Abstract
Iron tailings are among the largest industrial solid wastes in China, making their high-value utilization essential for sustainable resource management. This study evaluates the environmental and economic performance of an integrated recovery process for the comprehensive utilization of iron tailings, in which high-purity quartz sand, feldspar, and iron concentrate are simultaneously recovered. The system includes fine grinding, high-intensity magnetic separation, flotation, roasting, acid leaching, and wastewater treatment, with 1 ton of iron tailings selected as the functional unit. The LCA results indicate that primary energy demand (PED), water use (WU), global warming potential (GWP), and acidification potential (AP) represent the major environmental burdens, with characterization results of 2.72E+03 MJ, 4.76E+03 kg, 1.56E+02 kg CO2 eq, and 6.18E-01 kg SO2 eq, respectively. Hydrochloric acid and electricity were the major environmental hotspots, while tap water, oxalic acid, quicklime, and flotation reagents also contributed substantially to specific impact categories. The leaching stage was the dominant contributor to most environmental impacts. Sensitivity analysis identified electricity, hydrochloric acid, tap water, oxalic acid, and water-treatment chemicals as key parameters. The economic assessment showed that operating costs dominated the annual cost structure, with raw materials and utilities accounting for the largest shares. LCC sensitivity analysis identified flotation reagents, leaching acid, and electricity as the major cost drivers, while NPV was highly sensitive to the price of high-purity quartz sand. Overall, the integrated process shows potential for high-value iron-tailings utilization, while its economic performance remains sensitive to product prices and operating costs, providing a basis for process optimization.