The paper studies sulfonyl aminothiophene derivatives as potential collecting agents in ion flotation of non-ferrous metals. The study determines optimal flotation conditions of Cu(II), Co(II), Ni(II), Zn(II) and Cd(II): range of pH values, process time, and amount of reagent. It demonstrates effectiveness of compounds as collecting agents for non-ferrous metals in standardized test solutions by the method of ion flotation.

The paper studies the effect of an additive component PbO (up to 8,1 mol.%) on physical and chemical properties of the KCl–PbCl2 molten system. The study experimentally measures temperature of primary crystallization of selected electrolyte compositions. It uses the method of impedance measuring in cells with parallel electrodes and finds dependencies of electrolyte conductivity on the temperature and PbO content.
It uses Archimedean method to measure temperature dependence of the KCl–PbCl2 equimolar melt density containing up to 8,1 mol.% of lead oxide, and calculates values of molar volumes. The paper demonstrates that concentration dependence of the molar volume is of an extreme nature.

The paper outlines the results of electrochemical processing of HAS32-VI heat-resistant alloy in nitric acid solutions. The main technological idea is based on running an electrochemical process at a controlled anodic potential value, thus providing for a preferential transition into nickel solution with nickel as basis metal, and synthesis of a cathodic product – metal nickel with purity of at least 95 %. Experiments in electrochemical dissolution of the said alloy were conducted using a nitric acid solution with concentration of 100 g/l at different values of anodic potential. It was determined that at Еa = 1,05 V cathodic product contains, %: Ni – 94,9, Re – 0,2, Co – 4,7, Cr – 0,1. The study determines that introduction of chloride ion (20 g/l) into the nitric acid electrolyte has no significant effect on the process parameters: the amount of nickel in anodic slime is reduced from 2,4 to 1,6 % with no significant increase of nickel content in the cathodic product. An exception is a considerable increase in the transition speed of rhenium into electrolyte: after a 10-hour process, rhenium concentration in a nitric acid electrolyte was 1,26 g/l; in a nitric acid electrolyte with addition of chloride ion – 8,90 g/l. The study demonstrates that the process of electrochemical dissolution of Re-containing heat-resistant nickel-based alloys at a controlled anodic potential Еa = 1,05 V in nitric acid electrolytes provides for a one-stage synthesis of nickel concentrate with a purity of not less than 95 % and allows to concentrate rhenium in anodic slime.

The paper reviews the current state of world and Russian markets of arsenic and its compounds, and shows prospects of the domestic market. The paper considers dynamics of world production of As and its prices over the last years. It assesses the need for arsenic and its compounds in the medium and long term, and analyzes trends of market development. The paper reviews manufacturers of this metal and As-compounds. Particular attention is paid to the market of high purity arsenic as a primary component for the growing market of gallium arsenide, for which purpose the paper provides a brief analysis of the current state of GaAs and GaAs-based devices market. It considers modern methods of deep arsenic purification, as well as the situation with arsenic emissions during roasting and smelting of non-ferrous metal raw materials in domestic enterprises. The paper discusses a problem of destruction of lewisite, mustard gas, and their mixture stockpiles in Russia. It analyzes proposals on the use of resulting reaction masses as an unconventional source of arsenic.

The paper studies the effect of tin (II) chloride additive agents on the sorption of rhodium (III) on ion-exchange resin Purolite S920 with isothiouronium functional groups, weak base anion-exchange resin Purolite S985, and a strong-base anion-exchange resin Purolite A500. It is found that introduction of SnCl2 leads to a substantial improving of selectivity of all tested ion-exchange resins to Rh(III), and increases sorption rate on ion-exchange resins S985 and S920. The paper determines the optimum dosage of SnCl2 (0,01 mol/l), at which partition coefficients of Rh(III) during adsorption on all tested ion-exchange resins reach maximum values. It is shown that quantitative recovery of Rh(III) is achieved in practice during flowing of the multicomponent chloride solution composed of, g/l: 0,2 Rh(III); 72,9 HCl; 53,5 NH4Cl; 2,7 Al(III); 1,23 Fe(III); 5,9 Sn(IV) with addition of SnCl2, through the ion-exchange resin Purolite S920 with isothiouronium functional groups. Desorption of Rh(III) from the saturated ion-exchange resin Purolite S920 with the use of an acidified thiourea solution is not full, no more than 60 %.

Determined the iHTC (interface Heat Transfer Coefficient) between AK7ch (A356) aluminum alloy casting and no-bake mold. The heat transfer coefficient is determined by minimizing the error function values, representing the difference between the experimental and calculated temperature in the mold values during pouring, solidification and cooling. Determined the values of the heat transfer coefficient above the liquidus temperature of the alloy hL = 900 W/(m2·K) and below the solidus temperature hS = 600 W/(m2·K).
Changing of the heat transfer coefficient within hL = 900÷1200 W/(m2·K) and hS = 500÷900 W/(m2·K) has no sufficient effect on the error value, and it remains within ~22 °C. It was shown the usability of the simplified approach using constant heat transfer coefficient h = 500 W/(m2·K), whereas error value is 23,8 °C. Changing of iHTC as function of height of the cylindrical ingot was experimentally confirmed. This owes to the different values of metallostatic pressure applied to the solid skin of the solidifying casting, leads to closer contact of the metal and mold in the bottom of the casting.

The paper develops a mathematical model of the flange cold rolling process on the cylindrical workpiece made of L63 alloy. It analyzes stressed and strained states of the workpiece during three stages of a flanged piece forming. It is found that at the first stage the base area of the formed cone is most problematic in terms of possible workpiece destruction. Risks at the second and the final stage of flange forming are in the flange end surface and cylindrical hub surface of the rolling component.

The paper uses calculation (Thermo-Calc) and experimental (optical and electron scanning microscopy, electron microprobe analysis) methods and studies phase composition of the system Al–Ca–Si–Sc in the region of aluminum alloys. It studies the effect of annealing in the range of up to 550 °C on the structure and hardness of alloys containing 0,3 % of Sc. The study demonstrates that maximum hardening due to release of Al3Sc (L12) phase nanoparticles is achieved after annealing at temperatures of 300–350 °C in alloys falling within the phase region (Al) + Al4Ca + Al2Si2Ca ((Al) – solid aluminum-based solution). Scandium enters the (Al) composition in alloys of this region in full, and silicon concentration in such composition is minimal. On the other hand, hardening effect in alloys of the (Al) + (Si) + Al2Si2Ca phase region is near-zero. The study substantiates fundamental possibility of creating (Al) + Al4Ca + Al2Si2Ca eutectic-based cast alloys, which can be hardened without quenching.

The paper studies the effect of temperature on the formation of (αTi) grain boundary layer in Ti–2wt.%Co and Ti–4wt.%Co alloys in the (αTi) + (βTi) two-phase region of the Ti–Co phase diagram within the temperature range of 690–810 °C. The paper studies kinetics of thickness growth (∆) of the (αTi) phase grain boundary layer in Ti–2wt.%Co alloy at a temperature of 750 °C. It demonstrates dependence of the thickness of grain boundary layer on the annealing time as ∆ ~ t 1/3. Analysis of experimental results suggests that increase in ∆ is a manifestation of the (αTi) coalescence process controlled by volume diffusion.

The paper studies mechanical mixing and subsequent compaction of a powder mixture consisting of a powdered carrying agent (electrolytic copper having particles size of 20–100 µm) and a nanopowder modifying composition (silicon carbide powders (SiC) – 50÷70 %, silicon nitride (Si3N4) – 20÷30 %, sodium hexafluoroaluminate (Na3AlF6) – 10÷20 %) having particles size of 70–100 nm, obtained using azide self-propagating high-temperature synthesis technology. Modifying agent content in powder mixtures was 2,5, 5, 10 and 15 %. Mechanical mixing was carried out for 30–45 min at a rate of 150 rpm using the «Pulverizette-5» planetary mill. The study analyzes intermixing of initial powder components. It determines some physical and technological properties of powder mixtures obtained, such as granulometric composition, density, bulk mass, flowability. Nanopowder pseudo-ligatures briquettes are formed of Cu–(SiC + Si3N4) powder mixtures with various content of the modifying agent by cold pressing in a cylindrical press mold using the PSU-50 hydraulic press at a pressure of 85–310 MPa. The study determines dependencies of relative density and porosity of briquettes on compaction pressure. It presents microstructures of pressed pseudo-ligatures at the maximum compaction pressure. Obtained nanopowder pseudo-ligatures briquettes with a diameter of 25 mm, up to 2 mm in height, weighing 5 g, with a relative density of 53–85 % and porosity of 15–47 are intended for subsequent introduction into aluminum melt for further modification.