SU1014992A1 - Method for starting-up and putting in normal operation electrolytic cell for producing aluminium - Google Patents

Abstract

Starting and entering the normal operation of the electrolyzer for aluminum production, including electrolyte filling, controlled voltage boost on the electrolyzer before the anode effect and subsequent reduction of the electrolyte to the working voltage, i have i, i i have i, i i have i i'm, i i i i i i i i i i-i-i-to-i , fluoride salts at start-up and PSF increase in the service life of the electrolyzer, the voltage rise is carried out at a speed of 5-10 V / h, and the voltage decrease is carried out in two stages: at the first - at the same speed up to a voltage of 8.0 - 8.5 V ,, and on the second - with speed O, 3 - O, 5 V to (L voltage 4, O - V.

Description

aluminum by an electrolytic method and is aimed at improving the technological operations of the start-up and the post-launch period of any type of aluminum electrolysis cells. The known method (start-up of aluminum electrolysis cells, including pouring electrolyte and raising the voltage to the anode effect and the subsequent reduction of the voltage across the compressor to the worker 11. The disadvantage of this method is extremely low pressure to the working one. The result is a method of starting and putting the electrolyzer into normal operation for producing aluminum, including electrolyte filling, controlled voltage rise on the electrolyzer to The anode effect and its subsequent reduction to operating voltage f 2. The disadvantages of this method are the high consumption of electricity, fluoride salts at start-up and the short life of the electrolyzer. The purpose of the invention is to reduce the consumption of electricity of fluoride salts at start-up and increase the service life of electrolysis. is achieved by the fact that in the method of starting and putting into operation the electrolyzer to produce aluminum, including pouring electrolyte, controlled voltage rise on the electrolyzer to the anodic effect of an ect4) and its subsequent reduction to the operating voltage, the voltage rise is carried out at a speed of 5-10 V / h and the voltage reduction is carried out in two stages: at the first stage, at the same speed up to voltage 8, 0 - 8.5 V, and on the second - with a speed of 0.3 - 0.5 V / h to a voltage of 4.0 - 4.4 V. Regulating the start of the electrolyzer, set the time at which the electrolyzer at the start is on the increased voltage of the anode effect (in (1)) increases by a factor of 3–4. During this time, the cathode device warms up to the operating temperature, and the surface carbon bottom and side lining reach 950 970 C. The anode remaining from the previous campaign is aligned with the volt arc of the repaired electrolyzer. The good condition of the anode, the high temperature of the majority of Kettode device nodes make it possible to quickly in an intensive enhanced mode to reduce the interpolar distance to the explosive ground within 8-10 hours. As practice has shown, the average voltage fluctuations during the start-up of 5-1O V / h and when conducted after a usable period of 0.3-0.5 V / h are optimal and allow the aluminum electrolyzer to be put into normal operation within the earliest time. A decrease in the rate of change of voltage less than 5 V / h can lead to overheating of the cathode device, and an increase in excess of 1 OV / h during start-up will not allow to obtain operating temperatures. An increase in the rate of decrease in voltage of more than 0.5 V / h does not allow the necessary system to control the technological parameters (electrolyte composition, electrolyte level). Reducing the operating voltage at a speed of 3 V / h is impractical, since the entire cathode device is already heated to operational telesheaths and increases the prolongation of the post-launch period, for example. The proposed start-up method and the post-launch period are carried out for 2 industrial ones. electric gasers. In the electrolyzer, according to the existing standards, raw materials are loaded: refined circulating electrolyte, cryolite, magnesite, sodium fluoride. After pouring 2.5 tons of electrolyte and increasing the interelectrode distance, the voltage of the electrolyzer is set to 12 V with half an hour exposure. Filling the second bucket with electrolyte (2.2 tons) and unscrewing the anode voltage of 18 V takes 0.5 h, after half an hour aging, pour 2.5 tons of electrolyte for 0.5 h and unscrew the anode to 25 V, for the next hour The fourth bucket (2.6 tons) of electrolyte is poured in and a voltage of 30 V is established with a discharge of 0.5 h. The decrease in the operating voltage from the HF B by decreasing the interelectrode distance is carried out as follows: to 25 V, followed by exposure for 1 hour, to 20 V with subsequent aging for 1 hour, to 15 V - for 1 hour, up to 12 V - shutter speed 0,5 h

3,014,924

up to 8 V - 0.5 h. Thus. Start-up and entry times into normal

aom, the start-up of the process for 7 hours, which is taken off from the electrolyzer No. 1,

Known working voltage from 8 V to nor-is 16.5 hours and for the electrolyzer

minor t, e. to 4,4 - 4B for 9 hours № 2 - 15.5 hours

30 mVn (every 0.5 h is snugly stressed. S Obtained data from two experimental

pushed on 0.2 V). electrolyzers are tabulated.

The use of the proposed method of starting the electrolyzer for the fabrication of alkalis provides the advantages as compared with the well-known sources: an increase in the service life by 0.19 g, a decrease in the electric power consumption not less than 30 thousand kW / h during the start-up of one electrolyzer;

reducing the consumption of fluorine salts, for example, krvolit, on O, 5 t at the start of one electrolysis a.

The economic effect of using

: inventions, composites 59 Tbfc. rub. to finish the overhaul of the electric series.

Claims (1)

METHOD OF STARTING AND ENTRY IN NORMAL OPERATION OF THE ELECTROLYZER FOR PRODUCTION OF ALUMINUM, including pouring the electrolyte, controlled increase of voltage on the electrolyzer to the anode effect and its subsequent reduction to the operating voltage, distinguishing it from the fact that, in order to reduce the energy consumption, salt when starting and increasing the life of the electrolyzer, the voltage is raised at a speed of 5-10 V / h, and the voltage is reduced in two beds: on the first - at the same speed to a voltage of 8.0 - 8.5 V, and at g in the second - at a speed of 0.3 - 0.5 V to a voltage of 4.0 - 4.4 V. SLL. " 1014992