Control Technology Of Rock Movement Caused By Zoned Caving Method In Xiaowanggou Iron Mine

The mineral amount that explored by the sublevel caving method stands more than 80%of the total amount of underground mining in China's iron mine.There exists two big problems concerning large loss and dilution and large compensation for requisition of land since sublevel caving is implemented for gently inclined and inclined orebody as a mining method.Combined with actual production of Xiaowanggou iron mine,granular shift zone's detail control method using zoned mining of high strength and its controlling and utilizing method related to surface subsidence area is analyzed to provide theoretical guidance and key technology for these two major problems based on observations in the field,statistical analysis,industrial test and numerical simulation.The main research results in this paper described as follows:Firstly,the main reason of loss and dilution using sublevel caving method in the present proposed is errors of detail control of ore drawing shift zone through observations in the field.The mechanism of increasing ore loss and dilution that is caused by decreasing of the width of granular shift zone and morphological variation of draw body brought about the ore drawing port blocked up by boulder and destruction of eyebrow is analyzed,and the importance of timely disposing boulder and protecting eyebrow line of ore drawing port to restrict the width of granular shift zone to decrease ore loss and dilution is shown.In addition,according to condition of the inclined and gently inclined orebody in Xiaowanggou iron mine,the two step mining mode of sublevel caving method is put forward,which is the primary ore body is mined with large parameter first,and the residual body of footwall is extracted by the smaller parameter in latter 1?2 stages.The model can significantly increase the mining intensity for inclined and gently inclined orebody and improve space and time distribution of ore drawing granular shift zone in order to realize mining goal of high efficiency and low loss and dilution.Secondly,based on study results of zoned mining in Xiaowanggou iron mine,caving process of the mined-out area is studied by a combination method of tracing observation in the working face and surface drilling monitoring.The relationship between initial caving and continuous mass caving as the area of mined-out area of evenly extending is revealed so as to provide basis for protecting from caving on the working face.Thirdly,time and position of mined-out area caving is simulated and analyzed,and the method of delineating the subsidence area at the right moment is put forward,which can improve reliabilityof prevention and control of subsidence disaster.Fourthly,the effect of fast filling collapse pit with waste rocks to control the subsidence area is studied.The collapse angle of Xiaowanggou iron mine maintains around 76%through fast filling and keeping height of the critical medium column,by this the surface subsidence range is decreased by nearly 70%.Fifthly,the relationship of caving arch shift of mined-out area and the place of surface subsidence is got through tracking and actually measuring method.The mechanism of regularly caved surface subsidence pit that is caused by continuous caving after mined-out area caved up to the surface is revealed,and according to existing collapse pits,the next collapse pit is predicted to provide reference for scientific prevention and control of surface subsidence disaster and dynamic reclamation.Sixthly,prevention and control of operation risk of mine highway in the subsidence area in Xiaowanggou iron mine has been maintained through comprehensive rock movement control measure of drilling monitoring,fast filling collapse pit with waste rocks and supplement waste rocks after granular media settlement,which can protect safe operation of this highway and develop new building and protecting highway technology in the surface subsidence area.Theoretical analysis and practical application of Xiaowanggou iron mine indicates that detailed control of detail control method of granular shift zone and control technology of surface subsidence area advanced in this paper can be suitable for the condition of Xiaowanggou iron mine and effectively solved the problems of loss and dilution and surface subsidence control for inclined and gently inclined orebody using sublevel caving method,which will make sublevel caving more perfect and protect the mine sustainably safe and efficient mining in the mine.