Investigation of optimal surface paste disposal design based on crack intensity

There are many factors affecting the mechanical and geochemical stability of the surface paste disposal (SPD) method. The most important of these are the cracks occurring during the storage of tailings. The relationship between the volumetric water content (VWC), matrix absorption (MS), and oxygen (O₂) values of the paste material are important in the formation of cracks. In this study, surface crack formations of the paste material stored at the laboratory in accordance with 3 different storage methods (cemented and uncemented) were observed during the pour and after the deposition, and crack intensity factor (CIF) was measured. The relationship between CIF with VWC, MS, and O₂ parameters was examined. As a result, the CIF value decreases approximately by %75 with cement addition in the lowest and highest layers in the SPD method. In a case receiving the most rain, the crack intensity value of the highest layer was determined to be 3,9% in the Design 3 where cement was used in the lowest and highest layers. In addition, VWC, MS, and O₂ levels were 35%, −29 kPa, and 17.5%, respectively, making the paste material more efficient in terms of mechanical and geochemical stability.