Abstract: Semi autogenous grinding process has the advantages of simple process flow and conve⁃ nient production management，small occupation and low civil construction cost，easy to realize production automation，intelligence，efficiency and accuracy，strong adaptability to ore with high mud and water content，conducive to the separation of useful minerals and gangue because of the selective crushing and grinding characteristics，and easy to realize large-scale production. While the process has not been applied in the beneficiation of lepidolite ore at present. In order to promote the application of the process in the beneficiation of lepidolite ore，a representative lepidolite ore (high mud content，more weathered ore，easy to mud and over grind，which target mineral has the coarse embedded particle size，and is fragile and difficult to grind) in Yichun，Jiangxi Province is taken as the object to study about application of semi autogenous grinding process and is analyzed in terms of theory，investment and operation cost. The study results showed that the combination of the two is not only theoretically feasible，but also has certain advantages in terms of investment and operating costs. In the future，it should be increased about the research and demonstration of the reasonable and efficient integration of the two，so as to promote the application of semi autogenous grinding technology in Yichun area and similar lepidolite ore processing.

Key words: semi autogenous grinding process, lepidolite ore, beneficiation, investment and operat? ing costs