Kinetics and mechanism of heavy metal leaching from copper slag under conditions of acid fallout

The study aimed to find regular patterns in migration of metals and in kinetics of metal leaching from copper slug under conditions conformable with natural operation and storage settlings. Emphasis was laid on the influence exerted by medium pH, temperature and particle size on the velocity and amount of metal passing into solution. The subject of study was copper slag samples after size classification. The systematic modeling tests of leaching in aqueous solutions with fixed pH and temperature were performed. The study involved the analysis of dissolution dynamics of basic minerals (fayalite, willemite, metallic sulphides) and influence of particle sizes on leaching efficiency. The results show that the value of pH takes a decisive part in the leaching process. At low pH (4.3), the concentration of metals in solution essentially increased. The size of particles directly influenced the leaching velocities. Fine fractions demonstrated higher indices of leaching, which was governed by a large surface of contact with the aggressive medium. It is shown that the leaching process has two distinct stages: fast migration of metals because of the presence of surface contamination and minerals of high-rate solubility; formation of protective films which prevent the further loss of metals. The energy consumption and dissolution degree of the main components of copper slag were assessed, which made it possible to optimize the experimentation conditions and interpretation of the obtained kinetic data. The thermodynamics of reactions in leaching of the main components of copper slag is analyzed, and the causes of variation in concentration of metals depending on the experimentation conditions are revealed. 

Shabanov M. V., Marichev M. S., Strekelev G. B., Popov Yu. V., Sokolova S. A. Kinetics and mechanism of heavy metal leaching from copper slag under conditions of acid fallout. MIAB. Mining Inf. Anal. Bull. 2026;(6):83-97. [In Russ]. DOI: 10.25018/0236_1493_2026_6_0_83.

The study was supported by the Russian Science Foundation, Grant No. 25-77-00021, https://rscf.ru/project/25-77-00021/, at the Saint-Petersburg State Agrarian University. 

M.V. Shabanov¹, Cand. Sci. (Agr.), Assistant Professor, Assistant Professor, e-mail: geohim.spb@gmail.com, Scopus Author ID: 35171489500, ORCID ID: 0000-0003-4725-3673,
M.S. Marichev¹, Cand. Sci. (Biol.), Head of Laboratory, e-mail: m.s.marichev@yandex.ru, Scopus Author ID: 57216298057, ORCID ID: 0000-0003-0429-2234,
G.B. Strekelev¹, Graduate Student, e-mail: strekulev@gmail.com, OIU-3902-2025, ORCID ID: 0009-0000-8265-243X,
Yu.V. Popov, Cand. Sci. (Geol. Mineral.), Assistant Professor, Deputy Director for Research and Innovation, Institute of Earth Sciences of the Southern Federal University; Head of Center for Research on Mineral Resources and Environment, 344006, Rostov-on-Don, Russia, e-mail: popov@sfedu.ru, ORCID ID: 0000-0002-0216-5998,
S.A. Sokolova, Laboratory Researcher, Southern Federal University, Academy of Biology and Medicine, 344090, Rostov-on-Don, Russia, e-mail: sosoko@sfedu.ru, ORCID ID: 0009-0002-4014-0887,
¹ Saint Petersburg State Agrarian University, Pushkin, Russia.

M.S. Marichev, e-mail: m.s.marichev@yandex.ru.

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