scholarly journals Obtaining Nickel Concentrates from Sludge Produced in the Process of Electrochemical Metal Surface Treatment

2021 ◽  
Vol 232 (12) ◽  
Author(s):  
Henryk Świnder ◽  
Paweł Lejwoda
Keyword(s):  
Surface Treatment ◽  
Sodium Hydroxide Solution ◽  
Nickel Sulphate ◽  
Sodium Sulphide ◽  
Nickel Plating ◽  
Icp Oes ◽  
Selective Precipitation ◽  
The Third ◽  
Nickel Concentrate ◽  
Electrochemical Surface Treatment

AbstractThe article presents the possibility of recovering nickel from waste produced as a result of wastewater neutralization during the electrochemical surface treatment of metals. Leaching the sludge with concentrated hydrochloric acid enabled the metals contained in the sludge from precipitate to the solution with the efficiency of 74.4% (Se) to 100% (Zn). The content of elements was determined using the ICP-OES method. The next step was the precipitation of metals from the obtained solution using various reagents. The precipitating reagents used were 0.5 M sodium hydroxide solution, 0.5 M sodium sulphide solution and 1% dimethylglyoxime solution. Selective precipitation made it possible to obtain nickel concentrates with the content of nickel ranging from 15.3 to 98.2% for the first two methods, whereas in the case of the third method based on a dimethylglyoxime solution, the obtained nickel concentrate purity was 94.3%. The process of leaching nickel-dimethylglyoxime complex (Ni-DMG) with sulphuric acid and crystallization enabled obtaining 99.4% purity nickel sulphate, which can be reused in the nickel plating of selected metals. The research shows that waste generated in the process of neutralization of wastewater from electroplating plants is a potentially important source of recycled nickel concentrates.

Ranking of metallic and non-metallic coatings in the electrochemical surface treatment sector

2021 ◽  
pp. 54-58
Author(s):  
E. G. Vinokurov ◽  
T. F. Burukhina ◽  
I. S. Kuroshev
Keyword(s):  
Surface Treatment ◽  
Correlation Coefficient ◽  
The United States ◽  
Critical Value ◽  
Electrochemical Methods ◽  
Metallic Coatings ◽  
Metal Coatings ◽  
Technical Research ◽  
Priority Areas ◽  
Electrochemical Surface Treatment

The distribution of coatings by the frequency of their application during surface treatment by electrochemical methods is considered. This is important not only for understanding the structure of the electrochemical surface treatment sector, but also for identifying priority areas of scientific and technical research. Nonparametric statistical methods show the uniformity of samples and reveal the relationship between the number of enterprises that sell a certain type of coating, i.e. the frequency of applying a certain type of coating in different countries (USA, Japan, Italy, France, Germany, Great Britain, Spain, Canada, Mexico, Russia, South Africa). The results of testing the hypothesis of a close relationship between the ranks of coatings showed that a significant correlation was found between the distribution of coatings by the frequency of their application (implementation) among all countries. For example, when comparing the United States and Canada, the rank correlation coefficient is 0.62 (the lowest value obtained), which is greater than the calculated critical value of 0.56; when comparing Italy and Spain, the correlation coefficient takes the highest value of 0.97, which is greater than the critical value of 0.19. The results obtained allowed us to use this data to compile a generalized rating of the frequency of use of all coatings based on data from different countries. Based on the analysis, metal coatings can be arranged in a row according to the descending frequency of their application: Cr > Ni > Zn > Cu > Cd. The results of the ranking of coatings showed that the most commonly used electrochemical methods for surface treatment are metal coatings with chromium and nickel, and among the inorganic non – metallic coatings-oxide and then phosphate, which allows us to highlight the research devoted to the application of these coatings as priority areas of scientific and technical research.

scholarly journals Reverse-bias leakage current reduction in GaN Schottky diodes by electrochemical surface treatment

2003 ◽  
Vol 82 (8) ◽  
pp. 1293-1295 ◽  
Author(s):  
E. J. Miller ◽  
D. M. Schaadt ◽  
E. T. Yu ◽  
P. Waltereit ◽  
C. Poblenz ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Leakage Current ◽  
Reverse Bias ◽  
Schottky Diodes ◽  
Current Reduction ◽  
Electrochemical Surface Treatment

THE SULPHUR CONTENT OF CRUDE NAPHTHA FROM TURNER VALLEY IN RELATION TO REFINING PRACTICE

1933 ◽  
Vol 8 (2) ◽  
pp. 119-128
Author(s):  
T. W. Shipley
Keyword(s):  
Sodium Hydroxide ◽  
Sulphuric Acid ◽  
Sodium Hypochlorite ◽  
Sodium Hydroxide Solution ◽  
Cupric Chloride ◽  
Sulphur Content ◽  
Residual Fraction ◽  
Sodium Sulphide ◽  
Yellow Color ◽  
Free Sulphur

Typical samples of Turner Valley naphtha were examined for their sulphur content and for their behavior towards common refining treatments. The sulphur content ranged from 0.15 to 0.19% and consisted of sulphides, organic disulphides and mercaptans. Thiophenes were present, but in very small amounts. No free sulphur or peroxides were detected. Distillation concentrated the color and color producing compounds and the gum and gum producing compounds in a small high-boiling residual fraction. Exposure to light, even in the absence of air, led to the development of a yellow color and to gum formation in all undistilled samples, treated or untreated. Distillation up to 165 °C. yielded a fraction (95% by volume) which remained colorless and free from gum formation when exposed to the air and to light for over eight months.Recovery of the propane and butane is recommended, and the treatment of the crude naphthas with sodium hydroxide solution or with sodium hydroxide and sodium sulphide solutions followed by distillation is suggested as a means of producing a fairly satisfactory gasoline. The caustic wash alone reduces the sulphur content to about 0.1%, while the alkaline-sodium sulphide wash reduces it to about 0.05%.Sulphuric acid, sodium hypochlorite, caustic wash, sodium plumbite and cupric chloride treatments were examined and the refined products compared for sulphur content, sweetness, corrosion, gum formation and color. None of these treatments prevented gum formation or the development of color when the treated samples were exposed to light.

scholarly journals Analysis of technological approaches to electrochemical surface treatment of aluminum alloys

2020 ◽  
Vol 3 (12 (105)) ◽  
pp. 44-55
Author(s):  
Ann Karakurkchi ◽  
Mykola Sakhnenko ◽  
Maryna Ved’ ◽  
Mykhailo Tulenko ◽  
Anatolii Dzheniuk
Keyword(s):  
Aluminum Alloys ◽  
Surface Treatment ◽  
Electrochemical Surface Treatment

Development of Electrochemical Surface Treatment for Improvement of Localized Corrosion Resistance of Zirconium in Chloride Environment

2020 ◽  
Vol 69 (11) ◽  
pp. 307-314
Author(s):  
Tomoyo Manaka ◽  
Yusuke Tsutsumi ◽  
Maki Ashida ◽  
Peng Chen ◽  
Hideki Katayama ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Surface Treatment ◽  
Localized Corrosion ◽  
Chloride Environment ◽  
Electrochemical Surface Treatment

scholarly journals Determination of the Content of Promoters in Magnetite and Wustite Phases in the Fused Iron Catalyst

2013 ◽  
Vol 15 (1) ◽  
pp. 27-29 ◽  
Author(s):  
Zofia Lendzion-Bieluń ◽  
Roman Jędrzejewski
Keyword(s):  
Aluminum Oxide ◽  
Iron Catalyst ◽  
Potassium Oxide ◽  
Oxide Content ◽  
Icp Oes ◽  
The Third ◽  
Instrumental Methods ◽  
Fused Iron Catalyst ◽  
Magnetite Phase

Taking advantage of differences in etching rates of crystallographic phases, forming an oxidized form of the fused iron catalyst, a content of promoters in main phases, magnetite and wustite, was determined. A calcium oxide content in magnetite and wustite was 0.54 wt% and 3.59 wt%, respectively. Aluminum oxide was found in the magnetite phase, and its content was 4.5 wt%. The third promoter, potassium oxide, was almost completely located outside these phases. XRD and ICP-OES instrumental methods were used in the investigations.

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