and consumption reduction of the concen⁃ trator was evaluated from the industrial test level.The test results show that the relative grindability K65 of the corresponding coarse fraction of the raw ore and the roller ore is 1.28~1.47，and the narrow fraction K65 is 1.20；the ball mill work index of the raw ore obtained by the Bond work index test is 18.34 (kW·h)/t， and the roller ore is 15.49 (kW·h)/t，which is reduced by about 15.54%. In the industrial production test， the average efficiency of the reference ball mill is 60.82 t/ h，the unit power consumption of grinding is 12.84 (kW·h)/t，and the unit consumption of steel ball is 0.951 kg/t. After increasing the crushing opera⁃ tion of the high pressure roller mill，the average unit efficiency of the test ball mill is 82.95 t/h，the unitpower consumption of the grinding unit is 9.59 (kW · h)/t，and the unit consumption of the steel ball is 0.699 kg/t，which is 36.39% higher than that of the reference ball mill. The unit power consumption and the unit consumption of the steel ball in the grinding operation are reduced by 25.31% and 26.50%，re⁃ spectively.The unit power consumption of the high pressure roller mill system is 2.34 (kW· h)/t，and the overall power consumption of the test ball mill and the high pressure roller mill system is 11.93 (kW·h)/t， which is 7.09% lower than that of the reference ball mill. Increasing the high pressure roller mill operation significantly improves the mill capacity，reduces the grinding operation cost，and achieves the purpose of energy saving and consumption reduction.

Key words: high pressure roller mill, copper ore, ultrafine crushing, relative grindability, Bond work index, increase production and reduce consumption