Papers by Keyword: Current Efficiency

Abstract: Established the possibility of galvanochemical obtaining of a plating stronger than in case of chrome precipitation. Proposed precipitation of ternary alloy Co-Мо-W, which allows using the effect of synergism. Proposed and researched usage instead of sulphate-anhydride electrolyte – citrate-diphosphate and ammonia-citrate one. Achieved an increase in current efficiency of precipitated alloy and decrease in current efficiency of hydrogen, with respect to chrome precipitation, which increased safety of the galvanochemical industry. Selected the optimal ratios of components in citrate-diphosphate and ammonia-citrate electrolytes for ternary alloy Co-Мо-W precipitation. Determined the parameters of electrical effect for the galvanic process: constant current – j = 2–8 А/dm², pulse unipolar current – j = 4–20 А/дм². Achieved a high microhardness of this plating and high adhesion to base surface. Achieved greater safety of the galvanochemical technological process of ternary alloy Co-Мо-W application compared with chromium plating.

Abstract: Nanocrystalline spinel zinc ferrite ZnFe₂O₄ thin film has been studied and synthesized via the electrodeposition-anodization process. Electrodeposited ZnFe₂ alloys were obtained from aqueous sulphate bath. The resulted alloys were electrochemically oxidized in strong alkaline solution (1 M KOH) at room temperature to the analogous hydroxides. The electroanodized ZnFe₂ alloy film was annealed in air at 400 °C for 2 h to get the required zinc ferrite. The electrochemical factors controlling of the electrodeposition of ZnFe₂ alloys such as the bath temperature, agitation, the current density were studied and optimized. The crystal structure, crystal size and microstructure of the produced ferrites were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The deposited film was mainly composed of ZnFe₂O₄ based on XRD studies. The produced film had a spinel structure and the crystallite size was 4.9 nm. SEM micrograph of the resulted zinc ferrite particles shows compact crystallites shapes and agglomerated chains with smallest semicircular particles like morphology.

Abstract: Because of distinctive properties, such as dendritic structure, high green strength, and low oxygen content, electrolytic copper powder has been widely used in aviation, aerospace, national defense industry and other domains. But at present, energy consumption of the electrolysis process in copper powder production is high, and the current efficiency is only about 90%. Therefore,the decrease in energy consumption of the electrolysis process has become the major bottlenecks in the development of the enterprises. In this paper, a new electrolysis cell with different electrolyte inlet arranged on the cell was manufactured. Then, the effect of flow pattern of electrolyte on the current efficiency, energy consumption and properties of copper powder was investigated. The experimental results showed that the electrolytic process had the higher current efficiency, lower energy consumption and smaller copper powders when the flow rate is 0.5l/min in the paralleled inlet and 1.5 l/min in the traditional inlet. Under the optimal conditions, the current efficiency, energy consumption and copper powder size were 99.10%, 712.90kw∙h/t and 47.80um respectively. This means an obvious rise in current efficiency and decrease in energy consumption compared to traditional feeding method.

Abstract: The main aim of this paper is to study copper ions electroplating, evaluating the cathodic current efficacy, from cyanide ion free alkaline baths, stabilized by different complexant agents for the Cu²⁺ ions. The cathodic current efficacy was assessed through quartz microbalance measurements, employing different current modulations. Results revealed that the pulsed current application has great influence on the cathodic current efficacy during electroplating in the baths under study.

Abstract: The model of electrolytic cleaning for cold rolled strip was established, and the simulation of cleaning process was carried out in the finite element method with the software (Ansoft). The influence of processing parameters was investigated. The results show that, the processing parameters, such as the current efficiency, the electrode plate intervals and the insulation board have intense influence on current efficiency, which is significant for improving cleaning efficiency and energy conservation.

Abstract: In order to achieve the goal of purifying the nickel-containing waste,use the Spouted bed particulate electro-deposition to treat it . Experimental studies show that the best condition is the concentration of nickel influence 1000mg/L, the current is 15A, pH 4.5, and particle size of 1.8mm under the condition of blowing nitrogen. The removal rate of nickel can reach 74.77%. Nitrogen can effectively reduce the concentration of dissolved oxygen in the water and obtain a higher electro-deposition efficiency and current efficiency.

Abstract: In this research, heavy metal copper was chosen for this study, with its sulfate solution simulated wastewater, using spouted particulate electrodes to purify wastewater and recycle metal copper. Experimental studied the effects on different conditions of electrodeposition, such as pH, constant current, copper ion concentration, the size of the cathode particle and nitrogen sparging. The results showed the optimum conditions were that pH was 3.0, constant current was 10.0A, the size of cathode particle was 1.8mm and with nitrogen sparging. In particular, nitrogen sparging not only reduced dissolved oxygen in wastewater to prevent the metal back to solution, but also handled the problem of low current efficiency due to concentration polarization and electrochemical polarization.

Abstract: An organic emitting device with well structure is reported. The well structure fabricated by alternating deposition of constituent tris-(8-hydroxyquinoline) aluminum (Alq) and 4, 7-diphenyl-1, 10-phenanthroline (BPhen) layers improved the current efficiency. The enhanced efficiency can be attributed to the strong accumulation of electrons and holes in the emitting layer, which leads to an increase of the exciton formation and exciton recombination probability. The single well device exhibits the highest current efficiency of 4.12cd/A at 4V, which is more than 1.2 times than that of the conventional organic light-emitting devices. It is an effective and simple way to improve the efficiency of the organic devices by utilizing well structure as the emitting layer with proper well number.

Abstract: In order to achieve the goal of purifing the waste water and recycling of copper, use the electrodeposition to treat the copper-containing wastewater. The experiment studies the effects of electrode materials, cell voltage, plate distance, pH and other experimental conditions in the process of deposition and the effect of blowing nitrogen in the process of deposition. The results show that the best condition is using graphite-aluminum electrode, cell voltage is 7V, plate distance is 10mm and pH is 3 under the condition of blowing nitrogen. From which the removal rate of copper can reach more than 93%. Nitrogen can effectively reduce the concentration of dissolved oxygen in the water, reduce the degree of corrosion of the metal and eliminate the concentration polarization and electrochemical polarization in the deposition process to obtain a higher electrodeposition efficiency and current efficiency.

Abstract: Electrodeposition recovery of heavy metals in concentrated solution of wastewater treatment by complexation ultrafiltration was studied. In the study, cheap plategraphite electrode was applied in the traditional electric cell reactor. Current density and mass concentration of the electrodeposition for cupric and zinc recovery were discussed, and the optimal condition were determined. The results showed that the current efficiency of cupric and zinc recovery were more than 60%, and corresponding power consumptions were 11.5 kW·h/kg and 14.0 kW·h/kg, respectively.