Cathode section of aluminium electrolyser. RU patent 2510818.
 Electrolytic cell for production of aluminium / 2509830On hearth surface placed are baffles and/or grates, and/or open-pore cellular structures wetted by aluminium made of material with lower electric conductivity compared with that of aluminium perpendicular and/or at 45°-90° to heart surface, perpendicular and/or at 45°-90° to lengthwise axis of cathode rods preventing partially or completely the flow of horizontal components of cathode currents in aluminium layer along the hearth. Electrolytic cell can operate with consumable or nonconsumable anodes, that is, "inert" anodes. |
 Electrolysis unit for aluminium manufacture / 2499085Electrolysis unit includes a cathode device containing a bath provided with a coal bottom and composed of coal blocks enclosed in a metal housing, with refractory and heat-insulating materials arranged between the metal housing, an anode assembly containing coal anodes connected to anode sludge, arranged in upper part of the bath and submerged into molten electrolyte; at the coal bottom, under each of the anodes there located are floats with higher specific electric conductivity in comparison to that of electrolyte, stable to destruction in cryolite-alumina melts and liquid aluminium; with that, upper surface of the float projects above the level of cathode aluminium and the floats can be moved and/or replaced to reduce inter-pole gap between anode and cathode. The floats are made from carbon, or from silicon carbide, or from a mixture of titanium diboride and carbon based on high-temperature binding substance and are covered with titanium diboride. Upper surface of the float is flat, or convex, or concave, or inclined to horizon and has capillaries and/or channels, and/or planes attaching the upper surface of a pedestal to cathode metal. |
 Composites for wet cathodes and their use in aluminium production / 2487956Composite has composition defined by formula (C-N-B-MR)x(Al-MR)y(R)z, where MR is one or several carbides, nitrides or borides of one or more heat-resiatant metals of IV, V, VI groups, C-N-B-MR is one or several carbides, nitrides or borides of one or more heat-resistant metals of IV, V or VI groups, Al-MR is one or several aluminides of one or several aforesaid heat-resistant metals. Note here that if MR=Nb, Ta, Hf, Zr, Ti, V, then Al-MR=Al3MR; is MR-W, Cr, then Al-MR=Al4MR; if MR=Mo, then Al-MR=Al8Mo3 or Al17Mo4. Note here that the condition should be satisfied whereat if C-N-B-MR=TiB2, Al-MR is not Al3Ti; R is residual component other than carbon containing one or several phases from Al4C3, AlN, AlB2, Al1·67B22, MRtAlu(C-N-B)v, where t, u, v are numbers larger than or equl to zeto; x, y, z are volume fractions of appropriate components. Note here that x>y; x+y>0.5; x+y+z=1 and 0.01<y<0.5. |
 Cathode of electrolytic cell for production of aluminium and method of its repair / 2483142Proposed cathode comprises jacket and lining with base made of heat-insulation and refractory materials, side lining, bottom of hearth sections with cathode rods and cathode downleads. The latter are made from the stack of flexible aluminium tapes, contact plate and steel adapter to be welded as-assembled to cathode rod and plugged to cathode bus. Cathode downleads are assembled in installing the lining by welding them to cathode rods and bolting downlead contact plates to the bracket. After disassembly of side lining, cathode rods with their downleads are extracted from cathode jacket, cleaned and transferred to cutting bay. Cutting is performed along the line or in zone of joint between rod and downlead metal adapter. After skinning the metal adapter end, cathode downlead is transferred for reassembly. |
 Cathode device for aluminium electrolytic cell with embossed hearth / 2482224Cathode device of an aluminium electrolytic cell with an embossed hearth contains a lined cathode shell ad a hearth composed of higher bottom blocks with projections and lower bottom blocks. The lower bottom blocks are installed at the cathode device hearth butt ends. The lower bottom blocks alternate with higher bottom blocks with projections or are installed in the projection centre of the electrolytic cell anode array, with at least two higher bottom blocks with projections, alternating with lower bottom blocks, installed at the both ends of the electrolytic cell anode array. The bottom block projection height is equal to 0.1÷0.6 of that of the smaller bottom block. The top parts of higher bottom blocks have level edges. The bottom blocks projections are made of a refractory non-carbon material, resistant to hot melt effect. |
 Method of producing metal by molten-salt electrolysis / 2471892Method for electrolytic production of metal in an electrolysis cell, having a cathode, an anode and collectors of impurities dissolved in the electrolyte, involves passing cathodic current through the cathode to obtain metal at the cathode and deposit impurities on the collector. The collector, which is placed between the anode the cathode, is a bipolar porous collector electrode which is a cellular matrix which is inert to the metal deposited at the cathode and the electrolyte. The bipolar porous collector electrode is in form of an open porous structure having internal pores or capillaries, or channels, or cavities, which are particularly V-shaped and/or W-shaped and/or S-shaped and are filled with the metal which is deposited at the cathode. The method employs a bipolar porous collector electrode, wherein the internal pores or capillaries, or channels or cavities are wettable by metal, and have dimensions, particularly diameter and length, which are sufficient for them to hold the metal and prevent spontaneous flow of metal from them due to surface tension forces of the metal. |
 Cathode device of aluminium electrolyser / 2458185Cathode device of aluminium electrolyser includes housing, bottom blocks with cathode rods, refractory casing under bottom blocks, side refractory, insert blocks from carbide-silicon material mounted close to side refractory. From above the side refractory is equipped with flange sheet mounted horizontally, between the upper surface of insert carbide-silicon block and flange sheet there is combined fire-resisting insert that is equipped with filling material and fire-resisting dielectric elements, the height of the insert is equal to 0.10-0.20 of insert block height. |
 Doped sintered article based on zircon and zirconium dioxide / 2456254Invention relates to sintered articles made from zircon and zirconium dioxide for use in a glass-melting furnace, particularly in articles used as supporting blocks for electrodes, or in an electrolysis cell in contact with molten cryolite. The initial load for producing the articles contains 5-50% zircon and has the average chemical composition given below, in wt % based on oxides with sum total of 100%: silicon dioxide SiO2 and zirconium dioxide, where content of zirconium dioxide ZrO2 is at least 75%, 0.2-6% dopant selected from Nb2O5, Ta2O5 and mixtures thereof, possibly a stabiliser selected from Y2O3, MgO, CaO, CeO2 and mixtures thereof in amount of 6% or less, 'other oxides' in amount of 6.7% or less. Components are formed from the initial charge and then sintered to obtain articles. |
 Electrolysis unit for aluminium manufacture / 2454490Electrolysis unit consists of the following: cathode device including pit with carbon bottom, the pit is formed by carbon blocks enclosed in metallic casing with flame proof and heat-insulating materials arranged between metallic casing and carbon blocks; anode device including carbon anodes connected to anode bus, the anodes are arranged in upper part of bath and absorbed in fused electrolyte; and point feeding system (PFS) including punch pin for electrolytic crust and alumina feeder. On carbon bottom under each PFS feeder there are units installed resistant to destruction in cryolite-alumina melt and molten aluminium. Upper base of unit is located at level and above level of molten aluminium not exceeding 2 cm. Units may be made from carbon or from silicon carbide, or from mixture of titanium diboride and aluminium oxide on high-temperature connection. Inserts from heavy material, such as cast iron, may be mounted inside units. Relation of squares of upper and lower bases of units changes from 1:1 to 1:2. Square value of upper basis of unit is chosen considering quantity of alumina loaded by dosemeter - from 30 to 80% - falling on it. Units may be covered by titanium diboride. Upper basis of units may be flat or convex, or inbent. |
 Electrolysis unit bottom for obtaining aluminium / 2449060Invention refers to metallurgy, and namely to devices used during aluminium manufacture with electrolytic method. Electrolysis unit bottom for obtaining of aluminium includes bottom units with slots, current-carrying bars, inter-unit connection in the form of refractory elements from silicone carbide, which are connected by means of inter-unit pulley from bottom mass and having the length equal to length of bottom unit, and the height equal to 0.35-1 of height of inter-unit joint. |
 Graphitic cathode for electrolysis of aluminum / 2245395The invention presents a graphitic cathode for electrolysis of aluminum and is dealt with the field of metallurgy, in particular, with the graphitic cathodes used in production of aluminum by an electrolysis. The graphitic cathode for electrolysis of the aluminum is produced by graphitization of the cathodic block from a carbonaceous material. At that the cathode is made as the entire block with different specific electrical resistance along its longitudinal axis. At that the specific electrical resistance in the end areas of the cathode is more, than in its central area. The technical result - increased service life of the graphitic cathode at the expense of increased erosion resistance in the end areas of the cathode. |
 Impregnated graphitic cathode for electrolysis of aluminum / 2245396The invention presents an impregnated graphitic cathode for production of aluminum by electrolysis and is pertinent to the field of metallurgy, in particular, to production of the graphitic cathodes used in production of aluminum by electrolysis. The invention offers an impregnated graphitic cathode for electrolysis of aluminum and a method of its production. The cathode contains in its pores an impregnating product heat-treated. At that in the capacity of the impregnating product the cathode contains a carboniferous product heat treated under the temperature of no less than 1600°С to provide resistance to erosion at the expense of protection by the formed graphitized binding substance. The method includes production of the graphitic cathode, its impregnation by dipping into the impregnating product in vacuum and a thermal treatment. At that the graphitic cathode is produced from coke, with graphite or without it, and also from a pitch, and before impregnation it is exposed to calcination at the temperature exceeding 2400 °С. The impregnation is realized by a carboniferous product at the temperature of its viscous state and the thermal treatment of the impregnated cathode is conducted at the temperature of less than 1600 °С, but sufficient for hardening and-or sintering of the impregnating product and formation of the non-graphitized coal layer for protection of graphitizing binding substance against erosion. The technical result is an increase of service life of the graphitic cathode. |
 Cathodic device of aluminum electrolyzer / 2245397The invention I pertinent to nonferrous metallurgy and may be used in a design of electrolyzers for production of aluminum by electrolysis of fused salts. The technical result of the invention is hardening of a hearth, a decrease of thickness of a metal layer on the hearth and an interpolar space, a decrease of speeds of circulatory flows of cathodic metal, a decrease of losses of current. The cathodic device contains a lined cathodic housing and a hearth made out of from carbonaceous blocks with channels of a rectangular cross section. On the surface of the hearth there is a wetted with aluminum cover and the channels have the length equal to the width of the stack of the cathodic device, and with a width equal 1,1-2,2 well of the carbonaceous block, depth, equal to 0.2-0.4 of height of the carbonaceous block and thy are formed by the lateral longitudinal surfaces of the carbonaceous blocks and the carbonaceous blocks of the lateral cathodic lining. The electro-conductive cover wetted with aluminum is made out of titanium diboride. |
 Aluminum cell / 2256009Cathode casing of aluminum cell includes lengthwise walls with windows for outlet of cathode rods, end walls, bottom and ring frames rigidly joined with walls and bottom. In order to lower labor consumption, simplify mounting and dismounting operations. Ring frames adjacent at least to one of lengthwise walls (except boundary ring frames) from their upper part till inner edge in range of height of windows for outlet of cathode rods are freely adjoined to said lengthwise wall. According to other variant of invention at least one lengthwise wall is detachable. Parting places of said wall are arranged between boundary ring frames in range of height of windows for outlet of cathode rods. In parting places members providing rigid joint of detachable wall with fixed portion of casing wall are mounted. |
 Method of forming protective coating for carbon containing components of electrolysis cell / 2257425Method comprises steps of preparing liquid suspension of refractory material dispersed in solution of lignosulfonate binder; applying suspension as coating on surface of carbon containing component; drying coating. |
 Side lining of aluminum electrolyzer / 2263162Proposed side lining includes interconnected members - plates and blocks made from non-metallic refractory compounds possessing high resistance and interconnected by means of end faces in form of inversed symmetrical projections and recesses and adhesive or cementing mix. Plates and blocks are made from silicon carbide. Angular blocks are made in form of strip, 70 mm thick and 600-800 mm long which is bent at center around longitudinal axis at angle of 90° relative to vertical whose end faces are inclined at angle of 18° relative to vertical and are narrowing downward by 219 mm each. End faces are made in form of inversed symmetrical projections and recesses at radius of 14-15 mm which are parallel to vertical axis of walls of aluminum electrolyzer. |
 Cathode facing to aluminum cell / 2266983Cathode facing includes carbon blocks, heat insulation layer and refractory part having two protection layers, upper layer adjoining to carbon blocks and lower layer made of powder materials. Upper protection layer includes alumosilicate composition resistant against action of electrolyte components containing 27 -35% of Al2 O3 with fraction size no more than 2.5 mm and with thickness consisting 10 - 50% of height of refractory part. Lower protection layer is made at least of one sealed metallic vessel filled with refractory material including carbon-containing composition resistant against action of melt aluminum and electrolyte components and having heat conductivity factor no more than 0.1 Wt/(mK). In lower protection layer vessels are filled with carbon black; thickness of said layer consists 50 - 90% of height of refractory part. |
 Method of mounting side lining of cathode device for aluminum electrolyzer / 2270887Proposed method includes mounting the heat-insulating and refractory components of electrolyzer and applying protective material on base of covalent nitrides to surface of side lining. Used as protective material is boron nitride-based material which ensures reduction of after-start period, increases electrolyzer service life, enhances aluminum grade, increases yield by current and daily productivity of electrolyzer; protective material is applied flush with top in continuous layer. Lower boundary of coat is located below "electrolyte-metal" interface. Thickness of coat is maintained within 0.1-1 mm. Open surface porosity is maintained within 2-3%. Consistency of material of coat changes from fluid to viscous-flow state. Application of coat is performed by spraying, painting or concrete-spraying method. |
 Method of forming hearth for aluminum electrolyzer / 2270888Proposed method includes preliminary estimation of quality of hearth modules by proximate ultrasonic inspection, mounting of complete set of hearth modules and forming of hearth; electrolyzer is equipped with hearth modules at inhomogeneity index not exceeding 0.65 relative units according to ultrasonic inspection; inhomogeneity index is determined by the following formula Iinhom = (tmax/tmin-1), where Iinhom is inhomogeneity index according to ultrasonic inspection; tmax is maximum magnitude of index of ultrasonic inspection for definite electrolyzer; tmin is minimum magnitude of index of ultrasonic inspection for definite electrolyzer; hearth is formed in such way that adjacent modules with close indices of ultrasonic inspection are mounted in longitudinal and transversal directions; modules with minimum indices of ultrasonic inspection are mounted in center of hearth at smooth increase of this index toward end faces of electrolysis bath. |
 Method of mounting cathode section of aluminum electrolyzer / 2270889Current-supply metal rod is placed in slot of carbon block on layer of carbon-containing conducting material. Surface of carbon block slot is preliminarily coated with carbon-based surfactant and layer of carbon-containing conducting material is compacted by vibration applied on current-supply metal rod, thus ensuring reliable electromechanical "conducting rod-carbon block" contact and reducing probability of penetration of aluminum melt into hearth body. At application of vibration in local zone on side of flush area, maximum reduction of voltage drop is ensured in contact layer between rod and block slot. Maximum thickness of layer of carbon-containing conducting material before vibration is equal to optimal magnitude determined by definite formula. |
FIELD: metallurgy.
SUBSTANCE: invention relates to a design of a cathode section of an aluminium electrolyser. The cathode section includes a cathode carbon unit, a cathode current-carrying rod with an electrically conducting part from material with high specific electric conductivity, which is installed in an internal cavity of the cathode carbon unit and fixed in it by means of a cast iron cast. The electrically conducting part of the rod is made in the form of an insert of individual elements attached to each other with a gap, which is installed on one or more outer surfaces of the cathode current-carrying rod through a cast iron casting layer. The individual elements of the insert can be of round or rectangular shape or any other type of cross section. Inserts can be installed throughout the length from 10% to 100% of length of the cathode current-carrying rod.
EFFECT: reduction of voltage drop in a cathode unit and low electric contact resistance between a cathode current-carrying rod and an electrically conducting insert with high specific electric conductivity throughout the length of the cathode current-carrying rod.
3 cl, 3 dwg
The invention relates to the field of non-ferrous metallurgy, namely to the production of aluminum by electrolysis of molten salts, in particular, to the design of the cathode section of an aluminium electrolyzer.
Cathode section, usually from coal block and steel steel bar that is attached in place of carbon-containing cathode block by means of electrically conductive material cast iron.
Known cathode section of an aluminium electrolyzer, including cathode carbon unit with fixed it with by using cast iron fill the cathodic current-conducting core, which is designed as two elements of the same cross-section rigidly connected among themselves, and some of the rod under the anode, made of copper, and the external part is made of steel (patent SU 1260412, M. class. SS 3/08, 1986).
One of the main drawbacks of the technical solutions is that copper part of the cathodic current-carrying rod has solid containment, preventing access of air and oxidation of copper at high temperatures, in addition, with the temperature growth from copper significantly reduced strength. All this leads to the growth of the contact resistance "carbon block - cathode conductor pins" and, accordingly, will lead to an increased voltage drop cathode cell.
Another disadvantage of the invention are the complications that arise when creating a connection "copper part - steel part cathodic current-carrying rod with an acceptable level of voltage drop in him, as the problems associated with the different coefficients of thermal expansion of copper and steel, high oxidation and low strength of copper at temperatures close to the working temperature electrolysis, and high temperature region of the connection of copper and steel, does not allow to get a good connection.
Similar deficiencies have a cathodic current-carrying terminals on patents US 2846388; US 3551319; RU №2303654.
Closest to the invention to the technical nature and effect is achieved is technical solution for cathodic current-carrying terminals, installed in the groove of carbon-containing cathode cathode block device aluminium pot, including a metal rod (steel) with the internal cavity and liner from a material with high specific conductivity (copper), set in the inner cavity with the possibility of electrical contact with the rod. The internal cavity in the cathodic current-carrying rod made from its internal finish and does not reach the outside end and has a cross-section polygonal profile or round profile (patent RU №2239007). The main disadvantages of the invention refers to the technological difficulties in the manufacture of cathode current-carrying rod internal cavity for liner and the liner, so as to create a good electrical contact along the entire length of the cathode current-conducting core required high accuracy of processing of the products or need complex technological equipment the pressing of copper core in steel conductor pins, making it difficult to ensure good electrical contact with the temperature of the cathode rod ~850 to 960°N
The objective of the invention is to simplify and reduce the cost of construction cathode sections, reducing the complexity and design the manufacture of cathode sections.
The technical result consists in reducing the power failure in the cathode block through the development of simple and cheap to manufacture of cathode sections. This ensures low electrical contact resistance between the cathodic current-carrying rod and conductive liner with high electrical conductivity along the entire length of the cathode current-conducting core.
To solve the set tasks in the design of the cathode section aluminum electrolytic cell, including cathode carbon block, cathodic current-conducting core, equipped with conductive part of the material with high heat conductivity, set in a hollow cathode carbon block and fastened it with a cast-iron casting, according the present invention, the conductive part is executed as insertion of separate elements fastened together with a gap that is installed on one of the external surface or several external surfaces of the cathodic current-conducting core, through the fill layer of iron.
The proposed design is complemented by private distinctive features that improve the technical result.
Individual elements of the inserts can be performed round, rectangular or other type section.
The insert can be installed in length from 10% to 100% of the length of the cathode current-conducting core.
The presence in the proposed design characteristics other than signs counterparts, allows to make a conclusion on the compliance of the proposed solutions to the condition of patentability "novelty".
The essence of the proposed design of the cathode sections with conductive liners shown in figure 1 and figure 2.
Cathode section includes cathode carbon block 1, in the groove of which placed cathode conductor pins 2, conductive paste from components 3 fastened together with a gap and installed on one of the external surface or several external surfaces cathodic current-carrying terminal 2 in length from 10% to 100% of the cathodic current-conducting core, through the fill layer of iron 4. Individual elements 3 inserts made of round, rectangular or other type section.
This design can be applied with preliminary heating of the cathode sections, and without pre-heating the cathode sections.
The Assembly cathode section is in the following order: stacked cathodic current-conducting cores from two sides bottom of a block, after which this construction is pre-flame heating within 100-200 minutes to achieve the following parameters of heating:
- optimal temperature interval after heating it should be: on the surface of the cathode rods - 450 EV 530 Degrees; on the surface of bottom blocks of 250 to 350 degrees C.
- target heating temperature of the cathode rods - 500°N
After heating the cathode current-carrying rod is laying the conductive inserts on its surface and pouring of molten pig iron, the temperature of the melt of pig-iron before and during the fill should be in the range from 1100 to 1250°N The cooling of this design is the natural way without additional cooling.
Declared cathode section tested in the manufacture of industrial cathode sections, the results achieved to reduce voltage drops shown in figure 3.
1. Cathode section aluminum electrolyzer containing cathode carbon block, cathode conductor pins with conductive part of the material with high heat conductivity, set in a hollow cathode carbon block and fastened it with a cast-iron casting, wherein conductive part of the rod is made in the form insert of separate elements fastened together with a gap that is installed on one of the external surface or several external surfaces of the cathodic current-carrying rod through the layer of iron casting.
2. Cathode section according to claim 1, wherein the individual elements of the insert is made of round, rectangular or other section.
3. Cathode section according to claim 1, characterized in that the insert is installed in length from 10% to 100% of the length of the cathode current-conducting core.