The method of recovery of contaminating components from sweepings of the aluminum production for their further return into the electrolyzer is proposed. To concentrate the material, the following processing flowsheet is proposed: milling-classification-reverse flotation-thickening. For the most complete removal of silicon and iron oxides during the flotation of sweepings, the Flotigam 7266 flotation reagent produced by Clariant (Germany), which is a mixture of primary fatty alkyl amines, is used. To remove carbon particles, the combination of pine oil in a mixture with kerosene is used. Flotation is performed using a FML 0.3 flotation machine. The initial material, chamber product, and tails are analyzed for the content of carbon and aluminum, iron, and silicon oxides using X-ray spectral (XSA), X-ray phase (XPA), and chemical analyses. It is established that processing the total material mass does not make it possible to acquire a product with an acceptable content of silicon and iron oxides. Based on the XPA of various fractions of the initial material, it is proposed to process the material fractions containing the minimal amount of contaminating substances (carbon and silicon and iron oxides). Two fractions are selected for processing using the flotation method by the XRS results of various material fractions: -0.071 mm and +5.0 mm. When processing the first of them, the chamber product of the acceptable quality is acquired. A product with a high content of alumina and fluorinated components at low carbon and iron oxide concentrations but a considerable amount of silicon oxide is acquired from a coarse electrolyte-containing fraction (+5.0 mm). The further use of this product is possible to fabricate aluminum-silicon alloys.

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The article presents the results of work on dismantling the large installation equipment of Research Building B at the Bochvar High-technology Research Institute of Inorganic Materials (Bochvar Institute). The works were carried out as part of Building B preparation for decommissioning. The purpose of dismantling the large-sized capacitive equipment was to reconstruct the large installation site for managing radioactive waste generated during Building B decommissioning. The works on decommissioning a radioactively contaminated building within a densely populated district of megalopolis were carried out for the first time. The characteristics of the large-sized capacitive equipment are presented. Radioactive contamination of the capacitive equipment is determined by long-lived a-emitting isotopes: 235U, 238U, 239Pu. The sequence of works on dismantling the radiation-contaminated capacitive equipment includes preparatory work, dismantling the tank piping, localizing radioactive contamination of the external surface of the equipment as well as dismantling and moving it into a transport container. Dismantling and decontamination of the large-sized capacitive equipment was carried out by the Bochvar Institute Decommissioning Department. The following tools were used during the works: (1) a mobile foam decontamination facility to perform decontamination works and (2) a mobile high pressure facility to apply localizing and decontaminating film coatings. The tanks were dismantled by means of low-spark tools, i.e., reciprocating saws. Crane runways were made in order to move the dismantled equipment into transport containers: the movement was carried out with the help of a winch. The main results of dismantling and decontaminating the radioactively contaminated tanks are the dismantling of four units of long-length column-type equipment with heights from 4.2 to 6.4 m and 26 units of capacitive equipment (maximum capacity = 8 m3) as well as decontamination of the internal surfaces of radiation-contaminated equipment (decontamination factor = 25–70). As a result, the activity of the accumulated radioactive waste was reduced (the RW class was changed from 3 to 4). The main conclusion regarding the managment of large-sized radiation-contaminated tanks during Building B decommissioning is as follows: the works were organized and carried out at a high technical level, using modern decontamination and dismantling equipment and modern methods to ensure work safety at the Bochvar Institute site in the city of Moscow.

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