scholarly journals An Automated Instrument for the Determination of the Effects of Impurities on the Cathodic Current Efficiency During the Electrowinning of Zinc

1976 ◽  
Vol 9 (5) ◽  
pp. 531-542
Author(s):  
A.P. Saunders ◽  
I. Philip ◽  
J.P. Martin
Keyword(s):  
Current Efficiency ◽  
Cathodic Current ◽  
Cathodic Current Efficiency ◽  
Automated Instrument

scholarly journals Electrodeposition of Zn-Fe Alloy from Non-Cyanide Alkaline Sulphate Bath Containing Tartarate

2020 ◽  
Vol 6 (1) ◽  
pp. 180-183 ◽  
Author(s):  
V. Narasimhamurthy ◽  
L.H. Shivashankarappa
Keyword(s):  
Surface Morphology ◽  
Current Efficiency ◽  
Iron Content ◽  
Operating Conditions ◽  
Cathodic Current ◽  
Cyclic Voltammetric ◽  
Cathodic Current Efficiency ◽  
Voltammetric Studies ◽  
Sulphate Bath ◽  
Cyclic Voltammetric Studies

Electrodeposition of Zn-Fe alloy from an alkaline sulphate bath containing tartarate has been carried out. The effect of plating variables on the composition of alloy and on cathodic current efficiency was studied. The cyclic voltammetric studies carried out to know the mutual co-deposition of zinc and iron. Hardness and the surface morphology of the alloy deposits were found to be dependent on the iron content in the alloy. An alloy containing 20% wt. Fe showed smooth, uniform and finer grained deposits. Under the optimum composition and operating conditions, Zn-Fe alloy deposition from alkaline sulphate bath containing tartarate followed anomalous depositing process.

scholarly journals Methods to Determine the Current Efficiency in AC Electrolysis

2020 ◽  
Vol 46 (1) ◽  
pp. 343-352
Author(s):  
S. Yu. Kireev ◽  
Yu. P. Perelygin ◽  
S. N. Kireeva ◽  
M. J. Jaskula
Keyword(s):  
Current Efficiency ◽  
Double Layer ◽  
Pulse Current ◽  
Metal Deposition ◽  
Cathodic Current ◽  
Cathodic Current Efficiency ◽  
Deposition Processes ◽  
Methods Analytical ◽  
Experimental Researches

AbstractThe paper presents several methods (analytical, electromechanical and electronic) for determining the cathodic current efficiency of the metal deposition processes carried out by AC or pulse current. Based on the results of own experimental researches (for indium, cadmium, nickel, tin and zinc), the appropriate equations are given and the distribution of both faradaic and non-faradaic parts of charge (charging of the electrode double layer) is calculated.

The Research about EDTA Plating Solutions of Non-Cyanide Copper Plating

2012 ◽  
Vol 472-475 ◽  
pp. 2795-2800
Author(s):  
Ren Chun Fu ◽  
Zhong Cheng Guo ◽  
Wei Min Zhou ◽  
Zhen Chen
Keyword(s):  
Current Efficiency ◽  
Complexing Agent ◽  
Copper Plating ◽  
Cathodic Current ◽  
Throwing Power ◽  
Cathodic Current Efficiency ◽  
Plating Solution ◽  
Better Than ◽  
Covering Power

Six formulae of plating solution were studyed in the experiment. The first formula was cyanide plating solutions. The others formulae based on the EDTA as primary complexing agent, C6H5O7K3•H2O and KNaC4H4O6•4H2O as auxiliary complexing agent. Bath quality of the six formulae were examined and Compared. The results show that the EDTA system improve the ability of throwing power, covering power, current efficiency and reduce the bath voltage. In some ways, the performance of EDTA system were better than cyanide plating solutions, such as the deep plating ability, dispersing power, cathodic current efficiency.

Dependence of Titanium Deposition upon Its Ionic State in Molten Salt

2004 ◽  
Vol 449-452 ◽  
pp. 453-456 ◽  
Author(s):  
Toshihide Takenaka ◽  
Masahiro Kawakami ◽  
Naoyuki Suda
Keyword(s):  
Current Efficiency ◽  
Molten Salt ◽  
Electrode Reaction ◽  
Disproportionation Reaction ◽  
Cathodic Current ◽  
Ionic State ◽  
Average Valence ◽  
Cathodic Current Efficiency ◽  
Ionic Valence ◽  
Fluoride Addition

The ionic valence of Ti changed with electrorefining process of Ti in a bath equi-molar mixture of NaCl-KCl containing TiCln(n=2 or 3); The average valence was about 2.3 initially, and became about 2.1 after electrolysis. The cathodic current efficiency was getting better with electrolysis. It should be necessary to maintain the average ionic valence lower for efficient electrolysis in the molten salt. The dominant Ti ion and its electrode reaction changed with the addition of NaF-KF in the molten salt; The average valence shifted from about 2 to about 3, and the total amount of Ti in the bath decreased. The result indicates the disproportionation reaction: 3Ti2+= Ti + 2Ti3+is induced by the fluoride addition. The quantity of electricity for Ti deposition changed consequently, and the purity of the Ti deposit was also affected.

scholarly journals The study of Zn–Co alloy coatings electrochemically deposited by pulse current

2012 ◽  
Vol 66 (5) ◽  
pp. 749-757 ◽  
Author(s):  
Jelena Bajat ◽  
Miodrag Maksimovic ◽  
Milorad Tomic ◽  
Miomir Pavlovic
Keyword(s):  
Surface Roughness ◽  
Current Efficiency ◽  
Direct Current ◽  
Current Density ◽  
Pulse Current ◽  
Pulse Plating ◽  
Cathodic Current ◽  
Average Current Density ◽  
Corrosion Stability ◽  
Average Current

The electrochemical deposition by pulse current of Zn-Co alloy coatings on steel was examined, with the aim to find out whether pulse plating could produce alloys that could offer a better corrosion protection. The influence of on-time and the average current density on the cathodic current efficiency, coating morphology, surface roughness and corrosion stability in 3% NaCl was examined. At the same Ton/Toff ratio the current efficiency was insignificantly smaller for deposition at higher average current density. It was shown that, depending on the on-time, pulse plating could produce more homogenous alloy coatings with finer morphology, as compared to deposits obtained by direct current. The surface roughness was the greatest for Zn-Co alloy coatings deposited with direct current, as compared with alloy coatings deposited with pulse current, for both examined average current densities. It was also shown that Zn-Co alloy coatings deposited by pulse current could increase the corrosion stability of Zn-Co alloy coatings on steel. Namely, alloy coatings deposited with pulse current showed higher corrosion stability, as compared with alloy coatings deposited with direct current, for almost all examined cathodic times, Ton. Alloy coatings deposited at higher average current density showed greater corrosion stability as compared with coatings deposited by pulse current at smaller average current density. It was shown that deposits obtained with pulse current and cathodic time of 10 ms had the poorest corrosion stability, for both investigated average deposition current density. Among all investigated alloy coatings the highest corrosion stability was obtained for Zn-Co alloy coatings deposited with pulsed current at higher average current density (jav = 4 A dm-2).

Substitution of Cupric Sulfate for Mercuric Oxide as Catalyst for the Kjel-Foss Instrument

1976 ◽  
Vol 59 (1) ◽  
pp. 219-220
Author(s):  
Larry L Wall ◽  
Charles W Gehrke
Keyword(s):  
Standard Deviation ◽  
Mercuric Oxide ◽  
Experimental Sample ◽  
Cupric Sulfate ◽  
Protein Nitrogen ◽  
Feed Control ◽  
Relative Standard ◽  
Standard Configuration ◽  
Automated Instrument

Abstract A mixture of cupric sulfate and titanium dioxide and cupric sulfate alone were evaluated as possible catalysts to replace mercuric oxide in the determination of protein nitrogen, using the Kjel-Foss automated instrument. It was necessary to modify the instrument to increase the digestion time from 6 to about 12 min to achieve acceptable protein nitrogen recovery with cupric sulfate as the catalyst. An experimental sample set of nitrogen-containing salts and American Association of Feed Control Officials check feed samples were analyzed with the Kjel-Foss instrument in its standard configuration with mercuric oxide and as modified with cupric sulfate as the catalyst. The average per cent nitrogen, standard deviation, and relative standard deviation with mercuric oxide and cupric sulfate were 10.37 and 10.36, 0.040 and 0.042, and 0.53 and 0.56, respectively. The substitution of cupric sulfate for mercuric oxide is feasible, and it eliminates the use of the potential pollutant, mercury.

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