Abstract: In the grinding operation of tower mill in complex refractory iron ore，the traditional high chromium cast iron liner has the problems of short service life，frequent maintenance and high operation cost. Taking Karara Mining Co.，Ltd. (KML) as the engineering background，in view of the poor service conditions of the tower mill and the prominent wear of the liner，the composite ceramic liner is innovatively introduced，and the bimetallic composite structure of outer high chromium alloy + inner zirconia ceramic is adopted. The targeted component subdivision design，core performance optimization and industrial applica⁃ tion continuous improvement are carried out. The industrial application shows that the average service life of the composite ceramic liner is extended from 2 850 h to 4 000 h，which is increased by more than 40 %. The equipment failure rate is reduced by 30%，and the average annual maintenance frequency is reduced from 2.51 times to 1.8 times. The annual procurement cost of 5 sets of tower mills is 738 thousand yuan， the maintenance cost is 1.785 million yuan，and the total annual cost is 2.523 million yuan. At the same time，the operation safety is significantly improved，and the protection effect of tower mill shaft and spiral vane is significantly improved. The research shows that the composite ceramic liner effectively solves the wear-resistant short plate of the traditional liner，significantly improves the operation efficiency and eco⁃ nomic benefits of the tower mill，and has important reference value for the upgrading of grinding equip⁃ ment of similar complex refractory iron ore.

Key words: tower mill, high-chromium cast iron liner, composite ceramic liner