The Study Of Induction Caving Mining Technology In Yingkou Hengtai Magnesite Mine

YingKou HengTai magnesite as a large metamorphic hydrothermal magnesite deposits at lower Proterozoic, ore body located in mountain, composed by multi-layered gently inclined magnesite ore, the total thickness of the ore body was 2 ～ 200m. The upper layer of ore deposit has formed many different gobs due to many years disordered exploitation small mines. Since the shape of gobs, direction, altitude and horizon is extremely complex, and most gobs have been caving, some empty area in caving activities, so that the processing work of gobs become extremely difficult. Yingkou HengTai Magnesite Ltd obtain the mining rights in January 2005, conducted a number of research and program design, proposed filling empty area, room and pillar mining, open-pit mining, and other programs, ultimately did not pass the security review because of security cannot be guaranteed, make this valuable magnesite resource not been developed and utilized. In this condition, this paper studies the application of induced caving technology of Northeastern University.First, by investigation the surface subsidence area and the surrounding gobs status, basic grasp the gobs distribution ranges, gobs occurrence state surrounding collapse pit and rock steady state. Secondly, though structural plane survey of the collapse pit and gobs surrounding rock and point load strength tests, the stability of rock mass is classified and analysis the caving ability of these complex gobs. Third, according to gobs status and caving ability of ore and rock, proposes induction caving program. Fourth, according to the complexity conditions of the ore body occurrence proposed a technical ideas of processing and ore extraction unified consideration and in accordance with safe and efficient stoping requirements, presented "caving sublevel and produced" program for ore bodies with complex gobs, which induced caving underground and mined ore from the open pit. Fifth, calculated critical caving span and critical caving area, combined with the ore body condition, proposed 3180 exploration line as the boundary of two zones induced caving technical solutions, and designed induced project location and arrangement of works in two zones. Sixth, analysis the gobs hazards forms of "caving sublevel and produced" program, put forward the corresponding control measures.The "caving sublevel and produced" method has passed the expert appraisal organization by Administration of work Safety of Liaoning province, make Yingkou HengTai magnesite which shelved for years to enter the mining program. Analysis shows that this " caving sublevel and produced " program, by the obvious advantages like simple in stoping technology, high efficiency, less power of ore transportation, good work conditions, will well adapt the complex gobs conditions of this mine and acquire a safe and efficient stoping results.