Analysis of structural variations of the precipitate based on monitoring the industrial electrolysis of copper powders of various brands

This study is associated with the solution to the blending problem of the charge for the output of ready articles. The main requirements are claimed to the specific surface and the packed density of the powders of basic brands PML0, PMS-1, and GG. The dynamics of the development of the dendrite depositions for powders of mentioned brands with the simultaneous registration of the cathodic overvoltage is investigated under industrial experimental conditions. The procedure is developed and the results of the continuous monitoring of the deposition growth with the direct immersion of a video camera into the electrolyte are presented. The reproducibility of the results is evaluated statistically. Based on the galvanostatic crystallization model of the dendrite deposition on the rod electrode, the dynamics of varying the density (N) and radius (r t) of growing tips on the growth front is calculated. It is established by variance analysis that structural parameters N and r t are individual for depositions of every brand, so that the preparation conditions of the deposition during the electrolysis should be strictly fulfilled as the charge forms. © 2013 Allerton Press, Inc

About the stabilization of the dendritic structure of GG brand copper powder

In industry copper powder is recieved under constant current load. Surface roughening occurs during evolution of the dendritic particles. It is suggested to create a new impulse of current equal to the initial current density of 3200 A/m2 in order to obtain uniform structure of the precipitate. Current load was evaluated by the result of chronopotentiometry research of the dynamics of the dendritic precipitate on cylindrical electrode. Four-impulse galvanostatic electrolysis was investigated for the copper powder GG. New current impulse shifts the electrode potential to the cathodic area, crystallization process flows more rapidly.This work was done under financial support from RFBR № 11-03-002296

Электрохимическое обезмеживание медно-сульфатного электролита

Copper and nickel ions are accumulated in the solution during electrolytic refining of copper. These ions need to be extracted from the solution from time to time. In industry copper extraction is carried out in two stages. It results in copper ions concentration reducing to 1 g/l. Numerical simulation was used to define dependence of the process of copper extraction from particular parameters: mixing of electrolyte, volume of electrolyte, area of cathodic surface. The process of copper extraction was investigated in still electrolyte and during mixing of the solution. Smooth and compact precipitate crystallized on the cathode in all experiments. Rate of copper extraction during mixing of electrolyte is higher than in still electrolyte. The industrial method of abuseive sulphate electrolyte results in the formation on the cathode dendritic sediment copper ions which are restored in extreme conditions. The decrease in the concentration of copper at I = const causes the formation of dendritic sludge that is easily crumbles to the bottom of the cell, enriching copper sludge. Guarantee smooth sediment when basmajian with obtaining compact copper, excluding besides the recovery of arsenic emitting poisonous arsina cars is the organization of intensive mixing or electrolyte circulation, ensuring the recovery of copper ions in limitless conditions smooth and sediment.При электролитическом рафинировании меди в растворе электролита накапливаются ионы никеля и меди, которые необходимо периодически извлекать. В промышленности извлечение меди проводят в две стадии, снижая концентрацию меди до 1 г/л. Численным моделированием установлена зависимость скорости обезмеживания от отдельных параметров: перемешивания электролита, его объема, площади катодной поверхности,. Экспериментально исследован процесс обезмеживания в спокойном электролите и при перемешивании раствора. Во всех опытах на катоде кристаллизовался гладкий, компактный осадок меди. Скорость обезмеживания при организации принудительного перемешивания выше, чем в спокойном электролите

Multiple rare-earth ion environments in amorphous (Gd2_2O3_3)0.230_{0.230}(P2_2O5_5)0.770_{0.770} revealed by gadolinium K-edge anomalous x-ray scattering

A Gd K-edge anomalous x-ray scattering (AXS) study is performed on the rare-earth (R) phosphate glass, (Gd$_2$O$_3$)$_{0.230}$(P$_2$O$_5$)$_{0.770}$, in order to determine Gd⋯Gd separations in its local structure. The minimum rare-earth separation is of particular interest given that the optical properties of these glasses can quench when rare-earth ions become too close to each other. To this end, a weak Gd⋯Gd pairwise correlation is located at 4.2(1)Å, which is representative of a metaphosphate R⋯R separation. More intense first-neighbor Gd⋯Gd pairwise correlations are found at the larger radial distributions, 4.8(1), 5.1(1), and 5.4(1)Å. These reflect a mixed ultraphosphate and metaphosphate structural character, respectively. A second-neighbor Gd⋯Gd pairwise correlation lies at 6.6(1)Å which is indicative of metaphosphate structures. Meta- and ultraphosphate classifications are made by comparing the R⋯R separations against those of rare-earth phosphate crystal structures, R(PO$_3$)$_3$ and RP$_5$O$_{14}$, respectively, or difference pair-distribution function (ΔPDF) features determined on similar glasses using difference neutron-scattering methods. The local structure of this glass is therefore found to display multiple rare-earth ion environments, presumably because its composition lies between these two stoichiometric formulae. These Gd⋯Gd separations are well-resolved in ΔPDFs that represent the AXS signal. Indeed, the spatial resolution is so good that it also enables the identification of R⋯X(X=R, P, O) pairwise correlations up to r∼9Å; their average separations lie at r∼7.1(1), 7.6(1), 7.9(1), 8.4(1), and 8.7(1)Å. This is a report of a Gd K-edge AXS study on an amorphous material. Its demonstrated ability to characterize the local structure of a glass up to such a long range of r heralds exciting prospects for AXS studies on other ternary noncrystalline materials. However, the technical challenge of such an experiment should not be underestimated, as is highlighted in this work where probing AXS signal near the Gd K edge is found to produce inelastic x-ray scattering that precludes the normal AXS methods of data processing. Nonetheless, it is shown that AXS results are not only tractable but they also reveal local structure of rare-earth phosphate glasses that is important from a materials-centered perspective and which could not be obtained by other materials characterization methods

Prevention of scaling and corrosion by reagent KISK-1

The influence of the reagent KISK-1 (Russia) on the rate of corrosion of Steel 3 in mineralized (“hard”) waters of two industrial plants was studied. The water supply system of the two plants used in the study had sufficient difference in chemical composition. Thermostability of these waters was investigated in the presence of KISK-1 (the complex inhibitor of scaling and corrosion). It was shown that when used at correct dosage, KISK-1 is capable of significantly reducing the rate of corrosion of Steel 3 while also providing the water system’s thermostability in evaporation, i.e. preventing the formation of sediments and deposits of salts. It was shown that the optimum dosage of KISK-1 remains relatively stable, while the tested waters were evaporated by 1.7–2.5 times. At the same time, the existence of some threshold concentration, above which the increase in the concentration of KISK-1 does not produce a proportional decrease in the rate of corrosion of Steel 3 was established. The approach offered in this study provides a useful framework to conduct comparative analysis and choose suitable reagents for the prevention of scaling and corrosion in water supply systems in a variety of industrial plants. © 2015 Balaban Desalination Publications. All rights reserved