Tailings Subaerial and Subaqueous Deposition and Beach Slope Modeling

Abstract

The tailings beach slope is a fundamental parameter for the design and operation of tailings storage facilities because it affects the tailings storage capacity, pond levels, and phreatic surfaces within the containment structures. Understanding tailings beach development is particularly important for thickened and paste tailings facilities, where the tailings can form a self-stacking structure. This paper presents a theoretical tailings deposition model that can describe the formation of tailings beach slopes in both subaerial and subaqueous deposition environments. The depositional behavior and deposition mechanisms are investigated from both geotechnical and hydraulic engineering perspectives. The model is developed to capture deposition mechanisms based on the principles of soil mechanics and fluid mechanics. The governing differential equations can be solved using a numerical technique, and the solution scheme can readily be implemented in computer languages. Case studies for subaerial deposition demonstrate that the modeling results are in agreement with laboratory flume testing and field measurements. The proposed model considers geotechnical and rheological properties of tailings, water pressures, operation parameters, and site topographic conditions. A sensitivity study was carried out to provide insight into the effects of influencing factors on the beach slope.