Abstract: The detailed investigation of Longtangyan Iron Mine uses a 100 m×100 m net to explore and control the resource reserves.In the past two years,it has been discovered that the original exploration project spacing can no longer meet the requirements of mine development and mining projects through production exploration and development,mining and cutting,and mining projects.The layout requirements result in waste of engineering and mine volume.Through the comparison and verification with the detailed investigation stage,the density method is used to compare the exploration project spacing of the Longtangyan Fe25 ore body,and another reasonable project investigation spacing is determined in combination with the specifications to explore the resource reserves controlled by a network of 50 m×50 m.

Key words: iron mine,Fe25 ore body,survey engineering interval,comparison and verification,encryption method