Proceedings of the International scientific and practical conference ―Advances in Science and Humanity‖ (March 29-31, 2026) / Publisher website: www.naukainfo.com. – Vienna, Austria, 2026. - 176 p.

32 conservation time is a factor determining hydraulic activity, and the glass phase content depends on the temperature of the slag discharge [12]. The chemical composition significantly affects the latent hydraulic activity of dump blast furnace slag. Optimum hydraulic activity was recorded with the following composition of slag 47CaO: 20Al2O3: 33SiO2 [13]. The reactivity of blast furnace slag depends on the chemical and particle size distribution, glass phase content, heat of hydration, and microstructure development [14]. The hydraulic activity of blast furnace slag can be increased upon activation in several ways [15]: in a strongly alkaline medium with pH> 1 or at pH=11.8–12.2 with the addition of calcium hydroxide and its soluble salts – chloride, bromide, nitrate, formate and acetate. The presence of hydraulic activity of slags formed the basis for the development of methods for producing slag-alkali binders based on them [16]. Metallurgical slags contain impurities that can be toxic and pose an environmental hazard. So, in the composition of dump blast furnace slag, the following elements were detected, mg/kg: Ba – 611, Pb – 8 [17]; secondary and microelements: As, Au, Ba, Ce, Co, Cr, Cu, Fe, Hf, La, Mn, Mo, Rb, Sb, Sc, Sm, V, W, and Zn [18]; S, P, Mn, Cr, Sr, Zn, Ba, Ti [19]. No correlation was found between the mineral composition, the crystalline fraction of the substance, the structure of blast furnace and steel slag, and the concentration of impurity elements [20]. In the blast furnace slags Nb concentrations vary widely, but do not exceed 15 mg/kg, Ta concentration is <1 mg/kg, Sc <17 mg/kg, Y is about 30 mg/kg. Besides, rare earth elements were detected in concentrations of 0.5‒ 36.6 mg/kg [20]. The number of elements released into the environment does not always correspond to the volumetric chemical composition of the slags. Leaching metal impurities from blast furnace slags is less intense than from non-ferrous metallurgy slags resulting from the formation of an alkaline medium in them [21]. Metals Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, V, and Zn were leached from steel slag. Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn showed less leachability. Toxic metals As, Cd, Se, and V were not leached using leaching and toxicity tests [22]. Most metals are firmly bound to