RU2237112C1 - Side liner for aluminum electrolyzer - Google Patents

Abstract

FIELD: non-ferrous metallurgy, in particular, production of aluminum on various kinds of electrolyzers.

SUBSTANCE: side liner has plates and blocks made from non-metallic refractory compounds of increased strength and connected with one another by means of end faces made in the form of inverse-symmetric protrusions and slots and gluing or cementing solution. Plates and blocks are manufactured from silicon carbide. Coal lumps used as blocks are made in the form of 5 mm thick and 650 mm long strips bent in the middle part around longitudinal axis at an angle of 90 deg, with side faces of strip extending in strictly vertical plane. End faces are made in the form of reverse-symmetric protrusions and slots having trapezium-shaped section with 22 mm and 24 mm sized bases of 88 mm height, said faces extending in vertical plane.

EFFECT: increased service life and enhanced reliability in operation, reduced consumption of lining material, increased useful volume of electrolyzer and increased yield of aluminum.

4 dwg

Description

The invention relates to non-ferrous metallurgy, in particular to the electrolytic production of aluminum, and in particular to the design of the cathode device of an aluminum electrolyzer, and can be used on electrolyzers of all types.

Known lateral lining of the electrolyzer, consisting of coal stoves and heat-insulating refractory. - Reference metallurgist on non-ferrous metals. Aluminum production. M.: Metallurgy, 1971, p.203-206.

The disadvantages of this side lining of the electrolyzer are: low strength, reliability, short service life.

As a result of the action of the components of the cryolite-alumina melt, a neck is formed on the lateral faces of the coal plates facing the melt, which, constantly increasing, leads to the destruction of the coal plates. Such destruction of coal stoves also leads to the destruction of the side lining, to the penetration of the melt to the metal casing and to the breakthrough of the melt from the bath of the cell.

Known lateral lining of an aluminum electrolyzer in the description of the invention to the patent of the Russian Federation No. 2186880 IPC, 7 C 25 C 3/08, dated 05.03.2001, ed. Gromov B.S., Pak R.V., Akhmedov S.N., publ. 08/10/2002.

1. The side lining of an aluminum electrolyzer, consisting of two parts made of a material with different resistance to the melt contained in the cell, of which the upper part is made of plates of non-metallic refractory compounds having high resistance, and the lower part is interconnected blocks of carbon-containing material having reduced resistance, characterized in that the plates of non-metallic refractory compounds are installed in a groove made in the upper faces of the blocks of carbon containing material, and connected to blocks of carbon-containing material by an adhesive or cementitious mortar or by sealing said groove with carbon-containing material.

2. Lining according to claim 1, characterized in that the plates of non-metallic refractory compounds are installed in two rows with ligation of the seams.

3. Lining according to claim 2, characterized in that the plates of non-metallic refractory compounds of the first and second row are interconnected by an adhesive mortar or cementitious composition.

4. Lining according to claim 1 or 2, characterized in that the plates of non-metallic refractory compounds are interconnected by adhesive or cementitious mortar.

Disadvantages: low strength, reliability, short service life.

The presence of a horizontal connecting seam between the two parts of the lining around the entire perimeter of the side surface of the aluminum electrolyzer dramatically reduces the reliability of the entire lining of the aluminum electrolysis cell, since such connecting seams are always subject to more intensive penetration of cryolite-alumina melt components into them, the absence of whole cast blocks at the corners of the aluminum electrolysis cell increases the likelihood of melt penetration to the casing of the aluminum electrolyzer in the corner joints of the lining, consisting of two hours This is because angles always experience increased mechanical stresses during operation of an aluminum electrolyzer.

The closest technical solution is the side lining of the aluminum electrolyzer in the ed. Certificate No. 377419, MKI C 22 D 3/02, publ. bull. No. 18, 1973, ed. Romanov V.N., Tsyplakov A.M.

1. On-board lining of an aluminum electrolyzer made of carbon-containing materials, characterized in that, in order to reduce the cost of the lining and create a more rational shape of the cell of the cell, it is made in height of materials with different resistance to melt contained in the cell of the cell, with the upper part it is made of material with increased resistance, and the lower part is made of material with reduced resistance.

2. The lining according to claim 1, characterized in that to perform its lower part as a carbon-containing material using graphite plates.

3. The lining according to claim 1, characterized in that to perform its lower part as a carbon-containing material using fired coal blocks.

4. The lining according to claim 1, characterized in that the lower part is made of a stuffed carbon-containing mass. Disadvantages: low strength, reliability, short service life. The presence of components (upper and lower) of the lateral lining of the aluminum electrolyzer increases the likelihood of the penetration of the components of the cryolite-alumina melt through the horizontal connecting seams to the casing of the aluminum electrolyzer. The absence of whole cast corner blocks in the corners of the aluminum electrolysis cell leads to a breakthrough of the aggressive molten medium in the corner joints of the lateral lining of the aluminum electrolysis cell. All this reduces the reliability and service life of the entire lining of the aluminum electrolyzer.

The technical result of the invention: increasing the service life, strength, reliability, saving the lining material, increasing the useful volume of the aluminum electrolyzer, the yield of finished aluminum.

The technical result is achieved due to the fact that the lateral lining of an aluminum electrolyzer, consisting of interconnected elements - plates and blocks made of non-metallic refractory compounds having increased resistance, using end faces in the form of inversely symmetrical protrusions and depressions and an adhesive or cementitious mortar, characterized in that the plates and blocks are made of non-metallic refractory compounds having high resistance - silicon carbide, and blocks are used corner blocks made in the form of a strip 65 mm thick, 650 mm long, bent in the middle around a longitudinal axis at an angle of 90 °, the faces of which are strictly vertical, and the end faces are made in the form of inversely symmetrical protrusions and recesses having a trapezoid shape with bases 22 mm and 24 mm, 8 mm high, which are also located vertically.

Achieving increased reliability and strength, increasing the service life is ensured by the fact that the lateral lining of the aluminum electrolyzer is completely made of silicon carbide plates of a special design, the corners of the aluminum electrolyzer are lined with whole cast corner blocks, which completely eliminates the joints in the corners of the aluminum electrolyzer as the least reliable elements of the whole lining of the aluminum cell, and the flat surfaces of the side walls of the aluminum cell lined with carbide cream flush plates that are joined together by end faces, which are inversely symmetrical protrusions and indentations. All four corner blocks have similar inverse-symmetrical protrusions and recesses, which, together with the plates, when assembling the lining in a closed loop along the entire side surface of the aluminum electrolytic cell with vertical walls, are glued with a special solution to increase the hydrostatic resistance to penetration of cryolite-alumina melt components into the joint seams, which increases lining life.

The claimed invention allows to increase the resistance of this lining to the melt contained in the aluminum electrolyzer at least 1.5 times, to save the lining material by at least 15%, to exclude the joining of plates in the corners of the aluminum electrolyzer, as the most loaded and least reliable elements of the side lining of the aluminum electrolyzer, especially in the start-up period of the aluminum electrolyzer and in the initial period of its operation. A distinctive feature of the claimed invention is that the plates and corner blocks have reverse symmetric protrusions and recesses in the form of a trapezoid on the end faces, the surfaces of which are lubricated with a special cementitious mortar. These measures lead to an increase in the service life of the aluminum electrolyzer; electrolyte leakage is eliminated.

The achievement of the above technical result is ensured by the fact that in the design of the side lining of the electrolyzer for aluminum production, plates and whole corner blocks are used to completely eliminate the joining of plates in the corners of an aluminum electrolyzer, which are the least reliable elements of the side lining. The use of inverse symmetrical protrusions and recesses in the form of a trapezoid on the connecting faces of all elements of the side lining of the aluminum electrolyzer also contributes to the achievement of the above technical result in increasing the resistance of the side lining and is the next significant difference between the proposed side lining and the prototypes. The use of lateral lining of an aluminum electrolyzer of smaller thickness allows to save the amount of lining silicon carbide material by 15% at no additional cost, increase the useful volume of the aluminum electrolyzer by 14% and, as a result, increase the yield of finished aluminum by 14% from each heat, which is an additional advantage and the difference of the proposed side lining from analogues. Thus, the proposed lateral lining of an aluminum electrolyzer meets the criteria of the invention of “novelty."

Comparison of the proposed solution not only with prototypes, but also with other technical solutions in the art shows that the use of silicon carbide materials to protect the side walls of the electrolyzer to produce aluminum is known, but in this case through the use of plates, corner blocks and inversely symmetrical protrusions and recesses on the connecting faces of all elements of the side lining of the aluminum electrolyzer, which are glued together with a special mortar when assembling the side lining of the aluminum electrolyzer rum on the surfaces of inversely symmetrical protrusions and recesses, allows to increase resistance and increase the service life of the side lining of the aluminum electrolyzer no less than 1.5 times. The above advantages are absent in the analogues.

The use of inverse symmetrical protrusions and recesses in the cross section, made in the form of a trapezoid, is much preferable to having the shape of a square, because the working perimeter of the trapezoid with an upper base of 22 mm and a height of 8 mm is 1.3 times larger than the working perimeter of a square with a side of 10 mm, which is an additional resistance to the penetration of cryolite-alumina melt into the joint seams, thereby providing a significant increase in the reliability of the entire lateral lining of the aluminum electrolyzer . Therefore, the claimed invention meets the condition of “technical level”.

All these advantages make it possible to create a mechanically strong lined surface, to organize a powerful skull layer that protects the lining surface from aggressive molten medium, which reduces the magnetohydrodynamic effect in an aluminum electrolytic cell.

Thus, the present invention has features that allow us to conclude that it meets the criterion of “significant differences”.

Figure 1 shows a fragment of the side lining, a top view;

Figure 2 shows a section aa, a cross section of a side lining.

Figure 3 shows the block angular in a perspective view.

Figure 4 shows a plate in a perspective view.

SUMMARY OF THE INVENTION

The lateral lining of the aluminum electrolyzer consists of two main elements: a plate with dimensions 650 × 360 × 65 3, an angular block 5, which are laid on the vertical walls of the aluminum electrolyzer 1, and the corner blocks 5 are made in the form of a strip 65 mm thick, 650 mm long, bent in the middle around the longitudinal axis at an angle of 90 ° so that both faces of a rectangular shape are located strictly vertically, and the inverse-symmetrical projections 6 and recesses 7 on the connecting faces of all the elements are also made vertically, at Inversely symmetrical protrusions 6 and recesses 7 are made in the form of concave and convex trapezoids, with a base of 22 and 24 mm and a height of 8 mm.

Industrial applicability

Installation of the lateral lining of the aluminum electrolyzer is carried out after installing the hearth sections and masonry edge, which is the laying of fireclay bricks along the walls of the housing 1 of the aluminum electrolyzer. The installation of the elements of the lateral lining of the cell begins with the installation of corner blocks 5 on the edge along the corners of the aluminum cell. Then, after lubricating the surfaces of the inverse symmetrical protrusions 6 and the recesses 7 on the connecting faces of all the elements with the above plates 3, using a special cementitious mortar, all four walls of the aluminum electrolyzer are sequentially taken from one corner block 5 to another, pressing and knocking out the inverse symmetrical protrusions 6 and the recesses 7 on the connecting faces of all elements, starting from the first plate 3 to the corner block 5 and then all subsequent plates to the previous one. In this case, the extrusion of the cementitious mortar along the entire length of the inversely symmetrical protrusions 6 and the recesses 7 on the connecting faces of all the elements is a sign of filling the gaps between the surfaces to be glued. A 15 mm gap between the elements of the silicon carbide lining and the casing 1 of the aluminum electrolyzer is maintained using wooden wedges. Then, after mounting the entire lining and setting the cementitious mortar, wedges are successively removed and the gap is clogged by the heat-insulating mass 2, which should have at least two properties: mechanical strength and low thermal conductivity. With such an installation, silicon carbide corner blocks 5 and plates 3 ensure their reliable fixation with the corner blocks and with each other. The hardened cementitious mortar prevents the penetration of cryolite-alumina melt components into the joint seams. The final stage of the installation of the side lining of the aluminum electrolysis cell is to fill the gap between the side lining and the bottom of the aluminum electrolytic cell with a rammed hearth mass. The bottom mass must act as a barrier against the penetration of the electrolyte to the bottom of the aluminum cell.

Claims (1)

The lateral lining of an aluminum electrolyzer, consisting of interconnected elements - plates and blocks made of non-metallic refractory compounds with increased resistance, using end faces in the form of inversely symmetrical protrusions and recesses and an adhesive or cementitious mortar, characterized in that the plates and blocks are made from a non-metallic refractory compound having increased resistance, silicon carbide, and corner blocks made in the form of a strip of thickness are used as blocks 65 mm long, 650 mm long, bent in the middle around the longitudinal axis at an angle of 90 °, the lateral faces of which are strictly vertical, and the end faces are made in the form of inversely symmetrical protrusions and indentations having a trapezoidal cross section with bases 22 mm and 24 mm high 8 mm, which are also located vertically.

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