Download or read book Using Zinc Cathodes for Zinc Electrowinning written by Ernest R. Cole and published by . This book was released on 1979 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Zinc Cathodes for Zinc Electrowinning written by Ernest R. Cole and published by . This book was released on 1979 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Zinc Electrowinning written by Roberto C. Villas-Bôas and published by CYTED-CETEM. This book was released on with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive study on zinc electrowinning and the fundamentals and practices of the same, under the influence of several important industrial variables and impurities associated with the leached concentrate.
Download or read book Fundamental Study of the Role of Cathode Structure on Zinc Electrowinning written by Horacio M. Aros and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The influence of cathode macromorphology on the current efficiency of zinc electrowinning was determined. The studies have shown that surface roughness affects current efficiency during zinc electrowinning, particularly when the electrolyte contains impurities such as nickel and antimony. Current efficiency does not change with surface roughness as long as the electrolyte is sufficiently pure. Zinc deposited on smooth zinc cathodes tends to retain a more favorable structure and macromorphology, which is less sensitive to the effects caused by antimony and nickel. Glue helps to counteract the effect of the impurities; however, its presence in the electrolyte at certain combinations with other additives produces an increase in surface roughness and a dramatic decrease in current efficiency. A definite relationship was observed between the data obtained by cyclic voltammetry and the long time current efficiency tests. A statistical screening design program was conducted to determine the individual effects and interactions of temperature (35-45°C), antimony (0.02-0.06 mg/l), nickel (1-5 mg/l), glue (5-15 mg/l) and acid concentrations (175-225 g/l) on current efficiency. The results show that smooth zinc cathodes are less susceptible to impurity attack while rough deposits give consistently lower current efficiencies than smooth zinc. Under certain conditions, glue proved to be an important factor in influencing roughness evolution. The influence of cathode current distribution on current efficiency was also investigated. The effect of current density (up to 50 mA/cm2) and sulfuric acid concentration (150-250 g/l) on current efficiency was determined. The results show that low current densities (up to 10 mA/cm2) cause an increase in hydrogen evolution and an eventual dissolution of the zinc deposits. At the same operating conditions of current efficiency tests (12 hour deposition time), cyclic voltammetry tests show that the current rise measurements present a good correlation with current efficiency. Electrolytes containing antimony and glue show that, at low current densities, glue does not completely counteract the effect that antimony and high acid concentrations have on current efficiency. A proper chemical balance of the electrolyte was very critical. The experimental results have shown that surface macromorphology of the electrode was an important factor to be considered in the evaluating the efficiency of zinc electrowinning. In addition, surface macromorphology plays an important role in the interpretation of the impurity effects"--Abstract, leaves iii-iv
Download or read book Effect of Impurities and Additives on the Electrowinning of Zinc written by Harold H. Fukubayashi and published by . This book was released on 1974 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrowinning of Zinc from Zinc Chloride in Monopolar and Bipolar Fused salt Cells written by S. D. Hill and published by . This book was released on 1981 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Insoluble Anodes for Electrowinning Zinc and Other Metals written by Ernest R. Cole and published by . This book was released on 1981 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Addition Agents on Zinc Electrowinning from Kidd Creek Electrolyte written by D. J. MacKinnon and published by . This book was released on 1990 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Study to determine an effective additive control strategy for the Kidd Creek zinc electrorefinery. In this phase of the study, systematic laboratory tests followed by several plant evaluations were done to determine the optimum mix of the various reagents required to maximize zinc deposition current efficiency and maintain a low deposit lead content. The individual and combined effects of antimony, sodium silicate, Dowfroth and Saponin on zinc deposition current efficiency and polarization and on the zinc deposit morphology and preferred orientation were determined in 6-h electrolysis tests conducted at 38C and 500 A/sq m current density. Platinum anodes and aluminum cathodes were used with Kidd Creek electrolyte containing 55 g/L Zn and 200 g/L H2SO. The trends identified in the 6-h experiment were confirmed in 24-h electrolysis tests employing Pb-Ag anodes with SrCO3 additions to simulate plant operating conditions.
Download or read book The Electrowinning of Zinc in a Spouted Bed Electrode written by Juan Carlos Salas-Morales and published by . This book was released on 1994 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Corrosion and Electrochemistry of Zinc written by Xiaoge Gregory Zhang and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humankind's use of zinc stretches back to antiquity, and it was a component in some of the earliest known alloy systems. Even though metallic zinc was not "discovered" in Europe until 1746 (by Marggral), zinc ores were used for making brass in biblical times, and an 87% zinc alloy was found in prehistoric ruins in Transylvania. Also, zinc (the metal) was produced in quantity in India as far back as the thirteenth century, well before it was recognized as being a separate element. The uses of zinc are manifold, ranging from galvanizing to die castings to electronics. It is a preferred anode material in high-energy-density batteries (e.g., Ni/Zn, Ag/Zn, ZnJair), so that its electrochemistry, particularly in alkaline media, has been extensively explored. In the passive state, zinc is photoelectrochemically active, with the passive film displaying n-type characteristics. For the same reason that zinc is considered to be an excellent battery anode, it has found extensive use as a sacrificial anode for the protection of ships and pipelines from corrosion. Indeed, aside from zinc's well-known attributes as an alloying element, its widespread use is principally due to its electrochemical properties, which include a well-placed position in the galvanic series for protecting iron and steel in natural aqueous environments and its reversible dissolution behavior in alkaline solutions.
Download or read book An Investigation of the Failure Mechanisms of Aluminum Cathodes in Zinc Electrowinning Cells written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Zinc Electrowinning Analysis in a Modified Hull Cell written by Thomas Dean McColm and published by . This book was released on 1998 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of steelmaking slags by atomic absorption spectrophotometry using pressure dissolution written by Raymond F. Farrell and published by . This book was released on 1979 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrodeposition of Zinc written by Glen C. Ware and published by . This book was released on 1963 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrometallurgy 2012 written by Michael L. Free and published by John Wiley & Sons. This book was released on 2012-05-09 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of a symposium sponsored by The Metallurgy and Materials Society of CIM and the Hydrometallurgy and Electrometallurgy Committee of the Extraction and Processing Division of TMS (The Minerals, Metals & Materials Society) Held during the TMS 2012 Annual Meeting & Exhibition Orlando, Florida, USA, March 11-15, 2012
Download or read book Electrolytic Deposition and Hydrometallurgy of Zinc written by Oliver Caldwell Ralston and published by . This book was released on 1921 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simultaneous Recovery of Zinc and Manganese Dioxide written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Commonly solutions from which zinc is to be electrowon contain manganous ions resulting from manganese being present in the zinc concentrate or as a result of the addition of MnO2 to the process circuit as an oxidant. The process is aimed at maintaining a certain selected level of dissolved manganese in the zinc electrolyte, lower than would adversely affect the zinc electrowinning. Spent electrolyte is normally recycled to the leach plant to produce fresh electrolyte part or all of which is then fed to a primary electrolytic cell operating above 70 degrees C and preferably at 85 to 90 degrees C and with a low H2SO4 content - below 25 g/l. The surface area of the anode is approximately 3 times that of the cathode. Carbon is a suitable anode material and aluminium for the cathodes. The electrolyte leaving the primary cell will preferably contain 35 g/l H2SO4 but not more than 75 g/l. Zinc will have plated out on the cathode and MnO2 on the cathode. The electrolyte then passes to a secondary cell which is a conventional zinc electrowinning cell. Preferred current densities are about 300 A/m2 for the cathode and 100 A/m2 for the anode. The surface area of the anode is approximately 3 times that of the cathode. The cell must be agitated. A polyelectrolyte flocculent was used as a smoothing agent to suppress the formation of zinc dendrites. Typically the primary electrolyte will contain about 160 g/l of zinc and 20 g/l MnO2.
