Prebaked anode and high-temperature kneading method thereof

Abstract

The invention provides a prebaked anode and a high-temperature mixing and kneading method thereof, and relates to the technical field of prebaked anodes. The high-temperature mixing and kneading method comprises the following steps: carrying out dry mixing on carbon particles of various sizes for manufacturing the prebaked anode to obtain dry-mixed aggregate; the dry-mixed aggregate is continuously heated, so that the temperature of the aggregate reaches the temperature TH or above of the mixed and kneaded paste, conditions are provided for using a high-coking-value binder, and wet mixing in the later period is facilitated; a binder with a high coking value is added into the heated aggregate for high-temperature mixing and kneading, so that the binder is completely melted and fully infiltrates the aggregate, and a mixed and kneaded paste material is obtained; the paste is used for preparing a prebaked anode; the temperature of the mixed and kneaded paste is controlled to meet TR * 1.1 + 40 DEG C lt; tHlt; the temperature range is TR * 1.1 + 60 DEG C. The paste obtained within the temperature range is appropriate in flowability and wettability and good in comprehensive performance, and when the paste is used for preparing the prebaked anode, the volume density, the conductivity, the oxidation resistance and the loadable current density of the prebaked anode can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of prebaked anode preparation, and in particular to a prebaked anode and a high-temperature kneading method thereof. Background Art

[0002] Prebaked anode is a carbon block made of petroleum coke and asphalt coke as aggregate and coal tar as binder, which is used as anode material for prebaked aluminum electrolytic cells. This carbon block has been baked and has a stable geometric shape, also known as prebaked anode carbon block or carbon anode for aluminum electrolysis.

[0003] The aluminum electrolysis industry has put forward higher requirements for the performance of prebaked anodes. The performance of existing prebaked anodes is gradually unable to meet the needs of the industry, so it is necessary to provide a method to improve the performance of prebaked anodes. In the preparation process of prebaked anodes, kneading is one of the important processes, which is generally divided into dry mixing and wet mixing. The first is dry mixing. The carbonaceous aggregate prepared in a certain proportion is added to the dry mixing equipment for mixing, and the aggregate is heated by heat transfer oil at the same time. Then the mixed and preheated aggregate is poured into the wet mixing equipment, and the binder is added for wet mixing. Due to the limitation of the heating method, the wet mixing temperature is generally in the range of 160℃ to 190℃, so only binders with a softening point below 120℃ can be used. Summary of the invention

[0004] The present application provides a prebaked anode and a high-temperature kneading method thereof to solve the following technical problem: how to improve the performance of the prebaked anode.

[0005] In a first aspect, an embodiment of the present application provides a method for high temperature kneading of a prebaked anode, comprising the following steps:

[0006] Dry mixing the aggregate;

[0007] Continuing to heat the dry-mixed aggregate to a first set temperature T1;

[0008] Adding a high coking value binder to the heated aggregate and kneading at high temperature to obtain a paste;

[0009] Using the paste to prepare a prebaked anode;

[0010] Wherein, the first set temperature T1> the paste temperature after kneading T H ;

[0011] The temperature of the paste after kneading is completed T H Satisfies the following relationship:

[0012] T R ×1.1+40℃ <T H <T R ×1.1+60℃

[0013] Where TR It is the softening point temperature of the high coking value binder.

[0014] Optionally, the high coking value binder includes at least one of the following: high coking value coal tar pitch, coal liquefaction pitch and petroleum-based pitch.

[0015] Optionally, the softening point temperature T R It is 130℃~250℃.

[0016] Optionally, the mass of the high coking value binder is 14% to 17% of the total mass of the paste.

[0017] Optionally, the first set temperature T1 is 200°C to 350°C.

[0018] Optionally, the heating method includes: microwave heating or electric heating element heating.

[0019] Optionally, the dry mixing of aggregates specifically includes:

[0020] Prepare aggregate;

[0021] At a second set temperature T2, dry-mixing the prepared aggregate;

[0022] Wherein, the second set temperature T2 is 130°C to 160°C.

[0023] Optionally, the paste is used to prepare a prebaked anode, specifically comprising:

[0024] forming the paste to obtain a prebaked anode green body;

[0025] The prebaked anode green body is calcined to obtain a prebaked anode.

[0026] In a second aspect, an embodiment of the present application provides a prebaked anode, which is produced by the high-temperature kneading method for the prebaked anode described in the first aspect.

[0027] Optionally, the performance of the prebaked anode satisfies at least one of the following: a volume density greater than 1.6 g / m 3 , resistivity is less than 53μΩm, air reaction residual rate is greater than 85%, and carbon dioxide reaction residual rate is greater than 90%.

[0028] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0029] The present application provides a prebaked anode and a high-temperature kneading method thereof, wherein the high-temperature kneading method comprises the following steps: obtaining dry-mixed aggregates; heating the dry-mixed aggregates so that the aggregate temperature reaches the paste temperature T after kneading. HThe above provides conditions for using a high coking value binder, which is convenient for subsequent wet mixing; adding the binder with a high coking value to the heated aggregate for high-temperature kneading, so that the binder is completely melted and fully infiltrates the aggregate to obtain a kneaded paste; using the paste to prepare a prebaked anode; controlling the paste temperature after kneading to meet T R ×1.1+40℃ <T H <T R ×1.1+60℃. The paste obtained within this temperature range has suitable fluidity and wettability and good comprehensive performance. It can be used to prepare prebaked anodes to improve the performance of prebaked anodes, including volume density, conductivity, oxidation resistance and current density. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0032] Figure 1 The present invention is a schematic flow chart of a method for high-temperature kneading of a prebaked anode according to some embodiments of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0034] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range; in addition, whenever a numerical range is indicated in this document, it is meant to include any cited numbers (fractions or integers) within the indicated range.

[0035] In this document, the terms including "including" and "including" mean "including but not limited to". Relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone; where A and B can be singular or plural. "At least one" means one or more, and "plurality" means two or more; "at least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items; for example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. "Parts" such as parts by weight and parts by mass indicate the proportional relationship between the components. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, if the mass ratio of substance A, substance B and substance C is 1:2:3, then substance A, substance B and substance C should correspond to the proportional numbers in the proportional formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0036] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this article can be purchased from the market or prepared by existing methods.

[0037] Figure 1 A schematic flow chart of a method for high-temperature kneading of a prebaked anode according to some embodiments of the present application;

[0038] like Figure 1 As shown, the embodiment of the present application provides a method for high temperature kneading of a prebaked anode, comprising:

[0039] S1. dry-mixing the aggregates;

[0040] S2, continuing to heat the dry-mixed aggregate to a first set temperature T1;

[0041] S3, adding a high coking value binder to the heated aggregate and kneading at high temperature to obtain a paste;

[0042] S4, using the paste to prepare a prebaked anode;

[0043] Wherein, the first set temperature T1> the paste temperature after kneading T H ;

[0044] The temperature of the paste after kneading satisfies the following relationship:

[0045] T R ×1.1+40℃ <T H <T R ×1.1+60℃.

[0046] Where T R It is the softening point temperature of the high coking value binder.

[0047] In the above embodiment, the aggregate can be petroleum coke or asphalt coke. The dry-mixed aggregate is further heated to the paste temperature T after kneading. H The purpose is to provide conditions for using a high coking value binder, and to mix the high coking value binder with the heated aggregate to obtain a paste. The dry-mixed aggregate is heated to a first set temperature T1, and T1 is greater than the paste temperature T1 after mixing. H , which can ensure that the binder can be fully melted and evenly distributed between the aggregates and infiltrate the aggregates during the kneading process. The temperature of the paste after kneading is T H Controlled in T R ×1.1+40℃ to T R ×1.1+60℃ can not only avoid excessive volatilization and coking of the binder due to high temperature, but also ensure sufficient wetting and bonding between the binder and the aggregate; in addition, it makes the paste fluidity and wettability suitable, and has good comprehensive performance. It can be used to prepare prebaked anodes to improve the volume density, conductivity, oxidation resistance and current density of prebaked anodes. High coking value binders can form more coke during the roasting process, which helps to improve the volume density, conductivity and density of prebaked anodes.

[0048] Effect analysis:

[0049] 1. Improvement of volume density: The use of high coking value binder and the control of kneading temperature help to form a tighter structure and reduce porosity during the kneading process. More coking formed during the roasting process also helps to increase the volume density of the prebaked anode.

[0050] 2. Improvement of conductivity: The use of high coking value binder and the control of kneading temperature form more coking and reduce porosity, which helps to improve the internal conductivity of prebaked anode and reduce its resistivity.

[0051] 3. Improved anti-oxidation performance: High-quality binders and optimized kneading processes can reduce defects in prebaked anodes and reduce air permeability, thereby improving their anti-oxidation performance. Dense structure and uniform composition also help improve the stability and service life of prebaked anodes in harsh environments.

[0052] In summary, the use of high coking value binders to produce prebaked anodes and the precise control of process parameters such as kneading temperature can significantly improve the volume density, conductivity and oxidation resistance of prebaked anodes. This method has broad application prospects and important practical significance.

[0053] As an optional embodiment, the high coking value binder includes at least one of the following: coal tar pitch with a high coking value, coal liquefaction pitch and petroleum-based pitch.

[0054] In the above-mentioned embodiments, coal tar pitch with high coking value, coal liquefaction pitch and petroleum-based asphalt all belong to the asphalt category and have high softening points. They are used to prepare prebaked anodes, which have the advantages of more coking and reducing the pores after volatile matter analysis. Coal tar pitch with high coking value: it is a product obtained by further processing from coal tar, with a high softening point and good bonding properties. Coal tar pitch with high coking value can maintain good fluidity at high temperatures, thereby ensuring sufficient mixing and uniform distribution with aggregates. During the roasting process, coal tar pitch with high coking value can form a dense coke structure, which helps to improve the volume density and conductivity of the prebaked anode. Coal liquefaction pitch with high coking value: it is obtained through the liquefaction process of coal, has a high carbon content and a low ash content, and it also has good bonding and fluidity, and can be tightly combined with aggregates at high temperatures. The use of coal liquefaction pitch with high coking value helps to improve the strength and antioxidant properties of the prebaked anode. High coking value petroleum-based asphalt: High coking value petroleum-based asphalt is obtained from the petroleum processing process. It has a high softening point and coking value. It can maintain stable performance at high temperatures and is not easy to volatilize or decompose. The use of high coking value petroleum-based asphalt helps to increase the coke content of prebaked anodes, thereby improving their conductivity and bulk density. The selection and use of these high coking value binders are crucial to improving the performance of prebaked anodes. They not only help to improve the bulk density, conductivity and antioxidant properties of prebaked anodes, but also meet the aluminum electrolysis industry's demand for high performance, green energy saving and low carbon. In the actual production process, the appropriate type and ratio of binders can be selected according to specific production conditions and performance requirements to optimize the performance and production cost of prebaked anodes. At the same time, attention should also be paid to the quality control and stability of the binder to ensure the quality and consistency of the prebaked anode.

[0055] As an optional embodiment, the softening point temperature T R It is 130℃~250℃.

[0056] In the above embodiment, the softening point temperature T R It is the temperature at which the binder begins to soften under certain conditions. It directly affects the behavior of the binder during mixing and baking, and thus affects the performance of the prebaked anode. During the mixing process, the binder needs to have a certain fluidity so that it can be fully mixed and infiltrated with the aggregate. Control the softening point temperature T of the high coking value binder RThe reason for the 130℃~250℃ is that in order to obtain a good kneading effect, the kneading starting temperature of the patent technology is generally higher than the softening point by about 100℃. If the softening point is higher than 250℃, the kneading starting temperature must reach above 350℃. High temperature is easy to cause the volatile matter of the binder to precipitate, degenerate and coke, making it difficult to obtain a good kneading effect. If the softening point is lower than 130℃, the coking value of the cost-effective binder is generally low, making it difficult to obtain good anode quality. For example, the softening point temperature T R The temperature of the adhesive is 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C or 250°C.

[0057] As an optional implementation manner, the mass of the high coking value binder is 14% to 17% of the total mass of the paste.

[0058] In the above embodiment, the mass of the high coking value binder is 14% to 17% of the total mass of the paste, and this ratio range is determined based on actual production experience and performance requirements. The reasons for controlling the mass ratio range of the binder include: 1. Influencing the performance of the prebaked anode: The mass ratio of the binder directly affects the key indicators of the prebaked anode such as the volume density, conductivity, and oxidation resistance; the right amount of binder can ensure the close bonding between the aggregates and form a dense coke structure, thereby improving the performance of the prebaked anode. 2. Control production costs: The binder is one of the important raw materials in the production of prebaked anodes, and its cost accounts for a large proportion; by reasonably controlling the mass ratio of the binder, the production cost can be reduced while ensuring performance. If the mass fraction is higher than 17%, the prebaked anode may have a high porosity, affecting its density and oxidation resistance; if the mass fraction is lower than 14%, the paste may have poor fluidity, resulting in uneven distribution of the binder, generating internal defects, and affecting the quality of the prebaked anode.

[0059] As an optional implementation manner, the first set temperature T1 is 200°C to 350°C.

[0060] In the above embodiment, in the preparation process of the prebaked anode, heating the dry-mixed aggregate to 200°C to 350°C is a key step. This step usually occurs before the kneading process, aiming to increase the temperature of the wet-mixed aggregate, making it more suitable for mixing with the binder, and ensuring that the kneaded paste has the desired properties and structure. Purpose of heating: 1. Increase the temperature of the aggregate: Heating the aggregate to 200°C to 350°C can make it reach a temperature range suitable for kneading with the binder; this temperature range helps to ensure that the binder can be evenly distributed among the aggregates. 2. Promote the melting of the binder: Binders with high coking values ​​usually have higher softening point temperatures; heating the aggregate to a higher temperature helps the binder melt, making it easier to mix with the aggregate and form a stable structure. 3. Improve the kneading effect: When the heated aggregate is mixed with the binder, due to the higher temperature, the kneading process is more uniform and sufficient, which helps to form a high-quality paste. The purpose of controlling the first set temperature range is to ensure that the initial temperature of the aggregate when mixed with the high coking value binder is high, which can not only melt the binder, but also form a certain suction force on the binder due to the temperature difference when stirring with the binder, which is conducive to mixing and uniform infiltration. When the first set temperature is higher than 350°C, it is easy to cause the volatile matter of the binder to precipitate, denature and coke, and it is difficult to obtain a good kneading effect; when the first set temperature is lower than 200°C, it may be difficult to meet the need for the high coking value binder to completely melt and infiltrate the aggregate, reducing the quality of the prebaked anode. Exemplarily, the first set temperature T1 can be 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C or 350°C.

[0061] As an optional implementation, the heating method includes: microwave heating or electric heating element heating.

[0062] In the above embodiment, the heating method can be selected according to the specific conditions of the production equipment and the process requirements. Common heating methods include: Microwave heating: Microwave heating has the advantages of fast heating speed and uniform heating, and is suitable for rapid heating of aggregates. Electric heating element heating: Heat is transferred to the aggregate through the electric heating element to make it reach the required temperature. This method heats stably and is easy to control.

[0063] As an optional implementation, the dry mixing of aggregates specifically includes:

[0064] Prepare aggregate;

[0065] At a second set temperature T2, dry-mixing the prepared aggregate;

[0066] Wherein, the second set temperature T2 is 130°C to 160°C.

[0067] In the above embodiment, the aggregate is a raw material used to prepare the prebaked anode, which can be a petroleum coke aggregate or a petroleum coke aggregate composition, or other aggregates or aggregate compositions that can be used to prepare the prebaked anode. The reason for controlling the second set temperature is to make full use of the existing prebaked anode production equipment for heating. In the preparation process of the prebaked anode, dry mixing of the aggregate is a crucial preliminary link. This link not only affects whether the aggregate can be evenly mixed, but also directly affects the subsequent kneading effect with the binder and the performance of the final prebaked anode. Aggregate preparation: First, various aggregates need to be accurately weighed according to the established formula. These aggregates may include granular materials and powders of different particle sizes. They each play a specific role in the prebaked anode, such as providing structural support, enhancing conductivity, etc. The type, particle size distribution and ratio of the aggregate are carefully designed to meet the performance requirements of the prebaked anode. Dry mixing equipment: The dry mixing process is usually carried out in a dedicated dry mixing equipment, such as a dry mixing pot or a preheating screw; these equipment are designed with an efficient stirring mechanism to ensure that the aggregates are fully mixed while being heated. Mixing uniformity: During the dry mixing process, close attention should be paid to the mixing uniformity of aggregates; by adjusting the stirring speed, mixing time and equipment parameters, the ideal mixing effect of aggregates can be ensured, laying a solid foundation for the subsequent kneading with binders. Dry mixing effect evaluation: After the dry mixing is completed, the quality of the mixed aggregates needs to be checked; this includes but is not limited to checking the mixing uniformity, whether the aggregate temperature meets the standard, etc.; through strict quality control, it can be ensured that the dry mixing process meets the established standards and provide high-quality aggregates for the subsequent kneading steps.

[0068] As an optional embodiment, the paste is used to prepare a prebaked anode, specifically comprising:

[0069] forming the paste to obtain a prebaked anode green body;

[0070] The prebaked anode green body is calcined to obtain a prebaked anode.

[0071] In the preparation process of prebaked anodes, the paste is converted into the final prebaked anode product through two core steps: molding and baking. Paste molding: The paste obtained by high-temperature kneading is converted into a prebaked anode green body with a certain shape and size through a molding process. The molding process must ensure that the internal structure of the green body is uniform, without defects such as bubbles and cracks, to ensure the smooth progress of the subsequent baking process and the performance of the final product.

[0072] Molding method: Common molding methods include compression molding, extrusion molding and vibration molding. Compression molding is to put the paste into a mold and mold it into the desired shape by applying pressure; extrusion molding is to use equipment such as a screw extruder to continuously extrude the paste into strips or other shapes; vibration molding is to use the vibration waves generated by a vibration table to gradually compact and shape the paste in the mold. Molding equipment: Molding equipment needs to be selected according to the selected molding method and production scale. Commonly used equipment for compression molding include hydraulic presses, mechanical presses, etc.; extrusion molding often uses screw extruders, piston extruders, etc.; vibration molding often uses equipment such as vibration tables or vibration molding machines.

[0073] Prebaked anode green body baking: The prebaked anode green body after forming is baked at high temperature to make the binder inside it react by pyrolysis and carbonization to form a dense coke structure. The baking process also needs to ensure that the moisture and volatile matter inside the green body are completely discharged to improve the conductivity and oxidation resistance of the prebaked anode. Baking temperature: The baking temperature is usually set in a higher range to ensure that the binder can fully react and form a coke structure. The specific baking temperature needs to be determined according to factors such as the type of binder selected, the size and shape of the green body, and production requirements. Baking equipment: The baking equipment needs to be able to withstand high temperatures and long-term operation requirements. The common baking equipment is an open ring baking furnace for prebaked anodes. Baking process control: During the baking process, parameters such as temperature, atmosphere and time need to be strictly controlled to ensure that the green body can be evenly heated and fully reacted. The baked product also needs to be inspected for quality, including appearance, size, conductivity, oxidation resistance and other aspects.

[0074] In a second aspect, based on a general inventive concept, an embodiment of the present application provides a prebaked anode, which is produced by the high-temperature kneading method of the prebaked anode described in the first aspect.

[0075] Prebaked anodes made by high temperature kneading usually have significantly improved performance compared to anodes made by conventional medium temperature kneading technology. The specific performance includes:

[0076] 1. Advantages of high temperature kneading technology: 1. Improve kneading uniformity: High temperature environment can accelerate the chemical reaction between materials, making the binder more evenly distributed between aggregates, thereby improving the uniformity of kneading. 2. Enhance the bonding strength of materials: High temperature kneading helps to form a stronger chemical bond between the binder and the aggregate, thereby improving the bonding strength of the materials. 3. Prebaked anodes can be produced using high coking value binders (usually with high softening points), improving the physical and chemical properties of prebaked anodes.

[0077] 2. Performance characteristics of prebaked anodes: 1. High conductivity: Due to the high temperature kneading, a close bond is formed between the binder and the aggregate, and the conductive network inside the prebaked anode is more perfect, thereby improving its conductivity. 2. High compressive strength: The use of high temperature kneading technology and high coking value binders makes the internal structure of the prebaked anode denser, thereby improving its compressive strength. 3. Good antioxidant properties: The use of high temperature kneading technology and high coking value binders makes the product structure dense and uniform, reduces air permeability, and reduces the probability of selective oxidation, thereby improving the antioxidant properties of the prebaked anode. 4. Low porosity: The use of high temperature kneading technology and high coking value binders makes the product structure dense and uniform, forming a low porosity structure, which helps to improve the density and stability of the anode.

[0078] 3. Application prospects: With the continuous development of the aluminum electrolysis industry, the performance requirements for prebaked anodes are also increasing. The prebaked anodes made by high-temperature kneading technology have broad application prospects due to their excellent performance characteristics. This anode can not only improve the operating efficiency of aluminum electrolysis cells and reduce production costs, but also reduce environmental pollution, which is in line with the current green and environmentally friendly production concept.

[0079] The prebaked anode is prepared based on the above-mentioned prebaked anode high-temperature kneading method. The specific steps of the method can refer to the above-mentioned embodiment. Since the prebaked anode adopts part or all of the technical solutions of the above-mentioned embodiment, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here one by one.

[0080] As an optional implementation, the performance of the prebaked anode meets at least one of the following requirements:

[0081] Bulk density greater than 1.6g / m 3 , the resistivity is less than 53μΩm, the air reaction residual rate is greater than 85%, and the carbon dioxide reaction residual rate is greater than 90%.

[0082] In the above embodiment, the bulk density is controlled to be greater than 1.6 g / m 3 The reason is that this indicator reflects the density of the prebaked anode and has an important influence on the conductivity and mechanical strength. The resistivity is less than 53μΩ·m. The lower the resistivity, the better the conductivity, which helps to reduce energy consumption and improve electrolysis efficiency. The air reaction residual rate is greater than 85%. This indicator reflects the anti-oxidation performance of the prebaked anode in the air. The higher the residual rate, the better the anti-oxidation performance. The carbon dioxide reaction residual rate is greater than 90%. This indicator reflects the reaction performance of the prebaked anode with carbon dioxide at high temperature. The higher the residual rate, the more stable the prebaked anode can remain during the electrolysis process and is not easily oxidized.

[0083] The present application is further described below in conjunction with specific examples. The experimental methods in the following examples where specific conditions are not specified are usually measured in accordance with national standards / industry standards; if there are no corresponding national standards / industry standards, they are measured in accordance with common international standards, conventional conditions or conditions recommended by the manufacturer.

[0084] Example 1

[0085] This embodiment provides a method for high temperature kneading of a prebaked anode, comprising the following steps:

[0086] Prepare aggregate: prepare petroleum coke coarse particles: medium particles: small particles: powder in a mass ratio of 18:21:26:35 to obtain petroleum coke aggregate;

[0087] Dry-mixed aggregate: Add the prepared petroleum coke aggregate into the dry-mixing pot and dry-mix at a temperature of 135°C;

[0088] Aggregate heating: Put the dry-mixed petroleum coke aggregate into an industrial microwave oven and heat it to 340°C using microwaves. Then put the high-temperature petroleum coke aggregate into a wet mixing pot.

[0089] High temperature kneading: Add the softening point temperature T R The temperature of the paste after kneading is T H is 308℃, meeting T R ×1.1+40℃ <T H <T R ×1.1+60℃;

[0090] Preparation of prebaked anode: The prebaked anode carbon block obtained by molding and calcining the paste was subjected to performance testing, and its volume density was found to be 1.69g / m 3 , the resistivity is 50.3μΩm, the air reaction residual rate is 89.6%, and the carbon dioxide reaction residual rate is 93.1%.

[0091] Example 2

[0092] This embodiment provides a method for high temperature kneading of a prebaked anode, comprising the following steps:

[0093] Prepare aggregate: prepare petroleum coke coarse particles: medium particles: small particles: powder in a mass ratio of 20:22:25:33 to obtain petroleum coke aggregate;

[0094] Dry-mixed aggregate: Add the prepared petroleum coke aggregate into the dry-mixing pot and dry-mix at a temperature of 155°C;

[0095] Aggregate heating: The dry-mixed petroleum coke aggregate is heated to 285°C using an electric heater, and then the high-temperature petroleum coke aggregate is loaded into a wet mixing pot;

[0096] High temperature kneading: Add the softening point temperature T R The coal liquefaction asphalt at 186℃ accounts for 16.5% by mass. The high temperature kneading is carried out. The temperature of the paste after kneading is T H is 257℃, meeting T R ×1.1+40℃ <T H <T R ×1.1+60℃;

[0097] Preparation of prebaked anode: The prebaked anode carbon block obtained by molding and calcining the paste was subjected to performance testing, and its volume density was found to be 1.67g / m 3 , the resistivity is 51.7μΩm, the air reaction residual rate is 86.1%, and the carbon dioxide reaction residual rate is 91.6%.

[0098] Example 3

[0099] This embodiment provides a method for high temperature kneading of a prebaked anode, comprising the following steps:

[0100] Prepare aggregate: prepare petroleum coke coarse particles: medium particles: small particles: powder in a mass ratio of 23:21:26:30 to obtain petroleum coke aggregate;

[0101] Dry-mixed aggregate: Add the prepared petroleum coke aggregate into the dry-mixing pot and dry-mix at a temperature of 155°C;

[0102] Aggregate heating: Put the dry-mixed petroleum coke aggregate into an industrial microwave oven and heat it to 215°C using microwaves. Then put the high-temperature petroleum coke aggregate into a wet mixing pot.

[0103] High temperature kneading: Add the softening point temperature T R The coal tar pitch at 135°C, with a mass ratio of 15%, is kneaded at high temperature. The temperature of the paste after kneading is T H is 197℃, meeting T R ×1.1+40℃ <T H <T R ×1.1+60℃;

[0104] Preparation of prebaked anode: The prebaked anode carbon block obtained by molding and calcining the paste was subjected to performance testing, and its volume density was found to be 1.63g / m 3 , the resistivity is 51.6μΩm, the air reaction residual rate is 85.1%, and the carbon dioxide reaction residual rate is 92.7%.

[0105] Example 4

[0106] This embodiment provides a method for high temperature kneading of a prebaked anode, comprising the following steps:

[0107] Aggregate preparation: petroleum coke coarse particles: medium particles: small particles: powder are prepared in a mass ratio of 19:22:27:32 to obtain petroleum coke aggregate;

[0108] Dry-mixed aggregate: Add the prepared petroleum coke aggregate into the dry-mixing pot and dry-mix at a temperature of 143°C;

[0109] Aggregate heating: Put the dry-mixed petroleum coke aggregate into an industrial microwave oven and heat it to 285°C using microwaves. Then put the high-temperature petroleum coke aggregate into a wet mixing pot.

[0110] High temperature kneading: Add the softening point temperature T R The coal tar pitch at 189°C, with a mass ratio of 14%, is kneaded at high temperature. The temperature of the paste after kneading is T H is 256℃, meeting T R ×1.1+40℃ <T H <T R ×1.1+60℃;

[0111] Preparation of prebaked anode: The prebaked anode carbon block obtained by molding and calcining the paste was subjected to performance testing, and its volume density was found to be 1.66g / m 3 , the resistivity is 50.7μΩm, the air reaction residual rate is 88.4%, and the carbon dioxide reaction residual rate is 91.9%.

[0112] Comparative Example 1

[0113] This comparative example provides a method for high-temperature kneading of prebaked anodes, which is the same as that in Example 1, except that the temperature of the paste after kneading is T H is 300℃, which does not meet T R ×1.1+40℃ <T H <T R ×1.1+60℃, the performance of the obtained prebaked anode was tested, and the results showed that its volume density was 1.58g / m 3 , the resistivity is 56.9μΩm, the air reaction residual rate is 78.1%, and the carbon dioxide reaction residual rate is 85.7%.

[0114] Compared with Example 1, the prebaked anode prepared by the prebaked anode high temperature kneading method in this comparative example has lower volume density, air reaction residual rate and carbon dioxide reaction residual rate. It can be seen that if the paste temperature T H Does not meet TR ×1.1+40℃ <T H <T R ×1.1+60℃, the quality of the prepared prebaked anode is low.

[0115] Comparative Example 2

[0116] This comparative example provides a method for high-temperature kneading of a prebaked anode, which is the same as that in Example 2, except that the addition amount of the high coking value binder is 12%. The performance test of the obtained prebaked anode is as follows: its volume density is 1.50 g / m 3 , the resistivity is 65.4μΩm, the air reaction residual rate is 77.1%, and the carbon dioxide reaction residual rate is 80.7%.

[0117] Compared with Example 2, the prebaked anode prepared by the prebaked anode high-temperature kneading method in this comparative example has lower volume density, air reaction residual rate and carbon dioxide reaction residual rate, and higher resistivity. It can be seen that if the amount of high coking value binder added is small, the quality of the prepared prebaked anode is lower.

[0118] Comparative Example 3

[0119] This comparative example provides a method for high-temperature kneading of prebaked anodes, which is the same as the method in Example 3, except that the softening point temperature T R The final paste temperature satisfies T R ×1.1+40℃ <T H <T R ×1.1+60℃, the performance of the obtained prebaked anode was tested, and the results showed that its volume density was 1.57g / m 3 , the resistivity is 56.0μΩm, the air reaction residual rate is 73.2%, and the carbon dioxide reaction residual rate is 88.3%.

[0120] Compared with Example 3, the prebaked anode prepared by the prebaked anode high temperature kneading method in this comparative example has lower volume density, air reaction residual rate and carbon dioxide reaction residual rate, and higher resistivity. It can be seen that if the selected binder is not a high coking value binder, the softening temperature is too low, even if the final paste temperature meets T R ×1.1+40℃ <T H <T R ×1.1+60℃, the quality of the prepared prebaked anode is also low.

[0121] Comparative Example 4

[0122] This comparative example provides a method for high-temperature kneading of prebaked anodes, which is the same as that in Example 4, except that the temperature of the paste after kneading is TH is 269℃, which does not meet T R ×1.1+40℃ <T H <T R ×1.1+60℃, the performance of the obtained prebaked anode was tested and the results were: its volume density was 1.53g / m 3 , the resistivity is 57.6μΩm, the air reaction residual rate is 77.1%, and the carbon dioxide reaction residual rate is 84.0%.

[0123] Compared with Example 4, the prebaked anode prepared by the prebaked anode high temperature kneading method in this comparative example has lower volume density, air reaction residual rate and carbon dioxide reaction residual rate, and higher resistivity. It can be seen that if the paste temperature T H Does not meet T R ×1.1+40℃ <T H <T R ×1.1+60℃, the quality of the prepared prebaked anode is low.

[0124] In summary, in the embodiment of the present application, by adding a rapid heating process of carbonaceous aggregate between dry mixing and wet mixing, the kneading temperature of the prebaked anode paste reaches 200-350°C, which creates conditions for using a high coking value binder to produce prebaked anodes; at the same time, the paste temperature T after kneading is controlled H Meet T R ×1.1+40℃ <T H <T R ×1.1+60℃, the performance of the final prebaked anode is improved to meet the following requirements: volume density greater than 1.6g / m3, resistivity less than 53μΩm, air reaction residual rate greater than 85%, and carbon dioxide reaction residual rate greater than 90%.

[0125] The above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. It will be apparent to those skilled in the art that various modifications to these embodiments are possible, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown in the present application, but will conform to the widest scope consistent with the principles and novel features applied for by the present application.

Claims

1. A method for high temperature kneading of prebaked anodes, comprising the following steps: Dry mixing the aggregate; Heating the dry-mixed aggregate to a first set temperature T1; Adding a high coking value binder to the heated aggregate and kneading at high temperature to obtain a paste; Using the paste to prepare a prebaked anode; Wherein, the first set temperature T1> the temperature T of the paste after kneading H ; The temperature of the paste after kneading is completed T H Satisfies the following relationship: T R ×1.1+40℃<T H <T R ×1.1+60℃ Where T R It is the softening point temperature of the high coking value binder.

2. The method according to claim 1, wherein the high coking value binder comprises at least one of the following: coal tar pitch with a high coking value, coal liquefaction pitch and petroleum-based pitch.

3. The method according to claim 1, wherein the softening point temperature T of the high coking value binder is R It is 130℃~250℃.

4. The method according to claim 1, wherein the mass of the high coking value binder is 14% to 17% of the total mass of the paste. 5 . The method according to claim 1 , wherein the first set temperature T1 is 200° C. to 350° C.

6. The method according to claim 1, wherein the heating method comprises: Microwave heating or electric heating.

7. The method according to claim 1, wherein the dry mixing of aggregates comprises: Prepare aggregate; At a second set temperature T2, dry-mixing the prepared aggregate; Wherein, the second set temperature T2 is 130°C to 160°C.

8. The method according to claim 1, wherein the paste is used to prepare a prebaked anode, specifically comprising: forming the paste to obtain a prebaked anode green body; The prebaked anode green body is calcined to obtain a prebaked anode.

9. A prebaked anode, made by the high temperature kneading method for a prebaked anode according to any one of claims 1 to 8.

10. The prebaked anode according to claim 9, wherein the properties of the prebaked anode satisfy at least one of the following: a bulk density greater than 1.6 g / m 3 , the resistivity is less than 53μΩm, the air reaction residual rate is greater than 85%, and the carbon dioxide reaction residual rate is greater than 90%.

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