Resource Efficiency Evaluation of Pyrometallurgical Solutions to Minimize Iron-Rich Residues in the Roast-Leach-Electrowinning Process

摘要

The Roast-Leach-Electrowinning process generates considerable quantities of iron-rich precipitates that must be landfilled, potentially causing a problem for the zinc smelters as well as negatively affecting the society and the environment. The integration of pyrometallurgical flowsheets into existing Roast-Leach-Electrowinning plants is evaluated in this paper. Ten different cases, including Direct Zinc Smelting, ferrite fuming or pyrometallurgical treatment of iron-rich residue, are assessed to find the most resource efficient and environmentally friendly solution to minimize the hydrometallurgical precipitates of the electrolytic process for the zinc production. The simulation-based methodology used provides indicators to evaluate the material recovery and losses, residue production, resource consumption, exergy destruction, and environmental impacts, which are used to find the best alternative that improves the resource efficiency and the environmental impact of the Roast-Leach-Electrowinning process. Furthermore, the social, environmental, and economic impacts associated to the different alternatives are discussed based on the indicators provided by the simulation.