Prediction of Postflotation Tailings Behavior in a Large Storage Facility

Abstract

Extracting and copper production on a large scale generates large volumes of postflotation mine tailings. The scale of operation and development of tailings storage facilities (TSFs) forces the use of innovative solutions enabling safe storage now and in the future. Any changes to the operation require multi-directional monitoring of the impact of these changes on storage safety. The ongoing exploitation will be ensured by expansion of the TSF and a change in tailings storage technology. This approach will preclude the need for changes to the new location, such as changes of land use, and will minimise the volume of mine waste. The paper presents the results of pilot studies carried out to implement the change in postflotation tailings storage technology at Żelazny Most TSF (Poland) in the future. The aim of the paper was settlements prediction of tailings and comparison of deformations with observed settlements. Settlements prediction of tailings was made on the basis of the results of the DMT (Marchetti Dilatometer Test), recommended for the prediction of natural soil settlement. Depending on the analysed zone of the TSF, settlements ranged from a few centimetres to over 1.5 m. Despite the difference shown, the results of DMT and geodetic measurements indicate a convergent trend of settlement.

Tailings Behavior Assessment Using Piezocone Penetration Test

“…These zones were delineated, among other factors, based on grain size distribution: the beach, the transitional zone between the beach and the tailings pond (transitional zone), and the tailings pond (Figure 2). A detailed characterization of the embankment was presented in [18]. The simultaneous expansion and operation of the storage require continuous monitoring, including the prevention of failures.…”

“…Understanding the properties of tailings plays a crucial role in assessing their behavior, response to loads, and paraseismic shock reactions. More information about the tailings and their detailed characteristics are provided in the bibliography concerning Żelazny Most TSF [1,18].…”

“…Understanding the properties of tailings plays a crucial role in assessing their behavior, response to loads, and paraseismic shock reactions. More information about the tailings and their detailed characteristics are provided in the bibliography concerning Żelazny Most TSF [1,18]. According to the standard for the Cone Penetration Test, two main types of test are distinguished: CPT-without measuring pore water pressure in soil, and CPTU-with the measurement of this pressure.…”

“…The input parameters for the MCC model consist of physical, mechanical, and filtration parameters of tailings, determined based on the results of CPTU (Table 5, columns 5-17). As mentioned earlier, the application of the MCC model requires additional parameters, which were compiled based on the TXT tests (Table 5, columns [18][19][20]. The analysis was conducted based on the results of the tests carried out at point 1+000.…”

“…The recommendation typically pertains to estimating settlements according to Equation (17). The constrained modulus M (M CPTU ) is determined using the method proposed by Mayne [26] according to Equation (18).…”