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.

34 Table 1 Results of electron probe microanalysis of Zaporizhstal dump waste blast furnace slag fractions Element mass fraction, % Blast furnace slag fraction, mm < 0.63 2.5–5 > 20 Si 10.42 10.80 8.69 Ca 30.81 25.67 28.53 Al 1.65 1.87 1.10 Fe 0.92 0.66 0.18 S 2.12 2.04 2.64 Mg 0.84 0.97 0.72 K 0.53 0.57 0.33 Na 0.33 0.38 – Cu 0.50 – – Ti 0.17 0.18 0.10 Cl – – 0.08 O 51.70 51.69 57.63 The results of the microroentgen analysis of slag fractions clearly correlate with the results of the X-ray and phase analysis [26]. The chemical elements: K, Na, S, Cl, Cu and Ti, that are not part of the minerals, are registered with a scanning electron microscope; it enables us to suggest that mineral particle surfaces sorb them. For example, the maximum content of K, Na and Ti is characteristic of the fraction 2.5–5 mm. Zaporizhstal slag contains minor amount (< 1 %) of the compounds of the metals Fe, Ti and Cu (table 1), which belong to the third class of a substance hazard. However, it does not prevent slag from further utilization. A hazard class of Zaporizhstal dump waste blast furnace slag . In order to quantitatively estimate the impact of dump waste slag on the environment, the method to assess the hazard class of industrial wastes is used, taking into consideration a toxicity index [27]. Calculations indicate that a toxicity index varies within a range of 4.3–5.4; it is hazard class III (moderately hazardous wastes), i. e. Zaporizhstal dump waste blast furnace slag can be used as secondary raw materials in construction engineering.