KR20150022993A - Electrolysis tank used for aluminum electrolysis and electrolysis process using the electrolyzer - Google Patents

Abstract

The present invention describes an electrolytic cell for aluminum electrolysis comprising a bath main body in which an anode and a cathode are disposed in the bath main body, the bath main body is further filled with an electrolyte, and at least a part of the anode is contained in the electrolyte Impregnated; Wherein the anode is disposed on the bath main body, the cathode is disposed on the bottom of the electrolytic cell and is coated with a predetermined amount of aluminum liquid, the electrolyte is positioned between the anode and the cathode, and; And an insulating layer is disposed on the inner wall of the bath body and is used to separate oxygen or the electrolyte from the carbon block. Said electrolytic cell for aluminum electrolysis is characterized in that said anode comprises components comprising Fe, Cu, Ni and Sn wherein Fe and Cu function as main components; And the electrolyte is composed of 30 to 38 wt% of NaF, 49 to 60 wt% of AlF ₃ , 1 to 5 wt% of LiF, 1 to 6 wt% of KF and 3 to 6 wt% of Al ₂ O ₃ , Wherein the molar ratio of NaF to AlF ₃ is 1.0 to 1.52. The electrolyzer can be used to produce industrial electrolytic aluminum.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic bath used for aluminum electrolysis and an electrolytic method using the electrolytic bath. ≪ RTI ID = 0.0 >

The present invention relates to an electrolyzer for aluminum electrolysis and an electrolysis method using the electrolyzer, and belongs to the non-ferrous metal refining industry.

In the aluminum electrolysis industry, a conventionally applied conventional Hall-Heroult molten salt aluminum electrolysis process is typically applied to the molten salt of cryolite-alumina in a pre-fired carbon anode electrolyzer That is, the salt of the cryolite Na ₃ AlF ₆ fluoride is taken as a flux, aluminum oxide (Al ₂ O ₃ ) is dissolved in the salt of the fluoride, the carbon body is taken as the anode And a carbon body which is inserted vertically into the electrolytic cell and which carries an aluminum liquid which covers the bottom of the electrolytic cell is taken as a cathode and is introduced into the electrolytic cell at a high temperature in the range of 940 to 960 캜 after introduction of a strong direct current. An electrochemical reaction is carried out on the anode and the cathode, and the resulting aluminum liquid product is supplied to the bottom of the bottom of the electrolyzer Pole. Due to the high electrolytic temperatures, the conventional aluminum electrolysis processes described above have properties such as volatilization amounts of large amounts of electrolytes, oxidation losses of large amounts of carbon anode, large amounts of energy consumption and poor working conditions .

In the prior art, the delivery system to keep the temperature, Chinese Patent Publication No. CN101671835A discloses and describes a low-temperature molten salt system, the molten salt composition of the system, aluminum fluoride _{(AlF 3), Al 2 O} 3 , and potassium fluoride ( KF), sodium fluoride (NaF), magnesium fluoride (MgF _2), calcium fluoride (CaF _2), sodium chloride (NaCl), lithium fluoride (one or more selected from the group consisting of LiF) and barium fluoride (BaF ₂₎ Salts, and the electrolytic temperature of the electrolyte can be lowered within a wide range of 680 to 900 DEG C depending on the purpose of operation.

The addition of NaCl to the aforementioned electrolytes is intended to lower the liquidus temperature of the electrolyte, however, NaCl causes corrosion of metal parts such as electrolytic cell assemblies at the aforementioned electrolysis temperatures Moreover, NaCl tends to be extremely volatile in the electrolytic process and tends to form hydrochloric acid (HCl) toxic gas, making its application difficult; In addition to the addition of NaCl, a reduction in the molar ratio of NaF to AlF ₃ may also lower the liquidus temperature of the electrolyte from the standpoint of common sense in the art, but in the existing industry, the molar ratio of NaF to AlF ₃ Is generally greater than 2.2, indicating that if the molar ratio of NaF to AlF ₃ is further reduced, the liquidus temperature of the electrolyte will be lowered while NaF and AlF ₃ will become " keratinized " crusting 'phenomenon. The reason for this'keratinization' phenomenon is that sodium ions and aluminum ions in the electrolyte can collect on the cathode during the electrolytic process to produce sodium cryolite, It is hardly melted at a low temperature due to its high melting point so that the surface of the negative electrode is covered with a layer of refractory cryolite crust, It can significantly affect the normal delivery of the Year at the fair. Due to the abovementioned problems in the prior art, the industrial application of electrolysis is largely limited, and in the prior art it avoids corrosion and human risks to electrolytic devices and ensures adequate electrical conductivity and alumina solubility, It is an unsolved problem to find a way to further lower the liquidus temperature of the electrolyte whilst not causing the cathodic 'keratinization' phenomenon of the resulting electrolyte.

In addition to the high electrolytic temperature that needs to be solved, the carbon anode in a conventional aluminum electrolytic cell is constantly consumed by oxidation during the electrolytic process, thus requiring constant replacement of the carbon anode; In addition, carbon dioxide, carbon monoxide and other off-gases are continuously produced at the anode during aluminum electrolysis. Thus, in the prior art, a number of documents describe the study of cathode materials in order to reduce the consumption of anode materials in the aluminum electrolytic process and at the same time to reduce the emission of waste gases, for example in Chinese Patent CN1443877A Describes an inactive cathode material which is applied to aluminum, magnesium and rare earth electrolytic industries and which is a binary or multi-element material consisting of chromium, nickel, iron, cobalt, titanium, copper, aluminum, magnesium and other metals Alloy, and the manufacturing method thereof is smelting or powder metallurgy. The prepared positive electrode material has good electrical conductivity and thermal conductivity and produces oxygen during the electrolytic process wherein the positive electrode in Example 1 is composed of 37 wt% cobalt, 18 wt% copper, 19 wt% nickel , 23% by weight of iron and 3% by weight of silver, and used for aluminum electrolysis, said anode having a current density of 1.0 A / cm < 2 > during the electrolysis process at 850 [ And maintained within the range of 4.1 V to 4.5 V during the electrolytic process, and the produced aluminum has a purity of 98.35%.

Compared to the carbon material, the alloy cathode material in the above-mentioned techniques can be processed into any shape and with higher electrical conductivity and lower corrosion resistance during the electrolytic process, The anode anode of the composition still has a high overvoltage, which results in industrial power consumption and low product quality, and in addition, since a large amount of expensive metal materials are used, the anode material is expensive and the demand for industrialization . ≪ / RTI >

In addition, in the prior art, when a layer of an oxide film is formed on the surface of the alloy anode thus produced, and the oxide film is destroyed, the anode material exposed to the surface can be oxidized into a new oxide. The oxide film on the surface of the alloy anode in the prior art tends to form products that have low oxidation resistance and can also be corroded by the electrolyte due to the oxidation reaction, The anode electrode tends to break in the process; After the oxide film has been corroded or destroyed, the material of the alloy anode exposed to the surface can generate a new oxide film by the reaction. Substitution between the new oxide film and the old oxide film causes continuous consumption of the cathode material, Resulting in corrosive effects; In addition, the corroded or destroyed oxide film may enter the liquid aluminum during the electrolytic process of the alumina resulting in lowering the purity of the final aluminum product, and as a result, the manufactured aluminum product can not satisfy the national standards requirements Therefore, it can not be used directly as a finished product.

The first technical problem to be solved by the present invention is that the prior art avoids corrosion and human hazards to electrolytic devices and ensures proper electrical conductivity and alumina solubility as well as cathode " And does not further lower the liquidus temperature of the electrolyte. Accordingly, the present invention provides an electrolytic cell comprising an electrolytic solution for aluminum electrolysis, which has a low liquidus temperature, is free of metal corrosion, does not tend to volatilize, is suitable for electrical conductivity and alumina solubility, and has no cathode 'keratinization' phenomenon.

At the same time, the second technical problem to be solved by the present invention is that the alloy anode made of the metal components in the prior art has high overvoltage, high power consumption in the aluminum electrolytic process, and expensive metal components, Resulting in an increase in the cost of; In addition, the oxide film on the surface of the alloy anode in the prior art tends to be low in oxidation resistance and to break, which results in the continuous consumption of the alloy anode and low corrosion resistance, and furthermore, The oxidized film enters the liquid aluminum and lowers the purity of the final aluminum product; Accordingly, there is provided an electrolytic cell for electrolytic aluminum electrolysis wherein the inactive cathode material used is low in over-voltage, low in cost, resistant to oxidation and stability of the oxide film formed on the surface thereof, and resistant to electrolytic corrosion.

At the same time, the present invention provides an aluminum electrolytic process using the electrolytic bath.

In order to solve the above-mentioned technical problems, the present invention includes a cell body, wherein an anode and a cathode are disposed inside the bath body, and the bath body is further filled with an electrolyte; The anode is disposed on the bath body, and at least a portion of the anode is impregnated in the electrolyte; Said cathode being disposed on the bottom of said electrolytic cell and being coated with a predetermined amount of aluminum liquid; The electrolyte is positioned between the anode and the cathode; Wherein the anode comprises components comprising iron (Fe), copper (Cu), nickel (Ni) and tin (Sn), wherein Fe and Cu function as major components; Wherein the electrolyte comprises 30 to 38 wt% NaF, 49 to 60 wt% of AlF ₃ , 1 to 5 wt% of LiF, 1 to 6 wt% of KF, and 3 to 6 wt% of Al ₂ O ₃ , Here, an aluminum electrolytic cell having a molar ratio of NaF to AlF ₃ of 1.0 to 1.52 is provided.

The bottom surface of the anode is held parallel to the electrolytic cell and an insulating layer is disposed on the inner wall of the electrolytic cell and used to separate oxygen or the electrolyte from the carbon block.

A cell cover is disposed at the upper end of the bath main body and is provided with an exhaust port and a supply port; A cathode rod is disposed within the cathode and one end of the anode is provided to be connected to a binding post for passage through the coarse cover and for connection to a power source.

The mass ratio of Fe: Cu: Sn is (23 to 40): (36 to 60): (0.2 to 5).

The components of the anode further include Ni.

Wherein the anode comprises Fe, Cu, Ni and Sn, wherein the content of Fe is 23 to 40 wt%, the content of Cu is 36 to 60%, the content of Ni is 14 to 28 wt% The content is 0.2 to 5% by weight.

The components of the anode further include aluminum (Al) and yttrium (Y).

Wherein the anode comprises Fe, Cu, Ni, Sn, Al and Y wherein the Fe content is 23 to 40 wt%, the Cu content is 36 to 60 wt%, the Ni content is 14 to 28 wt% %, The content of Al is 0 or more and 4 wt% or less, the content of Y is 0 or more and 2 wt% or less, and the content of Sn is 0.2 to 5 wt%.

The molar ratio of NaF to AlF ₃ is 1.12 to 1.52.

The liquidus temperature of the electrolyte is 620 to 670 캜.

The electrolytic process using the electrolytic bath

(1) a specific amount of a melting furnace for mixing and melting NaF, AlF _3, LiF, KF and by addition of Al ₂ O ₃ to form a melt, or; Or adding a certain amount of NaF, AlF ₃ , LiF and KF to the melting furnace for mixing and melting and subsequently adding Al ₂ O ₃ to obtain a melt; And

(2) raising the temperature of the melt produced in step (1) to above 720-760 ° C, and subsequently pouring the melt into the electrolytic cell and performing electrolysis while maintaining the temperature at 720-760 ° C ;

.

The electrolytic temperature is 730 to 750 ° C.

Al ₂ O ₃ is quantitatively supplied to the electrolytic process.

The electrolytic process using the electrolytic bath

(1) a specific amount of a melting furnace for mixing and melting NaF, AlF _3, LiF, KF and by addition of Al ₂ O ₃ to form a melt, or; Or adding a certain amount of NaF, AlF ₃ , LiF and KF to the melting furnace for mixing and melting and subsequently adding Al ₂ O ₃ to obtain a melt; And

(2) raising the temperature of the melt produced in step (1) to above 720-760 ° C, and subsequently pouring the melt into the electrolytic cell and performing electrolysis while maintaining the temperature at 720-760 ° C ;

.

The electrolytic temperature is 730 to 750 ° C.

Al ₂ O ₃ is quantitatively supplied to the electrolytic process.

The electrolytic process using the electrolytic bath and the electrolytic bath in the present invention has the following advantages:

(1) The electrolytic cell for aluminum electrolysis according to the present invention comprises a bath main body, wherein an anode and a cathode are disposed inside the bath main body, and the bath main body is further filled with an electrolyte; The anode is disposed on the bath body, and at least a portion of the anode is impregnated in the electrolyte; Said cathode being disposed on the bottom of said electrolytic cell and being coated with a predetermined amount of aluminum liquid; The electrolyte is positioned between the anode and the cathode; Wherein the anode comprises components comprising Fe, Cu, Ni and Sn wherein Fe and Cu function as major components; Wherein the electrolyte comprises 30 to 38 wt% NaF, 49 to 60 wt% of AlF ₃ , 1 to 5 wt% of LiF, 1 to 6 wt% of KF, and 3 to 6 wt% of Al ₂ O ₃ , Here, an aluminum electrolytic cell having a molar ratio of NaF to AlF ₃ of 1.0 to 1.52 is provided.

The anode comprising metal Sn and comprising the above-mentioned metal components has a high electrical conductivity and a low overvoltage, the voltage of the bath in the electrolytic process of the electrolytic bath is about 3.1 to 3.4 V, and the power consumption in the aluminum electrolytic process And the power consumption per an aluminum tone is 11000 kWh or lower, so that the above process cost is low; Wherein the anode material is an alloy of Fe, Cu and Sn so that the oxide film formed on the surface of the anode in the electrolytic process has a high oxidation resistance and is not substantially corroded by the electrolyte and the oxide film formed is stable and destructive Therefore, the anode is provided with a significantly high oxidation resistance and a strong corrosion resistance to ensure the purity of the aluminum product, that is, the purity of the produced aluminum can reach 99.8%. The following problems in the prior art are avoided: the alloy anode has a high overvoltage, the oxide film on the alloy surface tends to be low in oxidation resistance and destroyed, which leads to the continuous consumption of the alloy anode and poor corrosion resistance And furthermore, an oxide film that is corroded or destroyed enters the liquid aluminum and lowers the purity of the final aluminum product. In addition, Fe and Cu function as main components of the alloy anode and their content ratio is considerably high, and hence the production cost of the cathode material is low.

The electrolyte used has a pure fluoride system, the material composition in the electrolyte is limited, the contents of these materials are more defined and the molar ratio of NaF to AlF ₃ is from 1.0 to 1.52, and the liquidus temperature of the electrolyte is Deg.] C to 640 [deg.] C to 670 [deg.] C, so that electrolysis can be carried out at 720 to 760 [deg.] C according to the electrolytic process, which reduces the volatilization loss of the fluoride salt and avoids corrosion and harm to the electrolytic devices Improve the working environment, significantly reduce energy consumption in the electrolytic process, and achieve the goals of energy saving and emission reduction; On the other hand, in the present invention, it is possible to form lithium cryolite and potassium cryolite having appropriate amounts of LiF and KF added thereto and combined with sodium ions and aluminum ions in the electrolyte to have low melting points Thereby avoiding the keratinization phenomenon in the electrolytic process; Compared with the existing industry, the electrolyte for aluminum electrolysis in the present invention does not contain CaF ₂ and MgF ₂ therein, but instead has KF having a function of increasing the solubility and dissolution rate of alumina, ₃ is added to the system wherein the molar ratio of NaF to ₃ is between 1.0 and 1.52, thereby improving the disadvantages of low alumina solubility in a low molar ratio electrolyte; In general, the electrical conductivity of the electrolyte decreases as the temperature decreases, and thus typically, the electrical conductivity at low electrolytic temperatures scarcely satisfies the requirements of conventional electrolytic processes; The electrolysis temperature is lowered by lowering the liquidus temperature of the electrolyte of the present invention, but since LiF with a higher electrical conductivity is added and the proportions of the components in the electrolyte are optimized, The electrical conductivity can still satisfy the requirements in the electrolytic process and thus improve the current efficiency in the electrolytic process. According to the present invention, the content of LiF is limited to 1 to 5%, which means that an excessively low content of LiF improves electrical conductivity and fails to prevent keratinization, and a too high content of LiF reduces the solubility of alumina Results, and the above two situations are effectively avoided by limiting the content of LiF in the present invention to 1 to 5%; And, if the electrolyte with the above ratios in the present invention is used, there is no corrosion of the metallic device, and in this way the service life of the electrolyzer is extended.

(2) In the electrolytic cell for aluminum electrolysis of the present invention, the positive electrode is made of Fe, Cu, Ni, Sn, Al and Y, wherein the content of Fe is 23 to 40 wt% 36 to 60 wt%, Ni content of 14 to 28 wt%, Al content of 4 wt% or less, Y content of 2 wt% or less, and Sn content of 0.2 to 5 wt%.

Similarly, the aforementioned inert alloy anode has the advantages of low material cost and high electrical conductivity, and furthermore, the metal aluminum contained in the above-mentioned inert alloy anode plays a role of oxidation resistance and the metal of the inert anode alloy Can function as a reducing agent for a metallothermic reduction reaction with an oxide, thereby preventing the metals in the inactive alloy anode from being oxidized, i.e., the main components, and reducing the electrical conductivity of the alloy anode ≪ / RTI > On the other hand, the added metal Y may be used to control the crystal structure for the formation of the anode material in the production process of the inert anode so as to achieve the antioxidative purpose.

(3) In the electrolytic cell for aluminum electrolysis in the present invention, specified amounts of NaF, AlF ₃ , LiF, KF and Al ₂ O ₃ are mixed and the resulting mixture is heated to form a melt; Or specified amounts of NaF, AlF ₃ , LiF and KF are mixed and subsequently Al ₂ O ₃ is added to obtain a melt and the melt produced is electrolyzed at 720 to 760 ° C. The electrolytic temperature is directly related to the volatilization of the electrolyte, the keratinization phenomenon of the electrolyte, the energy consumption of the process, the electric conductivity and the solubility of alumina, and the inventors of the present invention, after a long period of research, The electrolysis temperature is set within a range of 720 to 760 ° C so that the cathodic phenomenon is prevented and the volatilization of the electrolyte and the energy consumption of the electrolysis process are reduced while the electricity Both the conductivity and the alumina solubility are increased and the economic performance of the process is improved. Preferably, the electrolytic temperature is set within the range of 730 to 750 DEG C in the present invention.

1 is a structural diagram of an electrolytic cell for aluminum electrolysis in the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the subject matter of the present invention may be more readily understood, the technical solution of the present invention will be described in further detail below with reference to the drawings and embodiments.

In this figure, reference symbols are as follows: 1 denotes a bath body, 2 denotes an anode, 3 denotes a cathode, 4 denotes an electrolyte, 5 denotes an insulating layer, 6 denotes an electrolyte, Reference numeral 7 denotes an exhaust port, 8 denotes a supply port, 9 denotes a tangential column, 10 denotes a cathode rod, and 11 denotes an aluminum liquid.

The electrolytic bath for aluminum electrolysis of the present invention is as shown in Fig. 1 and comprises a bath main body 1 in which an anode 2 and a cathode 3 are disposed inside the bath main body 1, The anode 2 and the cathode 3 may be disposed in a random manner according to actual requirements and in this embodiment the anode 2 is disposed on the bath main body 1, 2 is kept parallel to the bath main body 1, the cathode 3 is disposed at the bottom of the electrolytic cell and is coated with a predetermined amount of aluminum liquid 11; Wherein the bath body 1 is further filled with an electrolyte 4 and the impregnation of the anode 2 and the cathode 3 in the electrolyte 4 is dependent on the selected electrolyzer structure, At least a portion of the anode (2) is impregnated into the electrolyte (4); The cathode (3) is disposed on the bottom of the electrolyzer and is coated with a predetermined amount of aluminum liquid (11); Wherein the electrolyte (4) is positioned between the anode (2) and the cathode (3) and is coated with the aluminum liquid (11); Wherein the anode (2) comprises components comprising Fe, Cu, Ni and Sn wherein Fe and Cu function as main components and the mass ratio of Fe: Cu: Sn is between 23 and 40: 36 To 60): (0.2 to 5); Wherein the electrolyte (4) comprises 30 to 38 wt% NaF, 49 to 60 wt% of AlF ₃ , 1 to 5 wt% of LiF, 1 to 6 wt% of KF, and 3 to 6 wt% of Al ₂ O ₃ Wherein the molar ratio of NaF to AlF ₃ is 1.0 to 1.52, preferably 1.12 to 1.52, and the liquidus temperature of the electrolyte (4) is 620 to 670 ° C, preferably 640 to 670 ° C .

As a variable embodiment based on this basis, it is possible to separate the inner wall of the bath main body 1 from the electrolyte 4 and oxygen so that the electrons between the side wall of the bath main body 1 and the electrolyte 4 (5) is disposed on the inner wall of the bath main body (1), and the high temperature and the electrolyte (4) are disposed on the inner wall of the bath main body (E.g., corundum, aluminate spinel refractory, etc.) that are resistant to corrosion of the substrate (e. G. In this embodiment, a carbon block is disposed between the inner wall of the bath main body 1 and the insulating layer 5, and the carbon block and the cathodes 3 are integrally formed. Undoubtedly, the carbon block and the cathode 3 can also be arranged in a separate manner.

On the basis of this basis, in order to isolate the electrolytic environment for the electrolytic cell from the outside without obstructing the exhaust and supply, a lid cover 6 is disposed at the upper end of the bath main body 1, (7) and a supply port (8) are provided, and the sizes and positions of the exhaust port (7) and the supply port can be randomly determined according to actual requirements, and in this embodiment, the exhaust port (7) 2).

A cathode rod 10 is disposed on the cathode 3 at the bottom of the electrolyzer and the cathode 3 is disposed at the bottom of the electrolyzer to facilitate connection of the anode 2 and the cathode 3 to a power source. For connection to the power source; One end of said anode (2) penetrates through said bottom cover (6) and is connected to a tangential post (9) and is provided for connection with said power source of said anode (2); And the cathode 10 and the tangential post 9 may be made of any material having good electrical conductivity, including steel, iron and alloy materials and the like.

On the basis of this basis, in order to improve the combination firmness between the metals Fe, Cu and Sn, the components of the anode 2 additionally contain Ni, and preferably the anode 2 ) Is composed of Fe, Cu, Ni and Sn, wherein the Fe content is 23 to 40 wt%, the Cu content is 36 to 60 wt%, the Ni content is 14 to 28 wt% The content is 0.2 to 5% by weight.

The anode 2 is preferably made of Fe, Cu, Ni, Sn, Al and Y, and the added Al prevents oxidation of other major metal components of the anode 2 and improves oxidation resistance And the component Y can be used to control and control the structure of the alloy crystals prepared to achieve the antioxidant purpose wherein the content of Fe is 23 to 40 wt% 36 to 60 wt%, Ni content of 14 to 28 wt%, Al content of 4 wt% or less, Y content of 2 wt% or less, and Sn content of 0.2 to 5 wt%.

When the above-mentioned electrolytic cell is used for aluminum electrolysis, the electrolytic temperature is 720 to 760 캜, preferably 730 to 750 캜.

Hereinafter, a detailed description will be given with reference to embodiments.

Example 1

Fe, Cu, Ni and Sn metal ingots are mixed based on 23 wt% Fe, 60 wt% Cu, 14 wt% Ni and 3 wt% Sn, and the mixture is melted by heating at high temperature , And subsequently to the casting to obtain the anode (1). The anode (1) has a density of 8.3 g / cm 3, a specific resistance of 68 μΩ · cm and a melting point of 1360 ° C.

Components of the electrolyte in the present embodiment are as follows: 32% of NaF, 57% of AlF _{3, 3%} of LiF, 4% of KF, and 4% of Al ₂ O _3, from here on aluminum fluoride AlF ₃ The molar ratio of NaF is 1.12. In this embodiment, the liquidus temperature of the electrolyte is 640 占 폚 according to the measurement. The electrolyte has a density and the saturation concentration of alumina of 5% of about 1.7Ω ^-1 ㎝ and electrical conductivity, 2.03g / ㎤ ^-1.

The process for using the electrolyte of the present invention for aluminum electrolysis is as follows:

(1) melting the above-mentioned amounts of NaF, AlF ₃ , LiF, KF and Al ₂ O ₃ by the anode (1) and the carbon body anode in a melting furnace to form a melt; And

(2) raising the temperature of the melt produced in step (1) above 720 DEG C in the melting furnace, pouring the melt into the electrolytic bath, connecting a switch to the positive and negative power supplies, and the electrolysis was run for 40 hours with the other hand holding the temperature at 720 ℃, was quantitatively fed to the Al ₂ O ₃ herein.

There was no crust on the bottom of the bath body during the electrolytic process, the bath voltage of the electrolytic bath was 3.1 V, the power consumption per ton of aluminum during the electrolytic process was 10040 kWh, and the aluminum produced was 99.85 %. ≪ / RTI >

Example 2

Fe, Cu, Ni and Sn metal ingots are mixed based on 40 wt% Fe, 36 wt% Cu, 19 wt% Ni and 5 wt% Sn, and the mixture is melted by heating at high temperature , And subsequently to the casting to obtain the anode (2). The anode had a density of 8.1 g / cm 3, a resistivity of 76.8 μΩ · cm and a melting point of 1386 ° C.

Components of the electrolyte in the present embodiment are as follows: 38% of NaF, 50% of AlF _3, 2% of LiF, 5% of KF and 5% of Al ₂ O _3, on aluminum fluoride AlF ₃ where The molar ratio of NaF is 1.52.

In the present embodiment, the performance of the electrolyte was measured, and the measurement result is that the liquidus temperature of the electrolyte in this embodiment is 670 캜. The electrolyte has a saturation concentration of alumina of about 1.8Ω ^-1 ㎝ ^-1 and electrical conductivity, density, and 6% of 2.05g / ㎤ of.

The process for using the electrolyte of the present invention for aluminum electrolysis is as follows:

(1) melting the above-mentioned amounts of NaF, AlF ₃ , LiF and KF by the anode (2) and the carbon body anode in a melting furnace, and subsequently adding Al ₂ O ₃ in the above- So as to obtain a melt by melting; And

(2) raising the temperature of the melt produced in the step (1) to 760 DEG C or higher in the melting furnace, pouring the melt into the electrolytic bath, connecting a switch to the power supplies of the anode and the cathode, The electrolysis was carried out for 40 hours while maintaining the temperature at 760 占 폚.

The bottom of the bath body during the electrolytic process was free of shells, the bath voltage of the electrolytic cell was 3.39 V, the power consumption per tonne of aluminum during the electrolytic process was 10979 kWh, and the aluminum produced had a purity of 99.82% Respectively.

Example 3

Fe, Cu, Ni and Sn metal ingots are mixed based on 25 wt% Fe, 46.8 wt% Cu, 28 wt% Ni and 0.2 wt% Sn, and the mixture is melted by heating at high temperature , And subsequently to the casting to obtain the anode (3). The anode had a density of 8.2 g / cm 3, a resistivity of 72 Ω ㆍ m and a melting point of 1350 캜.

Components of the electrolyte in the present embodiment are as follows: 32% of NaF, 57% of AlF _{3, 3%} of LiF, 4% of KF, and 4% of Al ₂ O _3, from here on aluminum fluoride AlF ₃ The molar ratio of NaF is 1.12.

In the present embodiment, the performance of the electrolyte was measured, and the measurement result is that the liquidus temperature of the electrolyte in this embodiment is 640 캜. The electrolyte has a density and the saturation concentration of alumina of 5% of about 1.6Ω ^-1 ㎝ and electrical conductivity, 2.03g / ㎤ ^-1.

The process for using the electrolyte of the present invention for aluminum electrolysis is as follows:

(1), so that the melt was melt-formed in the anode 3 and the cathode by the carbon material, the amount of NaF, AlF _3, LiF, KF and Al ₂ O ₃ referred to above melting furnace; And

(2) raising the temperature of the melt produced in the step (1) to 730 DEG C or higher in the melting furnace, pouring the melt into the electrolytic bath, connecting a switch to the power supplies of the anode and the cathode, The electrolysis was carried out for 40 hours while maintaining the temperature at 730 캜, and Al ₂ O ₃ was quantitatively supplied thereto.

The bottom of the bath body during the electrolytic process was free of shells, the bath voltage of the bath was 3.15 V, the power consumption per ton of aluminum during the electrolytic process was 10202 kWh, and the aluminum produced had a purity of 99.85% Respectively.

Example 4

Fe, Cu, Ni and Sn metal ingots are mixed based on 24.2 wt% Fe, 60 wt% Cu, 14 wt% Ni and 0.2 wt% Sn, and the mixture is melted by heating at high temperature , Followed by addition of a 1.8 wt% Al metal mass to continue melting and mixing, and finally a 0.8 wt% Y metal mass was added, melted and mixed and the anode 4 was obtained by casting of the mixture . The anode had a density of 8.3 g / cm 3, a resistivity of 68 μΩ · cm and a melting point of 1360 ° C.

Components of the electrolyte in the present embodiment are as follows: 32% of NaF, 57% of AlF _{3, 3%} of LiF, 4% of KF, and 4% of Al ₂ O _3, from here on aluminum fluoride AlF ₃ The molar ratio of NaF is 1.12.

In the present embodiment, the performance of the electrolyte was measured, and the measurement result is that the liquidus temperature of the electrolyte in this embodiment is 640 캜. The electrolyte has a density of alumina and 6% of the saturation concentration of about 1.8Ω ^-1 ㎝ and electrical conductivity, 2.04g / ㎤ ^-1.

The process for using the electrolyte of the present invention for aluminum electrolysis is as follows:

(1), so that the melt was melt-formed in the positive electrode 4 and by the carbon material negative electrode, the amount of NaF, AlF _3, LiF, KF and Al ₂ O ₃ referred to above melting furnace; And

(2) raising the temperature of the melt produced in step (1) to 750 DEG C or higher in the melting furnace, pouring the melt into the electrolytic bath, connecting a switch to the power supplies of the anode and the cathode, and the electrolysis was run for 40 hours with the other hand holding the temperature at 750 ℃, was quantitatively fed to the Al ₂ O ₃ herein.

The bottom of the bath body during the electrolytic process had no shell, the bath voltage of the electrolytic cell was 3.12 V, the power consumption per aluminum tone during the electrolytic process was 10105 kWh, and the aluminum produced had a purity of 99.8% Respectively.

Example 5

Fe, Cu, Ni and Sn metal ingots are mixed based on 40 wt% Fe, 36 wt% Cu, 14.9 wt% Ni and 5 wt% Sn, and the mixture is melted by heating at high temperature , Followed by addition of 0.1 wt% Al metal mass to continue melting and mixing, and finally 0.1 wt% Y metal ingot was added, melted and mixed and the anode 5 was obtained by casting of the mixture . The anode had a density of 8.1 g / cm 3, a resistivity of 76.8 μΩ · cm and a melting point of 1386 ° C.

Components of the electrolyte in the present embodiment are as follows: 30% of NaF, 60% of AlF _3, about 1% of LiF, 6% of aluminum fluoride AlF ₃ from KF and 3% of Al ₂ O _3, where The molar ratio of NaF is 1.0.

In the present embodiment, the performance of the electrolyte was measured, and the measurement result is that the liquidus temperature of the electrolyte in this embodiment is 620 캜. The electrolyte has a density and the saturation concentration of alumina of 5% of about 1.6Ω ^-1 ㎝ and electrical conductivity, 2.03g / ㎤ ^-1.

The process for using the electrolyte of the present invention for aluminum electrolysis is as follows:

(1) melting the above-mentioned amounts of NaF, AlF ₃ , LiF, KF and Al ₂ O ₃ by the anode (5) and the carbon body anode in a melting furnace to form a melt; And

(2) raising the temperature of the melt produced in step (1) above 720 DEG C in the melting furnace, pouring the melt into the electrolytic bath, connecting a switch to the positive and negative power supplies, and the electrolysis was run for 40 hours with the other hand holding the temperature at 720 ℃, was quantitatively fed to the Al ₂ O ₃ herein.

The bottom of the bath body during the electrolytic process was free of shells, the bath voltage of the electrolytic bath was 3.27 V, the power consumption per ton of aluminum during the electrolytic process was 10,591 kWh, and the aluminum produced had a purity of 99.81% Respectively.

Example 6

Fe, Cu, Ni and Sn metal ingots are mixed based on 25 wt% Fe, 38 wt% Cu, 28 wt% Ni and 4 wt% Sn, and the mixture is melted by heating at high temperature , Followed by addition of 4 wt% of Al metal mass to continue melting and mixing, and finally 1 wt% Y metal ingot was added, melted and mixed and the anode 6 was obtained by casting of the mixture . The anode had a density of 8.2 g / cm 3, a resistivity of 70 μΩ · cm and a melting point of 1365 ° C.

Components of the electrolyte in the present embodiment are as follows: 38% of NaF, 54% of AlF _{3, and} 4% of the LiF, the Al ₂ O 1% of KF, and 3% _3, on aluminum fluoride AlF ₃ where The molar ratio of NaF is 1.4.

In the present embodiment, the performance of the electrolyte was measured, and the measurement result is that the liquidus temperature of the electrolyte in this embodiment is 670 캜. The electrolyte has a saturation concentration of alumina of about 1.8Ω ^-1 ㎝ ^-1 and electrical conductivity, density, and 6% of 2.05g / ㎤ of.

The process for using the electrolyte of the present invention for aluminum electrolysis is as follows:

(1), so that the melt was melt-formed in the positive electrode 6 and by the carbon material negative electrode, the amount of NaF, AlF _3, LiF, KF and Al ₂ O ₃ referred to above melting furnace; And

(2) raising the temperature of the melt produced in the step (1) to 760 DEG C or higher in the melting furnace, pouring the melt into the electrolytic bath, connecting a switch to the power supplies of the anode and the cathode, and the electrolysis was run for 40 hours with the other hand holding the temperature at 760 ℃, was quantitatively fed to the Al ₂ O ₃ herein.

The bottom of the bath main body was free of shells during the electrolytic process, the bath voltage of the electrolytic bath was 3.35 V, the power consumption per ton of aluminum during the electrolytic process was 10850 kWh, and the aluminum produced had a purity of 99.83% Respectively.

Example 7

Fe, Cu, Ni and Sn metal ingots are mixed based on 40 wt% Fe, 36.5 wt% Cu, 18 wt% Ni and 3 wt% Sn, and the mixture is melted by heating at high temperature , Followed by addition of a 1.5 wt% Al metal mass to continue melting and mixing, and finally 1 wt% Y metal ingot was added, melted and mixed and the anode 7 was obtained by casting of the mixture . The anode had a density of 8.1 g / cm 3, a resistivity of 76.8 μΩ · cm and a melting point of 1386 ° C.

Components of the electrolyte in the present embodiment are as follows: 34% of NaF, 49% of AlF _3, on aluminum fluoride AlF ₃ in the Al ₂ O _3, where a 5% of LiF, 6% of KF and 6% The molar ratio of NaF is 1.39.

In the present embodiment, the performance of the electrolyte was measured, and the measurement result is that the liquidus temperature of the electrolyte in this embodiment is 660 ° C. The electrolyte has a saturation concentration of alumina of about 1.8Ω ^-1 ㎝ ^-1 and electrical conductivity, density, and 6% of 2.05g / ㎤ of.

The process for using the electrolyte of the present invention for aluminum electrolysis is as follows:

(1), so that the melt was melt-formed in the anode 7 and the cathode by the carbon material, the amount of NaF, AlF _3, LiF, KF and Al ₂ O ₃ referred to above melting furnace; And

(2) raising the temperature of the melt produced in the step (1) to 760 DEG C or higher in the melting furnace, pouring the melt into the electrolytic bath, connecting a switch to the power supplies of the anode and the cathode, and the electrolysis was run for 40 hours with the other hand holding the temperature at 760 ℃, was quantitatively fed to the Al ₂ O ₃ herein.

The bottom of the bath body during the electrolytic process was free of shells, the bath voltage of the electrolytic bath was 3.38 V, the power consumption per aluminum tone during the electrolytic process was 10947 kWh, and the aluminum produced had a purity of 99.8% Respectively.

The electrolyzer in the above-mentioned embodiments is any one of the electrolytic baths in the present invention.

It will be apparent to those skilled in the art that modifications and variations in any form on the basis of the present invention may be made without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that it belongs to the contents.

Claims (13)

An electrolytic cell for aluminum electrolysis, comprising: a bath main body (1) in which an anode (2) and a cathode (3) are arranged inside and further filled with an electrolyte (4);
An anode (2) disposed on the bath main body (1), wherein the anode (2) in which at least a part of the anode (2) is impregnated into the electrolyte (4);
Said cathode (3) disposed on the bottom of the electrolytic cell and covered with a predetermined amount of aluminum liquid (11);
And an electrolyte (4) positioned between the anode (2) and the cathode (3), the electrolytic cell comprising:
Wherein said anode (2) comprises components comprising Fe, Cu, Ni and Sn, wherein Fe and Cu function as major components;
Wherein the electrolyte (4) comprises 30 to 38 wt% of NaF, 49 to 60 wt% of AlF ₃ , 1 to 5 wt% of LiF, 1 to 6 wt% of KF, and 3 to 6 wt% of Al ₂ O ₃ , And the molar ratio of NaF to AlF ₃ is from 1.0 to 1.52. The method according to claim 1,
The bottom surface of the anode 2 is kept parallel to the bath main body 1 and the insulating layer 5 is disposed on the inner wall of the bath main body 1 and oxygen or the electrolyte 4). ≪ / RTI > 3. The method according to claim 1 or 2,
A vessel cover 6 is disposed at the upper end of the bath main body 1, and an exhaust port 7 and a supply port 8 are provided; A cathode rod 10 is disposed in the cathode 3 and one end of the anode 2 penetrates through the can lid 6 and is connected to the tangential post 9, Characterized in that the electrolytic bath for aluminum electrolysis is provided. 4. The method according to any one of claims 1 to 3,
Wherein the mass ratio of Fe: Cu: Sn is (23 to 40): (36 to 60): (0.2 to 5). 5. The method according to any one of claims 1 to 4,
Characterized in that the components of the anode (2) further comprise Ni. 6. The method of claim 5,
Wherein the anode 2 is made of Fe, Cu, Ni and Sn, the Fe content is 23 to 40 wt%, the Cu content is 36 to 60 wt%, the Ni content is 14 to 28 wt% Wherein the content of Sn is 0.2 to 5 wt%. 7. The method according to any one of claims 1 to 6,
Characterized in that the components of said anode (2) further comprise Al and Y. < RTI ID = 0.0 > 11. < / RTI > 8. The method of claim 7,
Wherein the anode 2 is made of Fe, Cu, Ni, Sn, Al and Y, the content of Fe is 23 to 40 wt%, the content of Cu is 36 to 60 wt%, the content of Ni is 14 to 28 By weight, the content of Al is 0 to 4% by weight, the content of Y is 0 to 2% by weight, and the content of Sn is 0.2 to 5% by weight. 9. The method according to any one of claims 1 to 8,
An electrolytic cell for electrolytic aluminum, characterized in that the molar ratio is 1.12 to 1.52 in NaF to AlF _3. 10. The method according to any one of claims 1 to 9,
And the liquidus temperature of the electrolyte (4) is 620 to 670 占 폚. An electrolytic process using the electrolytic bath according to any one of claims 1 to 10,
(1) a specific amount of a melting furnace for mixing and melting NaF, AlF _3, LiF, KF and by addition of Al ₂ O ₃ to form a melt, or; Or adding a specific amount of NaF, AlF ₃ , LiF and KF to the melting furnace for mixing and melting, and subsequently adding Al ₂ O ₃ to obtain a melt; And
(2) raising the temperature of the melt produced in step (1) above 720 to 760 ° C, pouring the melt into the electrolytic bath and maintaining the temperature at 720 to 760 ° C An electrolytic process using an electrolytic bath containing the electrolytic bath. 12. The method of claim 11,
And an electrolytic temperature of 730 to 750 占 폚. 13. The method according to claim 11 or 12,
Al ₂ O ₃ is quantitatively supplied to the electrolytic process.