Insights into the design of polymetallic ore flotation circuits, including tailing desulfurization

Abstract

Flotation is a main mineral concentration technology, which is why the design of flotation circuits has been extensively studied in the literature. However, studies on flotation circuit designs for polymetallic ores have rarely been reported in the literature. On the other hand, sulfide mineral flotation tailings are potential generators of acid mine drainage (AMD), which is one of their main environmental drawbacks. Although there are several strategies to prevent and control AMD, the most proactive attitude is to generate tailings without sulfur species. This paper investigates the circuit design of polymetallic ores, including desulfurization within the flotation process. Three types of circuit designs are analyzed: fractional flotation with the generation of a bulk concentrate and its subsequent separation, fractional flotation using selective flotation, and integrated flotation with combined bulk and selective flotation. Various aspects are analyzed, such as the effect of stage recovery uncertainty on the design; the impact of the design type on costs, energy use, and environmental effects; and the influence of the design strategy applied. Additionally, the design of a Cu–Ni plant that includes desulfurization is employed to deepen the research. The results show that it is useful to design these separation systems holistically to obtain more efficient designs. It is also concluded that the most traditional way of processing polymetallic ores consumes more energy, water, and materials, resulting in a more significant environmental impact. Finally, based on these results, a methodology for designing these complex systems is outlined.