WO2012175419A2 - Ringförmige elektrolysezelle und ringförmige kathode mit magnetfeldkompensation - Google Patents
Ringförmige elektrolysezelle und ringförmige kathode mit magnetfeldkompensation Download PDFInfo
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- WO2012175419A2 WO2012175419A2 PCT/EP2012/061431 EP2012061431W WO2012175419A2 WO 2012175419 A2 WO2012175419 A2 WO 2012175419A2 EP 2012061431 W EP2012061431 W EP 2012061431W WO 2012175419 A2 WO2012175419 A2 WO 2012175419A2
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
- C25C3/08—Cell construction, e.g. bottoms, walls, cathodes
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
- C25C3/16—Electric current supply devices, e.g. bus bars
Definitions
- the present invention relates to an electrolytic cell, in particular for the production of aluminum, as well as a cathode, which is suitable for use in such an electrolytic cell.
- Electrolysis cells are used, for example, for the electrolytic production of aluminum, which is usually carried out industrially by the Hall-Heroult process.
- a melt composed of alumina and cryolite is electrolyzed.
- the cryolite, Na3 [AlF6] serves to reduce the melting point from 2,045 ° C for pure alumina to approximately 950 ° C for a cryolite,
- Lower alumina and additives such as aluminum fluoride and calcium fluoride containing mixture.
- the electrolysis cell used in this process has a cathode bottom, which consists of a plurality of adjacent, the
- Cathode forming cathode blocks may be composed.
- the cathode In order to withstand the thermal and chemical conditions prevailing in the operation of the cell, the cathode is usually composed of a carbonaceous material.
- grooves are usually provided, in each of which at least one bus bar is arranged, through which the current supplied via the anodes is removed.
- layer of liquid aluminum is arranged, in particular of individual anode blocks, anode, between which and the surface of the aluminum, the electrolyte, that is, the alumina and cryolite-containing melt is.
- the aluminum formed is deposited below the electrolyte layer due to its greater density compared to that of the electrolyte, ie as an intermediate layer between the upper side of the cathode and the electrolyte layer.
- the dissolved in the melt aluminum oxide is split by electric current flow to aluminum and oxygen.
- the layer of liquid aluminum is the actual cathode because aluminum ions are reduced to elemental aluminum on its surface.
- the term cathode will not be understood below to mean the cathode from an electrochemical point of view, ie the layer of liquid aluminum, but rather the component forming the base of the electrolytic cell, for example composed of one or more cathode blocks.
- a major disadvantage of the Hall-Heroult method is that it is very energy intensive. To produce 1 kg of aluminum about 12 to 15 kWh of electrical energy is needed, which accounts for up to 40% of the manufacturing cost. In order to reduce the manufacturing costs, it is therefore desirable to reduce the specific energy consumption in this process as much as possible.
- the driving force for the wave formation in the layer of liquid aluminum and the melt layer arranged above it is the Lorentz force density generated there, which is defined as the vector product of the electrical current density present at the respective location and the magnetic flux density present at this location.
- the current density distribution in the anode and in the melt layer is comparatively homogeneous
- the current density distribution in the aluminum layer and on the surface of the cathode is very inhomogeneous due to large horizontal current density components in the direction of the cathode.
- the strong horizontal components of the electric current density with the magnetic field which is likewise usually substantially horizontal, lead to a high vertical Lorentz force density, which in turn, as explained, leads to a pronounced wave formation, in particular in the aluminum layer.
- These strong horizontal current density components in Direction of the cathode result from the effect that the current in the cathode and in the aluminum bath preferably takes the path of least electrical resistance.
- the electrical current flowing through the cathode typically concentrates on the lateral edge regions of the cathode where the connection of the cathode contacting busbars to the current supply elements occurs because the resulting electrical resistance transients from the current delivery elements to the surface of the cathode when flowing the lateral edge regions located near the current supply elements are lower than when they flow across the center of the cathode.
- the inhomogeneous current density distribution and the increased current density at the lateral edge regions of the cathode also lead to increased wear of the cathode in these lateral edge regions compared to that in the middle of the cathode, which typically increases after prolonged operation of the electrolysis cell a characteristic in cross-section approximately W-shaped wear profile of the cathode blocks in the longitudinal axis leads.
- the object of the present invention is therefore to provide an electrolytic cell which has a reduced specific energy consumption and an increased service life during its operation.
- an electrolytic cell is to be provided, in which the thickness of the melt layer is reduced, without as a result of increased wave formation tendency in the layer of liquid aluminum instabilities, such as short-circuits or reoxidations of the aluminum formed occur.
- an electrolysis cell for the production of aluminum, which has a cathode, on the top of the cathode, a layer of liquid.
- a cryolite-containing melt layer thereon and above the melt layer comprises an anode, wherein the cathode has at least one vertically extending through the cathode opening in which at least one vertically extending through the opening and with the anode and / or is provided with the cathode electrically connected power supply, and wherein the electrolytic cell comprises at least one arranged outside the opening of the cathode further power supply, which extends at least partially in the vertical direction and which is electrically connected to the cathode and / or to the anode.
- the current supply provided in the opening of the cathode in relation to the current flowing in the rectified direction at least one external current supply, a magnetic field is generated which opposes the magnetic field generated by the current flowing through the at least one external current supply arranged outside the cathode opening is. For this reason, the magnetic field generated by the current supply provided in the opening of the cathode compensates for the magnetic field generated by the current flow in the at least one external current supply.
- the individual power supply lines can be used to optimize the compensation of the magnetic fields. In particular, if a plurality of external power supply lines are arranged uniformly around the power supply provided in the opening of the cathode, a particularly complete compensation of the magnetic fields and / or a particularly homogeneous magnetic field distribution can be achieved.
- an opening extending vertically through the cathode is understood as meaning an opening which, with respect to the vertical, is at an angle of less than 45 °, preferably less than 30 °, particularly preferably less than 15 ° most preferably of less than 5 ° and most preferably extends through the cathode at an angle of 0 °.
- the border of the opening may, as seen in the cathode cross-section, extend obliquely or straight through the cathode with respect to the vertical direction, such that the opening may, for example, be in the form of a straight or oblique prism with a particular polygonal base or the shape of a straight or oblique cylinder can have.
- the opening may also have a shape that tapers in the vertical direction and, in particular, may have an approximately frustoconical or pyramidal-truncated shape.
- a current supply extending vertically through the opening is understood to mean a current supply which, with respect to the vertical, is at an angle of less than 45 °, preferably less than 30 °, particularly preferably less than 15 °, very particularly preferably of less than 5 ° and most preferably extends through the cathode at an angle of 0 °.
- a further current supply extending at least in sections in the vertical direction is understood to be a current supply which is at least sectionally, with respect to the vertical, at an angle of less than 45 °, preferably less than 30 °, particularly preferably less than 15 °, most preferably less than 5 ° and most preferably at an angle of 0 °.
- the layer of liquid aluminum, the melt layer and the anode seen in plan view one of the cathode substantially corresponding outline shape.
- the opening of the cathode accordingly extends vertically through preferably the entire electrolysis cell. Good results are achieved in particular when the at least one opening in the cathode, viewed in plan view, is arranged substantially centrally.
- the at least one power supply extending through the opening is arranged at least substantially in the center of the opening and thus at least substantially in the center of the cathode. In this arrangement of the opening, a particularly uniform compensation of the magnetic fields is achieved in the regions of the cathode located around the opening.
- the power supply extending through the opening of the cathode may also extend through the layer of liquid aluminum disposed above the cathode, through the melt layer disposed thereon, and the anode disposed above it.
- an opening is also provided in the layer of liquid aluminum, in the melt layer arranged thereon and the anode arranged above it, which opening extends vertically through the layer of liquid aluminum, the melt layer or the anode, and, which considered aligned with the opening of the cathode in the plan view of the electrolysis cell; in other words, the layer of liquid aluminum, the melt layer arranged thereon and the anode arranged above it are designed in the same way as the cathode.
- the current lead extending through the opening of the cathode can extend through only two or one of the layers of liquid aluminum, the melt layer and the anode or to extend only through the opening of the cathode. Consequently, the electrolysis cell as a whole can have an opening which extends vertically through one or more and in particular through all of the cathode, liquid aluminum layer, melt layer and anode. the group selected components of the electrolytic cell extends through, wherein in the opening at least one vertically extending through this opening extending and electrically connected to the anode and / or to the cathode power supply is provided.
- this formulation includes not only an opening extending exclusively through the cathode, but also, in particular, an opening described above which passes through the cathode and additionally through other components of the electrolytic cell extends.
- the inner power supply is at least over part of their arranged within the at least one opening length and in particular over its entire disposed within the opening length not directly electrically with the surrounding the respective opening part, such as cathode, layer of liquid aluminum, melt layer and Anode, connected, but electrically isolated from the respective component of the electrolytic cell.
- the inner power supply can be arranged in the opening over its respective length at a distance from the respective component of the electrolysis cell and / or surrounded by an electrically insulating substance or medium, such as, for example, air.
- the inner power supply extend from the layer at least over its entire length extending through the opening provided in the layer of liquid aluminum and in the melt layer is electrically insulated from liquid aluminum and the melt layer and more preferably also over its entire extending through the opening provided in the cathode and in the anode opening extending length cathode and anode is electrically isolated.
- the cathode can be formed in any manner known to those skilled in the art.
- the cathode may form the bottom of a liquid aluminum layer or the melt layer supporting well forming a liquid aluminum liquid pool and the melt layer, preferably in a ring shape around that in the liquid aluminum layer the melt layer formed opening passes around.
- the basin in the direction towards the opening is preferably bounded by outer walls provided in the trough, which form a shaft through which the inner power supply extends, the inner power supply preferably being spaced from the outer walls forming the shaft is.
- the side walls of the basin may be formed by a refractory material.
- the cathode viewed in plan view, is designed annular. In this way, it is particularly easy to provide a cathode which has an opening arranged centrally in the cathode.
- the layer of liquid aluminum, the melt layer and the anode of the electrolytic cell corresponding to the cathode are also preferred
- annular configuration of a constituent of the electrolysis cell ie in particular the cathode, the layer of liquid aluminum, the melt layer and the anode, is understood to mean that the respective constituent forms the shape of a ring, which is either closed can be or can be open at one or more places.
- the layer of liquid aluminum and the melt layer a configuration in the form of a closed ring is preferred, whereas in particular the anode is also in the form of an open ring, for example in the Shape of a segmented ring which is designed to be open in several places, may be formed, wherein such an open ring may be formed, for example, by a plurality of annularly arranged around the opening and spaced apart anode blocks.
- the inner (s) and outer (s) power supply (s) are preferably electrically connected to the same of electrode, which can be realized, for example, that the inner and outer power supply are connected directly to the same conductor, which is connected to the Electrode is connected directly.
- the cathode viewed in plan view, an at least approximately circular outline shape.
- the rotational symmetry of the magnetic flux density of the power supply lines is modeled by the geometry of the cathode.
- the cathode can in principle be designed as a closed ring running around the opening.
- the cathode may be formed as a partially closed ring which is open at one or more locations.
- the cathode viewed in plan view, have an at least approximately polygonal annular outline shape.
- an approximation to the preferred shape of a circular ring and the associated shape achieved advantageous effects, with the additional advantage that a polygonal annular cathode is easier and cheaper to produce than a circular cathode.
- the outer circumference and / or the inner circumference of the polygon-shaped outline shape of the cathode considered in plan view has the shape of a preferably regular polygon with n corners, where n is preferably 3 to 100, more preferably 3 to 10 and most preferably 3, 4, 5, 6, 7 or 8.
- n is preferably 3 to 100, more preferably 3 to 10 and most preferably 3, 4, 5, 6, 7 or 8.
- the cathode in this embodiment is most preferably designed as a regular polygon ring with 6 or 8 corners.
- the cathode of the electrolysis cell can be configured in one piece or in several pieces, with a multi-part embodiment being preferred from a manufacturing point of view.
- the individual cathode blocks forming the cathode are preferably arranged in the circumferential direction around the current supply extending through the opening, forming an annular cathode next to one another and preferably adjacent to one another.
- an annular or polygonal ring-shaped configuration is preferred.
- Such a segmented construction of the cathode facilitates the provision of the individual components and the composition of the electrolysis cell during installation.
- the cathode may be composed of 6 such cathode blocks juxtaposed circumferentially around the opening of the cathode.
- a substantially trapezoidal cathode block can be produced in a particularly simple manner by cutting apart an elongated starting body in angles directed transversely to its longitudinal direction, the orientation of the angles alternating from cut to cut.
- the ratio between the inner diameter and the outer diameter of the cathode is between 0.01 and 0.99, preferably between 0, 1 and 0.8, particularly preferably between 0.2 and 0.6 and completely more preferably between 0.3 and 0.5.
- the at least one opening also extends through one or more of the layer of liquid aluminum, the melt layer and the anode, the above numerical ranges preferably also apply to the ratio between the inner diameter and the outer diameter of these components.
- Internal diameter is understood to mean the diameter of the largest circle running in the horizontal plane, which can be arranged in the opening of the respective component of the electrolyte cell without cutting the inner circumference of the opening.
- outer diameter is understood analogously to the diameter of the smallest circle running in the horizontal plane, which can be arranged around the outer circumference of the respective component without cutting the outer circumference of the component.
- the electrolysis cell comprise a plurality of power supply lines, in particular between 2 and 10, preferably between 4 and 8, particularly preferably between 5 and 7 and very particularly preferably 6 outside the opening of the cathode. It is preferred that all power supply lines of the electrolysis cell provided outside the cathode opening extend at least in sections in the vertical direction and are in each case electrically connected to the cathode and / or to the anode.
- the magnetic flux densities generated by the electric current in the Stromzu- guides can compensate each other more effectively, so that a further increase in the stability and energy efficiency is achieved in the operation of the electrolysis cell.
- a high symmetry of the arrangement and thus a particularly good magnetic field compensation is achieved if the number of power supply lines arranged outside the cathode opening is identical to the number of cathode blocks forming the cathode.
- Optimal compensation of the magnetic flux density is achieved when the further power supply lines are viewed in the circumferential direction of the cathode and are arranged at least approximately regularly, ie in particular at approximately regular angular intervals, around the current supply extending through the opening.
- the additional or external power supply lines preferably surround the current supply extending through the opening concentrically.
- the entire electric cell current used for the electrolysis preferably flows through the at least one current supply extending through the cathode opening and through the one or more power supply lines of the electrolysis cell arranged outside the cathode opening.
- the power supply extending through the opening of the cathode and the further power supply lines are preferably matched to one another, for example by suitable selection of the conductor cross sections of the power supply lines, such that the cell current is divided between the power supply lines in such a way that optimum magnetic field compensation in the region of the Layer of liquid aluminum and the melt layer is achieved.
- the cathode has at least two pin-like contacting elements on its underside, which contact the cathode strom foid.
- this type of contacting makes it possible to adapt the current density distribution at the surface of the cathode and in the layer of liquid aluminum arranged above it to the melt layer in such a way that over the entire cathode surface results in a particularly homogeneous current density distribution. In this way, horizontal current density components in the layer of liquid aluminum are particularly largely avoided, which is why the wave formation in the layer of liquid aluminum and the melt layer arranged above are minimized.
- At least one of the pin-like contacting elements extends and preferably extends all contacting elements at an angle of less than 30 ° and preferably less than 10 ° with respect to the vertical and particularly preferably perpendicular to the cathode , This produces a particularly good electrical contact between the contacting elements and the cathode.
- the contacting elements are preferably electrically conductively connected at their side facing away from the cathode side with a common base plate.
- the base plate for example, at least partially abut directly on the underside of the cathode and thereby even make a direct electrical contact with the cathode.
- the base plate is arranged at a distance to the cathode lower side.
- the contacting elements When the contacting elements extend into the cathode, they are preferably connected to the cathode via a screw connection, wherein preferably the contacting elements have on their outside an external thread of the screw connection.
- material for the contacting elements and the base plate if present, is in principle any suitable electrically conductive material in question, for which purpose preferably a steel, aluminum, copper and / or carbon-containing material or graphite is used.
- the length of the contacting elements is preferably between 100 and 500 mm and the diameter of the contacting elements is preferably between 30 and 200 mm.
- the contacting elements can at least regionally be arranged in a density of 4 to 1000 Mulltechniks- elements per square meter base area of the cathode. With such a density, the distribution of the contacting elements can be specifically adjusted so that an at least particularly uniform current density distribution results at the cathode surface.
- a particularly high energy efficiency of the electrolytic cell can be achieved if the distance between the anode and the layer of liquid aluminum between 15 and 45 mm, preferably between 15 and 35 mm and particularly preferably between 15 and 25 mm.
- the smallest possible distance is to be striven for under energy efficiency aspects, a certain minimum distance is nevertheless advantageous in order to maintain the operating temperature of the electrolysis cell via the Joule heat arising there.
- the small distance is made possible by the reduction of the wave formation tendency in the layer of liquid aluminum due to the magnetic field compensation by the power supply extending through the opening of the cathode.
- the cathode or at least one cathode block forming the cathode contains or preferably consists of a graphite composite material or a carbon composite material, wherein the graphite composite material in addition to graphite and / or amorphous Carbon contains at least one hard material with a melting point of at least 1000 ° C.
- the graphite composite material or carbon composite material may in particular contain between 1 and 50% by weight and more preferably between 15 and 50% by weight of the hard material.
- hard material is understood, in accordance with the customary definition of this term, to mean a material which is particularly stable even at high temperatures.
- the cathode can also be constructed in two layers, namely composed of a cover layer provided on its side facing the layer of liquid aluminum and an underlying base layer, wherein the cover layer is composed of the carbon composite material containing the hard material and / or graphite composite material is and the
- Base layer is composed for example of hard-material graphite.
- the hard material may, for example, have a Knoop hardness of at least 1,000 N / mm 2 , preferably at least 1,500 N / mm 2 , more preferably at least 2,000 N / mm 2, and very particularly preferably at least 2,500 N, as measured in accordance with DIN EN 843-4 / mm 2 have and can be selected for example from the group consisting of titanium diboride, zirconium diboride, Tantaldiborid, titanium carbide, boron carbide, titanium carbonitride, silicon carbide, tungsten carbide, vanadium carbide, titanium nitride, boron nitride, silicon nitride, zirconia, alumina and any chemical combinations and / or mixtures consists of two or more of the aforementioned compounds.
- the cathode has an at least partially profiled surface on which the layer of liquid aluminum is arranged and which may be formed, for example, by a covering layer of the cathode containing a hard material as described above.
- a surface profiling corrugation in the layer of liquid aluminum can be particularly effectively prevented during the operation of the electrolysis cell.
- the surface of the cathode For example, have a plurality of elevations and / or depressions, wherein the depth of a recess is preferably 10 to 90 mm, more preferably 40 to 90 mm and most preferably 60 to 80 mm.
- Another object of the present invention is a cathode for an electrolytic cell and in particular a cathode for an electrolytic cell for the production of aluminum, which has at least one vertically extending through the cathode opening.
- a cathode is suitable for use in an electrolysis cell according to the invention as described above.
- the cathode When viewed in plan view, the cathode is preferably designed to be at least approximately annular and preferably at least approximately annular or polygonal ring-shaped.
- the outer circumference and / or the inner circumference of the polygonal outline shape of the cathode viewed in plan view is at least substantially in the form of a preferably regular polygon with n corners, where n is preferably 3 to 100, particularly preferably 3 to 10 and most preferably 3, 4, 5, 6, 7 or 8.
- n is preferably 3 to 100, particularly preferably 3 to 10 and most preferably 3, 4, 5, 6, 7 or 8.
- the cathode according to the invention may be composed of a plurality of cathode blocks, which are preferably arranged in the circumferential direction around the opening of the cathode adjacent to each other and adjacent to each other.
- At least one cathode block and preferably all the cathode blocks in plan view have an at least approximately hexagonal, at least approximately circular-ring-shaped or at least approximately trapezoidal outline shape.
- Such a basic shape can be produced easily and is particularly suitable for producing an at least approximately annular cathode by appropriately assembling the individual cathode blocks.
- the cathode blocks can each be connected to one another via a ramming compound or in another suitable manner.
- the ratio between the inner diameter and the outer diameter of the cathode is between 0.01 and 0.99, preferably between 0, 1 and 0.8, particularly preferably between 0.2 and 0 , 6 and most preferably between 0.3 and 0.5. In this way, a particularly uniform and low magnetic flux density can be achieved in the entire cathode with good space utilization based on the extent of the cathode in the horizontal plane.
- the cathode has on its underside at least two recesses for each of a pin-like contacting element. This creates the possibility of contacting the cathode via pin-type contacting elements inserted into the recesses of the cathode. Ren, whereby the current density distribution at the surface of the cathode and in the layer of liquid aluminum arranged above it and the melt layer can be adjusted specifically so that over the entire cathode surface results in a particularly homogeneous Stromêtvertei- ment.
- At least one of the recesses extends for a pin-like contacting element and particularly preferably all recesses extend for a pin-like contacting element with an angle of less than 30 ° and preferably less than 10 ° with respect to the vertical and very particularly preferably perpendicular to the Cathode inside. This makes it possible to produce a particularly good electrical contact between a pin-like contacting element provided in the respective recess of the cathode and the cathode.
- the cathode is preferably connected via a screw connection with a pin-like contacting element arranged in a recess of the cathode, wherein the recess preferably has on its inside an internal thread for such a screw connection.
- the length of the recesses for the pin-like contacting elements is preferably between 100 and 500 mm and the diameter of the recesses for pin-like contacting elements is preferably between 30 and 200 mm.
- the recesses for pin-like Kontak- t istsetti can be arranged at least partially in a density of 4 to 1000 recesses per square meter base of the cathode. With such a density, the distribution of the contacting elements used in the recesses can be specifically adjusted so that an at least particularly uniform current density distribution results at the cathode surface.
- Fig. 2 is a sectional view of an electrolytic cell according to a
- FIG. 3 is a perspective view of a segment of an electrolytic cell according to an embodiment of the invention.
- FIG. 4 shows a schematic representation of the electrical current flow in the segment of an electrolysis cell shown in FIG. 3 according to an embodiment of the invention
- FIGS. 5a-c show a graphic representation of the electrical current density distribution on the cathode surface of one of FIGS. 2, 3 and 4, according to an embodiment of the invention (FIG. 5a) and, for comparison, the electric current density distribution at the surface of the cathode of a conventional electrolysis cell (FIG. 5b), FIG.
- Fig. 6a-c is a graphical representation of the distribution of the magnetic
- Fig. 7 is a plan view of a cathode of an electrolytic cell according to a
- FIG. 8 is a plan view of a cathode of an electrolytic cell according to another embodiment of the invention.
- FIG. 9 is a plan view of a cathode of an electrolytic cell according to another embodiment of the invention.
- FIG. 10 shows a segment of an electrolysis cell according to a further embodiment of the invention with horizontal contacting of the cathode in a perspective view
- FIG. 1 shows an electrolysis cell according to the prior art in cross section.
- the electrolysis cell comprises a conventional rectangular cathode 10 ', which forms a cathode bottom, above which there is a layer 12 of liquid aluminum.
- the layer 12 of liquid aluminum adjoins a melt layer 14 arranged above the layer 12 of liquid aluminum.
- an anode 16 which is arranged above the melt layer 14 and also formed from a plurality of anode blocks 27, emerges, wherein the anode blocks 27 are connected in an electrically conductive manner to an external power supply 22.
- the cathode 10 'of the electrolysis cell shown in FIG. 1 is electrically conductively connected to a bus bar 34 extending laterally into the cathode 10'.
- Fig. 2 shows an electrolytic cell according to an embodiment of the present invention in plan view.
- the electrolytic cell comprises a cathode 10, on top of the cathode 10 a layer 12 (not shown) made of liquid aluminum, on a melt layer 14 (not shown) and above the melt layer 14 an anode 16 (not shown).
- the latter components are not shown in Fig. 2, so as to release the view of the cathode 10 of the electrolysis cell.
- the cathode 10 comprises a vertically extending, ie in FIG. 2 perpendicular to the plane of the drawing, through the cathode 10 extending through opening 18, in which a "inner" power supply 20 extending through the opening and electrically connected to the anode 16 (not shown) is provided.
- the electrolysis cell has a plurality of "outer" power supply lines 22 arranged outside the opening 18, which are arranged laterally offset from the cathode, extend vertically upwards and are likewise connected to the anode 16 as shown in FIG.
- the outer power leads 22 are substantially annular and disposed at regular angular intervals about the opening 18.
- the cathode 10 has substantially the shape of a regular hexagonal ring when viewed in plan view, wherein both the outer periphery and the inner periphery of the cathode 10 form a regular hexagon and are arranged concentrically with each other.
- the shape of the cathode 10 approximates that of a concentric annulus, and can be easily manufactured as compared to a concentric annulus.
- the cathode 10 is composed of a plurality of segments or cathode blocks 24 which, when viewed in plan view, have the outline shape of a symmetrical trapezium and are arranged in the circumferential direction around the opening 18 next to one another to form the hexagonal ring-shaped cathode 10.
- the cathode 10 has a hexagonal symmetry when viewed in plan view, wherein three vertical planes of symmetry 26, as shown in FIG. 2, extend through the middle of the cathode blocks 24 and additionally three symmetry planes not specifically marked in FIG each along the arranged between two adjacent cathode blocks 24 side surfaces of the cathode blocks 24 extend.
- FIG. 3 shows a perspective view of a segment of an electrolytic cell formed by a trapezoidal cathode block 24 according to an embodiment of the invention, which essentially corresponds to the embodiment shown in FIG. 2.
- the individual conductor sections namely an inner and an outer power supply 20, 22, are clearly visible, which are brought together above the anode 16 and contact the anode 16.
- the anode 16 also consists of a plurality of anode blocks 27, wherein the individual anode blocks 27 corresponding to the cathode blocks 24 essentially have the outline shape of a symmetrical trapezoid.
- Each anode block 27 may in principle be contacted by one or more power supply lines 20, 22 and a plurality of anode blocks 27 may be electrically conductively connected to each other along their side surfaces, but this is not absolutely necessary. In this case, the anode blocks 27 are suspended from electrically conductive suspension elements 25 and are electrically contacted via them.
- the cathode 10 is electrically contacted from below by a plurality of pin-like contacting elements 28 which each extend perpendicularly to the underside of the cathode 10 into the cathode 10 and the side facing away from the cathode 10 with a common via a current conductor 29 with a electrical power source connected base plate 30 are electrically connected.
- FIG. 4 the electric current flow in the segment of the electrolysis cell shown in FIG. 3 is illustrated by arrows 31.
- the upward electric current in the inner power supply 20 and The upwardly directed electrical current in the external power supply leads 22 also generate a magnetic field in each case, the magnetic fields generated by the inner and outer power supply leads 20, 22 in the area of the cathode 10, the layer 12 of liquid aluminum, the melt layer 14 and the anode 16 substantially cancel, so that in particular in the layer 12 of liquid aluminum and the melt layer 14 is present only a very small and very homogeneously distributed magnetic flux density.
- the entire electrolysis current flowing through the anode 16, the melt layer 14, the layer 12 of liquid aluminum and the cathode 10 is supplied through the power supply lines 20, 22.
- the division of the electrolysis current onto the inner power supply 20 on the one hand and the outer power supply lines 22 on the other hand is preferably adjusted by appropriate selection of the cross sections of the power supply lines 20, 22 in such a way that optimum extinction of the magnetic fields in the region of the annular cathode 10 results.
- the inner power supply 20 and the outer power supply lines 22 can have different large conductor cross sections for this purpose.
- Fig. 5a shows a graphical representation of the electrical distribution of the vertical component of the electric current density at the cathode surface of a segment of an electrolytic cell as shown in Figs. 3 and 4 viewed in plan view.
- FIG. 5a It can be seen from FIG. 5a that the particular type of contacting by means of pin-shaped contacting elements 28 shown in FIGS. 2, 3 and 4 achieves excellent uniformity of the vertical component of the electric current density over the entire cathode block surface. In this way, horizontal Current density components largely avoided, so that the wave formation in the layer 12 of liquid aluminum and the melt layer 14 and wear of the cathode 10 alone by the nature of the contacting of the cathode 10 can be reduced.
- FIG. 5b is a representation of the distribution of the vertical component of the electric current density on the surface of a conventional parallelepiped cathode 10 'of a conventional electrolytic cell, as shown in FIG. 5a.
- the electrolytic cell shown in FIGS. 3 and 4 has a distribution of the vertical electric current density at the cathode surface, which is significantly more uniform than the distribution of the vertical shown in FIG Current density at the surface of the conventional cathode 10 '.
- Fig. 5c is a legend indicating the values of the amount of vertical electric current density at the respective location of the cathode surface corresponding to the hatching shown in Figs. 5a and 5b.
- Fig. 6a is a graph showing the distribution of the amount of magnetic flux density in the interface between the liquid aluminum layer 12 and the melt layer 14 of a segment of an electrolytic cell as shown in Figs. 3 and 4 as viewed in plan.
- FIG. 6b is a distribution of the magnitude of the magnetic flux density in the interface between the layer 12 of liquid aluminum and the melt layer 14 of an electrolytic cell with conventional parallelepiped cathode 10 'corresponding to the representation of FIG. 6a.
- 6c is a legend indicating the values of the amount of magnetic flux density at the respective location in the interface between the liquid aluminum layer 12 and the melt layer 14, corresponding to the hatchings shown in FIGS. 6a and 6b.
- the electrolysis cell shown in FIGS. 2, 3 and 4 has a distribution of the magnetic flux density which is distributed both in terms of magnitude significantly less and significantly more uniformly than that in the Fig. 6b distribution shown in an electrolytic cell with conventional cathode 10 '.
- FIG. 7 shows an electrolysis cell in plan view which substantially corresponds to the electrolytic cell shown in FIGS. 2, 3 and 4, an additional example method for producing the cathode 10 of the electrolyte cell being illustrated.
- a plurality of trapezoidal cathode blocks 24 for the hexagonal annular cathode 10 can be made simply by cutting a substantially parallelepiped green body 32 into pieces transverse to its longitudinal direction, with the cuts viewed in the longitudinal direction of the green body 32 in an alternating manner Orientation are guided.
- a cutting tool for example, a milling or sawing tool can be used.
- FIG. 8 shows a further embodiment of an electrolytic cell in plan view, which substantially corresponds to the embodiment shown in FIG. 7 and in which the cathode 10 has an annular outline shape. has and is composed of annular segment-shaped cathode blocks 24.
- FIG. 9 shows a further embodiment of an electrolysis cell in a plan view, which substantially corresponds to the embodiments shown in FIGS. 7 and 8, and in which the cathode 10 is composed of cathode blocks 24 with a hexagonal outline in such a way that approx circular outline of the entire cathode 10 results.
- 10 shows a segment of an electrolysis cell according to a further embodiment of the invention in a perspective view.
- the embodiment shown in FIG. 10 essentially corresponds to the embodiments shown in FIGS. 2, 3, 4 and 7, although the contacting of the cathode 10 is not effected by pin-type contacting elements 28 (see FIGS. 3 and 4). but by horizontal busbars 34 takes place.
- FIG. 11 shows a perspective view of an electrolysis cell according to a further preferred embodiment, the electrolysis cell being essentially composed of segments as shown in FIGS. 3 and 4.
- the opening extends 18 vertically through the cathode 10 and also extends through the layer 12 of liquid aluminum, the melt layer 14 and the anode 16 vertically therethrough, these components each form around this opening a closed ring.
- the layer 12 of liquid aluminum and the melt layer 14 are located in a basin bounded by a tub, wherein the bottom of the tub is formed by the cathode 10, wherein the side walls of the tub in Fig. 1 1 are not shown.
- the anode 16 is preferably somewhat narrower in plan view than the cathode 10, the layer 12 of liquid aluminum and the melt layer 14 and immersed in the melt layer 14.
- FIG. 12 shows a perspective view of an electrolytic cell according to a further embodiment of the present invention, which essentially corresponds to the electrolytic cell shown in FIG. 11.
- the anode 16 of the electrolytic cell shown in FIG. 12 is composed of a plurality of anode blocks 27, each having a substantially trapezoidal outline as seen in plan view, which are annularly spaced around the opening 18 and spaced apart, and which respectively dip slightly into the melt layer 14 ,
- FIG. 13 shows a cross-sectional view of an electrolytic cell according to a further preferred embodiment of the present invention, which essentially corresponds to the electrolytic cells shown in FIGS. 11 and 12. Shown is also a steel tub 36, which forms a border for the electrolytic cell and - in accordance with the cathode 10 - viewed in plan view is annular. Towards the opening 18, the steel tub 36 is delimited by vertical side walls which extend vertically through the electrolytic cell. Define extending shaft for the inner power supply 20 through which the power supply 20 passes vertically through.
- the steel tub 36 is lined at its bottom with bottom bricks 38 and lined at their vertical side walls with side stones 40, wherein the bottom and side bricks 38, 40 each consist of a refractory material, which is preferably electrically insulating.
- the bottom and side bricks 38, 40 forming the lining of the steel tub 36 include a material selected from the group consisting of a white ceramic material, a silicon nitride bonded silicon carbide, carbon and graphite, and any combinations of these materials.
- the cathode 10 is arranged, which forms the bottom of a trough formed by the cathode 10 and the side stones 40, which in turn defines a pool for receiving the layer 12 of liquid aluminum and the melt layer 14.
- the anode blocks 27 dip into the melt layer 14, but not into the layer 12 of liquid aluminum, and for this purpose-seen in plan view-are somewhat narrower than the cathode 10, the layer of liquid Aluminum and the melt layer 14.
- a pin-shaped contacting element 28 extending vertically into the cathode 10 is also shown, which at its end facing away from the cathode 10 has a power supply designed to run horizontally Cathode is electrically connected.
- the pin-shaped contacting element 28 and the busbar 42 are electrically insulated from the steel tub 36.
- FIG. 14 the electrolysis cell shown in FIG. 13 is shown, in which, in addition, the technical flow of current in FIG. tion of the current flowing during operation of the electrolysis cell darg
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Metals (AREA)
Abstract
Description
Claims
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014516287A JP2014517157A (ja) | 2011-06-22 | 2012-06-15 | 磁場を相殺した環状電気分解セルおよび環状陰極 |
CN201280031002.6A CN103764877A (zh) | 2011-06-22 | 2012-06-15 | 具有磁场补偿的环形电解槽以及环形阴极 |
EP12727664.0A EP2723919A2 (de) | 2011-06-22 | 2012-06-15 | Ringförmige elektrolysezelle und ringförmige kathode mit magnetfeldkompensation |
AU2012271993A AU2012271993A1 (en) | 2011-06-22 | 2012-06-15 | Annular electrolytic cell and annular cathode with magnetic field compensation |
RU2014101691/02A RU2014101691A (ru) | 2011-06-22 | 2012-06-15 | Кольцеобразный электролизер и кольцеобразный катод с компенсацией магнитного поля |
CA2838940A CA2838940A1 (en) | 2011-06-22 | 2012-06-15 | Annular electrolysis cell and annular cathode with magnetic field compensation |
ZA2013/09289A ZA201309289B (en) | 2011-06-22 | 2013-12-10 | Annular electrolytic cell and annular cathode with magnetic field compensation |
US14/138,331 US20140110251A1 (en) | 2011-06-22 | 2013-12-23 | Annular electrolysis cell and annular cathode with magnetic field compensation |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102011078002.5 | 2011-06-22 | ||
DE102011078002A DE102011078002A1 (de) | 2011-06-22 | 2011-06-22 | Ringförmige Elektrolysezelle und ringförmige Kathode mit Magnetfeldkompensation |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US14/138,331 Continuation US20140110251A1 (en) | 2011-06-22 | 2013-12-23 | Annular electrolysis cell and annular cathode with magnetic field compensation |
Publications (2)
Publication Number | Publication Date |
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WO2012175419A2 true WO2012175419A2 (de) | 2012-12-27 |
WO2012175419A3 WO2012175419A3 (de) | 2013-04-04 |
Family
ID=46298419
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2012/061431 WO2012175419A2 (de) | 2011-06-22 | 2012-06-15 | Ringförmige elektrolysezelle und ringförmige kathode mit magnetfeldkompensation |
Country Status (11)
Country | Link |
---|---|
US (1) | US20140110251A1 (de) |
EP (1) | EP2723919A2 (de) |
JP (1) | JP2014517157A (de) |
CN (1) | CN103764877A (de) |
AR (1) | AR086974A1 (de) |
AU (1) | AU2012271993A1 (de) |
CA (1) | CA2838940A1 (de) |
DE (1) | DE102011078002A1 (de) |
RU (1) | RU2014101691A (de) |
WO (1) | WO2012175419A2 (de) |
ZA (1) | ZA201309289B (de) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014060422A2 (de) * | 2012-10-17 | 2014-04-24 | Sgl Carbon Se | Kathodenblock mit trapezförmigem querschnitt |
Citations (5)
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US4071420A (en) * | 1975-12-31 | 1978-01-31 | Aluminum Company Of America | Electrolytic production of metal |
DE4118304A1 (de) * | 1991-06-04 | 1992-12-24 | Vaw Ver Aluminium Werke Ag | Elektrolysezelle zur aluminiumgewinnung |
US20020166775A1 (en) * | 1999-10-26 | 2002-11-14 | Vittorio De Nora | Drained-cathode aluminium electrowinning cell with improved electrolyte circulation |
US20030196911A1 (en) * | 2002-04-22 | 2003-10-23 | Palmer Forrest M. | Process and apparatus for smelting aluminum |
DE60005301T2 (de) * | 1999-01-08 | 2004-06-17 | Moltech Invent S.A. | Elektrolytische zelle mit verbesserter tonerde-zufuhr |
Family Cites Families (9)
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GB802905A (en) * | 1954-01-14 | 1958-10-15 | British Aluminium Co Ltd | Improvements in or relating to electrolytic cells for the production of aluminium |
US3368960A (en) * | 1961-02-21 | 1968-02-13 | Elektrokemisk As | Alumina reduction cell |
ZA824257B (en) * | 1981-06-25 | 1983-05-25 | Alcan Int Ltd | Electrolytic reduction cells |
FR2583069B1 (fr) * | 1985-06-05 | 1987-07-31 | Pechiney Aluminium | Dispositif de connexion entre cuves d'electrolyse a tres haute intensite, pour la production d'aluminium, comportant un circuit d'alimentation et un circuit independant de correction du champ magnetique |
US5240569A (en) * | 1991-09-30 | 1993-08-31 | Rockwell International Corporation | Magnetically enhanced electrolysis cell system |
US5362366A (en) * | 1992-04-27 | 1994-11-08 | Moltech Invent S.A. | Anode-cathode arrangement for aluminum production cells |
US6692620B2 (en) * | 2002-04-27 | 2004-02-17 | Moltech Invent S.A. | Aluminium electrowinning cell with sidewalls resistant to molten electrolyte |
US6863788B2 (en) * | 2002-07-29 | 2005-03-08 | Alcoa Inc. | Interlocking wettable ceramic tiles |
EP1845174B1 (de) | 2006-04-13 | 2011-03-02 | SGL Carbon SE | Kathode zur Aluminiumelektrolyse mit nicht ebenen Rilledesign |
-
2011
- 2011-06-22 DE DE102011078002A patent/DE102011078002A1/de not_active Withdrawn
-
2012
- 2012-06-15 AU AU2012271993A patent/AU2012271993A1/en not_active Abandoned
- 2012-06-15 EP EP12727664.0A patent/EP2723919A2/de not_active Withdrawn
- 2012-06-15 CA CA2838940A patent/CA2838940A1/en not_active Abandoned
- 2012-06-15 CN CN201280031002.6A patent/CN103764877A/zh active Pending
- 2012-06-15 RU RU2014101691/02A patent/RU2014101691A/ru not_active Application Discontinuation
- 2012-06-15 WO PCT/EP2012/061431 patent/WO2012175419A2/de active Application Filing
- 2012-06-15 JP JP2014516287A patent/JP2014517157A/ja active Pending
- 2012-06-18 AR ARP120102164A patent/AR086974A1/es unknown
-
2013
- 2013-12-10 ZA ZA2013/09289A patent/ZA201309289B/en unknown
- 2013-12-23 US US14/138,331 patent/US20140110251A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4071420A (en) * | 1975-12-31 | 1978-01-31 | Aluminum Company Of America | Electrolytic production of metal |
DE4118304A1 (de) * | 1991-06-04 | 1992-12-24 | Vaw Ver Aluminium Werke Ag | Elektrolysezelle zur aluminiumgewinnung |
DE60005301T2 (de) * | 1999-01-08 | 2004-06-17 | Moltech Invent S.A. | Elektrolytische zelle mit verbesserter tonerde-zufuhr |
US20020166775A1 (en) * | 1999-10-26 | 2002-11-14 | Vittorio De Nora | Drained-cathode aluminium electrowinning cell with improved electrolyte circulation |
US20030196911A1 (en) * | 2002-04-22 | 2003-10-23 | Palmer Forrest M. | Process and apparatus for smelting aluminum |
Also Published As
Publication number | Publication date |
---|---|
AU2012271993A1 (en) | 2013-05-09 |
ZA201309289B (en) | 2014-08-27 |
DE102011078002A1 (de) | 2012-12-27 |
JP2014517157A (ja) | 2014-07-17 |
WO2012175419A3 (de) | 2013-04-04 |
US20140110251A1 (en) | 2014-04-24 |
EP2723919A2 (de) | 2014-04-30 |
CN103764877A (zh) | 2014-04-30 |
AR086974A1 (es) | 2014-02-05 |
RU2014101691A (ru) | 2015-07-27 |
CA2838940A1 (en) | 2012-12-27 |
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