Mineral carbonation of iron and steel by-products: State-of-the-art techniques and economic, environmental, and health implications

The escalating global warming has intensified concerns about climate change and prompted a swift shift towards worldwide carbon neutrality and a sustainable future. Among various carbon capture, utilization, and storage technologies, mineral carbonation enables the transformation of waste materials into valuable construction resources while mitigating their adverse impacts on the environment and public health. During the past two decades, mineral carbonation has found widespread application in carbon sequestration, primarily employing industrial by-products, notably those generated within the iron and steel sector. The inherent properties of these by-products, characterized by alkalinity, reactivity for carbonation, widespread availability, and substantial quantities, hold great potential for carbon mitigation. Developing efficient and resilient carbon sequestration protocols utilizing iron and steel by-products is vital, as it addresses key challenges associated with mineral carbonation, such as high costs, slow reaction kinetics, and environmentally detrimental feedstock mining. In this review paper, various carbonation techniques for iron and steel by-products are evaluated and summarized. Different stages of essential carbonation processes are examined, along with their detailed physicochemical mechanisms. The review also explores recent technological advancements in this field, including the utilization of additives, supercritical carbonation, microwave irradiation, and ultrasonic enhancement, while assessing their potential to enhance process efficiency and sustainability. Additionally, the paper critically assesses representative processes from economic, environmental, and health perspectives. By providing an in-depth discussion of scalability, industrial implementations, economic feasibility, environmental toxicity, health impacts, and current technical barriers, this paper presents a comprehensive summary that addresses challenges, opportunities, prospects, and key insights in the field of mineral carbonation using iron and steel by-products. This effort represents a unique contribution to fill critical knowledge gaps in the mineral carbonation of iron and steel by-products, encompassing state-of-the-art technical advances and addressing their economic, environmental, and health implications.