Editorial for Special Issue “Risk Assessment, Management and Control of Mining Contamination”

The exploitation of mineral resources around the world has always been a matter of controversy among governments, production companies, and organized society, giving rise particularly to conflicts about environmental matters. Among this, the effects of mining wastes and their possible risks for the ecosystem and population health receive concentrated attention and, in many cases, stop mining work or prevent others from starting. These issues have led science to find tools for assessing and controlling the impacts of mining. In this respect, researchers are trying to find solutions for decreasing potential risks resulting from mining wastes, reducing their volume to gain space, and recovering the elements of value, which represent environmental and economic benefits.

This Special Issue consists of seven papers providing examples of the efforts made in various countries to mitigate the impacts of mining wastes on the ecosystem and population health. Since arsenic is one of the most toxic metalloids, it is necessary to remove it or immobilize it as a precipitate. One of the strategies for solving this problem is using mineral bio-oxidation. Barahona et al. [1] show that Acidithiobacillus ferrivorans can be used for immobilizing arsenic from minerals rich in this metal, as an alternative for conventional processes that currently use high temperatures. Leiva et al. [2] treated solutions from zinc concentrate leaching to precipitate Fe, minimizing zinc loss, reducing the amount of waste precipitated during mining processes and obtaining solutions with iron content appropriate for electro-winning. To do this, they assessed six reactants for iron precipitation: CaO, Ca(OH)₂, Na₂CO₃, CaCO₃, NaOH, and MgO; they selected Ca(OH)₂ because it is the reagent recommended for zinc yield recovery, electrowinning efficiency, and iron precipitate filtration rate. Beltrá et al. [3] propose using different types and combinations of amendments for improving the soil fertility and favoring plant growth in a mining waste phytostabilization process. Zhang et al. [4] investigated health risks from soil contaminated by cadmium from a Chinese coal chemical plant and determined the safety threshold of this metal. Wei et al. [5] measured the effects of slurry concentration, binder content, and fly ash addition on the slump, slump flow, mortar consistency, layering degree, and bleeding rate when using a fly ash–waste rock mixed-backfilling slurry. Barral et al. [6] report the hydrogeological and hydrochemical characterization of a lake formed by Reocin’s old zinc mine and assess the potential use of the water stored in it. Finally, Bebandić et al. [7] focus on the mineralogical and geochemical characterization of the material within zinc and lead metallurgical wastes and assess the potential recovery of critical raw materials.

The papers in this Special Issue provide examples of opportunities for mining companies currently generating wastes or those engaged in closing plans to help fulfill their social responsibility. These papers also suggest that intervention of historical waste may generate important economic returns. These papers provide theoretical and practical evidence of how remediation or mitigation measures may contribute to reducing the risks from mining wastes for the population and ecosystems. The studies in this issue demonstrate opportunities for new researchers to further study this issue and, thus, contribute to the reduction of mining wastes and the mitigation of their harmful effects.

The co-editors of this Special Issue believe that a new look must be given to environmental mining liabilities as a potential source of resources and to generating new technologies that contribute to sustainable mining. Social and environmental aspects must be an essential part of new business ventures. Future generations have the right to the environmental, economic, and social resources necessary for a healthy and productive life.