Provided herein is a method of treating and upgrading industrial furnace by-products, such as steelmaking slag and incinerator bottom ash (IBA) into valuable products, the method comprising the steps (a) providing the industrial furnace by-product, (b) subjecting the industrial furnace by-product to separation crushing to obtain crushed industrial furnace by-products, (c) subjecting the crushed industrial furnace by-products to one or more magnetic separation step(s) to separate magnetic and non-magnetic particles, and (d) optionally subjecting said non-magnetic particles to fine grinding to obtain fine grinded particles. The fine grinded particles can then be used to produce cement clinkers in kiln.

A method of manufacturing molten pig iron into an electrical smelting unit. The method includes the following successive steps: providing a directly reduced iron product, feeding the DRI product into the smelting unit, feeding together with the DRI product at least one steel or ironmaking by-product-based material including at least 10% in weight of slag forming agents, and melting the DRI product and the at least one steel or ironmaking by-product-based material to produce molten pig iron. A steel manufacturing method using the pig iron is also provided.

A method of manufacturing molten pig iron into an electrical smelting unit. The method includes the following successive steps: providing a directly reduced iron product, feeding the DRI product into the smelting unit, feeding together with the DRI product at least one steel or ironmaking by-product-based material including at least 10% in weight of slag forming agents, and melting the DRI product and the at least one steel or ironmaking by-product-based material to produce molten pig iron. A steel manufacturing method using the pig iron is also provided.

A process, for the selective heavy metal removal from iron- and/or steelmaking flue dust, including steps of: preparing a feedstock (FS) by blending or mixing a chloride precursor material (CPM) and ironmaking and/or steelmaking flue dust including heavy metals (ISFD), the heavy metals including Pb and Zn and optionally Cd; in a first reaction step in a first reactor reacting the CPM with the ISFD by thermal treatment of the FS at a temperature in a range of 700 C. to 950 C. removing at least 70 wt. % of Pb from the ISFD; in a subsequent second reaction step in a second reactor further reacting the CPM with the ISFD by thermal treatment of the feedstock FS at a temperature in a range of 850 C. to 1200 C.; and obtaining a solid material after the second reaction step. The invention also relates to a plant implementing the process.