As a type of metallurgical solid waste with a significant output, chromium-containing metallurgical dust and slag are gaining increasing attention. They mainly include stainless steel dust, stainless steel slag, ferrochrome dust, and ferrochrome slag, which contain significant amounts of valuable elements, such as chromium, iron, and zinc, as well as large amounts of toxic substances, such as hexavalent chromium. Achieving the harmless and resourceful comprehensive utilization of chromium-containing metallurgical dust and slag is of great significance to ensuring environmental safety and the sustainable development of resources. This paper outlines the physicochemical properties of stainless steel dust, stainless steel slag, ferrochrome dust, and ferrochrome slag. The current treatment technologies of chromium-containing metallurgical dust and slag by hydrometallurgy, the pyrometallurgical process, and the stabilization/solidification process are introduced. Moreover, the comprehensive utilization of resources of chromium-containing metallurgical dust and slag in the preparation processes of construction materials, glass ceramics, and refractories is elaborated. The aim of this paper is to provide guidance for exploring effective technology to solve the problem of chromium-containing metallurgical dust and slag.

With the continuous improvement of the quality of steel for social development, high-quality iron ore resources have been gradually depleted. Meanwhile, the scrap steel reserve and recycling volume are gradually increasing, which will result in the continuous increase of the residual tin content in steel, which seriously restricts the improvement of steel quality and the circulation-utilization of scrap. Therefore, it is necessary to remove as much tin as possible in the ferrous metallurgy process. However, tin in steel cannot be effectively removed in the conventional smelting process. In this paper, the origination, the existing forms, and the content control levels of the residual tin in steel are presented, as well as the current processes of tin removal in the ferrous metallurgy process.

Copper slag and stainless steel slag of Electric Arc Furnace (EAF) are two typical metallurgical solid wastes, which contain a large number of valuables, such as Fe, Cr, and Cu. The transition metal elements in the waste slags, such as Cr and Fe, can be recycled as the coloring ions in the black ceramic tile. In this study, the Fe/Cr molar ratio in the raw materials of copper slag and stainless steel slag was adjusted, and the black ceramic tile was subsequently prepared by sintering. The results show that the optimum process parameters for the preparation of black ceramic tiles are the Fe/Cr molar ratio of 2.0, the sintering temperature of 1150 °C, and the sintering time of 30 min. The compressive strength of the black ceramic tile at optimum sintering conditions exceeds the minimum compressive strength of the Chinese national standard for standard polished tiles, and the concentrations of harmful elements, for example, Cr, Cu, Ni, As, Zn, Pb, and Cr(VI) are within the regulation thresholds specified by the Chinese national standard.

According to the coexistence theory of slag structure, a calculation model for the activity of FeO in the quaternary system SiO₂-CaO-Al₂O₃-FeO of depleted copper slag was established. The model was used to calculate and analyze the effects of temperature (T), basicity (B), and Al₂O₃ content on the activity of FeO (N_FeO). The results show that temperature has little impact on N_FeO. With increased basicity, N_FeO first increased slightly, then increased sharply, and finally decreased. It is easier for CaO to combine with SiO₂ than FeO to form calcium silicate, which replaces FeO in 2FeO·SiO₂ and increases N_FeO. However, when basicity is higher than 2.0, CaO not only reacts with SiO₂, but also combines with FeO to form calcium ferrate compounds to decrease N_FeO. In addition, the activity of FeO decreases with increased Al₂O₃ content because of the reaction between CaO and Al₂O₃. The results can be used as a theoretical basis to guide the carbothermal reduction process of copper slag.

Oxide particles are considered to be one of the reasons for the stability of cellular porous Al foam. Thus, the contact angle ( ө ) of molten pure aluminum on oxide substrates, including Al ₂ O ₃ , CaO·2Al ₂ O ₃ (CA2), CaO·6Al ₂ O ₃ (CA6), mullite (3Al ₂ O ₃ ·2SiO ₂ ), and SiO ₂ was measured in a vacuum heating microscope at a temperature of 950°C to determine the value of wettability of molten aluminum on various oxides. Thereafter, the measured contact angles followed the tendency as mullite (155°) > CA6 (152°) > MgAl ₂ O ₄ (151°) > Al ₂ O ₃ (149°) > SiO ₂ (124°) > CA2 (100°). Furthermore, the cross‐sectional area between molten aluminum and substrates was thoroughly analyzed, and the reaction products, such as the Al ₂ O ₃ layer at the interface, have been detected. Thermo‐Calc, with the combination of available databases, was used to perform thermodynamic simulations and to discuss and predict possible reactions under the current experimental conditions.