RU2687617C1 - Electrolysis cell for aluminum production - Google Patents

Abstract

FIELD: electrical engineering.SUBSTANCE: invention relates to electrolytic cell with self-baking anodes for aluminum production. Electrolysis cell comprises self-baking anode placed in anode casing, divided at boundary between coke-pitch composition and semi-coke zone by horizontal partition arranged at height from lower edge of anode casing and equipped with vertical cells, to form anode blocks held from falling into the melt by current-conducting pins, with cells arranged on the horizontal partition and with a gap, and an additional horizontal partition with windows arranged at the level of the upper edge of the anode cells, length and width of which is equal to length and width of vertical cells, and height of anode cells is equal to height of anode casing, at that space between horizontal partitions is filled with heat-insulating material.EFFECT: reduced heat losses through the anode device of the electrolytic cell and emissions of resinous substances from its surface.1 cl, 2 dwg

Description

The invention relates to the non-ferrous metallurgy and can be used to obtain aluminum in electrolyzers with self-caking anodes.

Known electrolyzer with self-baking electrode, comprising an anode divided into two sections, placed in two anode housings, between which a removable cover and cooling system are located in the form of loops of cooling air supply pipes [RU patent No. 2121014, dated January 6, 1995, publ. 10/27/1998].

The disadvantage of the known electrolyzer is the intensification of heat loss from the anode housings due to the increase in the total area of heat-generating surfaces and the use of air cooling with the help of pressure-blowing machines.

Known electrolyzer for aluminum, in which the self-caking anode contains three anode blocks, each of which is equipped with a longitudinal beam of the anode frame and two rows of current-carrying pins [patent RU №2187581, publ. August 20, 2002].

A disadvantage of the known electrolyzer is the difficulty of sealing the gas passage channels located between the anode blocks.

The closest in technical essence and the achieved result is an electrolyzer for aluminum production, which includes a self-caking anode placed in the anode casing at the border between the coke-pitch composition and the semi-coke zone separated by a horizontal partition placed at a height from the lower edge of the anode casing and equipped with vertical cells to form anode blocks held from falling into the melt by conductive pins, while the cells are placed with a gap between them to ensure the movement of anode gases in the gas exhaust system [RF patent 2657395 from 13.06.2018].

The disadvantage of the known electrolyzer is the risk of coking the liquid coke-pitch composition directly on the surface of the horizontal partition, as well as in a significant surface area of the liquid coke-pitch composition, from which the evaporation and entry of the resinous material into the atmosphere occurs.

The objective of the claimed invention is to reduce heat loss by the electrolyzer through the anode device and to reduce emissions of resinous substances from the surface of the self-caking anode.

The task is achieved by the fact that an electrolysis cell for aluminum production, including a self-baking anode placed in the anode casing, divided on the border between the coke-pitch composition and the semi-coke zone by a horizontal partition placed at a height from the lower edge of the anode casing and equipped with vertical cells, with the formation of anode blocks held by conductive pins from falling into the melt, with cells placed with a gap on the horizontal partition, at the same time, at the level of the upper edge of the anode cells ek equipped with an additional horizontal dividing wall with windows, the length and width of which is equal to the length and width of the vertical cells and a height equal to the height of the anode cell of the anode casing, wherein the space between horizontal partitions filled with insulating material.

The height of the anode cells equal to the height of the anode casing is justified by the fact that in this case all the anode mass consumed by the electrolyzer is loaded directly into the cell where the self-caking anode is formed - the melting of the anode mass and its transition to the liquid coke-pitch composition, and further coking, with initial formation char, and further - coke.

The expediency of an additional horizontal partition, at the level of the upper edge of the anode cells, is justified by the fact that in this case the layer of liquid coke-pitch composition is directly in the cell in which the self-caking anode is formed, and thus the emission of the resinous substances evaporating into the atmosphere is reduced from the surface of the anode.

The presence of a heat-insulating material between horizontal partitions reduces heat loss through the anode device and, thus, reduces the energy consumption of the electrolyzer and increases its energy efficiency.

The inventive aluminum electrolysis cell with a self-baking anode is illustrated by drawings.

 FIG. 1 shows a longitudinal section of the electrolyzer; FIG. 2 is a longitudinal section of the anode assembly of the electrolyzer, where: 1 is the anode housing; 2 - lower horizontal partition; 3 - current-carrying anode pins; 4 - anode cells; 5 - heat insulating layer; 6 - sintered anode blocks; 7 - cathode assembly of the electrolyzer; 8 - cryolite-alumina crust; 9 - exhaust pipe; 10 - upper horizontal partition; 11 - windows in a horizontal partition.

Aluminum electrolysis cell with a self-baking anode operates as follows. The anodic mass loaded into cells 4, as it is heated to a temperature of 80 ÷ 120 ° C, melts, passing first into the phase of the liquid coke-pitch composition, then into the solid phases of coke and coke. The formed anode block 6 is held in the cell by current-carrying anode pins 3. Rigid mounting of cells in the anode casing, the gaps between cells, and also between the cells and walls of the anode casing provide a horizontal partition 2 and 10, equipped with windows 11, the length and width of which are equal to length and width cells The reduction of heat loss through the anode device is provided by a layer of thermal insulation 5, placed between the horizontal partitions. The anode gases generated during coking and oxidation of the self-caking anode, through the gaps l ₁ between the cells 4, move to the gas outlet pipes 9, from where they are sent to the suction unit. The cryolite-alumina crust 8, covering the surface between the anode casing 1 and the cathode electrolysis unit 7, prevents the anode gases from being ejected into the atmosphere of the shell. Thus, reducing the path of movement of the anode gases under the anode blocks reduces the volume of the gas-containing electrolyte layer, and reducing the surface area of the liquid coke-pitch composition reduces emissions of evaporating resinous substances into the atmosphere of the housing.

The technical result of the proposed electrolyzer is to reduce heat loss through the anode device of the electrolyzer and emissions of resinous substances from its surface.

Claims (1)

Electrolyzer for aluminum production, containing a self-caking anode placed in the anode casing, divided at the boundary between the coke-pitch composition and the semi-coke zone by a horizontal partition placed at a height from the lower edge of the anode casing and equipped with vertical cells with the formation of anode blocks that are kept from falling into the melt by conductive pins, while the cells are placed with a gap on the horizontal partition, characterized in that it is provided placed at the level of the upper edge of the cells from the anode and further blocks with horizontal partition windows, the length and the width of which is equal to the length and width of said cells of said cell and the height equal to the height of the anode casing, wherein the space between horizontal partitions filled with insulating material.

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