SA515360744B1 - An Electrode for Aluminium Production and a Method of Making Same - Google Patents

Abstract

An electrode for production of aluminium metal by electrolysis of an aluminium containing compound dissolved in a molten electrolyte, where the electrowinning process is performed in smelting cells of conventional Hall-Hèroult design. The electrode comprises a calcinated carbon containing body being integrated with at least one composite metallic conductor comprising conducting elements of a Fe containing material and conducting elements of a Cu containing material. The composite conductor comprises a barrier layer material at the interface between the two conducting materials. Barrier materials of ceramic, Refractory Hard Materials (RHM), and of metallic types are proposed as well as methods for their application. Figure 1

Description

— \ — An Electrode for Aluminum Production and a Method of Making Same Full Description BACKGROUND The present invention relates to an Electrode for Aluminum Production and a Method of Making Same. Aluminum metal is currently produced by electrolysis of a compound containing aluminum dissolved in a molten electrolyte and the electroextraction process is performed in a WIA smelter of the conventional Hall-Heroult design. This electrolytic WIA is supplied with Eun, GE aligned electrodes. Today's WAY WLS conductive anodes and cathodes are made of carbon materials. The base of the electrolyte is a mixture of sodium fluoride 50010107 and aluminum fluoride with additions of alkaline halides and alkaline earth A 10©5a8. Electroplating occurs when the current (we) that flows through the electrolyte from the anode to the cathode electrostatically discharges aluminum ions into the cathode, producing bit aluminum. To secure the collector's steel rods to the cathode blocks, Bale cuts are made in the blocks that allow the rods to fit into them. The space between the wall of the cracks and the bars can be filled with molten Vo cast iron and/or conductive paste can be used. In a similar way, the grud roasted carbon anodes are fixed to steel uprights which are part of the anode bracket. The anode has a Brock hole that allows steel supports to be inserted. The anchoring of the supports to the anode is normally performed by pouring molten cast iron into the annular space between each independent support and the corresponding hole in the anode.

_ Ad —_

In one alternative, conductive particles can be used for cleaning with a metal rod as described in

Patent application for adie International Application No. 447708 4/0 .

In the race for low specific energy consumption of aluminum production, one well known tool aims

and strong to reduce the anodic voltage drop and/or anodic 756. in

In fact, reducing the cathodic voltage drop reduces ohmic energy losses

ohmic energy is contained in the cathode, allowing operators to either increase the line amperage and/or lower the amperage

pot voltage that ultimately lowers the specific energy consumption per ton m of aluminium, which is

Many methods have been used to achieve a reduction in the cathodic voltage drop, and one of the commonly known methods is the use of copper inserts to improve the conductivity of the commonly used steel collector bars.

common. Many prints show that the copper insert or element has a side or surface

At least one external that rests on one corresponding surface of the solid collector rod.

Examples are given in International Application No. 1071557 disclosing compound steel bars

which contain a copper core, and US Application No. 1-09976777 and International Application No. 1 0 0570141_ which disclose the various designs of the copper rod inserted

In the steel tube which is embedded in the notch of the cathode block

It has been shown in tests that copper inserts in the solid collector bars can reduce voltage drop

The cathodic current is about 01 millivolts with respect to conventional steel collector bars.

She Jian further proposed the use of copper as a highly conductive element in cathodes at a more uniform cathodic current density of 0 achieved with these designs. For ladle cathodes in particular,

Regular current shouldering further reduces the maximum wear rate, thus increasing the cathode life.

However, every millivolt saved with solutions that include the introduction of highly conductive elements is a challenge, because

In addition to the expensive copper rods used, the collector (drilling rod collector

Inserting a copper bar is about three times the cost of copper alone.

yyy

__In addition, the inventors noted that at the high temperatures present in this type of composite conductor, iron in the solid collector rod could diffuse into the copper metal of an adjacent copper insert. This diffusion can lead to an increase in the ohmic resistance of the assembled collector rod, and thus an increase in the cathodic voltage drop over time. Similar ohmic resistance effects can occur when composite conductors of the iron-copper type are used for the anodes. GENERAL DESCRIPTION OF THE INVENTION The present invention relates to electrodes, or anodes or cathodes, with composite conductors and a method of their operation, Vs where Say reduces or avoids these harmful effects. More specifically, the invention relates to an electrode for the production of aluminum metal by the electrolysis of a compound containing aluminum dissolved in an aie electrolyte where the electrolytic extraction process is performed in melting cells of conventional Hall-Héroult design. The electrode comprises a structure containing roasted carbon interspersed with at least one composite metallic lage comprising conducting elements of sale 1 containing iron and conducting elements of a copper-containing material. A composite conductor includes a diffusion barrier layer material at the interconnection between the two conductive materials. Several diffusion barrier layer materials as well as layer utilization methods have been investigated. At least two important objectives of the invention can be stated: Maintaining a minimum level of resistance during the life of the cell. 0 and (7) exploit thinner sensor profiles in composite conductors, ie, copper plates, to enhance the quality and cost positioning of the composite conductor. These and other By of the invention may be realized as protected in the yyy elements

Claims (1)

“yam” elements of protection by electrolysis aluminum metal to produce aluminum metal electrode 1 - for a compound containing aluminum 0 dissolved in molten electrolyte electrolysis where the process of extraction molybdenum from molten electrolyte traditional; The Hall-Héroult design smelting cells WA electrode in its “iis 0810108160 carbon” includes a structure containing roasted carbon, an electrode ©, connecting elements from dade, one composite on The least metallic conductor is a metallic conductor « Copper and connecting elements of a material containing copper Iron iron-containing material for conductive diffusion barrier layer barrier layer sale The compound includes Jagd where it is characterized by that in The interface between the two conducting materials where the electronic conductive of the electron is made of a ceramic or a metallic material of molypalladium sale by barrier layer formation of the barrier layer 0 ruthenium or tungsten rhenidium 60L 7/0A00; Tegensten, where it is distinguished that the barrier layer 0 is made for the protection element, Gy electrode, “Refractory Hard Material” electrode for diffusion from a solid, heat-resistant barrier layer.RHM 01, where it is distinguished that the barrier layer oY is made For the protective element Gy electrode electrode -*” TaN J (TiN selected from Borides or Borides Nitrides barrier layer TiB2 or 2852 or ZrN or 901 barrier where it is characterized by that the layer BARRIER Bile According to any electrode protection element -4 µm. — \ \ — 0— A method for forming an electrode according to protection element 1 or oF characterized by the fact that the ceramic diffusion barrier layer is aad in da slurry or by Plasma coating coating or supplied by powder coating. © +- A method of making an electrode according to any of the protections from 1 to of where it is characterized that the ceramic diffusion barrier layer in the form of dus slurry shall be prepared and applied to the connecting elements by dipping at least one of the two conductive elements into said slurry followed by drying; Or supplied by powder coating. Vs #7- A method of making a Gy electrode for protection element 0, where it is characterized by providing a barrier layer for metallic diffusion in the form of a metal foil; or by Chemical Vapor Deposition + or by Electroplating and use on at least one of the two conductive elements prior to assembling these parts Jae _— \ \ _ 1 manat SHY atahese Joo extended sosa ao Forge a FaciSage fac a 9 > Na TUR 2 sage what p and with DA selgm 8? 2 lm : a a ah ne m mn FON the RESIS 0 > : 1 © alain (EE pp 01 b it m and } b 1 Bhai 1 1 a turnip ne b a 3 PS i "1 aE ) for i bY 1 " 0 3 m 1 "8 or BOR BN % + type i 4 ri 57 . Ree ererrenrrrenrreeree i for r i 1 b oo placed © TRE SN a? H i mG, 1: : 1 8 b : 5 TH Etc. sa m l y N Srna 8 ' 2 88 4 fol i SERGE ma 4 ed l mi l ya + yi + wit in kasmala shah 1 yyy rh ————————— ——— ِ {i I Lo in SEL AFUE Shp i= Erar i i wi KE 19% 1 i 1 ES 0 Ben 1 | Squirt a Bhool jo CN fou © 8 0 Erm i Vo * bd a E 4 2 © J J J CE pe § * + A > A Cue Fe % HAA AAA AAA AAA AAA Aye Shamma? YN Die I'm sorry ey touch no xr xr x l i 1 ; i 4 § : a | 13 . BS B "NPR: AER ied Ho a hr i$ 1 Fe 14 º San 1 : 4 EU : 1 ad dah to 1 i i d 440 1182 ja i | [ omen 3 ; N 4 : A ; i 1 Co Ada .F INES .£. SE : a Tssissa [ban LON] | 0 ; for FUROR A Ania E | 1 3 : . : 0 e i i AL} 1 : a.! | 3 1 : : 1 : 1 | P" % = i Six Basically Dior TUNE URE OR [ Ys Xue Yona gw > Hw Hw ys Xue Yona gw > Hw 1 complain + mtr pc The validity period of this patent is twenty years from the date of filing the application, provided that the annual financial fee is paid for the patent and that it is not invalid or forfeited for violating any of the provisions of the patent system, layout designs of integrated circuits, plant varieties, and industrial designs, or its executive regulations issued by King Abdulaziz City for Science and Technology; Saudi Patent Office P.O. Box TAT Riyadh 57??11 ¢ Kingdom of Saudi Arabia Email: Patents @kacst.edu.sa