Siberian Federal University

Issue

Journal of Siberian Federal University. Engineering & Technologies. 2025 18 (2)

Authors

Borodin, Andrey D.; Krupnov, Leonid V.; Vaniukova, Natalia D.; Velichko, Vladimir V.

Contact information

Borodin, Andrey D. : Fedorovsky Polar State University Norilsk, Russian Federation; andrey9607@yandex.ru; Krupnov, Leonid V. : Fedorovsky Polar State University Norilsk, Russian Federation; Vaniukova, Natalia D. : Fedorovsky Polar State University Norilsk, Russian Federation; Velichko, Vladimir V.: ZF of PJSC MMC Norilsk Nickel Norilsk, Russian Federation

Keywords

fire refining; anode copper; casting; mold; non-stick coatings; carbon; chamotte mortar; synthetic anhydrite; neutralization of sulfuric acid; dihydrate gypsum; calcined anhydrite

Abstract

The article is a continuation of the research conducted [1] and reveals the features of the structure and chemical composition of copper anodes obtained in laboratory conditions. Natural and synthetic calcined anhydrite were used as a replacement for chamotte mortar when casting copper anodes in an amount of 50 %. A batch of natural anhydrite was delivered from the “Anhydrite” batch and the –0.071 mm fraction was screened out, then used to prepare a non-stick coating. Synthetic anhydrite was obtained by neutralizing limestone pulp from the “Mokulaevsky” quarry with strong sulfuric acid and subsequent filtration, drying and calcination of dihydrate gypsum. To cast anodes with these materials, a coating thickness of 0.1 mm on the mold was used due to the fact that acceptable results for gas saturation and impurity production were obtained in previous experiments. Two experiments were performed: 1 – a mixture of natural anhydrite and fireclay mortar in a 50/50 ratio; 2 – a mixture of calcined anhydrite and fireclay mortar in a 50/50 ratio. Four copper samples were obtained for each experiment. The composition of the cast anodes was determined by micro- X-ray spectral analysis using a Tescan TIMA 3 scanning electron microscope with an Oxford X-Act integrated microanalysis system. The composition of the powder components was determined using a Rigaku MiniFlex diffractometer. The obtained results indicate the possibility of using synthetic and natural anhydrite in the process of casting anode copper. Two key areas of anode copper castings were studied in detail – the boundary layer between the anode body and the mold and the body itself, as a result of which it was determined that the bulk of impurities from the non- stick coating accumulates on the surface, creating problems for the penetration of electric current during the electrorefining process

Pages

221–240

EDN

ICIAVA

Paper at repository of SibFU

https://elib.sfu-kras.ru/handle/2311/154993

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).