Preparation method of graphitized wettable cathode carbon block for aluminum electrolysis cell
By mixing boron powder and titanium powder with a binder, graphitized wettable cathode carbon blocks for aluminum electrolytic cells were prepared, solving the problem of insufficient density of the boronized titanium layer and improving the wettability and corrosion resistance of the aluminum melt.
Patent Information
- Application Number
- CN202511200739.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-26
- Publication Date
- 2025-12-02
AI Technical Summary
In the existing technology, when preparing graphitized wettable cathode carbon blocks for aluminum electrolytic cells, the density of the titanium boride layer is insufficient, which affects the wettability of the aluminum melt.
Boron powder and titanium powder are used as raw materials. After mixing, they are kneaded with a binder to form a wettable paste, which is integrally formed with the cathode substrate paste. After calcination and graphitization calcination, a titanium boride layer is generated, which avoids the formation of gaseous products and improves the density.
It improves the wettability of graphitized wettable cathode carbon blocks for aluminum electrolysis cells to molten aluminum, and enhances resistance to molten aluminum corrosion and thermal shock stability.
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Figure CN121044902A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of aluminum electrolytic cathode preparation technology, and in particular to a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell. Background Technology
[0002] The performance and quality of the cathode carbon blocks used in aluminum electrolysis cells directly affect the technical and economic indicators and service life of the cells; therefore, the selection of cathode materials is crucial. Cathode materials containing TiB2 exhibit good wettability to molten aluminum and good corrosion resistance to the electrolyte, and are thus known as wettable cathodes.
[0003] The synthesis of TiB2 generally requires high temperatures, and graphitized cathodes also require high-temperature treatment. Since the treatment temperatures used for both are relatively consistent, titanium boride can be synthesized during the cathode graphitization process. Existing methods for preparing graphitized wettable cathode carbon blocks for aluminum electrolytic cells mainly involve placing a well-mixed cathode matrix paste into a vibration molding machine mold, followed by placing a wettable layer paste composed of boric acid, TiO2, carbonaceous materials, and a binder into the mold, and then performing integrated vibration molding. The resulting carbon block green is then calcined and graphitized. This method uses boric acid and TiO2 as raw materials to prepare TiB2. However, boric acid undergoes dehydration during the reaction, and carbon dioxide is generated during the formation of titanium boride, affecting the density of the titanium boride layer and thus its wettability to the molten aluminum. Summary of the Invention
[0004] This application provides a method for preparing graphitized wettable cathode carbon blocks for aluminum electrolysis cells to solve the following technical problem: how to improve the density of titanium boride layers.
[0005] This application provides a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell, comprising the following steps:
[0006] Boron powder and titanium powder are mixed to obtain a boron-titanium mixture;
[0007] The boron-titanium mixture is kneaded with a binder to obtain a wettable paste.
[0008] The wettable layer paste and the cathode substrate paste are integrally molded to obtain a carbon block green body.
[0009] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0010] Optionally, the mass ratio of the boron powder to the titanium powder is from 0.50:1 to 0.55:1.
[0011] Optionally, the boron powder shall at least meet one of the following conditions: the purity of the boron powder is 90% to 95%, and the particle size of the boron powder is 1 μm to 150 μm.
[0012] Optionally, the titanium powder shall meet at least one of the following conditions: the purity of the titanium powder is not less than 99%, the oxygen content of the titanium powder is 0.1% to 0.6%, and the particle size of the titanium powder is 45μm to 150μm.
[0013] Optionally, the binder is 2% to 5% of the mass of the boron-titanium mixture.
[0014] Optionally, the binder is at least one of coal tar pitch, coal tar, or resin.
[0015] Optionally, the step of integrally molding the wettable layer paste and the cathode substrate paste to obtain a carbon block green body specifically includes:
[0016] A cathode substrate paste is obtained;
[0017] A wettable paste molding block is obtained;
[0018] The cathode substrate paste is applied to the surface of the wettable paste molding block to obtain a carbon block green.
[0019] Optionally, the thickness of the wettable paste layer is 2 cm to 3 cm;
[0020] Optionally, the thickness of the cathode substrate paste is 0.5 cm to 1 cm.
[0021] Optionally, the cathode substrate paste aggregate is at least one of calcined petroleum coke, pitch coke, graphitized petroleum coke, and graphitized metallurgical coke.
[0022] Optionally, the calcination temperature is between 730°C and 1100°C;
[0023] Optionally, the graphite is calcined at a temperature of 1800°C to 2850°C.
[0024] The technical solutions provided in this application have the following advantages compared with the prior art:
[0025] This application provides a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell, comprising the following steps: mixing boron powder and titanium powder to obtain a boron-titanium mixture, thereby achieving close contact between the two in the solid-phase reaction and reducing the material diffusion distance; kneading the boron-titanium mixture with a binder to achieve good contact between the binder and the boron and titanium powders, thereby obtaining a wettable layer paste; integrally molding the wettable layer paste with the cathode substrate paste to achieve good bonding between the wettable layer paste and the cathode substrate paste, thereby obtaining a carbon block green; finally, calcining the carbon block green to allow the boron and titanium powders to react and generate titanium boride; graphitizing and calcining to prepare a graphitized cathode while simultaneously forming a titanium boride wettable layer on the surface, ultimately obtaining a graphitized wettable cathode carbon block for an aluminum electrolytic cell.
[0026] This method uses boron powder and titanium powder as raw materials for the preparation of titanium boride, avoiding the generation of gaseous products during the preparation process, improving the density of titanium boride, and thus increasing the wettability of graphitized wettable cathode carbon blocks for aluminum electrolysis cells to the molten aluminum. Attached Figure Description
[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0029] Figure 1 This is a schematic flowchart illustrating a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell according to some embodiments of this application. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0031] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values within that range. For example, the range descriptions of "1 to 6" or "1 to 6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "including" and "comprise" as used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.
[0032] Figure 1 This is a schematic flowchart illustrating a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell according to some embodiments of this application.
[0033] like Figure 1 As shown in the embodiment of this application, a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell is provided, comprising:
[0034] S1. Mix boron powder and titanium powder to obtain a boron-titanium mixture;
[0035] The purpose of step S1 is to thoroughly mix boron powder and titanium powder, so that the resulting boron-titanium mixture can make the two come into close contact in the solid-phase reaction, shorten the material diffusion distance, and enhance the reaction process between boron and titanium.
[0036] S2. The boron-titanium mixture is kneaded with a binder to obtain a wettable paste.
[0037] The purpose of step S2 is to prepare the boron-titanium mixture into a paste, add a binder to increase adhesion, and obtain a high-performance wettable layer paste.
[0038] S3. The wettable layer paste and the cathode substrate paste are integrally molded to obtain a carbon block green body.
[0039] The purpose of step S3 is to eliminate the bonding seams that may occur during the traditional preparation process, and to improve the final product's resistance to molten aluminum erosion and thermal shock stability.
[0040] S4. The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cell.
[0041] The purpose of step S4 is to generate titanium boride at high temperature and promote the conversion of carbon materials in the cathode into graphite, ultimately obtaining graphitized wettable cathode carbon blocks for aluminum electrolysis cells.
[0042] In the above embodiments, boron powder and titanium powder are used as raw materials for the preparation of titanium boride to avoid the generation of gaseous products during the preparation process, improve the density of titanium boride, and thus increase the wettability of the graphitized wettable cathode carbon block for aluminum electrolysis cells to the aluminum liquid.
[0043] As an optional implementation, the mass ratio of the boron powder to the titanium powder is 0.50:1 to 0.55:1.
[0044] In the above embodiments, the reason for controlling the mass ratio of boron powder to titanium powder to be between 0.50:1 and 0.55:1 is that the utilization rate of titanium powder is higher within this ratio range; for example, the mass ratio of boron powder to titanium powder can be 0.50:1, 0.51:1, 0.52:1, 0.53:1, 0.54:1 or 0.55:1.
[0045] As an optional implementation, the boron powder shall at least meet one of the following conditions: the purity of the boron powder is 90% to 95%, and the particle size of the boron powder is 1 μm to 150 μm.
[0046] In the above embodiments, the reason for controlling the purity and particle size of boron powder is that boron powder of this purity meets the requirements for cathode preparation and aluminum electrolysis, has a high cost-performance ratio, and can reduce costs.
[0047] As an optional implementation, the titanium powder shall at least meet one of the following conditions: the purity of the titanium powder is not less than 99%, the oxygen content of the titanium powder is 0.1% to 0.6%, and the particle size of the titanium powder is 45μm to 150μm.
[0048] In the above embodiments, the reason for controlling the purity and oxygen content of titanium powder is that the titanium powder of this purity has met the requirements for cathode preparation and aluminum electrolysis, which can reduce costs.
[0049] As an optional implementation, the binder is 2% to 5% of the mass of the boron-titanium mixture.
[0050] In the above embodiments, the reason for controlling the mass of the binder to be 2% to 5% of the mass of the boron-titanium mixture is that within the above range, the surface of the material particles of the mixture can be covered with sufficient binder to form a paste with good performance; for example, the mass of the binder can be 2%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% or 5% of the mass of the boron-titanium mixture.
[0051] As an optional implementation, the binder is at least one of coal tar pitch, coal tar, or resin.
[0052] As an optional implementation, the step of integrally molding the wettable layer paste and the cathode substrate paste to obtain a carbon block green body specifically includes:
[0053] S31. Obtain cathode substrate paste;
[0054] The purpose of step S31 is to provide raw materials for the preparation of the cathode substrate for subsequent reactions.
[0055] S32. Obtain a wettable paste molding block;
[0056] The purpose of step S32 is to shape the wettable layer paste to facilitate subsequent covering of the cathode substrate paste.
[0057] S33. The cathode substrate paste is covered on the surface of the wettable paste molding block to obtain a carbon block green.
[0058] The purpose of step S33 is to cover the cathode substrate paste on the surface of the wettable paste, thereby reducing the loss of boron powder and titanium boride in the subsequent cathode preparation process.
[0059] Since titanium boride and boron powder will undergo some oxidation and volatilization at high temperatures, in the above embodiments, by covering the surface of the wettable layer paste with the cathode substrate paste, the loss of raw materials during cathode preparation can be reduced and the reaction cost can be lowered.
[0060] As an optional implementation, the thickness of the wettable paste layer is 2 cm to 3 cm;
[0061] In the above embodiments, the reason for controlling the thickness of the wettable layer paste to be 2cm to 3cm is that the thickness of the wettable layer paste meets the requirements for use during the subsequent service of the cathode; for example, the thickness of the wettable layer paste can be 2cm, 2.1cm, 2.2cm, 2.3cm, 2.4cm, 2.5cm, 2.6cm, 2.7cm, 2.8cm, 2.9cm or 3cm.
[0062] As an optional implementation, the thickness of the cathode substrate paste is 0.5 cm to 1 cm.
[0063] In the above embodiments, the reason for controlling the thickness of the cathode substrate paste to be 0.5cm to 1cm is that the function of this layer is to reduce the loss of raw materials during the calcination process. Furthermore, the graphitized layer on the surface of the titanium boride layer on the graphitized wettable cathode carbon block prepared after calcination will be washed away within a short period of time after the cathode is used. Only after the surface graphitized layer is washed away can the titanium boride layer begin to function, so it does not need to be too thick. For example, the thickness of the cathode substrate paste can be 0.5cm, 0.6cm, 0.7cm, 0.8cm, 0.9cm, or 1cm.
[0064] As an optional implementation, the cathode substrate paste aggregate is at least one of calcined petroleum coke, pitch coke, graphitized petroleum coke, and graphitized metallurgical coke.
[0065] As an optional implementation, the calcination temperature is between 730°C and 1100°C;
[0066] In the above embodiments, the reason for controlling the calcination temperature to be between 730°C and 1100°C is that at this temperature, boron and titanium react to form titanium boride; for example, the calcination temperature can be 730°C, 750°C, 780°C, 800°C, 830°C, 850°C, 880°C, 900°C, 950°C, 1000°C, 1050°C, or 1100°C.
[0067] As an optional implementation, the graphite is calcined at a temperature of 1800°C to 2850°C.
[0068] In the above embodiments, the reason for controlling the graphite calcination temperature to be between 1800°C and 2850°C is that within this temperature range, the carbon material in the cathode substrate paste is in the graphitization transformation stage; for example, the graphite calcination temperature can be 1800°C, 1900°C, 2000°C, 2100°C, 2200°C, 2300°C, 2400°C, 2500°C, 2600°C, 2700°C, 2800°C, or 2850°C.
[0069] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national / industry standards; if there is no corresponding national / industry standard, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.
[0070] Examples 1 to 5 provide methods for preparing graphitized wettable cathode carbon blocks for aluminum electrolytic cells with different parameters, as detailed in the specific parameters and performance below.
[0071] Example 1
[0072] This embodiment provides a method for preparing graphitized wettable cathode carbon blocks for aluminum electrolysis cells, including the following steps:
[0073] Boron powder and titanium powder at a mass ratio of 0.5:1 were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0074] The boron-titanium mixture is kneaded with a binder of 5% by mass to obtain a wettable paste; the binder is 100% coal tar pitch.
[0075] The wettable paste is pressed into a shape with a thickness of 3cm for later use;
[0076] 100% calcined petroleum coke was used as aggregate and mixed with a binder to prepare cathode substrate paste; the ratio of aggregate to binder was 84:16.
[0077] The cathode substrate paste is coated onto the surface of the molded wettable paste to form a carbon block green body; wherein the thickness of the cathode substrate paste is 1 cm.
[0078] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0079] The calcination temperature is 1000℃, and the graphitization calcination temperature is 2850℃. The specific calcination process parameters are shown in Table 1.
[0080] Example 2
[0081] This embodiment provides a method for preparing graphitized wettable cathode carbon blocks for aluminum electrolysis cells, including the following steps:
[0082] Boron powder and titanium powder with a mass ratio of 0.54:1 were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0083] The boron-titanium mixture is kneaded with a binder of 4% by mass to obtain a wettable paste; the binder is selected from 90% coal tar pitch and 10% coal tar.
[0084] The wettable paste is pressed into a shape for later use, with a thickness of 2.5 cm;
[0085] A cathode matrix paste was prepared by mixing 90% calcined petroleum coke and 10% graphitized petroleum coke as aggregates with 100% coal tar pitch; wherein the ratio of aggregate to binder was 4:1.
[0086] The cathode substrate paste is coated onto the surface of the formed wettable paste layer and integrally molded to obtain a carbon block green body; wherein the thickness of the cathode substrate paste is 0.7 cm.
[0087] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0088] The calcination temperature is 1050℃, and the graphitization calcination temperature is 2300℃. The specific calcination process parameters are shown in Table 1.
[0089] Example 3
[0090] This embodiment provides a method for preparing graphitized wettable cathode carbon blocks for aluminum electrolysis cells, including the following steps:
[0091] Boron powder and titanium powder at a mass ratio of 0.51:1 were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0092] The boron-titanium mixture is kneaded with a binder of 2% by mass to obtain a wettable paste; the binder is selected from 80% coal tar pitch and 20% coal tar.
[0093] The wettable paste is pressed into a shape with a thickness of 2cm for later use;
[0094] The cathode matrix paste was prepared by using 70% calcined petroleum coke, 10% graphite chips, 10% graphitized petroleum coke and 10% graphitized metallurgical coke as aggregates, and 90% coal tar pitch and 10% coal tar as matrix binders. The aggregates and matrix binders were mixed in a ratio of 78:22.
[0095] The cathode substrate paste is coated onto the surface of the formed wettable paste layer and integrally molded to obtain a carbon block green body; wherein the thickness of the cathode substrate paste is 0.6 cm.
[0096] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0097] The calcination temperature is 850℃, and the graphitization calcination temperature is 1800℃. The specific calcination process parameters are shown in Table 1.
[0098] Example 4
[0099] This embodiment provides a method for preparing graphitized wettable cathode carbon blocks for aluminum electrolysis cells, including the following steps:
[0100] Boron powder and titanium powder with a mass ratio of 0.53:1 were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0101] The boron-titanium mixture is kneaded with a binder of 4% by mass to obtain a wettable paste; the binder is 100% coal tar pitch.
[0102] The wettable paste is pressed into a shape with a thickness of 2.2 cm for later use;
[0103] A cathode matrix paste is prepared by mixing 50% calcined petroleum coke, 20% graphite chips, 20% graphitized petroleum coke and 10% graphitized petroleum coke as aggregates and 100% coal tar pitch as matrix binder.
[0104] The cathode substrate paste is coated onto the surface of the molded wettable paste to form a carbon block green body; wherein the thickness of the cathode substrate paste is 0.5 cm.
[0105] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0106] The calcination temperature is 730℃, and the graphitization calcination temperature is 2200℃. The specific calcination process parameters are shown in Table 1.
[0107] Example 5
[0108] This embodiment provides a method for preparing graphitized wettable cathode carbon blocks for aluminum electrolysis cells, including the following steps:
[0109] Boron powder and titanium powder at a mass ratio of 0.52:1 were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0110] The boron-titanium mixture is kneaded with a binder of 3% by mass to obtain a wettable paste; the binder is 100% resin.
[0111] The wettable paste is pressed into a shape with a thickness of 2.8 cm for later use;
[0112] The cathode matrix paste was prepared by mixing 70% calcined petroleum coke and 30% graphite powder as aggregates, 80% coal tar pitch and 20% coal tar as matrix binders, and mixing the aggregates and matrix binders in a mass ratio of 82:18.
[0113] The cathode substrate paste is coated onto the surface of the molded wettable paste to form a carbon block green body; wherein the thickness of the cathode substrate paste is 0.9 cm.
[0114] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0115] The calcination temperature is 1100℃, and the graphitization calcination temperature is 2600℃. The specific calcination process parameters are shown in Table 1.
[0116] Comparative Example 1
[0117] This comparative example provides a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell, comprising the following steps:
[0118] Boron trioxide and titanium dioxide were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0119] The boron-titanium mixture is then kneaded with carbonaceous materials and a binder to form a wettable paste. The weight ratio of carbonaceous materials, boron trioxide, titanium dioxide, and binder is 0.9:1.02:1:1; the binder is selected from 90% coal tar pitch and 10% coal tar.
[0120] The wettable paste is pressed into a shape with a thickness of 2.5 cm for later use;
[0121] The cathode matrix paste was prepared by mixing 90% calcined petroleum coke and 10% graphitized petroleum coke as aggregates and 100% coal tar pitch as matrix binder.
[0122] The formed wettable paste is applied to the surface of the cathode substrate paste to obtain a carbon block green body.
[0123] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0124] The calcination temperature is 1050℃, and the graphitization calcination temperature is 2300℃. The specific calcination process parameters are shown in Table 2.
[0125] Comparative Example 2
[0126] This comparative example provides a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell, comprising the following steps:
[0127] Boron trioxide and titanium dioxide were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0128] The boron-titanium mixture is then kneaded with carbonaceous materials and a binder to form a wettable paste. The weight ratio of carbonaceous materials, boron trioxide, titanium dioxide, and binder is 1:1.1:1:0.9; the binder is selected from 80% coal tar pitch and 20% coal tar.
[0129] The wettable paste is pressed into a shape with a thickness of 2.0 cm for later use;
[0130] The cathode matrix paste was prepared by mixing 70% calcined petroleum coke, 10% graphite chips, 10% graphitized petroleum coke and 10% graphitized metallurgical coke as aggregates, and 90% coal tar pitch and 10% coal tar as matrix binders.
[0131] The formed wettable paste is applied to the surface of the cathode substrate paste to obtain a carbon block green body.
[0132] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0133] The calcination temperature is 850℃, and the graphitization calcination temperature is 1800℃. The specific calcination process parameters are shown in Table 2.
[0134] Comparative Example 3
[0135] This comparative example provides a method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell, comprising the following steps:
[0136] Boron trioxide and titanium dioxide were mixed using a three-dimensional mixer to obtain a boron-titanium mixture.
[0137] The boron-titanium mixture is then kneaded with carbonaceous materials and a binder to form a wettable paste. The weight ratio of carbonaceous materials, boron trioxide, titanium dioxide, and binder is 1:1.08:1:1; the binder is 100% coal tar pitch.
[0138] The wettable paste is pressed into a shape with a thickness of 2.2 cm for later use;
[0139] The cathode matrix paste was prepared by mixing 50% calcined petroleum coke, 30% graphite crushed stone, 20% graphitized petroleum coke and 10% graphitized metallurgical coke as aggregates and 100% coal tar pitch as matrix binder.
[0140] The formed wettable paste is applied to the surface of the cathode substrate paste to obtain a carbon block green body.
[0141] The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
[0142] The calcination temperature is 730℃, and the graphitization calcination temperature is 2200℃. The specific calcination process parameters are shown in Table 2.
[0143] Table 1 shows the experimental data parameters from Examples 1 to 5 and Comparative Examples 1 to 3, as well as the density results of titanium carbide formed on the graphitized wettable cathode carbon block for the aluminum electrolytic cell.
[0144] Table 1. Process parameters and product indicators for Examples 1 to 5
[0145]
[0146]
[0147] Table 2. Process parameters and product indicators for Comparative Examples 1 to 3
[0148]
[0149] As can be seen from the data in Tables 1 and 2, the titanium boride layer on the surface of the graphitized wettable cathode carbon block for aluminum electrolysis cell obtained by the preparation methods in Examples 1 to 5 has a density greater than 95%, and can reach up to 98.1%; while the titanium boride layer on the surface of the graphitized wettable cathode carbon block for aluminum electrolysis cell obtained in Comparative Examples 1 to 3 has a density less than 95%.
[0150] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.
Claims
1. A method for preparing a graphitized wettable cathode carbon block for an aluminum electrolytic cell, characterized in that, Includes the following steps: Boron powder and titanium powder are mixed to obtain a boron-titanium mixture; The boron-titanium mixture is kneaded with a binder to obtain a wettable paste. The wettable layer paste and the cathode substrate paste are integrally molded to obtain a carbon block green body. The carbon block green is roasted and graphitized to obtain a graphitized wettable cathode carbon block for aluminum electrolysis cells.
2. The preparation method according to claim 1, characterized in that, The mass ratio of the boron powder to the titanium powder is from 0.50:1 to 0.55:
1.
3. The preparation method according to claim 1 or 2, characterized in that, The boron powder must meet at least one of the following conditions: the purity of the boron powder is 90% to 95%, and the particle size of the boron powder is 1 μm to 150 μm.
4. The preparation method according to claim 1 or 2, characterized in that, The titanium powder shall meet at least one of the following conditions: the purity of the titanium powder shall not be less than 99%, the oxygen content of the titanium powder shall be 0.1% to 0.6%, and the particle size of the titanium powder shall be 45μm to 150μm.
5. The preparation method according to claim 1, characterized in that, The binder accounts for 2% to 5% of the mass of the boron-titanium mixture.
6. The preparation method according to claim 1 or 5, characterized in that, The binder is at least one of coal tar pitch, coal tar, or resin.
7. The preparation method according to claim 1, characterized in that, The step of integrally molding the wettable layer paste and the cathode substrate paste to obtain a carbon block green body specifically includes: A cathode substrate paste is obtained; A wettable paste molding block is obtained; The cathode substrate paste is applied to the surface of the wettable paste molding block to obtain a carbon block green.
8. The preparation method according to claim 7, characterized in that, The thickness of the wettable paste layer is 2 cm to 3 cm; and / or, the thickness of the cathode substrate paste covering the surface of the wettable paste layer molding block is 0.5 cm to 1 cm.
9. The preparation method according to claim 7, characterized in that, The cathode substrate paste aggregate is at least one of calcined petroleum coke, pitch coke, graphitized petroleum coke, and graphitized metallurgical coke.
10. The preparation method according to claim 1, characterized in that, The calcination temperature is 730°C to 1100°C; and / or, the graphite calcination temperature is 1800°C to 2850°C.