Compression behavior and particle breakage in iron ore tailings

The high stress levels in tall tailings dams can lead to particle crushing. Understanding the compressibility and breakage characteristics of tailings particles will contribute to the advancement to the design and construction processes of high-rise tailings dams, as well as the accurate evaluation of the stability of tailings storage facilities (TSFs). This paper presents the results of a series of detailed one-dimensional oedometer compression tests conducted to investigate the compression behavior and particle breakage of iron ore tailings (IOTs) collected from two typical TSFs, with different initial particle size distributions and a wide range of initial specific volumes, under effective vertical stresses of up to 4.8 MPa. The results show that the compression paths of the IOTs were slowly convergent, and this non-transitional mode of compression behavior experienced a significant amount of particle breakage. The relative breakage (B r) was used to quantify the amount of breakage and the input specific work (W) was adopted to evaluate the factors influencing B r. The initial breakage stress of the IOTs was less than 0.2 MPa. For the finer tailings, B r increased with increasing vertical stresses until it reached a threshold, after which B r tended to remain constant. However, coarser IOTs continued to experience crushing even at 4.8 MPa. The particle breakage in the coarser IOTs is much more significant than it in the finer IOTs overall. It was also observed that the tailings grains within the loose specimens broke more easily than those within the dense specimens. Additionally, three types of particle crushing modes were identified for IOTs under one-dimensional compression, namely, abrasion, chipping, and splitting.