Alternate Room-and-pillar Mining With Ascending BackfFill Method And Its Industrial Application

A safe and efficient mining method for thick, broken orebody with high value has always been a technical problem. New mining method for such kind of deposit in Sanshandao Gold Mine was studied in detial in this paper, using the comprehensive reserching means such as theoretical mechanics anslysis, numerical simulation, schematic design and field industrial test. The conclusions are summarized as follows:Firstly, the alternate room-and-pillar mining with ascending backfill method is proposed, which devides the deposit into several rooms and pillars being alternately arranged in one panel. And the room and pillar stopes are mined alternately and ascendingly, realizing the exchange of the function of protecting the roof. The method reduces the height of the second step stope, improving the stress conditions and security of the second step mining.Secondly, the plane mechanical model of calculating the varialbe step length is established by means of theoretical mechanical anslysis, which makes the system of the new mining technology more perfect. Then the model is used to the Sanshandao Gold Mine and the optimum varialbe step length is calculated out to be11.5m.Thirdly, the varialbe step length is proved to be safe by the index of the satbility of stopes, using the finite element software ANSYS, which provides a good working condition for mining.Finally, the technical economy analysis indicates that the method developed in this paper has great direct economic benefit. And the conclusion can be drawed that the alternate room-and-pillar mining with ascending backfill method is a green mining technology with the strong points such as high security, low loss ratio, high efficiency and large production capacity. And what’s more important is that the new mining technology is proved to be a feasible method for such type of deposits with the mining conditions of thick, broken orebody and high value.