Abstract: In order to ensure the stable operation and production safety of mine crushing equipment， Nanfen Concentrator has carried out the research and development of new ferromanganese detection equip⁃ ment and supporting technology in view of the problem that the traditional metal detector is difficult to identi⁃ fy the low intensity magnetic manganese steel parts due to insufficient sensitivity，which leads to the fre⁃ quent iron passing accidents of crusher.Based on the principle of electromagnetic induction，a flat CXJ- 1200 ferromanganese detector is developed. By optimizing the magnetic field monitoring and signal process⁃ ing mechanism，the eddy current effect changes are accurately captured，and the detection sensitivity of low intensity magnetic manganese steel parts is improved. A new iron removal process of ordinary detection-au⁃ tomatic iron picking-low magnetic metal sensitive detection-manual iron picking is adopted.The application results show that the new iron removal process significantly reduces the frequency of iron passing through the medium crushing cone crusher，eliminates the damage of bushing and eccentric sleeve caused by iron pass⁃ ing through，and reduces the oil loss caused by equipment wear，with significant economic benefits. The CXJ-1200 type manganese iron detector and the supporting iron removal process can effectively solve the problem of iron passing through the crusher caused by low intensity magnetic manganese steel parts，which can provide a reference example for similar concentrators.

Key words: crusher, manganese iron detection, low intensity magnetic metal detection, electromag? netic induction technology, mineral processing equipment maintenance