Abstract
The Lindy Effect can be formulated as: the older the technology, the longer it is expected to last. In this paper, we examine the historical aspects of hydrometallurgy through the lens of the Lindy Effect, aiming to understand why research efforts by academic and industrial groups seldom result in new commercial hydrometallurgical processes. We argue that many researchers, particularly in academia, fail to recognize that mining and extractive metallurgy are economic activities. Companies engaged in mining, extraction, and refining of metals must generate profits to sustain their operations. The technical feasibility of a hydrometallurgical process does not inherently guarantee its economic viability. The industrial installations in a hydrometallurgical plant are highly capital-intensive. We will demonstrate that for the development of a robust hydrometallurgical process that could become Lindy-proof in the future, it is crucial to avoid fatal flaws arising from intrinsic problems with the chemical reactions behind the process. The concept of circular hydrometallurgy and its twelve principles provides a valuable framework for assessing the robustness of new hydrometallurgical processes. A paradigm shift in hydrometallurgy is anticipated with the widespread availability of inexpensive, renewable energy. High energy costs will no longer be a prohibitive factor, allowing the development of energy-intensive processes that offer significant chemical advantages. This shift may even lead to a reconsideration of older hydrometallurgical processes that were previously deemed too energy-intensive.