Recovery of Value-Added Materials from Iron Ore Waste and Steel Processing Slags with Zero-Waste Approach and Life Cycle Assessment

A large amount of waste such as mine tailings, sludge, dust and slag is generated as a waste material or by-product from the iron and steel industries. The recovery of the valuable components, and their transformation into valuable products and the subsequent processing and utilization of these waste in construction material manufacturing can mitigate the high environmental risk related to storage, prevent landfill waste, reduce CO2 emissions and help preserve natural resources. The blast-furnace slags, basic-oxygen furnace steel slags and magnesium slags are used, or are under investigation for potential applications, in cements, and both copper and nickel slags can be utilized with cements as pozzolanic materials. Carbonation of alkaline iron ore and steel making slags is a promising technology for carbon capture and storage as a CO2 mitigation strategy in the context of climate change. To maximize the economic and environmental benefits, it is important to find out innovations and sustainable ways of carbonation and recycling of mining wastes.