Study On Cementitious Material Of Ultra-fine Tailings Filling And Reasonable Sequence Of Stage Stopingand Filling Mining

This paper focuses on a new cementitious material which is used together withultrafine tailings. Firstly, a study on the selection of main cementitious materials andactivators has been conducted. Then, based on the Matlab analysis and orthogonalexperiments of ultrafine tailings, cementitious materials and activators, the optimumcementitious material proportioning of ultrafine tailings is obtained. After that a study isconducted on flowability on the premise of the backfill strength can meet therequirements of the sites. Since the grain size of ultrafine tailings is excessively small,the slurry cannot flow by itself which can easily lead to pipe plugging, a water reduceris added to improve the flowability. At last, we take the goaf-stowing program ofJingding Mining Corporation as an illustration. According to the simulation of stagestoping chamber backfill stability via ABAQUS, a finite element analysis software, thedistribution of the first step excavated chamber backfill stress field is obtained. Here arethe main research concerns in this paper.(1) Based on the principle of cementitious materials proportioning, and the selectionexperiments of main cementitious materials and activators by using ultrafine tailingsas the aggregate, the preliminary proportioning is obtained.(2) Based on the Matlab analysis of large amounts of data and orthogonal experimentsof ultrafine tailings, cementitious materials and activators, the optimumcementitious material proportioning of ultrafine tailings is obtained. Then the fillingmaterial expansion experiments have been carried out by using the new cementitousmaterial to bring about the expansion.(3) A research on short distance pipeline transportation of ultrafine tailings filling slurryis carried out which also takes the site mining and goaf-stowing situations ofJingding Mining Corporation into consideration. In order to achieve theautomatically flowing, full piping, smoothly moving and high concentration of theslurry, a water reducer is added to improve the flowability and strength. Byconstructing the corresbonding mathematical model, a concentration meeting therequirements of piping in the project is obtained, which solves practical problems in pipeline transportation filling.(4) Based on the data obtained in the site geological survey and laboratory test, a fillingstability analysis model is built and numerical analysis is made of the fillingprocesses by employing the large three-dimentional finite element softwareABAQUS to obtain the distribution law of the stress field. An assessment is alsomade of the first step excavated chamber backfill stability. It is very important forfilling body strength design.