Moebius cell

The Moebius cell uses a more conventional and compact cell design with vertical electrodes. The anodes are enclosed in cloth bags and the cathodes are equipped with vertical mechanical scrapers to continuously remove the silver deposit, which drops to the bottom of the ceU. 

In the Moebius cell (Fig. 4.12k the anodes arc cast, drilled, then bolted to hanger bars, A woven cloth or polymer bag of conlrotted porosity surrounds the anodes to catch slime. The cathodes are usually stainless-steel plates which... 

Floor space Smalt Large (up to 5 times that of a Moebius cell)... 

The above requirements lead to the need for relatively simple geometries usually based on tank cells where the anodes are surrounded by porous bags, baskets or membranes to contain anode debris and slime. There are two traditional cell designs which, with modern improvements in engineering design and constructional materials, persist today. The Moebius cell uses a vertical electrode arrangement, while the Balbach cell (later improved by Thum) uses horizontal electrodes. 

Fig. 4.12 Sectional view of a Moebius cell for electrorefining of silver.

Feature Moebius cell Balbach-Thum cell... 

An acceptable industrial process for the electrorefining of gold was first developed and implemented at the Norddeutsche Affinenie, Hamburg, 1878, by Wohlwill. The Wohlwill cell is broadly similar to the Moebius cell for silver, as it... 

Balbach A variation of the Moebius process for electrolytically removing gold from silver, in which the anodes are placed horizontally in wooden trays lined with canvas to retain the slimes. The silver is deposited as crystals on graphite cathodes at the base of the cell. Invented by E. Balbach. See also parting, Parkes, Thum, Wohlwill. 

Moebius, J., Zahedi, R.P., Lewandrowski, U., Berger, C., Walter, U. and Sickmann, A. (2005) The human platelet membrane proteome reveals several new potential membrane proteins. Mol. Cell Proteomics 4, 1754-1761. 

Wubbolts, R.W., Leckie, R.S., Veenhuizen, P.T., Schwartzmann, G., Moebius, W., Hoemschemeyer, J., Slot, J.W., Geuze, H.J. and Stoorvogel, W. (2003) Proteomic and biochemical analyses of human B cell-derived exosomes potential implications for their function and multivesicular body formation. J. Biol. Chem. 7, 10963-10972. 

Bashforth F and Adams JC (1883) An attempt to test the capillary action, Cambridge University Press and Deighton Bell Co., Cambridge Chen P, Kwork DY, Prokop RM, del-Rio 01, Susnar SS and Neumann AW (1998) Axisymmetric drop shape analysis (ADSA) and its applications , in Drops and bubbles in interfacial research, D. Moebius and R. Miller Eds., Studies in Interface Science Series, Vol. 6, Elsevier, Amsterdam Dukhin SS, Kretzschmar G and R. Miller R (1995) Dynamic of adsorption at liquid interfaces. Theory, experiments, applications, D. Moebius and R. Miller Eds., Studies in Interface Science Series, Vol. 1, Elsevier, Amsterdam Joos P (1999) Dynamic Surface Phenomena, VSP, Utrecht, 1999 Kovalchuk VI, Zholkovskij EK, Kragel J, Miller R, Fainerman VB, Wiistneck R, Loglio G and Dukhin SS (2000) Bubble Oscillations in a Closed Cell. J Colloid Interface Sci 224 245-254... 

Moebius JM, Widera D, Schmitz J, Kaltschmidt C, Piechaczek C (2007) Impact of polysialylated CD56 on natural killer cell cytotoxicity. BMC Inununol 8 13... 

A wide variation is found in the detailed design and operating parameters of Moebius-type cells but the typical range of conditions may be summarized A cell may have between four and twenty cathodes operating at 100- 500 A and from -1 5 to —2 8 V The cells arc usually operated near ambient temperature with a cathode current density of 20--40 mA cm While the cathode silver purity is dependent upon anode quality, electrolyte purity and operating conditions >99 9% wt Ag is usually obtained, with 99.99% wt being realized in some cases. 

Table 4.9 Comparispn of silver refining In the Moebius and Balbach-Tbiun cells...

There are many advantages and drawbacks to each type of cell (Table 4.9). The Moebius type of design is perhaps best suited to modern automated processing, while the Balbach-Thum cell is preferred for smaller use in low-technology markets. There are many modifications and indeed hybrids of the two cell designs. 

Table 4.9 Comparison of silver refining in the Moebius and Balbach-Thum cells...

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