Anode Overvoltages on the Industrial Carbon Blocks

Abstract

40 years ago W.Haupin stressed that anode overvoltages on the carbon materials have a scatter more than 300 mV under the same current density. This is a reason to attempt to find out the reason for greater differences because decreasing the overvoltage promises high energy saving. Experiments in lab.cells in galvanostatic conditions have been conducted to determine the overvoltages for the smelter anodes used in Sayanogorsk and Boguchany smelters (Russia) (more than 80 curves currentsovervoltages are received). Overvoltages are compared with other carbon block properties. Recommendations to use these values as a parameter of carbon block quality were made.

Study of influence of the charge granulometric composition on the quality of burned anodes

“…According to production experience, there is an upper limit of fine fraction content above which deterioration of mechanical properties is observed. The mentioned limit is determined by fineness of applied dust as well [4][5]. High content of fine fractions and dust reduces coarse fraction content in anode frame that in turn causes weakening of cohesion between particles.…”

“…The relevant literature review showed that increase in anodes density causes a decrease in gas permeability. Consequently, the consumption rate of anodes is reduced during electrolysis of cryolitealumina melts [1][2][3][4].…”

“…framework made of coke grain (filler) and binding component (matrix) from coal pitch. According to the theory of composite materials, end-product -composite exceeds by properties both its constituents [4].…”

“…On the other hand, an increase in dust fraction quantity improves anode blocks' mechanical strength and density. Intermediate fractions of coke charge mainly crumble during electrochemical anode oxidation and their amount is regulated [1][2][3][4][5][6].…”

Analytical Modeling of Current and Potential Distribution over Carbon and Low-Consumable Anodes during Aluminum Reduction Process

“…Anodic electrolytical process on carbon anodes is associated with considerable activation overpotential of approximately 500 mV at 0.8 A cm −2 . 35,36 It is generally assumed that such overpotential is linked with slow heterogeneous chemical reaction of C x O surface complexes decomposition:…”