Abstract: Busbar arrangements for aluminum electrolytic cells. In a first aspect, the invention provides at least one generally horizontal collector busbar on each side of the cell and a number of current tapping points along each collector busbar so that current flows along the collector busbar in opposite directions on each side of the taps. This produces changes of sign in the vertical component of the magnetic field acting on the pad in the longitudinal direction and helps to prevent pad instabilities. In a second aspect, the current taps for the collector busbars are vertically disposed so as to convey current well below the level of the metal pad so that adverse magnetic effects caused by further distribution of the current are minimized.

Abstract: An aluminium potline comprises rows of reduction cells with the cells arranged transversely in each row. The invention provides an asymmetric arrangement of busbars (1, 1', 2, 2') for conducting current from the upstream collector bars 16 of an aluminium electrolytic reduction cell 10 underneath the cell to the next downstream cell 12 in the row. One or more of the busbars is displaced longitudinally of the cell towards the end facing a magnetically dominating neighboring row of cells. The extent of the displacement is such as to counteract the magnetic field induced by the neighboring row.

Abstract: A method for controlling the rate of aluminum fluoride addition to a cryolite-based electrolyte of an aluminum electrolytic reduction cell makes use of the known ratio between cell temperature and bath (NaF:AlF.sub.3) ratio. A target temperature is established corresponding to a target bath ratio. The cell temperature is measured at intervals and the rate of AlF.sub.3 addition altered depending on whether the measured temperature is above or below the target temperature. The method is faster than traditional methods involving analysis of electrolyte samples, and is amendable to computer control.

Abstract: An electrolytic reduction cell for the production of molten metal by electrolysis of a molten electrolyte, which is less dense than the molten metal includes a generally rectangular shell, one or more suspended anodes and a floor structure which supports a body of the molten metal. At least one essentially linear baffle member extends transversely of the cell and is formed with restricted flow channels for absorbing energy from the molten metal and to reduce the amplitude of the wave motion in the molten metal. The baffle may be in the form of a single member formed with apertures for metal flow restriction or may be constituted by a number of separate aligned members with metal flow channels between them.

Abstract: In a apparatus for the production of aluminium a molten alumina slag, containing combined carbon is circulated through one or more alternately arranged relatively low temperature zones where carbon is added to increase the combined carbon content of the slag by reaction with the alumina slag and high temperature zones where aluminium metal is released by reaction of aluminium carbide and alumina in the slag with consequent depletion of the combined carbon content. Alumina is supplied to the slag at one or more locations. The energy to drive the reactions is preferably supplied by resistance heating of the slag particularly in transit from a low temperature zone to a high temperature zone although usually additional energy is supplied to the slag in the return from a high temperature zone to the next low temperature zone.In most instances the aluminium-liberating reaction is carried out in an upwardly inclined passage and the gas evolved is employed to achieve the circulatory movement of the slag.

Abstract: An electrolytic reduction cell for the production of aluminium has current collector bars running across the floor of the cell unitarily or in separate sections. Deformation of the molten metal/electrolytic bath interface is reduced by leading current out of the collector bars or bar sections at positions remote from their ends by connector bars connected to said positions.