The paper presents an analysis of the desiccation process in mining materials, based on physical laws. Due to the process complexity, most of the previous approaches used have an empirical basis. In this case, however, a formulation using coupled hydromechanical equations has been considered. To show the capabilities of the theoretical framework, several laboratory tests were performed, and afterwards a numerical simulation of the measured variables was attempted. The material tested was a metallurgical waste in tailings form and it was exposed to atmospheric desiccation. Further cracking will eventually change its properties, and this may have an environmental impact. Some of the experiments were devoted to material characterization, including the water retention curve, the hydraulic conductivity, and the tensile strength. In addition, laboratory drying tests open to the atmosphere or in hermetically closed containers were also performed. The numerical analyses carried out attempted to simulate some of these tests. One of the main outcomes of the analyses was the prediction of the time and the location of crack initiation. Finally, it should be pointed out that good agreement between the experiments and numerical simulations indicates that the formulation is taking into account the fundamental mechanisms involved in the desiccation process.Key words: desiccation, drying cracks, unsaturated soils, waste material, coupled phenomena, modelling.

Mine tailing storage represents an important environmental issue. The generation and dispersal of dust from mine tailings can contaminate air and surrounding soils. In addition, metals and soluble salts present in these wastes could pollute groundwater and surface water. The recovery of metals from mine tailings can contribute to minimize the environmental risk and to achieve a circular economy model. The main objective of the present work is to study the use of two carbon-based materials, a commercial activated carbon (AC) and a commercial charcoal (VC) in the leaching of zinc and copper from low-grade tailing waste. Experimental results obtained show that it is possible to achieve the recovery of more than 87 wt% of Zn after 6 h of leaching with different sulfuric acid solutions. The addition of carbon-based materials increases the extraction of Zn at high sulfuric acid concentrations (1 M) from 89% to 99%. The addition of VC significantly increases the extraction of Cu in leaching solution with high sulfuric acid concentration (1 M), from 41 to 61%. Future research will be necessary to optimize the properties of carbon-based materials and their recovery after leaching experiments in order to assess their potential for industrial application.