This paper explores the possibility of zinc-manganese battery recycling in alkaline solutions. It was shown that three-stage washing could remove potassium chlorides from active mass of milled batteries. Influence pattern regularities were established for some parameters (temperature, alkali concentration and number of cycles) of alkaline leaching of a zinc-carbon and alkaline battery mixture in respect of zinc extraction into the solution. The reason of low zinc extraction from this material was found to be the presence of zinc and manganese compounds as heterolite and hydroheterolite that are difficult to dissolve in alkalis. It was found that zinc extraction increases by 2.6 times with an increase in the NaOH concentration from 100 to 205 g/dm³ , but further increase in the NaOH concentration, as well as an increase in temperature in the range of 30–85 °C, does not affect zinc extraction into the solution. Optimal process parameters of zinc-carbon and alkaline battery leaching at 30 min leaching time and 200 g/dm³ pulp density were determined as follows: temperature is 30 °C, NaOH concentration is 390 g/dm³ . Experiments on zinc ion accumulation with repeated filtrate leaching showed that increasing the initial NaOH concentration to 390 g/dm³ makes it possible to transfer the maximum possible amount of zinc into the solution at the same NaOH consumption due to the cyclic treatment of solutions. Zinc and NaOH concentrations in solutions after leaching reached 59 g/dm³ and 300 g/dm³ , respectively. Solutions obtained could be sent to zinc electrowinning and then returned to leaching again.

   Zirconium is one of the most commonly used materials, while the existing methods of its production are multi-stage and energy-intensive. The paper proposes a method for extracting zirconium from its oxide by KF–AlF₃ –Al₂O₃ –ZrO₂ low-temperature oxide-flu-oride melt electrolysis with a temperature of 750 °C. For this purpose, voltammetric methods were used to determine potentials of the electrochemical reduction of zirconium and aluminum ions on a glassy carbon electrode. It was shown that the electrochemical reduction of aluminum ions in the KF–AlF₃ –Al₂O₃ melt occurs at a more negative potential than –0.05 V relative to the aluminum electrode with the cathode peak formation in the potential range from –0.18 to –0.2 V. With the addition of 1 wt.% of ZrO₂ , cathode current growth on the voltammogram begins at a more negative potential than 0 V, and the cathode peak is formed at a potential of about –0.1 V. Similar results were observed in the study of the cathode process in the KF–AlF₃ –Al₂O₃ melt with and without ZrO₂ added by means of square wave voltammetry. It was suggested that zirconium-containing electroactive ions are discharged at a potential that is 0.05–0.08 V more positive than the discharge potential of aluminum-containing ions due to the lower bond energy. At a graphite cathode potential of –0.1 and –0.3 V relative to the aluminum electrode, the KF–AlF₃ –Al₂O₃ –ZrO₂  melt electrolysis was carried out, and the elemental and phase composition of deposits obtained was determined by X-ray phase analysis, scanning electron microscopy and energy dispersive microanalysis. It was shown that the 98.5 –99.5 wt. % zirconium deposit was obtained at a potential of –0.1 V. This indicates a reliable possibility of selective zirconium extraction using the proposed method.

   The paper studies the features of the extraction technology used to separate yttrium-group rare-earth elements taking into account sharply reducing prices for individual oxides. The latter, along with the low prices for lanthanum and cerium oxides, is associated with a predominant increase in the consumption of praseodymium and neodymium and a slow increase in the consumption of other rare-earth elements (REE), except for terbium and dysprosium. Since all REE are extracted from rare-earth concentrates, less marketable ones are stored or sold at extremely low prices. Elements such as samarium, europium, gadolinium, dysprosium are used in high-tech instruments and devices. At the same time, some low-profit production is possible, but process solutions must certainly be developed providing for minimum costs and be the most cost-effective. The authors propose a technology for separating yttrium-group elements including yttrium isolation stages in a single-stage mode by extraction with a mixture of three extractants (25 vol.% trialkylmethylammonium nitrate – 20 vol. % tributyl phosphate – 20 vol.% higher isomeric carboxylic acid) followed by separation of the triad of elements (samarium-europium-gadolinium) by extraction with organophosphoric acids: 30 vol.% solution of di-2-ethylhexylphosphoric acid or 30 vol.% solution of bis(2,4,4-trimethylpentyl)-phosphinic acid. At the last operation, yttrium-group REE concentrates are isolated simultaneously. The process is conducted in the conditions of complete internal irrigation with the 30 vol.% solution of bis(2,4,4-trimethylpentyl)-phosphinic acid used as an extractant. Initially, all the extraction cascade cells are filled with the initial solution. Separation zones are formed in the extraction cascade with the accumulation of terbium-dysprosium, holmium-erbium and thulium-ytterbium-lutetium concentrates in some cells. Once the products are accumulated, the concentrate solution is drained from cells, and the process starts again. If there is a need in some yttrium-group element, the corresponding binary or ternary concentrate is separated with the isolation of the element required.

   The paper focuses on establishing the effect of nanosecond electromagnetic pulses (NEPs) with different amplitudes on the formation of the structure of cast aluminum matrix composites of the Al–Mg₂Si pseudobinary system with hypoeutectic (5 wt. % Mg₂Si) and hypereutectic (15 wt. % Mg₂Si) compositions. As the NEP generator amplitude in composites containing 5 and 15 wt. % Mg₂Si increases, the matrix alloy structural components (α-solid solution and eutectic) are refined, while no significant differences in the sizes and morphology of Mg₂Si primary crystals were observed in the hypereutectic range of compositions. Presumably, the observed nature of the NEP effect on the structure of composites in the hypereutectic region of compositions is associated with the features of their crystallization behavior. The temperature range of the L + Mg₂Si two-phase region presence is much lower than NEP irradiation temperatures. Apparently, this is the reason why NEPs have no effect on the thermodynamic state of Mg₂Si primary crystal/melt interfaces. It was shown that a promising option for the simultaneous modifying effect on all structural components of Al–Mg₂Si aluminum matrix composites (solid solution, eutectic, Mg₂Si primary particles) is a combination of thermal-rate treatment and irradiation of melts by NEPs, as well as additional melt processing by NEPs during crystallization.

   The paper provides the results of studies into the effect of the charge composition on the structure and mechanical properties of Al–Si–Mg (AK9ch) and Al–Mg (AMg6l) cast aluminum alloys. It was shown that deformed waste included in the charge composition (electrical waste of aluminum and waste of beverage cans based on the 3104 alloy – for AK9ch; AMg6 alloy plates – for AMg6l) contributes to the formation of dispersed micro- and macrostructure of working alloys in the solid state. The effect of modification (AlSr20 master alloy – for AK9ch; AlTi5 master alloy – for AMg6l) on the structure and mechanical properties of alloys obtained with various charge options was studied. Experiments on the effect of the charge composition on the AK9ch and AMg6l modifiability showed that the deformed waste structure is partially inherited by working alloys through the liquid state. With similar chemical compositions, alloys obtained with an increased proportion of deformed waste in the charge composition feature by smaller micro- and macrostructure sizes and improved mechanical properties (tensile strength and tensile elongation). It was found that when a certain amount of the modifier element (0.06 % Sr for the AK9ch alloy; 0.04 % Ti for the AMg6l alloy) is exceeded in these alloys, the over-modification effect appears. This is expressed in enlarged micro- and macrostructure parameters, as well as lowered tensile strength. The results obtained show that the optimal amount of the deformed waste proportion in the charge composition will make it possible to reduce the consumption of expensive modifying master alloys with a guaranteed effect of modification in practice.

   In magnesium alloys castings, the casting defects such as shrinkage porosity are often occur. Such defects can be suppressed by repair welding or surfacing using a special filler rod. Unfortunately, in Russia, the low amount of filler rod is consumed. Therefore, native enterprises do not manufacture it, limiting themselves to imports or homemade low-quality substitutes. Nevertheless, there is a need for filler rod, and recently it has become unprofitable to replace them with imported materials due to a significantly increased price. Therefore, there is a need to study the technology of its production to replace imported filler rod with native material. Magnesium alloys based on the Mg–Zn–Zr (La, Nd) system: SV1, SV122, and ML12 (ZK51) that used as a filler rod for repair welding of ZK51 alloy castings were studied in this work. The samples were obtained by permanent mold casting into aluminum molds followed by hot extrusion into a filler rod with a diameter of 4 mm. It was shown that all the investigated alloys could be obtained in the form of a rod with a diameter of 4 mm. Therefore, the investigated rod samples from the SV122 alloy were used as filler material for repair welding of ZK51 magnesium alloy castings. The weld seam in the T1 condition has an ultimate tensile strength (UTS) about 80 % of the UTS of the casting material.

   The article discusses the features of Al–Mg–Sc aluminum alloy radial shear rolling (RSR). The RSR process was modeled by the finite element method in the QForm 3D program with the variable elongation ratio per pass and rolling speed. The results obtained were used as a basis for studying the temperature field of the rod in the deformation zone taking into account the cyclic nature of deformation and the configuration of flow paths. It was found that the temperature field in the deformation zone is determined by significant differences in the metal flow path geometry in surface layers and in the axial zone. When the elongation ratio is varied from 1.6 to 2.4, heating occurs inconsistently from the center to the surface. The highest temperature rise occurs for an area that is located ~0.3R from the surface. For the axial zone, temperature variation in the deformation zone occurs smoothly and with an insignificant temperature difference of 5–10 °C. Highest temperature fluctuations are observed on the rod surface, and this is explained by deformation heating and simultaneous contact with a cold roll during each deformation cycle. As the rolling speed decreases, a picture of the rod temperature field distribution in the deformation zone is observed with the temperature in central layers exceeding the surface temperature. Due to the long time of the rod contact with the roll, the surface temperature fluctuates up to 40–50 °C at each deformation cycle. As the rolling speed rises, the amplitude of temperature fluctuations on the surface decreases, and deformation heating increases. The data obtained on the relationship between control process parameters and rod temperature field variation can be useful in the design of rolling process modes.

   X-ray diffraction and scanning electron microscopy methods were used to study the effect of the planetary ball mill treatment time on the morphology, phase composition and microstructure of the Al–Mn–Cu-based alloy granules with and without nanodiamond particles. The phase composition of the alloy was determined by X-ray diffraction after casting and milling for 5–20 h. It was shown that nanodiamond particles promote granule coarsening, and this is especially noticeable with an increase in the milling time up to 20 h. At the same time, the size of initial alloy granules weakly depends on the processing time. Cu-bearing phases of crystallization origin dissolve during mechanical alloying. The lattice constant of the aluminum solid solution decreases after 5-hour treatment to 0.4028–0.4030 nm, and increases with further increasing milling time. Exothermic effects associated with the precipitation of secondary phases were revealed for mechanically alloyed granules during heating. An increase in the milling time reduces the intensity of peaks. The solidus temperature of samples decreased after mechanical alloying. For the nanodiamond-bearing sample, an exothermic effect is observed which can be ascribed to the aluminum carbide formation or oxidation reactions in nanodiamond particles. The maximum microhardness is achieved after 5–10 h of mechanical alloying, and the nanodiamond particles slightly increase the maximum microhardness from 316 to 330 HV. The results indicate the dissolution of copper and manganese in the aluminum solid solution after 5 h of treatment and their precipitation with the increasing milling time. Nanodiamond particles have no effect on the dissolution of elements but accelerate the solid solution decomposition with the increasing treatment time.

   The effect of iron and silicon impurities on the phase composition and properties of the Al–4.3Cu–2.2Yb quasi-binary alloy was determined. In addition to the aluminum solid solution and dispersed eutectic ((Al) + Al₈Cu₄Yb) containing about 1 % of dissolved iron, Al₃ Yb/(Al,Cu)₁₇Yb₂ and Al₈₀Yb₅Cu₆ Si₈ phases were identified in the cast alloy microstructure (the latter was not found in an alloy of a similar composition but without impurities). After homogenization annealing at t = 590 °C for 3 h, the structure is represented by compact fragmented and coagulated intermetallic compounds 1–2 μm in size, and a solid solution (Al) with a maximum copper content of 2.1 %. The hardness of deformed sheets significantly decreases after 30 min of annealing, and then changes slightly in the following 5.5 h of annealing at t = 150÷210 °C. After annealing at 180 °C (τ = 3 h), a substructure with a subgrain size of 200–400 nm is formed in the alloy structure. Rolled sheet softening occurs due to recovery and polygonization processes after annealing at temperatures up to 250 °C, and due to recrystallization after annealing at temperature above 300 °C. After annealing at 300 °C (τ = 1 h), the recrystallized grain size is 7 μm. The grain increases to 16 μm after annealing at t = 550 °C (τ = 1 h). The alloy under study has a high level of mechanical properties (conditional yield limit is 205–273 MPa, tensile strength is 215–302 MPa, relative elongation is 2.3–5.6 %) in the annealed state after rolling. Iron and silicon impurities do not lead to the formation of coarse lamellar intermetallic phases and do not reduce the ductility of the investigated alloy.