Abstract: The mining condition of deposit is extremely harsh in Tangdan Copper Mine, and the orebody and surrounding rock are loose, broken, unstable and have high mud content, so it causes a series of problems during mining such as difficulty of hole-forming and drawing, high dilution and loss rate and poor production capacity. Grouting technical scheme has been determined by the comparison of theoretical calculation and engineering analogy among different grouting schemes. The friable rocks will be bonded as a whole after the grout injected into orebody and part of hanging wall, and the mechanical property and integrity of the engineering rock mass, the hole-forming and mining index will all be improved. Through the comparison of 9 schemes based on mechanical calculation, lab experiments, and numerical simulation by using ANSYS and FLAC3D, the optimum design scheme in which the top pillars should be 15 m, the jams 16 m and the chamber 12 m has been concluded. The industrial experiment indicated that chemical grouting applied in short-hole shrinkage method can enhance ore's stability, improve the safety coefficient of stope, increase the fluidity of stored ores, decrease mining loss and dilution rate, which can realize the safety and efficiency mining of weak-broken ore.

Key words: weak-broken, chemical grouting, numerical simulation, safe and efficient mining, industrial experiment