Characterization and recovery of gold and silver fromores of Zamora Chinchipe, Ecuador

Abstract

Artisanal and small-scale mining (ASM) in Ecuador primarily uses mercury amalgamation to recover gold. Its widespread use stems mainly from its ease of implementation, low operating costs, and minimal need for specialized equipment. The purpose of this research is the mineralogical characterization and recovery of gold and silver from ores in southern Ecuador using a combined application of centrifugal gravity concentration and flotation. The sulfide ore was characterized by optical microscopy, X-ray diffraction (XRD), and X-ray fluorescence (XRF), identifying free gold and gold associated with pyrite, sphalerite, and galena. Concentration was performed using a Falcon L40 concentrator, and flotation tests were conducted in Denver D12 cells. The overall combined recovery (gravity concentration 16,77 % + flotation 70,93 %) was 87,7 % Au and 57,82 % Ag, demonstrating the technical and environmental viability of the proposed process for small-scale mining.