Over the past two decades, risk management in the mining sector has advanced significantly, increasingly prioritizing sustainable practices throughout the lifecycle of mining operations. A key component of this shift is the recovery of valuable materials from mining and mineral processing tailings, particularly critical and secondary raw materials, through the application of advanced reprocessing technologies. This review provides a comprehensive analysis of recent developments in tailings reprocessing, with a focus on leaching, and innovative hydrometallurgical techniques. Drawing on case studies from copper, silver, tungsten, antimony, and gold mining industries, the review highlights the potential for secondary resource recovery in response to rising global demand for critical metals such as rare earth elements, lithium, cobalt, and nickel, which are essential for clean energy and modern technologies. It also discusses the challenges and limitations associated with current recovery practices and outlines future trends aimed at improving metal extraction efficiency, while mitigating environmental impacts. The integration of circular economy principles into tailings management not only enhances resource efficiency but also supports decarbonization, strengthens supply chains, and contributes to the achievement of sustainable development goals. Ultimately, the transition to sustainable waste management and critical metal recovery is essential for minimizing environmental risks and promoting long-term economic and ecological resilience in the mining sector. Graphical Abstract

Nickel (Ni) and cobalt (Co) are strategic metals that have found applications in a wide range of metallurgical and industrial uses. In this study, the dissolution of a mixed nickel–cobalt hydroxide precipitate using organic acids (citric, oxalic, and malic acid) was investigated. Citric acid was found to be the best leaching agent yielding the following dissolution rates: 91.2% Ni, 86.8% Co, and 90.8% Mn. Oxalic acid resulted in low dissolution, which is likely due to the formation of insoluble metal oxalates. The impact of acid concentration, leaching time, and temperature on metal dissolution was systematically examined. The optimal dissolution conditions were identified as 0.5 M citric acid at 30 °C for 30 min, utilizing a 1/20 solid/liquid ratio and a stirring speed of 400 revolutions per minute (rpm). The attempt to use oxidants, such as potassium permanganate (KMnO₄) and hydrogen peroxide (H₂O₂), to achieve selective dissolution in an organic acid environment was not successful, which was different from that in the sulfuric acid case. As for the leaching kinetics in the organic acids, it seems that the leaching of Ni correlates with the Shrinking Core Model, specifically regarding porous-layer diffusion control. Based on the experimental results, the activation energy for the leaching of Ni was estimated to be 3.1 kJ/mol.