Funct. Mater. 2024; 31 (3): 432-441.

The sorption properties of metallurgical slag from the following enterprises were determined: Pobuzhsky Ferronickel Plant (PFNP), PJSC Nikopol Ferroalloy Plant (NFP) and blast furnace slag from PJSC ArcelorMittal Kryvyi Rih. The slag from PFNP (production of FeNi alloys) and NFP (production of FeSiMn) contain mineral diopside CaSiO₃.MgSiO₃, and NFР slag additionally contains titanite Ca(Ti_0.818Al_0.182))(O_0.818F_0.182)(SiO₄). The minerals okermanite 2CaO·MgO·2SiO₂, rankinite 3CaO·2SiO₂ and microcline КAlSi₃O₈, oldhamite CaS and calcite CaCO3 were identified in the composition of granular slag from ArcelorMittal. Some phases are in an amorphous sorption-active state. The possibility of chemical activation of slags with water, alkali and acid solutions for 1 day was shown; as a result, the slag surface area increases, hydroxyl and silanol groups form and dissociate with the formation of a negative surface charge, which is typical for Ca and Mg aluminosilicates. The most appropriate acid activation is in 0.5 M H₂SO₄ at 20 °C. It has been shown that adsorption is determined not only by the degree of loosening and charge of the slag surface, but also by the nature of organic dyes as sorbates. Dyes cationic forms are sorbed more efficiently. The nature of the interaction of slag adsorbents and organic compounds indicates the occurrence of specific, irreversible activated adsorption.