Investigation of Pre-concentration of the Lece Ore Using Dense Medium Gravity Concentration

Abstract

The pre-concentration of Pb–Zn ores is commonly performed using gravity concentration in a dense medium. The primary objective of this process is to remove coarse-grained gangue from fully crushed ore using a cost-effective method, while keeping the loss of valuable metals within acceptable limits—comparable to or lower than those observed in flotation processes.

Laboratory tests on ore from the Lece deposit indicate that gravity concentration in a dense medium can successfully remove over 60% of coarse-grained gangue from fully crushed ore. From a process applicability standpoint, this represents a promising result. However, the associated losses of valuable metals—particularly gold and silver—are substantial, reaching approximately 50%. Gold is the most valuable component in the Lece ore. Therefore, pre-concentration at the final crushing stage is not considered feasible at industrial scale.