Abstract: Process for early detection of an anode effect in an aluminum production cell based on molten salt electrolysis. The cell comprises at least one anode, at least one cathode and cathode connecting conductors and anode connecting conductors.

Abstract: Process for early detection of an anode effect in an aluminum production cell based on molten salt electrolysis. The cell comprises at least one anode, at least one cathode and cathode connecting conductors and anode connecting conductors.

Abstract: The invention concerns a method for regulating an electrolytic cell designed for aluminium production by fused bath electrolysis enabling accurate and reliable control, in time and optionally in space, of the amount of alumina dissolved in the electrolytic solution (13). The inventive regulating method is characterized in that it comprises: a) controlling the addition of a specific amount Qo of alumina in the solution (13); b) determining the value of an indicator A of the added amount Q of alumina which is rapidly dissolved in the solution (13); c) determining the amount &Dgr;Q of added alumina which is not rapidly dissolved in the solution (13); d) adjusting at least one setting means and/or one control operation and/or at least an intervention on the cell, on the basis of the value obtained for the amount &Dgr;Q, so as to maintain it or bring it down to a value lower than a reference value S.

Abstract: A process for control of the alumina content of the bath in a cell for production of aluminum by electrolysis of alumina dissolved in a molten cryolite-base salt, consisting of alternation of phases of alumina underfeeding and phases of alumina overfeeding compared with a theoretical mean rate of alumina consumption of the cell, the said alternation being a function of values, calculated at the end of each control cycle i of duration T, of the mean resistance R(i) measured at the cell electrode terminals, of the rate of change of this resistance or resistance slope P(i), of the rate of change of the resistance slope or curvature C(i) and of the extrapolated slope PX(i)=P(i)+C(i).times.T, these values being compared respectively with reference values Po, Co and PXo in order to modulate, according to an appropriate control algorithm, the alumina content of the bath in a very narrow concentration range between 1.5 and 3.5%.

Abstract: The process according to the invention solves the problem of the individual thermal regulation of electrolytic pots. It involves acting on the temperature of the pot by means of the setpoint resistance Ro which is modulated so as to correct the temperature both by anticipation and by reversed feedback. On the one hand, correction by anticipation, known as "a priori" correction allows for known, quantified disturbances and allows their effect on the temperature of the pot to be compensated in advance. On the other hand, reversed feedback correction, known as "a posteriori" correction, involves determining, from direct measurement at regular time intervals of the temperature of the electrolytic bath, a mean temperature corrected as a function of periodic operating procedures and allows the variations and deviations from the setpoint temperature to be compensated.