Iron Oxide Ore Mineralogy and Its Plant Flotation Circuits Nodal Analysis Simulation and Comparison

Mining operations usually provide ore of varying characteristics. At the Donganshan Sintering Plant, the ore is a low-grade, complex, hard-to-separate carbonate containing iron ore, and a two-step flotation circuit was previously developed to overcome the negative impact of the carbonates on the reverse flotation process. However, with the further expansion in the mining operations, it was difficult to maintain a highly efficient flotation process. Thus, the mineral liberation analyzer (MLA) was utilized to conduct an in-depth process mineralogy investigation. MLA showed that the main useful minerals in this ore are magnetite/hematite of 45% total iron, and the main gangue mineral is quartz of 29.97%, followed by 2.55% chlorite and 1.48% ankerite with about 0.03% siderite. Accordingly, flotation circuit modification was mandatory by eliminating the direct flotation process used prior to reverse flotation. Therefore, two-step and reverse flotation circuits were balanced using nodal simulation, and the two circuits produced 48.91% and 49.45% yield, 65.03% and 65.22% total iron grade, and 70.96% and 72.08% total iron recovery, respectively. Thus, reverse flotation is comparable with two-step flotation by 0.54%, 0.19%, and 1.12% higher yield, grade, and recovery, respectively. In addition, the process flow sheet was not only simplified but it also enhanced the performance with reduced reagent consumption.

Automated summary

This study conducted a detailed analysis of ore using a mineral liberation analyzer (MLA), which revealed that the main useful minerals in the ore are magnetite/hematite and the main gangue mineral is quartz. The study then modified the flotation circuit and found that reverse flotation outperforms two-step flotation, leading to a simplified and improved process flow sheet.