Abstract

ZAMORA E, Gerardo; BLANCO VINO, Walter  and  HINOJOSA CARRASCO, Octavio. Circular economy in mining: waste processing as an environmental remediation alternative  . REV. MAMYM [online]. 2019, vol.4, n.2, pp.3-18. ISSN 2519-5352.

Abstract Currently, many mining operations, within the framework of the linear economy, have generated large volumes of waste or sterile with low contents of the metals of economic interest from the exploited mining deposits either open pit or underground. In the context of the circular economy, storage sites for rock acid drainage generators can be metallurgically treated, with the purpose of recovering said metals of economic interest by hydrometallurgical processes, as an alternative to the environmental closure of themselves; trying also that, the tailings generated in these processes, be reused in the closing of the same, allowing a clear economic, social and environmental benefit for the mining industry. In this context, the present research paper presents a study of the alternatives of treatment of samples of dismantling of Pb-Ag-Zn complexes by: Direct cyanurant leaching by agitation; pretreatment in acidic medium and in the presence of H2O2 as oxidizing agent, and after washing and neutralization, the respective cyanidation of the residues; and finally, the retreatment thereof by aqueous oxidation in relatively acidic medium and presence of H2O2 as oxidizing agent and NaCl as complexing agent; all of them with the objective of obtaining the greatest extractions of Ag in the leaching, but also, obtaining the lowest sulfur contents in the tailings either for its disposal without environmental measures and / or its use as dry coverings in the closing stage of the same. Samples of clearings with different sulphide contents, which vary between 1.0 to 3.4% of Total Sulfur, and with concentrations between 68 to 53 g / t of Ag, were subjected to normal conditions of cyanidation by agitation, obtaining extractions that varied between 74 % to 31%, respectively. However, after the acid-oxidant pretreatment, the extractions at the later stage of cyanidation rose from 81% to 63%, respectively. Finally, by acid-chlorurant leaching, extractions of between 58 and 98%, respectively, were achieved; also obtaining, for samples with average sulphide contents, non-DAR tails; which, based on their geotechnical characterization, are also "suitable for use in the form of dry coverings" in the environmental closure stage.

Keywords : Circular Economy in Mining; Retreatment; - Cyanuration of waste; Hydrometallurgical pretreatment of waste; Cyanuration of clearings; Chlorident leaching.

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