Estudio de concentración gravimétrica natural y centrifuga de minerales auríferos aluviales. Experimentación y simulación : Determinación del tiempo óptimo de operación y simulación del caudal de fluidización del concentrador centrífugo Knelson.

Abstract

The Nambija mining district has employed mercury amalgamation to recover gold, with a maximum yield of 50%, which leaves a significant proportion of gold in the ore gangue, later discarded in nearby alluvial bodies. To improve recovery efficiency, it is proposed to implement a Knelson centrifugal concentration system, motivated by the increased gold content in sediments from a biofiltration system. The study focuses on analyzing the impact of operational variables such as time and liquid level on the concentration system. Various techniques were used to characterize the sediments, such as fire assay and X-ray diffraction, and grinding was performed to liberate the contained gold, determining the optimum particle size for concentration. During the experimentation, 40% solids were maintained in the feed and the speed of the cone concentrator was adjusted to ensure adequate centrifugal force on the gold particles. Tailings samples were collected to analyze the efficiency of the process over the operating time. The results showed that the liquid level in the storage tank hardly affected the fluidization flow rate, and a heterogeneous distribution of gold in particles smaller than 600 µm was observed in the sediments. An optimum operating time was determined to be between 3 and 7 minutes, indicating the feasibility of the Knelson system to improve gold recovery at Nambija with precise adjustments in the operating variables.