Reclasificación de blocks cubicados en la estimación de recursos, basado en la identificación del cobre secundario

Abstract

The present research aimed to reclassify the block model in the resource estimation of the Huanzalá deposit, distinguishing between primary and secondary copper, in order to improve ore characterization, optimize copper (Cu) recovery processes, and evaluate the economic impact derived from the new mineralogical classification. Additionally, the study sought to determine the influence of mineralization type on the selection of processing methods and estimate the potential reduction of operating costs associated with copper recovery. The applied methodology was based on a traditional geometric block modeling approach, supported by the calculation of areas, volumes, densities, and weighted grades, using data from drill holes, sampling, and chemical analyses. The data were processed and re-estimated using AutoCAD, incorporating mineralogical reclassification criteria that allowed for the identification of primary and secondary copper domains. The results showed that secondary copper is directly associated with the main fault structure and the hydrothermal alteration known as shiroji, confirming the presence of a supergene enrichment process subsequent to the primary mineralization, in which copper was redistributed and concentrated in fractured and permeable zones. This condition generated a marked mineralogical and metallurgical heterogeneity, where primary copper, mainly as chalcopyrite, coexists with secondary minerals such as chalcocite, covellite, malachite, and chrysocolla, affecting local grades and metallurgical recovery efficiency. The block reclassification improved the accuracy of the resource model, optimized the economic estimation, and defined differentiated processing strategies. Finally, it was determined that applying a proper process for secondary copper could increase recovery by approximately 25%, equivalent to an economic gain of about USD 2.1 million, demonstrating the technical and financial impact of this re-evaluation.