Experimental Study On Goaf Filling With Flyash By Air Delivery

This passage analyses the actuality of the research about the ground subsidence control caused by coal mining, does a summarize comment on the technology of goaf filling both in domestic and abroad at present, and supposes technology of filling the goaf by transporting the flyash by air delivery.Factors influencing the stability of the surrounding rock in the stope are analysed, and working behaviors of the filling pack in the goaf is introduced, including the mechanics working behaviors, structure working behaviors and the yielding working behaviors. In virtue of the block theory, we can identify the latent key blocks of the wall rock in the stopes which are made up of the structure faces. Through the analyses of the stability and the reliability of the key blocks, we compute the failure probability and forecast failure of surrounding rock.By analyzing the application of the filling material which are used more frequently, mainly including flyash, coal refuse, tailing and so on, and doing lab research on the physico-chemical characteristic of the flyash and coal refuse, we get some physico-chemical indexs of the flyash. In the angle of safety, economy and persistent development, how to choose the filling material to fill the goaf is presented.According to the fact of the LiYan coal mine, project of developing coal seam16 and 17 without migrating the villages is proposed, this is filling the goaf by transporting the flyash by air delivery, and characteristic of air delivery system, the dynamic characteristic and process control are analyzed. At last, filling test was done on the surface, and filling instruments was improved through the tests. It is stated venturi filling instrument is superior to others in stability, mixing water and flyash, reducing dust .