SU1740498A1 - Method of treating self-roasting anode of aluminium electrolyzer - Google Patents

Abstract

The invention relates to the technology of producing aluminum in electrolytic cells with self-baking anodes with an upper or side current lead and, in particular, to the technology of serving anodes. The aim of the invention is to improve the quality of the anode, reducing the consumption of carbonaceous materials and electricity. The sealing of the sintered part of the anode 1 is achieved by vibro-processing the liquid phase of the anode 2 with a package of vibrators 7 to a depth of 0.9 of the height of the liquid phase layer. The frequency of vibration is 15-200 Hz. 1 hp f-ly, 4 ill.

Description

The invention relates to a technology for producing aluminum in electrolyzers with self-firing anodes with top or side current supply, and, in particular, to the technology for servicing anodes.

The aim of the invention is to improve the quality of the sintered part of the anode, reducing the consumption of carbon materials and electricity.

The goal is achieved by deep vibration processing of the upper phase of the anode with an oscillation frequency of 15-200 Hz.

The industry is constantly growing the number of areas of application of vibration machines, but the basic information on the principles of operation, parameters of the vibration machine, the basics of their theory and calculation relate to the use of vibration technology in relation to concrete mixtures and building materials.

The anode mass, being in the liquid phase of the anode, has physico-mechanical properties that differ sharply from the properties of concrete mixtures: the temperature of the diluted anode mass is 150-250 ° C, the fluidity and viscosity of the liquid phase of the mass on the pitch binder differs from the fluidity of the concrete mixture in a water-cement mortar . These circumstances, as well as a high magnetic field and a gassed medium, dictate the need for mechanization of the operation of vibration processing of the liquid phase of the anode of an aluminum electrolyzer.

To mechanize the process of vibro-processing the liquid phase of the anode and to eliminate the harmful effects of vibration on humans, it is proposed that the vibrators in the form of a vibration package be equipped with portal open-rail machines (MPRs), which are in operation at a number of aluminum smelters. electrolyzer housings intended for processing electrolyzers: destruction of the electrolyte crust and filling of a new portion of alumina, or a vibrating package to transport and process the liquid phase of the anode using a bridge crane. To perform the operation of vibrating the liquid phase of the anode, the most appropriate exciters are sinusoidal vibrations - depth vibrators, for example, models PV-47 or IV-107 whose technical characteristics satisfy the technological requirement: mix and compact without segregation of coke fractions,

The proposed parameters of vibrational excitation of the liquid phase of the anode (ZHAM) of the aluminum electrolyzer are limited by the following factors .;

Oscillation frequency. Tests were conducted on several anodes of industrial electrolyzers of two centrifugal vibrators and a pneumatic jackhammer, generating various oscillations in frequency:

1. Planetary (deep), generating oscillations of 10,000 counts / min (^ 165-170 Hz), with an engine power of 0.75 kW.

2. Unbalanced, generating oscillations of the working body-2800 count / min (~ 50 Hz), with an engine power of 0.4 kW.

3. A pneumatic jackhammer generating vibration-shock vibrations of 600 counts / min (-I0 Hz).

When lowering (introducing) the planetary vibrator into the upper phase of the anode (high-medium environment), the vibrations of the vibrator gradually died out, i.e. were absorbed by the medium, which is explained by insufficient drive power to use a high vibration frequency in a viscous medium.

The working body of an unbalanced vibrator, similar in shape to a deep vibrator, was repeatedly introduced into a highly viscous medium without reducing the number of vibrations, ensuring the transmission of vibrations in the medium, which was densely deposited.

Although the action of vibration-shock vibrations of the pneumatic hammer influenced a viscous medium, this mechanism was rejected from further studies as it emits significant noise.

As a result, the conclusion was drawn: on a viscous medium, which is the anode mass in the upper phase of the anode, the most effective sealing effect is exerted by relatively low-frequency oscillations with less energy.

Thus, the range of optimal mechanical vibrations for the method of processing the upper phase of the anode can be limited to more narrow limits, i.e. 15-200 Hz.

To reduce the effect of high temperature of the medium on the vibrator bearings, the bottom of the vibrator housing must be increased with a cylindrical nozzle (tip) to a length of 250-350 mm. those. to the depth of processing of the liquid phase of the anode, or use forced pulsed blowing of the vibrator body at the moment of transition from one immersion position to another with compressed air. The vibration time at the place of one immersion of the working body of the vibrators in the anode mass should not exceed 30 s.

To direct coke particles in the liquid phase down and to the sides, i.e. compaction with stirring; mount the vibrators in the vibration package at an angle of 30-40 ° to the vertical axis. ·

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The vibrator motors must be protected with an antimagnetic and dustproof casing - a screen.

Figure 1 shows the anode of the electrolyzer, a cross section; figure 2 - vibropackage 5 of four vibrators, for example, model IV-47 with a flexible shaft, transported by an electric crane; in Fig.Z - open-rail car, front view; figure 4 is the same side view. 10

Figure 1 indicates: 1 - sintered (coked) part of the anode; 2-liquid phase of the anode; 3 - recommended longitudinal zones of vibration processing of the liquid phase of the anode: 4 places (rows) of the location of the anode top 15 lead pins; 5 - casing of the anode of the electrolyzer. .

The flexible shaft is shielded by a metal tube 6, rigidly connected to the body of the vibrator 7 and to the frame 8 of the vibration package. Electric 20 high-power trodigators are protected by an antimagnetic casing 9.

. The floor-rail machine is designed to process the crust of the electrolyte and load alumina into the electrolyzer, and is equipped with 25 vibropack of 10 vibrators 11 of model IV-47 IV-107. The contour line in Fig. 3 shows the size of the cell. The vibration package 10 is mounted in the guide frame 12. The vertical movement of the vibro-30 package from the transport to the working position is carried out using a winch 13, controlled by the MPR operator from the cab 14.

Vibration package 10 is in the transport (35) position and three rows of vibrators 11, four vibrators in a row, are mounted in it.

: The operation of vibrational excitation of the liquid phase of the anode is performed as follows.

The MPR operator installs the machine above the electrolyzer so that the last row of vibrators 11 is inside the end of the anode casing 5, includes 45 winch 13 for lowering the vibration package 10 from the transport position to the working one, and then turns on the power to the vibrators

11. The immersion depth of the vibrators in the liquid phase is controlled by a limit switch, after which the vibration package is automatically turned on 10. When the working bodies of the vibrators exit the anode mass, the MPR operator moves the MPR to the vibration processing step equal to the width of the vibropackage, towards the untreated part of the anode, and the operation is repeated . The processing time of one anode of the electrolyzer is approximately (with the movement of the MPR) 5-7 minutes.

The use of deep vibration processing of the liquid phase of the anode with deep vibrators allows you to compact the body of the anode, especially its periphery, i.e. improve the quality of the anode, its strength, reduce porosity; apply the anode mass with a reduced content of pitch (binder), without impairing its fluidity in the anode as a result of fluidization by vibrators; reduce the rate of combustion of the compacted anode mass; reduce flaking of the anode; to improve the contact of the anode mass - the conductive pin ;, reduce the consumption of technological electricity, as the current flows through the uniformly sealed coke-pitch mass of the primary anode.

Deep vibration of the liquid phase of the anode provides savings.

Claims (2)

Claim 1. A method of processing a self-baking anode of an aluminum electrolyzer, including forming the anode by loading, leveling and mixing the crude anode mass. Characterized in that, in order to improve the quality of the anode, the formation of the anode is carried out by applying vibration to the liquid phase of the anode to a depth of 0.9 of the height of the liquid phase. 2. The method according to claim 1, characterized in that the vibration is carried out with a frequency of 15-200 Hz. Compiled by S. Machov · Editor N. Shvydkaya Tehred M. Morgenthal Corrector M. Sharoshi Order 2055 Circulation Subscription VNIIIPI of the State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.