Resource utilization strategy of Fe-bearing smelting slag in China: A review

In China’s rapid development, the metallurgy industry plays a pivotal role. However, the processing and utilization of iron ore results in the production of a significant amount of iron-bearing smelting slags. Iron-bearing smelting slags contains iron, zinc, copper, calcium, potassium, and other metal elements. Challenges in processing technology and cost control in smelting enterprises contribute to the slag stockpile issue, leading to significant pollution of the surrounding environment and groundwater resources, and resulting in the underutilization of metal resources in iron-bearing smelting slags. This paper identifies the sources and hazards of iron-bearing smelting slag, delves into resourceful strategies for its comprehensive utilization, such as metal recycling technology and new building materials, summarizes various treatment processes, and employs reaction thermodynamics software to calculate the Gibbs free energy (ΔG^θ) of potential chemical reactions in the slag. This analysis helps elucidate the evolution of iron-bearing phases. Additionally, it examines the role of additives (CaO) in the reduction process of non-ferrous smelting slags and seeks to uncover the factors limiting their industrial application.