Abstract: In order to determine the optimal crushing and grinding classification process of a copper mine in Congo（DRC），the ore characteristics and crushing and grinding parameters are analyzed. Under the condition of determining the particle size requirements of subsequent operations，detailed investment and technical and economic comparison of the three processes of coarse crushing + single-stage semi-au⁃ togenous grinding + high-frequency vibration fine screening closed-circuit classification，three-stage closed-circuit crushing + ore washing（wet washing）+ one-stage ball milling + high-frequency vibration fine screening closed-circuit classification，coarse crushing + pre-screening + medium crushing + inspec⁃ tion screening and fine crushing closed-circuit + ball milling + high-frequency vibration fine screening closed-circuit classification are carried out. Through data comparison，it is determined that coarse crush⁃ ing + single-stage semi-autogenous grinding + high-frequency vibration fine screening closed-circuit clas⁃ sification is the best crushing and grinding classification process flow of the ore. The process simplifies the process structure and avoids the risk of process blockage. The traditional gravity classification is replaced by geometric classification，which improves the classification accuracy and copper leaching rate，reduces the production cost，and can significantly improve the economic benefits of the enterprise.

Key words: double metal composite liner, ball mill, performance optimization, economic benefits