Examples of Blasting Using Emulsion Explosive in Mining in the 200 Meters Ultra Deep Water

摘要

Somewhere's manganese ore in Hunan Province is about 170 m below the surface.The roof is limestone and the thickness is 170 ～ 175 m.The groundwater connects with the underground river and the water level is about 3 m below the surface.The method of deep well pumping ore has been employed while the effect is poor for the manganese ore having the cementation phenomenon and the flowability being bad.The loosening blasting technology has been adoptted to enhance the effect by drilling blast holes around the deep well.The diameter of the blast holes is 130 mm and the depth is 220 ～250 m.The glass microsphere sensitized emulsion explosive has been applied and the detonation velocity is 4500 m/s.The pressureproof and waterproof PVC tube has been used as the shell of the emulsion explosive.The diameter of the PVC tube is 90 mm and the length is 40 cm.The TNT-RDX explosive and the general electric detonator are used in making the metal shell shaped charge initiation.The 50 ～70 m long charge has been delivered accurately to the orebody 200～250 m below the surface through self-made wire winch.After several experiments,the explosion of the emulsion explosive is reliable,the successful blasting is achieved.