SU981454A1 - Method for starting-up aluminium electrolyzer - Google Patents

Description

The invention relates to the metallurgy of aluminum by the electrolysis of a cryolite-alumina melt and can be used during the launch of new electrolyzers and after their major overhaul.

There is a method of starting an aluminum electrolytic cell, according to which aluminum is first poured, and then electrolyte 1.

The disadvantage of this method is that, according to slits in the interlock seams, aluminum penetrates into the bottom base and often after 1-2 days. from the start of start-up flows out. If it is impossible to stop the flow, the electrolyzer is shut off for major repairs.

In addition, the aluminum penetrating under the blocks begins to dissolve the cathode current-carrying rods, contaminating the JY metal, with iron. With a significant supply of iron, in order to avoid an emergency, the electrolyzer is shut off for major repairs long before the end of the regulated period of its operation.

There is also known a method for launching an aluminum electrolysis cell, which involves pouring electrolyte, an holding of 6–12 h, and pouring a metal 2).

In this method of start-up, the electrolyte flows into the gaps of the coal lining and hardens them. After the metal is poured and the hearth is heated to the electrolyte melting point, aluminum, which has a higher density compared to it, displaces the electrolyte from (targets and penetrates under the cathode blocks. Although the number of aluminum fluxes from

At the same time, the reduction of Trolysvre in this case somewhat decreases; it does not solve the problem of increasing its service life, since it does not reduce the entry of iron into aluminum from the dissolution of the cathode rods. ,

The purpose of the invention is the elimination of metal proteins from the electrolyzer during the starting period and an increase in the overhaul life of the electrolyte.

The goal is achieved by the fact that, according to a known method of starting -. As an aluminum electrolysis cell, including electrolyte filling, shutter speed 25 and aluminum casting, the shutter speed is carried out 2-4 days.

A distinctive feature of the method is an increase in the exposure time of the electrolyzer without aluminum. Wherein

30 it heats up to a temperature close to the working / and the electrolyte fills the pores and slits of the lining. AluminaHB electrolyte alumina is mixed with bottom material. The resulting aluminum carbide prevents further penetration of the cathode metal into the bottom blocks.

Example. The start-up of 10 electrolyzers per 150 kA. After the cathodes are fired, the nozzles are filled with 1,618 tons of electrolyte. The operating voltage is 7-10 V. The metal is poured in 2-4 days. The electrolyte temperature in this case is 1000-1050 C.

These tests show the absence of proteins during the starting period and trouble-free operation during the first year of operation. In addition, the average iron content in the cathode metal in the test baths is .0.18%, while in the electrolytes-witnesses, it is 0.26%.

The implementation of this method gives a significant economic effect due to the increase in the time between repairs.

operation of the electrolyzer, eliminating the overhead of manual labor in eliminating the effects of metal leaks and improving the quality of the aluminum produced.

Claims (2)

1. Reference metallurgist on nonferrous metals. Aluminum production. M., Metallurgists, 1971, pp.257-261. 2.Type Instructions for Firing and Starting Aluminum High-Power Electrolysers with Top Current Supply to the Anode 10-7-78. YOU, L., 1978, p. 8-15.