Study On Seepage And Stability Of Dayukou Phosphogypsum Tailing Dam

Tailings dam as an important component of the mineral processing plant, its stability is related to the safety in production of mineral processing plant and people's life and property. Consequently, it has great significance to analyse the seepage and stability of tailings dam.Based on the investigation and stability evaluation project of Dayukou phosphogypsum tailings dam in HuBei province, the seepage and stability of the tailings dam for mineral processing plant are studied systematically by combining site investigation, site test, laboratory tests, theoretical analysis and numerical simulation. The variation law of the seepage field and stability for tailings dam are obtained. It will provide guidance for engineering design of tailings dam treatment.In this paper, the main works and results are as follows:A detailed site investigation and standard penetration test are carried, the typical engineering geological profiles which can be used to seepage and stability analysis have been obtained, the engineering geological characteristics of the tailings dam have been comprehensively evaluated. The physical and mechanical parameters about phosphogypsum have been obtained through a great deal of laboratory tests. Testing results show that phosphogypsum material particle size distribution is more concentrated, graded poor, good permeability and high shear strength.With saturated-unsaturated seepage theory, the influence of dry beach length, drainage clogging, phosphogypsum permeability and anisotropic permeability on the saturation line position are studied. The results show that, with the increase of dry beach length, the saturation line gradually drops; when the degree of drainage clogging increases, the saturation line gradually elevates; when the permeability of phosphogypsum decreases, the saturation line gradually drops; with the decrease of anisotropic permeability, the saturation line gradually drops.By means of unsaturated soil slope stability analysis methods, the stability of tailings dam is calculated, stability characters of dam slope with different conditions are obtained. Analysis results show:the factors which impact dam slope stability are dry beach length, drainage clogging degree, permeability of phosphogypsum, anisotropic permeability and dam height. The effects of drainage clogging and dam height are most obvious, but dry beach length, permeability of phosphogypsum and anisotropic permeability are weaker.These research results in the paper have been successfully applied in the treatment of Dayukou phosphogypsum tailings dam, good technical and economic effects have been obtained, and it will be an important reference to similar projects.