Por: Miguel A. Quispe, jefe de Metalurgia, y Miguel A. Gonzalez, gerente de Procesos, Pan American Silver – Mina Shahuindo.

Abstract

The Shahuindo mine is owned by the Canadian corporation Pan American Silver and extracts gold and silver. It is considered one of the most outstanding mining units in Peru in terms of safety, environmental protection and production. The mine process is carried out through different stages, including pad leaching (ROM), Adsorption, Desorption and Regeneration (ADR) and refining. It currently processes 36,000 tpd. Over the past three years, the mine has averaged annual production of 146 Koz of gold and 218 Koz of silver.

This paper presents the methodology used to improve the operation within the main pad, with the aim of addressing the problems presented by the increase in fines present in the ore fed to the pad.

This methodology contemplates a progressive increase in ore blending, improved cell removal, a decrease in the height of the lifts from 8 to 6 meters, increased metallurgical tests (granulometric, compaction - permeability and column leaching), better quality control of the percentage of fines, and a mineralogical characterization with a special focus on clays where, as will be seen below, illite predominates in a large proportion of the ore, as well as containing kaolinite and, in some samples, pyrophyllite.

Finally, the results obtained so far regarding the decrease in waterlogging, the increase in irrigation rates and thus the increase in gold recovery will be presented.