Purification of Industrial Copper Electrolyte from Bismuth Impurity

This work focused on purifying copper electrolytes from a bismuth impurity on a laboratory scale. The electrolyte came from Polish copper electrorefineries with the content of main components, g/dm3: 49.6 Cu, 160 H2SO4. The electrolyte was enriched in bismuth by Bi2O3 addition. Purification of bismuth contamination was carried out using selected agents with adsorbing effects, such as barium hydroxide octahydrate, strontium carbonate, barium carbonate, barium and lead sulfates. The trials were performed until achieving the Bi level—below 0.1 g/dm3. During the experiments, it was noticed that electrolyte purification degree depends on initial Bi concentration in electrolyte, time and temperature, as well as on the type and amount of the bismuth-lowering agent. The most satisfactory results of Bi impurity removal were with additions of barium hydroxide octahydrate, strontium carbonate and barium carbonate to electrolyte at 60 °C for 1 h. These parameters revealed the highest electrolyte purification degree. Bismuth is not removed effectively from electrolytes by barium sulfate or lead sulfate addition. The efficiency of the purification process is much higher when the agents are added to the solution in the form of carbonates or hydroxides. Extending the electrolyte purification process time may cause dissolution of bismuth from the resulting precipitate and increase of bismuth concentration in electrolytes.

Пленки Bi-замещенных ферритов-гранатов для термомагнитной записи, фотоники и плазмоники: оптимизация условий синтеза с использованием сканирующей зондовой микроскопии

We present the results of studies on the optimization of the synthesis of Bi-substituted iron garnet (Bi : IG) films by liquid-phase epitaxy and vacuum deposition followed by crystallization. The effect of the parameter of mismatch between the crystal lattices of the film and the substrate on the functional properties of thin single-crystal high-coercive Bi : IG films is demonstrated. The regime of high-temperature annealing of deposited films was optimized in order to form layers with a high bismuth concentration for magnetophotonic and magnetoplasmonic structures. It was established that annealing of the Bi : IG layer under a SiO_2 layer deposited on top will reduce the roughness of interfaces in multilayer structures.

Влияние висмута на структурное совершенство и люминесцентные свойства тонкопленочных упругонапряженных гетероструктур Al-=SUB=-x-=/SUB=-In-=SUB=-y-=/SUB=-Ga-=SUB=-1-x-y-=/SUB=-Bi-=SUB=-z-=/SUB=-Sb-=SUB=-1-z-=/SUB=-/GaSb

The effect of bismuth on the structural perfection and the luminescent properties of Al_ x In_ y Ga_1– x – y Bi_ z Sb_1– z /GaSb heterostructures has been studied. The optimal parameters of the process of zone recrystallization with temperature gradient at which epitaxial AlInGaBiSb layers have the minimum roughness and high structural perfection have been revealed: temperature gradient 1 ≤ G ≤ 30 K/cm, the liquid zone thickness 60 ≤ l ≤ 100 μm, the temperature range 773 K ≤ T ≤ 873 K, and bismuth concentration 0.3–0.4 mol fraction.

Identification of Nanocrystalline Inclusions in Bismuth-Doped Silica Fibers and Preforms

The nature of nanocrystalline inclusions and dopant distribution in bismuth-doped silicate fibers and preforms are studied by scanning and transmission electron microscopy, and energy and wavelength-dispersive X-ray microanalysis. The core compositions are Bi:SiO2, Bi:Al2O3–SiO2, Bi:GeO2–SiO2, Bi:Al2O3–GeO2–SiO2, and Bi:P2O5–Al2O3–GeO2–SiO2. Nanocrystals of metallic Bi, Bi2O3, SiO2, GeO2, and Bi4(GeO4)3 are observed in these glasses. These inclusions can be the reason for the background optical loss in bismuth-doped optical fibers. The bismuth concentration of 0.0048±0.0006 at% is directly measured in aluminosilicate optical fibers with effective laser generation (slope efficiency of 27% at room temperature).