Electrolytic aluminum carbon residue reducing method and device based on four-low two-high one keeping strategy

Abstract

The invention discloses an electrolytic aluminum carbon residue reducing method and device based on a four-low two-high one keeping strategy, and relates to the technical field of electrolytic aluminum. The method comprises the steps that electrolytic aluminum working condition parameters are obtained; the electrolytic aluminum working condition parameters specifically comprise cell voltage, alumina concentration, molecular ratio, cell temperature, polar distance and electrolyte level; and based on a four-low two-high one keeping strategy, performing refined electrolytic aluminum carbon residue reduction operation by dynamically adjusting electrolytic aluminum working condition parameters. The four-low two-high one maintaining strategy specifically comprises a low voltage strategy, a low alumina concentration strategy, a low molecular ratio strategy, a low cell temperature strategy, a high polar distance strategy, a high-precision operation strategy and an electrolyte level maintaining strategy. According to the method, the generation amount of carbon residues is reduced, so that the environmental pollution caused by electrolytic aluminum is reduced, the electrolytic aluminum efficiency is improved, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrolytic aluminum, in particular to an electrolytic aluminum carbon residue reduction method and equipment based on a four-low-two-high-one-maintain strategy. BACKGROUND

[0002] The selective oxidation of carbon anodes in the electrolysis process, the peeling off of cathode carbon blocks, and the sticking of electrolyte melt can be clearly seen on the cross section of the solid electrolyte. When the carbon residue content is 0.04%, the resistivity increases by 1%; when the carbon residue content is 1%, the resistivity increases by 11%. In industrial electrolyte, carbon residue particles of 1-10 microns are almost non-conductive. The presence of carbon residue not only increases the anode current density and carbon anode heating, but also increases the electrolyte resistance and causes the pressure to increase. The current efficiency is reduced, resulting in unnecessary consumption of electric energy, affecting the service life of the electrolytic cell, and consuming a large amount of fluorinated salt. Excessive carbon residue in the electrolyte generates heat, which in turn causes hot cells, long anode packages, and side leakage, making it difficult to form the electrolytic cell furnace, severely deteriorating the technical condition of the electrolytic cell, resulting in sick cells, and even causing the cell to leak, leading to the deterioration of economic indicators. The carbon residue contains 70% of the electrolyte, which increases the labor intensity and economic loss. The carbon residue in different parts of the cell has the following effects: the thick carbon residue in the middle joint isolates the addition and dissolution of alumina, resulting in a decrease in alumina concentration, causing a sudden effect, destroying the normal production technical conditions, and wasting electric energy.

[0003] In summary, the traditional electrolytic aluminum operation method has the problems of large amount of carbon residue, low electrolytic aluminum efficiency, high production cost, and high pollution. SUMMARY

[0004] The purpose of the present application is to provide an electrolytic aluminum carbon residue reduction method and equipment based on a four-low-two-high-one-maintain strategy, which can reduce the amount of carbon residue, reduce environmental pollution caused by electrolytic aluminum, improve the efficiency of electrolytic aluminum, and reduce production costs.

[0005] To achieve the above-mentioned purpose, the present application provides the following solutions:

[0006] In a first aspect, the present application provides an electrolytic aluminum carbon residue reduction method based on a four-low-two-high-one-maintain strategy, which comprises: obtaining electrolytic aluminum operating parameters; the electrolytic aluminum operating parameters specifically include: cell voltage, alumina concentration, molecular ratio, cell temperature, electrode distance, and electrolyte level; based on the four-low-two-high-one-maintain strategy, fine electrolytic aluminum carbon residue reduction operation is performed by dynamically adjusting the electrolytic aluminum operating parameters; the four-low-two-high-one-maintain strategy specifically includes: low voltage strategy, low alumina concentration strategy, low molecular ratio strategy, low cell temperature strategy, high electrode distance strategy, high precision operation strategy, and electrolyte liquid level maintenance strategy.

[0007] In a second aspect, the present application provides a computer device, comprising: a memory, a processor to store a computer program on the memory and run the computer program on the processor, and the processor executes the computer program to implement the electrolytic aluminum carbon reduction residue method based on the four-low two-high one-maintain strategy described above.

[0008] According to the specific embodiments provided in the present application, the following technical effects are disclosed:

[0009] The present application obtains the electrolytic aluminum working condition parameters, which specifically include: cell voltage, alumina concentration, molecular ratio, cell temperature, electrode distance and electrolyte level; based on the four-low two-high one-maintain strategy, the electrolytic aluminum working condition parameters are dynamically adjusted to perform fine electrolytic aluminum carbon reduction residue operation. The present application reduces the amount of carbon residue, reduces the environmental pollution caused by electrolytic aluminum, improves the efficiency of electrolytic aluminum, and reduces the production cost. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0011] Figure 1 A flowchart of a four-low two-high one-maintain strategy-based electrolytic aluminum carbon reduction residue method provided by the present application Figure One .

[0012] Figure 2 A flowchart of a four-low two-high one-maintain strategy-based electrolytic aluminum carbon reduction residue method provided by the present application Figure Two .

[0013] Figure 3 A flowchart of parameter setting of the four-low two-high one-maintain strategy provided by the present application.

[0014] Figure 4 A schematic diagram of monthly change of cell voltage provided by the present application.

[0015] Figure 5 A schematic diagram of monthly change of alumina concentration provided by the present application.

[0016] Figure 6 A schematic diagram of monthly change of molecular ratio provided by the present application.

[0017] Figure 7 A schematic diagram of monthly change of cell temperature provided by the present application.

[0018] Figure 8 A schematic diagram of the monthly variation of the polar distance provided for the embodiments of the present application.

[0019] Figure 9 A schematic diagram of the monthly variation of the electrolyte level provided for the embodiments of the present application.

[0020] Figure 10 A schematic diagram of the monthly variation of the carbon residue amount provided for the embodiments of the present application.

[0021] Figure 11 A schematic diagram of the structure of a computer device provided for the embodiments of the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] Explanation of terms:

[0024] 1. Principle of aluminum electrolysis production process: Modern electrolytic aluminum industry production adopts cryolite-alumina fused salt electrolysis method. The molten cryolite is the solvent, alumina is the solute, carbon body is the anode, and aluminum liquid is the cathode. After strong direct current is introduced, electrochemical reaction occurs at the two poles in the electrolytic cell at 950℃-970℃. The aluminum liquid is on the cathode, and the gas is on the anode.

[0025] At the anode: 3O 2- (complexed) + 1.5C-6e→1.5CO2.

[0026] At the cathode: 2Al 3+ (complexed) + 6e→2Al.

[0027] Overall reaction: 2Al2O3+3C=4Al+3CO2.

[0028] In the aluminum electrolysis process, the secondary reaction of aluminum often occurs, and the reaction formula is:

[0029] 2Al (dissolved) + 3CO2 (gas) = Al2O3 (dissolved) + 3CO (gas).

[0030] 2. Carbon residue: In the process of aluminum electrolysis, carbon residue is a byproduct. Since the anode is mainly composed of carbon materials (such as pre-baked anode), during the electrolysis process, the anode will undergo oxidation reaction and be consumed, and at the same time, part of the carbon particles will fall off. These fallen carbon particles mix with the electrolyte to form aluminum electrolysis carbon residue, which will have many adverse effects on the electrolysis process.

[0031] 3. Aluminum electrolysis cell voltage: refers to the potential difference between the two poles (anode and cathode) of the electrolysis cell during the aluminum electrolysis process. The aluminum electrolysis cell voltage is an important parameter in aluminum electrolysis production, and the size of the cell voltage directly affects the heat income of electrolysis and the level of energy consumption.

[0032] 4. Alumina concentration: refers to the content of alumina (Al2O3) in the electrolyte, which is a key parameter in aluminum electrolysis production. Suitable alumina concentration can ensure the stable operation of the electrolysis cell.

[0033] 5. Molar ratio: refers to the molar ratio of sodium fluoride (NaF) to aluminum fluoride (AlF3) in the electrolyte, which is an extremely important parameter in aluminum electrolysis production. In actual aluminum electrolysis production operation, the electrolyte composition adjustment operation needs to be reasonably adjusted according to the specific production target and the state of the electrolysis cell, so as to ensure the efficient and stable operation of the production.

[0034] 6. Cell temperature: refers to the temperature of the electrolyte in the aluminum electrolysis cell, which is a key parameter in aluminum electrolysis production. Suitable cell temperature is an important condition to ensure the smooth progress of the electrolysis process. Generally, cell temperature will affect the physical and chemical properties of the electrolyte, such as viscosity, electrical conductivity and alumina dissolution rate.

[0035] 7. Pole distance: refers to the vertical distance between the anode bottom palm and the cathode aluminum liquid mirror surface in the electrolysis cell. It is an important operating parameter of aluminum electrolysis. The pole distance has a great influence on the voltage and current efficiency of the electrolysis cell. If the pole distance is too small, it will intensify the fluctuation of the aluminum liquid. In actual production, the pole distance needs to be reasonably controlled according to the specific production requirements and the state of the electrolysis cell, and the best value of the balance of energy consumption and current efficiency is found.

[0036] 8. Superheat: refers to the difference between the temperature of the electrolyte in the aluminum electrolysis production process and the initial melting temperature of the electrolyte. It can be expressed by the formula: superheat = electrolyte temperature - electrolyte initial melting temperature, unit value: ΔT = 10-15℃. Suitable superheat helps to maintain the thermal balance of the electrolysis cell, maintain the height of the electrolyte liquid, and keep the temperature, electric field, magnetic field and other environments in the electrolysis cell relatively stable.

[0037] 9. Electrolyte liquid level: refers to the liquid level of the electrolyte (mainly ice crystal salt melt) in the aluminum electrolysis cell to the surface of the aluminum liquid, which directly affects the electrolysis reaction area and thermal balance.

[0038] The following problems exist in the conventional operation method: 1. The production technical condition setting is loose, resulting in a large amount of carbon residue, and a large amount of manual participation is required for the salvage operation for stable production, and the labor intensity of employees is high. 2. Anodic oxidation: resulting in a large amount of carbon residue, and the traditional operation of opening holes at the corner and side for salvage operation can easily oxidize the anode, increase heat loss, cause the leg to be large and the hearth to be deformed. 3. Human interference: extensive operation causes human interference to the electrolytic cell, which is not conducive to the stable operation of the electrolytic cell, a large amount of carbon residue is produced, and the production and operation indicators decrease. 4. Environmental pollution: a large amount of carbon residue is generated, and frequent salvage operation can cause smoke to leak, and at the same time, slag is formed, which pollutes the environment. Among them, the sources of carbon residue in the process of electrolytic aluminum production are as follows:

[0039] 1. Anode source: in the process of aluminum electrolysis production, the anode is one of the main sources of carbon residue. In the electrolysis process, the anode material (carbon anode) will undergo oxidation reaction to produce carbon residue. Part of the carbon residue comes from the carbon particles falling off the surface of the anode, and the other part is formed by the anode material falling off due to the scouring action of the electrolyte during the contact between the anode and the electrolyte.

[0040] 2. Cathode source: the cathode carbon block also has a peeling phenomenon during electrolysis, producing carbon residue. These carbon residues are usually caused by the reaction between the cathode carbon block and the electrolyte, and the mechanical stress generated during the electrolysis process.

[0041] 3. Secondary reaction of electrolysis: the secondary reaction of aluminum is also a reason for the generation of carbon residue. In the electrolysis process, aluminum reacts with other components in the electrolyte (fluoride (such as Na3AlF6, CaF2) in the electrolysis process, dissolved oxygen, impurity oxides (such as SiO2, Fe2O3) to undergo secondary reaction, which cooperatively promotes the peeling and deposition of anode carbon, and finally forms carbon residue.

[0042] 4. Electrolyte scouring: the flow and scouring action of the electrolyte during electrolysis can cause the anode and cathode materials to fall off and form carbon residue.

[0043] 5. Extensive operation: loose technical condition setting and operation allow carbon particles that do not participate in the electrolysis reaction to fall off in the electrolytic cell. When the electrolyte has good wettability for carbon residue, the separation ability of the two is poor, and the carbon particles that fall off are suspended in the electrolyte and mixed with the electrolyte, making it difficult to separate them. A part of the fallen carbon particles is soaked and permeated by the electrolyte for a long time, forming carbon residue floating on the surface of the electrolyte.

[0044] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0045] Example 1, as Figures 1-3As shown, this embodiment provides a method for reducing carbon slag in electrolytic aluminum based on a four-low, two-high, and one-maintenance strategy. The method for reducing carbon slag in electrolytic aluminum based on a four-low, two-high, and one-maintenance strategy includes:

[0046] S1. Obtaining the electrolytic aluminum operating parameters; the electrolytic aluminum operating parameters specifically include: cell voltage, alumina concentration, molecular ratio, cell temperature, interelectrode distance and electrolyte level.

[0047] In actual application, the "secondary reaction of aluminum" will increase the amount of carbon slag generated. The main reasons include:

[0048] 1) Anode overvoltage: When the anode overvoltage increases, side reactions are more likely to occur on the anode surface. For example, the carbon anode reacts with oxygen ions in the electrolyte to produce carbon monoxide (CO) and carbon dioxide (CO2), resulting in increased carbon anode consumption and the generation of more carbon slag.

[0049] 2) Changes in electrolyte composition: When the aluminum fluoride concentration is too high, the physical and chemical properties of the electrolyte change, increasing the reaction between the carbon anode and the electrolyte, resulting in increased carbon slag generation.

[0050] 3) Decreased current efficiency: When the current efficiency decreases, more electrical energy is used for side reactions rather than the formation of aluminum, resulting in increased carbon anode consumption and increased carbon slag generation.

[0051] 4) The temperature of the electrolytic cell fluctuates. When the temperature is too high or fluctuates greatly, the reaction between the carbon anode and the electrolyte intensifies, resulting in an increase in the amount of carbon slag generated.

[0052] 5) Rough operation of the electrolytic cell; Rough operation (such as uneven addition of alumina and insufficient stirring of the electrolyte) will lead to intensified local reactions, increased heat return from the bottom of the furnace, the formation of hot pools, and increased carbon slag formation.

[0053] 6) Poor electrolyte fluidity and electrolyte height fluctuations; When the electrolyte fluidity is poor and the electrolyte height is too high, the anode gas is not discharged smoothly, resulting in prolonged contact time between the anode and the electrolyte. When the electrolyte height is too low, the solubility of alumina is reduced, the precipitation tank condition worsens, and carbon slag generation increases.

[0054] In summary, the main reasons for the increase in carbon slag formation due to secondary reactions are anode overvoltage, changes in electrolyte composition, decreased current efficiency, temperature fluctuations, improper operation, poor electrolyte fluidity, and large fluctuations in electrolyte height. After the aluminum electrolytic cell roasting is started and a regular furnace is built, and normal production begins, the production technical parameter management and operation should maintain appropriate low voltage, low alumina concentration, low molecular weight ratio, low cell temperature, high inter-electrode distance, and high-precision operation, so as to ensure that aluminum electrolysis production is carried out at a low and stable superheat, improve current efficiency, reduce aluminum secondary reaction losses, and thus reduce carbon slag formation.

[0055] S2. Based on the four-low-two-high-one-maintain strategy, fine electrolytic aluminum carbon reduction residue operation is performed by dynamically adjusting the electrolytic aluminum operating parameters; the four-low-two-high-one-maintain strategy specifically includes: low voltage strategy, low alumina concentration strategy, low molecular ratio strategy, low bath temperature strategy, high pole distance strategy, high precision operation strategy, and maintain electrolyte level strategy.

[0056] 1) The low voltage strategy is: dynamically adjusting the cell voltage in the low voltage range; dynamically adjusting the cell voltage specifically includes: based on the real-time feedback of the electrolytic aluminum operating parameters, using the electrolytic cell heat balance model to dynamically adjust the cell voltage; the low voltage range is 3.8V-3.9V.

[0057] In actual application process, the voltage setting range of traditional aluminum electrolysis cell is wide and loose at 3.9-4.2V after starting and turning into normal production, while the low voltage control of embodiment 1 is set in the range of 3.8-3.9V under the condition of ensuring smooth production operation, improving current efficiency and realizing appropriate low temperature production, and reducing the secondary reaction of aluminum.

[0058] Optionally, the specific operation process of the low voltage strategy is as follows:

[0059] (1) Voltage dynamic adjustment mechanism, combined with electrolytic cell heat balance model and real-time parameter feedback (such as electrolyte temperature, molecular ratio, aluminum liquid height, etc.), to realize fine control of voltage.

[0060] (2) By optimizing the electrolyte composition (such as AlF3 content, see low molecular ratio control), the primary crystal temperature is reduced to support stable operation at low voltage.

[0061] (3) High-precision operation is realized on the electrolytic cell basic maintenance, anode replacement, anode adjustment, aluminum tapping operation, electrolyte composition adjustment, cell voltage adjustment, anode effect extinguishing, and lifting busbar aluminum electrolysis operation, to ensure smooth production operation at low voltage and appropriate low temperature.

[0062] 2) The low alumina concentration strategy is: dynamically adjusting the alumina concentration in the low alumina concentration range; dynamically adjusting the alumina concentration specifically includes: control parameter optimization, feeding rate adjustment, electrolytic cell state real-time monitoring, intelligent matching of feeding amount, and regular maintenance inspection; the low alumina concentration range is 1.5%-2.0%.

[0063] In actual application process, the alumina content in traditional aluminum industry is generally controlled at 2%-5%, and when low superheat or cold cell is encountered in production, the saturation concentration of alumina is low, which can only reach about 5%, and higher will produce precipitation. The low alumina concentration control of the operation method is to maintain the alumina concentration in the range of 1.5%-2.0%, to avoid excessive precipitation and increase the side reaction.

[0064] Optionally, the specific operation process of the low alumina concentration strategy is as follows:

[0065] (1)Adjust the computer system parameters, adjust the control system parameters through the host computer, shorten the benchmark underweight period, the benchmark overage period, the benchmark normal period, the blanking initialization time, the effect after blanking period, the maximum overage time, and extend the minimum sun shift time, and the underweight period is greater than the overage period.

[0066] (2) Adjust the slope, cumulative slope, and blanking rate, increase the lower limit of the precision value domain of the slope and cumulative slope, reduce the upper limit, narrow the precision value domain of the blanking rate, and slightly adjust the blanking rate according to the smaller change of the slope and cumulative slope, so that the alumina concentration is maintained within the target range.

[0067] (3) Pay attention to the state of the electrolytic cell, strengthen the monitoring and analysis of parameters such as cell voltage and resistance, and determine the change trend of alumina concentration according to voltage fluctuation. When the cell voltage appears abnormal fluctuation, it may be that the alumina concentration changes, and measures need to be taken in time. If the voltage rises, it may be that the alumina concentration is too low, and the blanking amount should be appropriately increased.

[0068] (4) Optimize the blanking operation, accurately calculate the required alumina blanking amount according to the actual situation of the production load and current intensity of the electrolytic cell, so that the blanking amount matches the actual consumption of alumina. Advanced blanking control technology and equipment such as intelligent blanking device can be used to achieve precise blanking.

[0069] (5) Strengthen daily maintenance, regularly clean the crust and sediment in the electrolytic cell during the anode changing operation to ensure the smoothness of the blanking port and make the alumina evenly enter the electrolytic cell. Check if the blanking system is working normally, and timely find and handle problems such as blanking device failure and leakage, to ensure the stability and accuracy of blanking.

[0070] 3) Low molecular ratio strategy: dynamically adjust the molecular ratio of electrolyte within the low molecular ratio range; the low molecular ratio range is 2.3-2.4.

[0071] Optionally, dynamically adjusting the molecular ratio of electrolyte specifically includes: balancing fluoride salt and molecular ratio, maintaining alumina solubility and conductivity; adjusting cell voltage and cell temperature, utilizing electrolyte fluidity to remove impurities; synergistically optimizing composition and thermal conditions, utilizing electrolyte self-purification capacity to purify electrolyte system.

[0072] In actual application process, the electrolyte liquid is mainly composed of molten cryolite and dissolved alumina and additives.

[0073] The current industrial electrolyte composition is generally: cryolite 82%~90%, molecular ratio 2.4~3.0; alumina content 2%~5%; calcium fluoride 4%~6%, magnesium fluoride 3%~5% or lithium fluoride 2%~3%. The composition of the electrolyte determines the properties of the electrolyte, and the molecular ratio of the main body of cryolite has a great influence on the physical properties of the electrolyte. In production, acid electrolyte (containing free aluminum fluoride) is often used, the main reasons are:

[0074] (1) It can reduce the primary crystallization temperature of the electrolyte, and further reduce the electrolysis temperature.

[0075] (2) Reduce the discharge of sodium ions.

[0076] (3) Reduce the density and viscosity of the electrolyte, which is beneficial to the separation of aluminum from the electrolyte.

[0077] (4) It is beneficial to the separation of carbon particles from the electrolyte and reduces the solubility of aluminum in the electrolyte.

[0078] (5) The electrolyte crust is loose and easy to break.

[0079] At the initial stage of starting the aluminum electrolysis cell, a high molecular ratio is used to build the hearth, and when normal production is turned on, appropriate low molecular ratio management and operation are used. Because low molecular ratio belongs to acid electrolyte, it is beneficial to the separation of carbon particles from the electrolyte.

[0080] Alternatively, the specific operation process of the low molecular ratio strategy is as follows:

[0081] By comprehensively balancing and controlling fluorinated salt and molecular ratio, voltage and cell temperature and other technical measures, the cell condition is improved, and the self-discharge capacity of the electrolyte is improved, thereby purifying the clear electrolyte system. At the same time, attention should be paid to: if the electrolyte composition is too acidic, the solubility of alumina will decrease, the conductivity of the electrolyte will decrease, the volatilization loss will increase, and the loss of aluminum will increase. Therefore, the electrolyte composition control is optimized and improved to 2.3~2.4 to reduce the generation of carbon residue in the cell.

[0082] 4) Low cell temperature strategy: dynamically adjust the cell temperature within the preset cell temperature range; the preset cell temperature range is 930℃-940℃.

[0083] In actual application, the cell temperature of the traditional aluminum electrolysis normal production stage is generally controlled at 940℃~970℃; and in this embodiment, the normal production stage is controlled at 930℃-940℃.

[0084] Alternatively, the specific operation process of the low cell temperature strategy is as follows:

[0085] (1) Reasonably adjust the molecular ratio: moderately reduce the electrolyte molecular ratio, but not too low, generally controlled between 2.3-2.4, to reduce the electrolyte primary crystal temperature, but attention should be paid to prevent the electrolyte conductivity from being poor and the alumina dissolution capacity from being reduced due to the electrolyte molecular ratio being too low.

[0086] (2) Keep the electrolyte level appropriate: control the electrolyte level in a higher range, increase the heat capacity of the electrolyte, make the tank temperature more stable, and also help the dissolution of alumina.

[0087] (3) Precise control of anode replacement: strictly replace the anode according to the replacement cycle and specifications, ensure the anode to be in good working condition, reduce the uneven current distribution and local overheating caused by anode problems. Ensure the installation accuracy of the new anode during replacement to avoid too small or too large anode distance.

[0088] (4) Strengthen the anode insulation: add enough thickness of insulation material on the upper surface of the anode, the thickness of the insulation material in summer is 16-18 cm, and in winter is 18-20 cm, reduce the heat dissipation of the anode, and help to maintain the tank temperature.

[0089] (5) Ensure uniform discharge: regularly check the working condition of the discharge equipment to ensure uniform discharge of alumina and prevent local over-discharge or under-discharge from causing tank temperature fluctuations.

[0090] (6) Precise control of voltage: according to the tank temperature and other parameters, finely adjust the tank voltage, reduce the voltage as much as possible to reduce heat input under the premise of ensuring normal electrolysis reaction, but prevent the electrolytic tank from being unstable due to too low voltage.

[0091] 5) High anode distance strategy: dynamically adjust the anode distance within the preset anode distance range; the preset anode distance range is 4.5-5 cm.

[0092] Further, the dynamic adjustment of the anode distance specifically includes: fixture pressure drop processing, furnace bottom sediment crust processing and blockage and leakage processing.

[0093] In actual application process, the high anode distance strategy is to eliminate reactive voltage drop, such as fixture pressure drop processing, furnace bottom sediment crust processing, timely discovery and processing of blockage and leakage, and reduce the occurrence of pressure anode distance.

[0094] 6) High-precision operation strategy specifically includes: electrolytic tank maintenance, anode replacement, measurement and determination, carbon residue salvage, anode adjustment, aluminum tapping operation, electrolyte composition adjustment, tank voltage adjustment, anode effect extinguishing and busbar lifting operation with preset precision requirements.

[0095] Optionally, the high-precision operation strategy mainly provides necessary production conditions by maintaining the stable running displacement of the electrolytic tank and reducing carbon residue operation.

[0096] Optionally, the electrolytic cell maintenance specifically includes: blocking treatment, machine head package treatment, strong insulation treatment, and strong insulation leakage treatment.

[0097] Optionally, during the anode replacement process, according to the average consumption speed of the anode, an infrared line is set, and high-precision return is performed to ensure that the anode does not overpressure and superflow before passing through the full current, the performance of the anode is not damaged, and the anode is not washed away by the electrolyte.

[0098] Optionally, the step of salvaging the carbon residue specifically includes:

[0099] (1) After the shift, clean the hole opening crust block and salvage the carbon residue; wherein during the process of salvaging the carbon residue, no electrolyte or crust block is taken out, and the salvaged carbon residue is cooled to be non-white and non-clumping.

[0100] (2) The setting standard of the flue end fire hole and the aluminum outlet fire hole is a regular small caliber, and the anode does not leak.

[0101] (3) Real-time machine head package treatment is performed.

[0102] (4) 30 minutes after the effect, the carbon residue of the cell is salvaged clean at the aluminum outlet and the flue end. When there is too much carbon residue, the corner is opened for salvage, and the fire hole is immediately sealed after salvage.

[0103] (5) When an abnormal cell condition occurs (when the cell temperature exceeds 960℃ or more), open the corner to salvage the carbon residue, and seal the fire hole in time after salvage.

[0104] In actual application, fine operation is crucial from the start of the aluminum electrolytic cell to the end of the electrolytic cell repair. The electrolytic cell maintenance, anode replacement, anode adjustment, aluminum outlet operation, electrolyte composition adjustment, cell voltage adjustment, anode effect extinguishing, and lifting of the busbar are all important operations. If the fine management is not in place, the operation quality is rough, the insulation material cover is not tight after the replacement, or even the fire is everywhere or exposed to the air, the high-temperature anode is in contact with the air, the slag is oxidized, and the carbon residue generation increases.

[0105] In practical application process, the high-precision operation strategy mainly improves the operation quality of electrolytic operation, such as electrode replacement and tank maintenance. During electrode replacement, infrared line setting is adopted according to the average consumption speed of anode, the return size accuracy is high, the anode is ensured not to be overvoltage and super flow in the early stage of passing through full current, the anode performance is not damaged, and the anode is not washed away by the electrolyte. Strengthening the anode anti-oxidation work, the fluid movement in the tank will also make the carbon residue float in the corner and the small head and the edge part, and the fishing is done frequently in this part to prevent the accumulation of carbon residue. After using the effect, fishing is done at the aluminum outlet and during electrode replacement, and the corner is specially fished. Through high-standard operation, great efforts are made in heat preservation and heat dissipation reduction, and in insulation and leakage reduction. The furnace bottom crust is cleaned up carefully to restore the good furnace state, and the no-load voltage drop is eliminated by careful operation, so that the voltage is fully used on the electrode distance to adapt to low-temperature operation. In addition, in the process of aluminum electrolysis production, the carbon residue in the electrolyte is consumed by burning. When the carbon residue in the electrolyte generates a large amount, the carbon residue cannot be completely burned, thereby affecting the fluidity of the electrolyte. At this time, the carbon residue must be fished out.

[0106] 7) The electrolyte liquid level strategy is to dynamically adjust the electrolyte liquid level within a preset electrolyte liquid level range; the preset electrolyte liquid level range is 18-20 cm.

[0107] In practical application process, whether the carbon block in the electrolytic aluminum production is oxidized and the residue is removed depends on the height of the electrolyte liquid level, and the change of the electrolyte liquid level depends on the control of the superheat. The electrolyte liquid level is kept between 19 cm±1 cm, which is the best, so that the heat of the anode bottom of the electrolytic cell can be dissipated, the cell temperature is reduced, and a solid electrolytic cell is formed. If the electrolyte liquid level is lower than the optimal level, the heat accumulated in the electrolytic cell will be reduced, and the situation in the electrolytic cell will be unstable. If the electrolyte liquid level is higher than 21 cm, even exceeding the plane of the electrode to be replaced within two days, the electrolyte solution will circulate on the surface of the carbon block, which will accelerate the oxidation of the surface of the carbon block and rapidly increase the amount of carbon residue.

[0108] Optionally, the specific operation process of the electrolyte liquid level strategy is as follows: the superheat of the electrolytic cell is controlled to be 10-15℃, the electrolyte height measurement data is accurate and timely, and the electrolyte liquid level is adjusted to keep it within the best range of 18-20 cm. Keeping appropriate electrolyte liquid level can improve the thermal stability of the electrolyte, reduce the electrolyte washing and degranulation of the anode, and reduce the oxidation of the surface of the carbon block, thereby reducing the generation of carbon residue.

[0109] Optionally, after obtaining the historical data of the cell voltage, the alumina concentration, the molecular ratio, the cell temperature, the electrode distance and the electrolyte level in the dynamic adjustment process, the electrolytic aluminum parameter control model can be trained by machine learning modeling, and the trained electrolytic aluminum parameter control model is used for parameter adjustment, and the high-precision operation strategy is used to complete the carbon residue reduction of electrolytic aluminum.

[0110] Table 1 shows the differences between the parameter setting ranges of the present application and those of the conventional ones.

[0111] Table 1 Parameter adjustment comparison

[0112]

[0113]

[0114] like Figures 4-10 As shown in the figure, after the implementation of the "Four Lows, Two Highs, and One Maintain" operation method, the amount of carbon slag per ton of aluminum was reduced from 9.98 to 5.25 kg / t, achieving a continuous reduction effect. The economic value and promotion value of this application are as follows:

[0115] 1) Reducing the amount of carbon slag in the electrolyte can reduce the "voltage gap" phenomenon and improve the current efficiency of the electrolytic cell. When the voltage gap forms a hot cell, the electrolytic cell furnace will be damaged, and the current efficiency of the electrolytic cell will be chronically low. By reducing carbon slag, the current efficiency is improved by 1%, and the annual production of a single cell increases by 14.7 tons of aluminum. Calculated at an aluminum price of 19,000 yuan per ton, the profit can increase by 280,000 yuan.

[0116] 2) A large amount of carbon slag floats on the surface of the electrolyte, which will induce the anode effect. By reducing the carbon slag, the total effect coefficient is reduced from the original 0.37 to 0.20, and 10,670 anode effects are reduced throughout the year. Each effect lasts for 30 seconds, which can save more than 880,000 kWh of electricity throughout the year.

[0117] Single effect power consumption = effect average voltage × current intensity × effect duration.

[0118] The electricity consumption saved throughout the year = reduced effect coefficient × annual slot day and night × single effect electricity consumption.

[0119] 3) By tapping into the potential of voltage, fully utilizing the pole pitch to improve efficiency, the voltage deviation can be optimized by approximately 2mV. This will reduce DC power consumption per ton of aluminum by 6.5kWh. A plant with a 230,000-ton production capacity will save 1.5 million kWh annually. At a price of 0.45 yuan per kWh, this translates to a savings of 675,000 yuan. DC power consumption per ton of aluminum = voltage / current efficiency × 2980.

[0120] 4) Social benefits: Reduce greenhouse gas emissions; reduce the use of effect rods; reduce the amount of hazardous waste generated; and reduce the cost of hazardous waste treatment for enterprises.

[0121] In summary, the technical effects of this application are as follows:

[0122] The application reduces the amount of carbon residue, reduces environmental pollution caused by electrolytic aluminum, improves the efficiency of electrolytic aluminum, and reduces production costs. Specifically, the application changes the traditional method of relying only on the quality of the anode and salvaging by a large number of manual operations to reduce the amount of carbon residue in the tank; the key technical parameters are monitored, adjusted, and operated in combination with fine operations, the high-precision operation standards of each link are solidified, the electrolytic tank is operated efficiently and stably, and the amount of carbon residue is reduced. The application reduces the amount of carbon residue in the electrolytic tank by adjusting and optimizing the technical parameters and combining fine operation, reduces the labor intensity of employees, reduces costs and increases efficiency, reduces environmental pollution, and improves production and operation indicators.

[0123] In embodiment 2, the application also provides a computer device, which can be a server or a terminal, and an internal structure diagram of the computer device can be as shown in Figure 11 The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is used to store processing data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through network connection. The computer program is executed by the processor to implement the above-mentioned methods.

[0124] Those skilled in the art can understand that Figure 11 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the application, and does not constitute a limitation on the computer device to which the scheme of the application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0125] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0126] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0127] The principles and implementation modes of the present application are described by using specific examples. The above description of the embodiments is only used to help understand the method and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present application should not be understood as a limitation.

Claims

1. A method for reducing carbon slag in electrolytic aluminum based on a four-low, two-high, and one-maintain strategy, characterized in that: The electrolytic aluminum carbon slag reduction method based on the four lows, two highs and one maintenance strategy includes: Obtaining electrolytic aluminum operating parameters; the electrolytic aluminum operating parameters specifically include: cell voltage, alumina concentration, molecular ratio, cell temperature, interelectrode distance, and electrolyte level; Based on the four lows, two highs and one maintenance strategy, refined electrolytic aluminum carbon slag reduction operation is carried out by dynamically adjusting the electrolytic aluminum operating parameters; the four lows, two highs and one maintenance strategy specifically includes: low voltage strategy, low alumina concentration strategy, low molecular ratio strategy, low tank temperature strategy, high electrode distance strategy, high precision operation strategy and maintaining electrolyte liquid level strategy.

2. The method for reducing carbon slag of electrolytic aluminum based on the strategy of four lows, two highs and one maintenance according to claim 1, characterized in that: The low voltage strategy is: dynamically adjust the cell voltage within a low voltage range; the dynamic adjustment of the cell voltage specifically includes: based on real-time feedback of electrolytic aluminum operating parameters, dynamically adjust the cell voltage using the electrolytic cell thermal balance model; the low voltage range is 3.8V to 3.9V.

3. The method for reducing carbon slag of electrolytic aluminum based on the strategy of four lows, two highs and one maintenance according to claim 1, characterized in that: The low alumina concentration strategy is: dynamically adjusting the alumina concentration within a low alumina concentration range; The dynamic adjustment of alumina concentration specifically includes: control parameter optimization, feeding rate adjustment, real-time monitoring of electrolytic cell status, intelligent matching of feeding amount and regular maintenance inspection; the low alumina concentration range is 1.5% to 2.0%.

4. The method for reducing carbon slag of electrolytic aluminum based on the strategy of four lows, two highs and one maintenance according to claim 1, characterized in that: The low molecular ratio strategy is: dynamically adjusting the molecular ratio of the electrolyte within a low molecular ratio range; the low molecular ratio range is 2.3 to 2.

4.

5. The electrolytic aluminum slag reduction method based on the four lows, two highs and one maintenance strategy according to claim 1 is characterized in that: The low tank temperature strategy is: dynamically adjust the tank temperature within a preset tank temperature range; the preset tank temperature range is 930°C-940°C.

6. The method for reducing carbon slag of electrolytic aluminum based on the strategy of four lows, two highs and one maintenance according to claim 1, characterized in that: The high pole distance strategy is: dynamically adjusting the pole distance within a preset pole distance range; the preset pole distance range is 4.5 cm to 5 cm.

7. The method for reducing carbon slag of electrolytic aluminum based on the strategy of four lows, two highs and one maintenance according to claim 6, characterized in that: The dynamic adjustment of pole pitch specifically includes: fixture pressure drop processing, furnace bottom sedimentation and crust processing, and material blockage and leakage processing.

8. The method for reducing carbon slag of electrolytic aluminum based on the strategy of four lows, two highs and one maintenance according to claim 1, characterized in that: The high-precision operation strategy specifically includes: performing electrolytic cell maintenance, anode replacement, measurement and determination, carbon slag salvage, anode adjustment, aluminum tapping operation, electrolyte composition adjustment, cell voltage adjustment, anode effect extinguishing and busbar lifting operations according to preset accuracy requirements.

9. The method for reducing carbon slag of electrolytic aluminum based on the strategy of four lows, two highs and one maintenance according to claim 1, characterized in that: The strategy for maintaining the electrolyte level is: dynamically adjusting the electrolyte level within a preset electrolyte level range; the preset electrolyte level range is 18 cm to 20 cm.

10. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the electrolytic aluminum carbon reduction slag method based on the four lows, two highs, and one maintenance strategy as described in any one of claims 1-9.

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