Aluminum Electrolysis Research Articles

A Numerical Approach on Waste Heat Recovery through Sidewall Heat‐Exchanging in an Aluminum Electrolysis Cell

This paper proposes a technical viewpoint for the recovery of waste heat in aluminum electrolysis. The idea of combining heat‐generating electrolysis process and the heat‐consuming alumina tube digestion process is discussed in detail. The structural design of the heat‐exchanging system as well as the matching problems between the heat exchanger and cell design are also mentioned. Several major concerns including the automatic temperature regulation of the cell sidewall and the preferred selection principles for the heat medium are introduced. A 2 kA heat exchangeable cell is developed and a series of tests are carried out in the laboratory. It is found that approximate 80% of the sidewall waste heat can be recovered while the cell behaves steadily. It is also proved possible to control the thickness of the frozen ledge through adjusting the heat convection rate of the heat exchanger. The heat‐exchanging system is also suitable for aluminum cells when the fluctuating wind power is applied as a major energy supply.

Stabilizing Na metal anode with NaF interface on spent cathode carbon from aluminum electrolysis.

We report the synthesis of spent cathode carbon (SCC) with a NaF interface from aluminum electrolysis, and its application as a Na metal anode host. The SCC anode exhibits superior ion conductivity and a high shear modulus. The natural NaF interface on the SCC anode can regulate Na+ transmission and inhibit dendrite growth. Furthermore, the anode can be used to turn waste into treasure through directly using spent cathodic carbon without any chemical processing. The green SCC electrode exhibits a higher flat voltage and better reversibility compared with purified cathode carbon without NaF.

Recent progress of inert anodes for carbon-free aluminium electrolysis: a review and outlook

This review introduces the latest research progress of inert anodes for aluminium electrolysis and compares the comprehensive performances of different kinds of materials, including metals, ceramics and cermets.

A Grid-Generator-Electrolytic Aluminum Multi-Agent Cooperative Game Model Based on Nash Negotiation Theory

In order to realize the local consumption of surplus electric energy, this paper proposes a multi-agent cooperative game model of power grid-generator-electrolytic aluminum based on Nash negotiation theory. The operation characteristics of the power grid, generator, and electrolytic aluminum are considered in the modeling of each agent. Then, a cooperative game framework considering electricity trading is further constructed based on Nash negotiation theory. Finally, a series of linearization methods are used to transform the complex problem into the mixed integer linear programming (MILP), which can be effectively solved by commercial solver. In the case studies, based on the actual situation of Yunnan power grids, a comparative analysis of the impact of cooperative and non-cooperative frameworks on multi-agents proves the feasibility of the cooperative game framework. Finally, the cooperative game model is applied to different provinces to verify its universality.

KF-NaF-AlF<sub>3</sub>体系结构性质的分子动力学模拟

近年来低温铝电解质的研究已成为铝电解工业上节能减排的热点问题，对其基本物理化学性质的探索是一个必然的过程。本文运用密度泛函理论与经典分子动力学方法相结合的方法系统研究了1100 K下xKF-2.2NaF-AlF3熔盐体系的结构性质和输运性质。研究结果表明在平衡的高温钾冰晶石熔盐体系中六配位[AlF6]3−、五配位[AlF5]2−、四配位[AlF4]−络合离子共同存在，且六配位铝氟离子集团占主导地位(70%以上)，并会发生部分的离解，生成五配位或者四配位离子团；当KF浓度增大时，电解质体系中游氟原子含量会增加，桥氟含量逐渐降低，体系的聚合程度也会随之下降。此外，KF的加入使得桥氟离子解离，Na、Al的自扩散系数会先增大后降低，体系显示出低粘度高电导率的特性，但当KF浓度达到2%后，电导率会逐渐降低。 The study of low temperature aluminium electrolytes has become a hot issue for energy saving and emission reduction in the aluminium electrolysis industry in recent years, and the exploration of their basic physicochemical properties is an inevitable process. In this paper, the structural and transport properties of the nKF-2.2NaF-AlF3 molten salt system at 1100 K have been systematically investigated using a combination of density flooding theory and classical molecular dynamics methods. The results show that in the equilibrium high-temperature potassium cryolite molten salt system, hexacoordinated [AlF6]3-, pentacoordinated [AlF5]2- and tetracoordinated [AlF4]- complex ions co-exist, and the hexacoordinated aluminium-fluorine ion group dominates (more than 70%) and undergoes partial dissociation to produce pentacoordinated or tetracoordinated ion groups; As the KF concentration increases, the amount of free fluorine atoms in the electrolyte system increases, the bridge fluorine content gradually decreases and the degree of polymerisation of the system decreases. In addition, the addition of KF causes the dissociation of the bridging fluorine ions, the self-diffusion coefficients of Na and Al will first increase and then decrease, and the system shows the characteristics of low viscosity and high conductivity, but when the KF concentration reaches 2%, the conductivity will gradually decrease.

Multimode Process Monitoring and Mode Identification Based on Multiple Dictionary Learning

In modern industrial systems, the processes often operate under different modes. Potential fault diagnosis and mode identification are extremely vital to maintain the system safe and reliable. Recently, many methods have been proposed to address these problems separately. Moreover, many of them make an assumption that the data from industrial site only contain the Gaussian noise. However, this assumption is not held in practice, which further reduces their performances. Considering the complicated noise feature of industrial data, we came up with an improved dictionary learning method to settle these problems simultaneously. First, the measurement data were decomposed into three parts: clean data, mode-based noise, and dense Gaussian noise. Then, the dictionary learning method was proposed to characterize each part separately. Inspired by the framework of label-consistent K-SVD, the mode information was incorporated into the dictionary learning method, and we developed a solution to settle the multiple dictionary learning optimization problem. Finally, when new samples arrive, we reconstruct them under the learned dictionary so that each sample's mode and abnormal data and can be determined. The experiments on two different types of simulated process and aluminum electrolysis process show the strength and reliability of our method, which indicates the engineering application value of the proposed method.

Time-Series Prediction of Iron and Silicon Content in Aluminium Electrolysis Based on Machine Learning

In analyzing dynamic characteristic of time-series data, classic prediction models rely heavily on static historical data, and tacit knowledge is difficult to be mined effectively. Therefore, a hybrid prediction model GS-GMDH is proposed based on growing neural gas (GNG) and the group method of data handling (GMDH). Firstly, a dynamic prediction mechanism, based on an incremental learning algorithm and time-series prediction, is established by GS-GMDH, by which the singularity is recognized and the prediction efficiency is improved. Secondly, to compare the performance of the proposed method, the multi-step ahead predictions with time-series data onto iron and silicon content are employed, and the new model is compared with classic machine models. Finally, the results show that the hybrid prediction model (GS-GMDH) proposed in this paper ensure an accurate and efficient prediction of time-series data for iron and silicon content.

Integrated Control Strategy for Electrolytic Aluminum Load Participation in Frequency Modulation

The introduction of electrolytic aluminum load in a large-scale power system with complex power station structure is essential for load frequency control (LFC). In this paper, we propose a control strategy for electrolytic aluminum load to participate in the frequency modulation of the power grid based on the IEEE standard two-region LFC model. Besides, a fractional-order PID (FOPID) controller is designed and compared with traditional PID, and the parameters of the FOPID controller are optimized by PSO algorithm. In addition, a two-region LFC model was built to verify the integrated control strategy for electrolytic aluminum load participation in frequency modulation, which show that the FOPID controller optimized by the PSO algorithm has stronger robustness in the LFC.

Estimating the Alumina Concentration During Aluminum Electrolysis by Identifying the Sensitive Frequency Band Using Marginal Kurtosis

The accurate and timely online estimation of the alumina concentration in an industrial aluminum electrolysis cell can improve its feed control performance. By using the proposed marginal kurtosis (MK), marginal kurtosis dominant frequency (MK-DF), integral feed frequency and sensitive frequency band (SFB), this study reveals that a normalized cell voltage with different current intensities and feed schemes has different alumina concentration SFBs and determines the general formula for calculating the SFB. On this basis, a general algorithm for acquiring the pseudo alumina concentration (PAC) using translation-invariant filtering is proposed in which the upper limit of the SFB provides the cutoff frequency of the low-pass filter. The PAC was used to estimate the absolute and relative concentrations of alumina. The absolute concentrations are validated using measured concentrations. Additionally, improved feed control performance of the industrial cells is presented using the relative concentration PAC-slope.

Efficient separation of fluoride and graphite carbon in spent cathode carbon from aluminum electrolysis by mechanical activation assisted alkali fusion treatment

Spent cathode carbon (SCC) is the largest and most inevitable hazardous solid waste continuously discharged from the aluminum electrolysis industry. In this study, mechanical activation was used to assist alkali fusion treatment in dissociating toxic substances and recovering graphite carbon from SCC. The effect of mechanical activation (i.e., milling speed, ball-to-material mass ratio, and milling time) on the alkali fusion treatment was investigated. Its effect on the physicochemical properties of SCC–Na2CO3 mixtures was also analyzed through particle size distribution, Brunauer-Emmett-Teller surface area analysis, scanning electron microscopy, X–ray diffraction and thermogravimetric analysis–differential scanning calorimetry. Results showed that mechanical activation enhanced the alkali fusion treatment by improving the physical separation of fluoride, the mixing uniformity and reaction contact area of SCC and Na2CO3, and promoting the conversion of Na2CO3 to Na2O. The formation of agglomerates was the main reason that the carbon content of recovered graphite carbon and the fluoride ion leaching rate increased initially then decreased with the increment in mechanical activation conditions. Under optimal mechanical activation conditions, the carbon content of recovered graphite carbon and the fluoride ion leaching rate increased from 89.35% and 76.50% (non-activated sample) to 93.93% and 95.02%, respectively, indicating that mechanical activation assisted alkali fusion treatment effectively enhanced the separation efficiency of fluoride and graphite carbon. In addition, thermodynamic analysis of the alkali fusion treatment and characterization of recovered graphite carbon (under the optimal mechanical activation conditions) were performed. Results demonstrated that the simultaneous conversion of multiple fluorides (i.e., Na3AlF6 and CaF2) and oxidative decomposition of cyanide in SCC can be achieved via mechanical activation assisted alkali fusion treatment. These findings indicate that mechanical activation–assisted alkali fusion treatment is a promising method for the detoxification and utilization of SCC.

Electrolyte viscosity and solid phase formation during aluminium electrolysis

This paper presents experimental data on the dependence on alumina and calcium fluoride concentrations of the viscosity of the industrial electrolytes NaF-AlF3-CaF2-Al2O3 with cryolite ratios (CR) of 2.1, 2.3, 2.5 in the temperature range 1243–1293 K. The temperature dependence of the formation of a solid phase on the graphite crucible wall in cryolite-alumina electrolyte during aluminium electrolysis was studied in a laboratory-scale electrolytic cell. The viscosity of the industrial electrolytes was found to depend more on the temperature and cryolite ratio than on the alumina concentration in the melt. A long period of electrolysis with controlled solid phase formation on the cell wall was carried out, with a constant electrolyte composition (CR = 2.4), a calcium fluoride concentration of 5 wt% and an alumina content of 4.0 wt%. The formation of a stable solid phase layer on the graphite crucible wall was found to depend on the electrolysis temperature. A correlation was observed between the formation of a solid under the influence of temperature and the viscosity of the melt.

Application of BP neural network models in predicting the desulfurization rate of petroleum coke calcination flue gas

Sulfur-containing prebaked anodes, mainly made from petroleum coke, can give rise to SO2 emission in the production of electrolytic aluminum. In order to study the correlation between the emission volume and desulfurization rate of the flue gas discharged from the calcination of petroleum coke, a traditional double hidden layer BP neural network model was established on the basis of BP neural network by taking the emission data of the petroleum coke calcination flue gas desulfurization system as input parameters. This model was used to predict the desulfurization rate of the petroleum coke calcination flue gas desulfurization system, with an aim to control the SO2 removal rate of flue gas through controlling the flue gas parameters of the desulfurization system, so as to reduce SO2 emission from the flue gas of the electrolytic aluminum industry. The study will be of practical significance for the SO2 removal of the petroleum coke calcination flue gas.

Technology for regeneration of gas cleaning solutions of PJSC RUSAL Bratsk from sulfur compounds using natural cold

The quality of petroleum cokes used in the aluminum industry is rapidly deteriorating, with the main criterion being an increase in the content of sulfur and vanadium. An increase in the mass fraction of sulfur has a more significant effect on the process of electrolytic production of aluminum. Previous studies show that this leads to a decrease in the performance of electrolysers. Therefore, cumulative accumulation of sulfur in gas cleaning solutions should be avoided and, if possible, sulfur should be removed from the process. The technology of regeneration of gas-cleaning solutions of aluminum electrolyzers from sulfur compounds has been studied. The advantages of the developed technology in comparison with other existing ones are substantiated. A technological scheme for the regeneration of the gas-cleaning solution is given, the theoretical foundations of the process are given, and methods for a possible further intensification of this technology are described. At PJSC RUSAL Bratsk, the technology for removing sodium sulfate from gas cleaning solutions has been successfully tested and implemented on a semiindustrial scale. Atmospheric air was used as a cooler during the cold season. According to the analysis of the chemical composition of desulfurized gas cleaning solutions, this technology will reduce the load on the sludge fields, excluding the withdrawal of solutions to maintain the balance of sulfur products, and reduce the consumption of soda ash. The obtained sodium sulfate can be used in related industries, for example cellulose or synthetic detergents production.

Dynamic evolutionary model based on a multi-sampling inherited HAPFNN for an aluminium electrolysis manufacturing system

It is technically difficult to accurately establish a dynamic adaptive model of an aluminium electrolysis manufacturing system (AEMS) because the system has many complex characteristics, such as multiple parameters, dynamic time variance, and a non-Gaussian distribution of process data. Inspired by the overall superiority of particle filtering theory in dealing with non-linear non-Gaussian problems, this paper presents a novel method based on a multi-sampling inherited hybrid annealed particle filter neural network (MSI-HAPFNN). Firstly, the neural network’s (NN’s) weights and thresholds are used as the state variables of hybrid annealed particle filter; Secondly, the hybrid proposal distribution obtained by sampling the above state variables is employed to replace the posterior proposal distribution in the standard particle filter (PF) algorithm as the importance density function, thereby adjusting the NN’s weights and thresholds in real time. Thirdly, the model achieves the features of multi-sampling and inheritance by introducing NN and PF weights, and using adaptive inheritance method. Therefore, this paper systematically proposes the theoretical construction framework and experimental procedure of MSI-HAPFNN. Furthermore, this article also introduces a genetic algorithm to thoroughly evaluate the prediction potential. The proposed model has been tested on the real-world system for aluminium electrolysis manufacturing and compared with several closely related frameworks. The experimental results show that the MSI-HAPFNN model can significantly improve the self-adaptive ability of the object system to working conditions and the prediction accuracy of power consumption, which is helpful in finding optimal design parameters in an AEMS.

Synthesis and Characterization of (Co,Ni)O Solid Solutions As Protective Coatings for Inert Anodes in Aluminum Electrolysis

The industrial production of primary aluminum from alumina ore (Al2O3) is still carried out by the Hall-Héroult process. The process relies on dissolving alumina in an electrolyte consisting mainly of liquid Na3AlF6 at 950-1000 °C. While the reduction of dissolved Al3+ ions in aluminum occurs at the cathode, the complementary reaction occurs at a carbon anode that is consumed to form carbon dioxide, which necessitates its regular replacement (every 25 days). The overall reaction is the following:Canadian aluminum smelters produce annually about 6 Mt of CO2 eq(reported in 2017), which is equivalent to the CO2 amount generated annually by about 2 million cars.The substitution of consumable carbon anodes with inert (O2-evolving) anodes in the electrochemical cells to produce aluminium would have significant environmental benefits because it would eliminate the emissions of carbon dioxide and perfluorocarbons associated with the consumption of the carbon anode. However, the design of inert anodes is a major challenge because of the severe Al electrolysis conditions (cryolithic medium at 960 °C), which requires materials with excellent resistance to corrosion and thermal shock as well as adequate electrochemical properties [1].Single phase Cu65Ni20Fe15 alloy is a promising inert anode for Al production due to its ability to form a protective NiFe2O4 layer upon Al electrolysis. However, its corrosion resistance is still insufficient and a protective layer is required to prevent the penetration of electrolyte into the nickel ferrite layer and the formation of fluorides during Al electrolysis [2-4].In this context, the use of (Co,Ni)O-based protective coatings for metallic anode appears promising [5]. However, it is challenging to prepare a single phase, coherent and crack-free oxide layer as required for industrial Al production. A potentially relevant method to produce (Co,Ni)O coated inert anodes is by direct deposition of (Co,Ni)O oxide compounds by spray deposition techniques such as suspension plasma spray (SPS) and high velocity oxygen fuel (HVOF). These additive manufacturing deposition are well-established technologies for producing protective oxide coatings for various industrial applications (e.g. gas turbines).As a first step toward this goal, pure CoxNi1−xO solid solutions have been prepared over the whole composition range by a two-step procedure that consisted of high-energy ball milling followed by a heat treatment of Co3O4 and NiO powders [6]. Then, the thermal stability and electrical conductivity of (Co,Ni)O solid solutions were determined at temperatures ranging between 700 and 1000 °C. Also, their dissolution rate was measured in K-based cryolite at 700 °C and in Na-based cryolite at 1000 °C.In a second step, (Co,Ni)O powders have been used as raw materials for the thermal spraying (HVOF and SPS) of protective coatings onto Cu-Ni-Fe inert anodes [7]. The morphological and microstructural characteristics of the coating depending on the thermal spray conditions will be presented. The oxidation behaviour of the coated inert anodes under air and argon is presented. Preliminary investigation of the electrochemical behaviour under Al electrolysis conditions of the (Co,Ni)O/Cu-Ni-Fe anodes will be also presented and discussed.

(Invited) Formation Efficiency of Anodic Porous Alumina in Sulfuric Acid Containing Alcohol As Additives

The properties of anodic porous alumina films, which are generally formed by the anodization of aluminum in an acid electrolyte, are well known to be affected by the dimensions of their structure (e.g., pore diameter, pore density, and film thickness). For instance, to increase the hardness of anodic films on aluminum, the anodization is industrially carried out at low-temperature to avoid chemical dissolution of the formed oxide film during anodization. Anodization in an electrolyte containing organic compounds is also one approach for improving the performance of anodic oxide film not only for aluminum but also for other light metals such as titanium and magnesium (1).One such initiative is anodization of aluminum at a relatively high current density or high voltage using a common acidic electrolyte (e.g., sulfuric acid, oxalic acid, or phosphoric acid) with an alcohol added. In such studies, the effects of adding an alcohol are summarized as follows: i) the alcohol functions as an anti-freeze agent in the electrolyte, enabling the anodization temperature to be lowered; ii) the alcohol acts as a cooling agent—specifically, the vaporization of alcohol at the bottom of the pore channels removes the heat generated at the aluminum/oxide interface; and iii) nonuniform growth of the anodic film (i.e., burning) is effectively prevented, even during high-field anodization. However, these effects are observed not only for monohydric alcohols with a boiling point less than 100 °C (e.g., methanol and ethanol) but also for polyhydric alcohols with a boiling point greater than 100 °C (e.g., ethylene glycol and glycerol). Therefore, the effect of alcohol addition cannot be reasonably explained solely on basis of the boiling point of the alcohol used as an additive. Understanding the effects of alcohol addition necessitates a systematic investigation comparing types of alcohols, in addition to further fundamental studies.In this study, monohydric alcohols or polyhydric alcohols were added to the sulfuric-acid-based electrolyte to examine their effects on the anodization behavior of aluminum, the coating ratio, the porosity, the maximum attainable film thickness, and the resulting etching ability. Anodization was conducted in sulfuric acid solutions containing various alcohols with different physical properties under mild anodization conditions with a constant current of 100 A·m−2 at 20 °C (2, 3). The influence of the type and concentration of alcohol on the coulombic efficiency of film formation and the structure of the porous alumina under a constant electric charge was also investigated. In terms of basic research, the potential impact of alcohol addition in electrolytes will be discussed. H. Asoh, K. Asakura, H. Hashimoto, RSC Advances, 10, 9026-9036 (2020).H. Asoh, M. Matsumoto, H. Hashimoto, Surface and Coatings Technology, 378, 124947 (2019).M. Matsumoto, H. Hashimoto, H. Asoh, Journal of The Electrochemical Society, 167, 041504 (2020).

Estimation of Net Carbon Consumption in Aluminum Electrolysis Using Multivariate Analysis

In the aluminum electrolysis, the amount of carbon consumed per unit of metal produced is always higher than the theoretical one. Raw material variability, anode properties, and reduction cell operation and performance can influence this discrepancy. Linking these factors to each individual anode could help close this gap thus improving the environmental footprint and reducing production cost. In today’s industrial environment, large volume of data, both structured and unstructured, are collected, otherwise known as big data. These capabilities could enable predicting the consumption for each anode as opposed to estimating it at the plant level as performed so far. This can be achieved using a tracking system to link the pot operation to individual baked and green anode properties. The performance of R&D Carbon Net Carbon Consumption formula was compared to a multivariate statistical approach that considers process data variables gathered from the aforementioned, linked, databases. Given the process data at hand, the prediction power of the net carbon consumption for individual anodes is significantly improved as opposed to using the existing model.

Thermodynamic Performance Analysis of a Waste Heat Power Generation System (WHPGS) Applied to the Sidewalls of Aluminum Reduction Cells.

To recover energy from the waste heat of aluminum reduction cells, a waste heat power generation system (WHPGS) with low boiling point working fluid based on Organic Rankine Cycle was proposed. A simplified model for the heat transfer around the walls of aluminum reduction cells and thermodynamic cycle was established. By using the model developed and coded in Matlab, thermal performance analysis of the system was conducted. Results show that the electrolyte temperature and the freeze ledge thickness in the cell can significantly affect the heat absorption of the working fluid in the heat exchange system on the walls. Besides, both the output power and the thermal efficiency of the power generation system increase with the system pressure. The output power and thermal efficiency of the system can also be affected by the type of working fluid used in the system. Working fluids for the best system performance under different output pressures were determined, based on the performance analysis. This WHPGS would be a good solution of energy-saving in aluminum electrolysis enterprises.

From wood to thin porous carbon membrane: Ancient materials for modern ultrafast electrochemical capacitors in alternating current line filtering

Ultrafast electrochemical capacitors with alternating current line filtering function have attracted growing attention owing to their potential to replace the state-of-the-art bulky aluminum electrolyte capacitors. In spite of rapid advance recently involving nanomaterials as electrode building units, it remains largely unexplored how to structurally and chemically engineer electrodes out of renewable resource with competitive or better rate performance. Herein, wood as a renewable resource was used to fabricate highly conductive, robust, porous thin carbon membranes as free-standing electrodes for ultrafast electrochemical capacitors. Transformation of wood slice to carbon membrane proceeds via wet-chemical treatment of wood slices and subsequent morphology-maintaining carbonization by spark plasma sintering. Judiciously combining high conductivity, characteristic porous architecture with low tortuosity and high continuity, and the ultrathin thickness down to 20 μm, the carbon membrane-based electrochemical capacitor exhibits excellent frequency response with efficient 120 Hz filtering (phase angle = −83.5o). Compared to the latest electrodes for line filtering application that are fabricated from carbon nanotubes, graphene, and MXene, the wood-derived carbon membranes possess a competitive specific areal capacitance of up to 509.7 µF cm−2, and extremely low resistance-capacitance constant of 164.7 µs, plus the inexpensive scalable fabrication strategy.

Detoxification and Recovery of Spent Carbon Cathodes via NaOH–Na2CO3 Binary Molten Salt Roasting–Water Leaching: Toward a Circular Economy for Hazardous Solid Waste from Aluminum Electrolysis

The conversion of solid waste into secondary resources has become a prerequisite for the sustainable development of the industry. This study focused on the development of the detoxification process for spent carbon cathode (SCC) without environmental pollution risks and the exploration of the recycling direction of recovered carbonaceous materials. First, the mechanism of thermodynamic conversion and decomposition of toxic substances was explored. Parameters of NaOH–Na₂CO₃ binary molten salt roasting were optimized through an orthogonal design and a single-factor experiment, and gas release behavior during detoxification treatment was investigated. Results showed that most of the fluoride and cyanide were dissociated and decomposed, and the leaching concentration of fluoride and cyanide was as low as 7.58 and 0.12 mg/L after detoxification treatment, respectively. Then, a multistage recovery process of fluorine from fluorine-containing leachate was designed, and the comprehensive utilization of exhaust gas and the recycling of the reaction reagent were realized simultaneously. The possibility of recovering graphitized carbon blending to prepare carbon anodes was discussed in detail, and the catalytic mechanism of main impurity elements on the O₂/CO₂ reactivity of carbon anodes was investigated via density-functional-based tight binding (DFTB). The results showed that the Boudouard reaction and carbon–O₂ reaction were affected because of the presence of Ca or Na, and the recovered graphitized carbon with a low blending ratio was more suitable for the preparation of carbon anodes. Finally, an economic benefit analysis was conducted to evaluate the industrial application potential of the proposed detoxification treatment. Compared with landfills, the proposed process reduced the disposal cost while eliminating environmental pollution risks and realized the on-site recovery and reuse of valuable components, showing considerable environmental and economic benefits.