DE1558757B2 - PROCEDURE FOR BREAKING THE CRUST IN THE EVENT OF CHARGING ALUMINUM FLOW ELECTROLYSIS CELLS - Google Patents

Description

already mentioned above, especially in connection with automatic furnace control and charging which the point in time is determined automatically

to be strictly differentiated from the 45 according to the invention to which alumina must be recharged in order to achieve a

Procedure for breaking the crust for charging.

The method according to the invention relates to breaking up the crusts when charging electrolysis cells for fused alumina for aluminum production with the aid of a movement of the anode system and is characterized in that, independently of the adjustment of the anodes, they are briefly moved vertically up and down. Thus the invention Anodenbeweguhgist ^{r j} sö well in time and dimensionally regardless of the above-described anode adjustment to comply with the optimal current flow during electrolysis. The vertical up and down movement according to the invention can be approximately 10 to 20 mm. The holding time between the opening processes is at least 20 times, expediently 200 times the movement time.

A device suitable for carrying out the method according to the invention has a lever 65 system on the suspension device for the anode system of each cell. By corresponding annealing impoverishment of the bath of alumina and thereby avoid polarization of the anodes (e.g. German Patents 1265 424 and 1260 156).

■ - : ■>' · ■■ Patent claims:

1. A method of breaking up the crusts when charging electrolytic cells for melt flow electrolysis, of alumina for aluminum production with the help of a movement 'v of the' anode system, characterized in that, independently of the adjustment of the anodes, these are briefly moved vertically up and down .

2. The method according to claim 1, characterized in that the vertical up and down movement the anode is about 10 to 20 mm.

3. The method according to claim 1 or 2, characterized in that the holding time between the Breaking operations is at least 20 times, preferably 200 times the movement time.

Claims (1)

The invention relates to a method for breaking up the crusts for charging electrolysis cells for melt flow electrolysis of alumina for aluminum production by moving the anode system. In the fused-salt electrolysis for the production of aluminum from alumina occur in particular in the automatic charging, because the crusts occur even with a healthy oven cycle often do not break in on the bath and thus the required clay is not supplied to the bath can be. In the past it was common for furnace personnel to occasionally use long poles for these Crusts broke open, leaving the fragments and broken pieces could sink into the bathroom. As is well known, however, forms in the shortest possible time even after such an oven poke Time again a hard crust, which often withstands further charging, and the oven aisle threatens to endanger. To this manual poking kung the lever system on a rail that the anode rods the cell sluggish, .at the ■. one side and the anode suspension on the rigid support on the other side is 'Rischen drive mechanism a raising and lowering of the working anodes over a certain amplitude a certain program allows. This up. and downward movement is independent of the so-called Electrode adjustment to keep the distance between the anodes and the mirror constant the aluminum melt lying on the bottom cathode. The setting of the electrode gap is generally done by adjusting the rigid support of the suspension device on its vertical Stands. The vertical movements according to the invention can have an amplitude of about 1 to 2 cm take place, whereby the Ausgarigslage is run through again and again. This lifting movement can, for. B. To avoid, one has to take complicated pokes from 2 to 5 seconds, followed by a holding time, the devices used, but which are expensive and generally at least 20 times, in particular which is 20 times the lifting time. The anode system of the ^ eIBn can either have only one or more anodes. The cell can be operated with self-baking or pre-fired anodes, which are attached to an anode rod on the adjusting mechanism. ** '- ^; ' ¹ It was used as an example of the inventive. Process a number of electrolysis cells with a current consumption of about 100 kVA and operated at the measuring anode of a current between 1.5 and 4 A / cm ² corresponding to a lower ^{alumina content of 2 1} Vo at the onset of the anode effect or an alumina content of 5 Vo . Each was checked every 15 minutes. The vertical movement of the anode system was 20 mm upwards and 30 mm downwards. In this way it was possible to break the crust to a satisfactory extent and to dissolve the recharged clay in the bath ment is required by the ongoing burn-up 40. ; / ' the working anodes on the one hand and the continuously increasing The method according to the invention is suitable, such as on the other hand, the metal mirror on the bottom electrode. This anode adjustment for compliance a steady flow of current through the bath are prone to failure. After all, attempts have already been made to shift the anode system to a certain extent, and although primarily a horizontal movement of the working anodes to break up the crust. The mechanics for such a lateral adjustment of the working anodes on the suspension device above each Cell is, as is easy to understand, quite complicated and prone to failure and the success is not satisfactory. Various mechanisms are known to: to carry out the so-called anode adjustment (USA.-Patents 2545413 and 2 930 746): ' This anode adjustment is used to ensure the optimal distance between the working anode and the mirror the aluminum melt, which rests on the bottom electrode, during the continuous melt flow electrolysis to be observed. This anode post