The joint review of particle capturing, aggregate separation and emerging subprocesses in the conditions of periodic froth free flotation showed that mineral load formed on a separate bubble during its ascent (τm). This load is part of the equilibrium mineral load that can be reached in an endless mineralization time. It was proposed to characterize the composition of mineral load and speed of its achievement with two dimensionless parameters, which depend on the intensities of the subprocesses. The type of the particle parameter (B) was uniquely determined by the ratio of separation intensity and capture intensity, and the dimensionless time D – by correlation of particle capture and separation speeds to the air bubble rise velocity. The kinetics equation of mineralization with many bubbles was formulated in the exponential form similar to the first order equation (Beloglazov’s equation). In the mineralization rate constant (Km), capture and separation subprocess intensities determine the value of individual bubble extraction (εbm) in time τm, and the air consumption defines the total removal value ε. 

Sorption of Pd(II), Ag(I) and Cu(II) from nitric acid solutions by silica chemically modified with γ-aminopropyltriethoxysilane was studied. Based on the research of solid phase by IR & X-ray photoelectron spectroscopy, as well as thermogravimetry, it was suggested that palladium sorption from nitric acid solutions includes the following processes: coordination of palladium ions to nitrogen atoms of the functional group, reaction of palladium ions with the silica matrix and formation of polynuclear complexes. It was also proposed to use 5 % thiourea solution in 0,1 M HCl as a palladium desorbent. It was determined that the time of constant sorption rate settling in static conditions was (min): for Ag(I) – 10, for Cu(II) – 20, Pd(II) – 30. The row of ion sorption (imbibition) from 2 M HNO3 is as follows: АAg(I) > АPd(II) >> АCu(II). At the same time, silver ions are not adsorbed from solutions with a concentration of HNO3 < 1 M thus creating prerequisites for separation of ions. 

The process of nuclear grade zirconium tetrafluoride (ZTF) production in a single decomposition stage was proposed and experimentally confirmed. To achieve this goal vapors of the source ZTF has to be run either through the layer of powdery zirconium dioxide with a height of 140–150 mm or above its layer with a length of 1000–1100 mm. The process cascade for the production of nuclear grade pure zirconium tetrafluoride and hafnium tetrafluoride with a hafnium content of over 99 % in a single decomposition stage and without any technological waste was developed and calculated. It was shown that the proposed process cascade for the single stage decomposition and enrichment of zirconium tetrafluoride and hafnium tetrafluoride allows to produce both zirconium tetrafluoride with a hafnium content of up to 0,01 wt.% from the source zirconium tetrafluoride having a hafnium content of 2,0 wt.% and hafnium concentrate containing more than 99 % of hafnium.

The research on the influence of melt processing with electromagnetic acoustic fields on the structure and properties of binary alloys Al–12%Si and Al–20%Si was conducted. The frequency of electromagnetic field induced in the loop antenna was changed between 500, 1000 and 2000 kHz during the experiments. Melts were processed after their degassing and refining. It was determined that this method of melt processing reduces the average total time of alloy production by 12 %. Short-term treatment of melts with electromagnetic acoustic fields helps to grind main phase alloy components and to improve their mechanical properties. Grinding of α-Al dendrites (from 30 to 22 μm) and eutectic Si crystals (from 13 to 10 μm) was observed while processing Al–12%Si eutectic alloy with a frequency of 500 kHz. At the same time, Al–20%Si hypereutectic alloy treatment with a frequency of 1000 kHz led to reduction of eutectic Si crystals from 8 to 5 μm, and of primary Si crystals – from 90 to 62 μm. Under specified processing conditions the tensile strength of Al–12%Si eutectic alloy increased by 13 %, and elongation – by 17 %, the same mechanical properties of Al–20%Si hypereutectic alloy increased by 9 and 65 % respectively. Based on the studies performed it was concluded that the choice of parameters for Al–Si melt processing with electromagnetic acoustic fields depended on the silicon content in the alloy. The increase in silica concentration needs treatment with the waves of higher vibration frequency. This processing technique allows modifying the fine crystalline structure of alloys and as a result causes an improvement of their mechanical properties. It can be successfully used for the production of fine-grained ligatures and Al–Si system alloys. However, further research is required to determine optimal processing parameters depending on the structure of the original charge and the nature of the alloys.

Rod and wire product manufacturing is usually accompanied by residual stresses. The reason for this is both plastic deformation and potential thermoplastic deformation that occurs due to the contact frictional heating of metal surfaces. Undesirable residual stresses in the surface layers affect the accuracy and increase the probability of hardware destruction that can be observed in drawing product manufacturing. The authors of the article propose a method of determining the contact heating conditions based on the criteria of residual stress prevention. Temperature conditions causing thermoplastic deformations are determined according to thermoelasticity equations. Critical values are calculated for the temperature difference between the center and the surface of the stretched wire, at which the latter transits to a plastic state followed by residual stress formation. The limiting drawing velocities for a number of nonferrous metals (copper, zirconium, titanium) are defined. The excess of those top velocities will lead to undesirable residual stresses in the stretched product. It is proposed as a recommendation to increase the critical speed by creating hydrodynamic (fluid) friction conditions in metal products manufacturing. 

Technological principles to improve performance of end mills made of R6M5K5 high-speed steel are considered by hardening of their cutting edges with ion nitriding as well as by complex hardening (ion nitriding and application of composite wear-resistant coating based on metal nitrides). A batch of mills was tested for resistance to optimize the nitriding conditions. The optimum hardening mode that provides the highest resistance of end mills in the processing of VT20 titanium alloy was chosen. The compositions of wearresistant coatings were proposed according to the experimental data of their effect on the end mill resistance. The impact of cutting conditions on the hardened tool resistance was determined. A theoretical analysis was performed as regards the results of hardened cutter performance tests. 

The study covers the influence of multi-stage annealing (up to 650 °C) on the value of electrical resistivity and hardness of low-alloy hot-rolled sheets made of aluminum alloys containing up to 0,5 wt.% of Zr. Experimental samples were produced in conditions close to those implemented in industrial machines for continuous casting and rolling. Testing methods including heat treatment were described. The structure of the cast (initial structure) as well as the structure of deformed experimental samples was analyzed. The graphs of the specific electrical resistivity (ρ) and hardness dependence on the temperature of the last annealing stage were drawn according to the results of the physical and mechanical tests. It was determined by computational and experimental techniques that the ρ value depends mainly on zirconium content in aluminum solid solution. The optimal ratio between zirconium content in alloy and annealing temperature providing the best combination of hardness and electrical resistivity was defined. 

The paper reviews structural changes after processing the roll billet manufactured of lightweight Al–Mn–Fe–Si aluminum alloys by ingotless rolling. It was also proposed to identify the texture by the generalized pole density index and to set the structural element dimensions depending on the field of coherent X-rays scattering. Correlating the findings with the phases of the material, as well as evaluating the matching of hardening with the cold rolling plastic deformation, the place of annealing between the passes was defined by selection and due to convergence of the generalized pole density value after its determination by X-ray patterns of the roll billet samples and the strip after each pass. 

The influence of calcium additives (from 0,1 to 1,0 wt.%) on the phase composition and the solidus temperature of ML5 magnesium alloy was studied. During the alloy crystallization in the presence of aluminum, calcium forms an intermetallic compound with a variable composition containing Al (53,4–57,4 %), Ca (42,6–42,8 %) and Mg (0,002–3,8 %). As the temperature decreases, this compound degenerates to Al2Ca combination. The impact of calcium on the number of Mg17Al12 and Al2Ca phases as well as its distribution in the structure of the cast and heat-treated ML5 alloy was analyzed. By means of the electron microprobe analysis, it was found that calcium and aluminum were concentrated along the boundaries of the solid magnesium solution. It was shown that satisfactory mechanical properties of magnesium alloys containing calcium could only be acquired by their smelting and casting according to the process preventing metal contamination with rough inclusions. It was found that small calcium additions (up to 1 wt.%) increased combustion temperature and reduced the oxidation of the alloy at elevated temperatures (up to 715 °C). The effect of sulfur hexafluoride on the loss of calcium in flux-free melting was found. 

The study describes main scientific and practical results obtained when researching new technologies and technical facilities for disposal of ash and slag wastes produced by thermal power plants. The issues of environmental safety provision in the area of thermal power plants are discussed and technologies for magnetic recovery of precious metals from ash and slag wastes are proposed. The data obtained is implemented in methodological documents, technical facilities and introduced into the industry with an economic effect.