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.

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The aluminum reduction process control system in recent decades has given great opportunities for improving the collection and processing of signals thatCitation: Puzanov I.I., Zavadyak A.V., Klykov V.A., Makeev A.V., Plotnikov V.N. Continuous monitoring of information on anode current distribution as means of improving the process of controlling and forecasting process disturbances,

The composition and fabrication technology of a repair mixture consisting of unmolded corundum with a TiB 2-C composite coating wettable with aluminum for repairing local fractures of bottom blocks without interrupting electrolysis have been developed. The proposed technical solution makes it possible to decrease the bottom wear and prolong the service life of an aluminum electrolyzer by six months. To fabricate a repair mixture with an optimal composition, the titanium diboride powder with a refractory powderlike binder in ratio 50 : 50 (wt %) is used. Unmolded corundum is coated with this mixture of a binder and titanium diboride. This material is dried at 150°C and thermally treated in a carbon bed at t = 700-900°C. Calcination in a reducing gas atmosphere results in the formation of the TiB 2-C composite material with a carbon content of 15-20 wt % on the unmolded corundum surface. The qualitative evaluation of the properties of the developed composite coating shows that it has rather high hardness, wear resistance, and adhesion to the base after calcination. To perform pilot tests, the repair mixture is poured with molten aluminum, which gives the platelike repair mass of the Al-TiB 2-C composition. Pilot tests of the repair mass using an RA-400 operating electrolyzer at the pilot shop of OAO RUSAL-Sayanogorsk show that the bottom wear decreases within three months after the repair of the local fracture with uninterrupted electrolysis. This fact is evidenced by a 13% decrease in an average fracture depth with a stable current force of 4.7-4.8 kA/bloom after the repair. Thus, the local use of the repair mass retards the overall wear of the cathodic surface and makes it possible to prolong the service life of the electrolyzer.