Aluminum Electrolysis Research Articles

Modified Recovered Carbon from Aluminum Electrolysis by Expansion Treatment as an Anode for Sodium-Ion Batteries

Modified Recovered Carbon from Aluminum Electrolysis by Expansion Treatment as an Anode for Sodium-Ion Batteries

Growth characteristics and properties of plasma electrolytic oxidation coatings produced in different electrolytes on SiCp/Al composite

PEO coatings on SiCp/Al composites generated in phosphate, silicate, and aluminate electrolytes are compared to reveal the effect of the electrolyte composition on the coating formation process and coating performance. The observed significant disparity in spark discharge highlights the considerable influence of the electrolyte composition on the coating growth of the SiCp/Al composite surface. Within the plasma discharge zone, the local temperature ranges are approximately 6000 K–12000 K for silicate electrolyte, 6000 K–10000 K for aluminate electrolyte, and 4000 K–5000 K for phosphate electrolyte. Regarding spark discharge intensity, silicate electrolyte exhibits the highest discharge, followed by aluminate electrolyte, while phosphate electrolyte displays the weakest discharge. Consequently, the resulting surface porosity reaches up to 9.1% for PEO-Si coating, 6.5% for PEO-Al coating, and 4.9% for PEO-P coating. Phase analysis reveals that coatings generated in aluminate and silicate electrolytes tend to consist of crystalline alumina and mullite, whereas the coating formed in phosphate electrolyte predominantly contains amorphous phases and some crystalline mullite. The electrochemical tests demonstrate that the anti-corrosive ability of the coatings follows the order of PEO-Al > PEO-Si > PEO-P. The electrical insulation protection performance of the three coatings is PEO-Al > PEO-Si > PEO-P under comprehensive consideration.

Greenhouse gas emissions embodied in the U.S. solar photovoltaic supply chain

Solar photovoltaic (PV) electricity is considered to be an important source of electricity generation in the quest for net-zero carbon emissions. However, the growth of solar electricity is creating both increased material demands and increased greenhouse gas (GHG) emissions from silicon and PV manufacturing (also referred to as embodied GHG emissions of solar electricity). Here we analyze the silicon and solar PV supply chain for the United States (U.S.) market and find that the embodied GHG emissions of solar PV panel materials (such as silicon), manufacture, logistics, and installation in the U.S. given the current supply chain are 36 g CO2e kWh−1 of solar electricity generated. Eighty-five percent of the embodied GHG emissions are from PV panel production processes in China and other Asia–Pacific countries. Moving the silicon and PV manufacturing to the U.S. would reduce the embodied GHG emissions of solar electricity by 16% from its current level, primarily because of the lower GHG emission intensity of the U.S. electrical grid and the lower GHG emissions for aluminum electrolysis in North America. Future scenario analysis shows that by 2030, with the U.S. PV domestic supply chain and its decarbonized grid electricity and aluminum production, as well as improving PV conversion efficiency, the embodied GHG emissions of solar electricity in the U.S. will be reduced to 21 g CO2e kWh−1.

Intelligent Online Inspection of the Paste Quality of Prebaked Carbon Anodes Using an Anomaly Detection Algorithm

Prebaked carbon anodes are a critical consumable in the aluminum electrolysis industry. Prebaked carbon anode paste is the intermediate product of the prebaked carbon anode, and its quality significantly impacts the prebaked carbon anode. Therefore, inspecting the quality of the prebaked carbon anode paste is essential. Currently, the quality inspection of the paste still relies on laboratory analysis or manual experience. A laboratory inspection cannot obtain results in real time, while manual inspection poses potential risks. To address these issues, an online intelligent inspection method for prebaked carbon anode paste based on an anomaly detection algorithm was proposed. Firstly, we acquired the temperature of the paste and the power of the kneading motor. Secondly, we transformed these time-series data into images using the Gramian Angular Field (GAF) technique and joined them to create the paste anomaly detection dataset. Thirdly, we trained a matched anomaly detection model based on the PatchCore algorithm. Finally, we compared two advanced models: HaloAE and TSRD. PatchCore performs best on our dataset with an AUC-ROC score of 0.9943, followed by HaloAE (0.9906) and TSRD (0.9811). Our proposed method enables on-time intelligent inspection of prebaked carbon anode paste quality. This eliminates the need for manual inspection, reduces labor requirements, and ensures worker safety.

ИССЛЕДОВАНИЕ МИНЕРАЛИЗУЮЩЕГО ЭФФЕКТА КРИОЛИТА И ЕГО ВЛИЯНИЯ НА ПРОЦЕССЫ КЛИНКЕРООБРАЗОВАНИЯ

The article discusses the possibility of using cryolite Na3AlF6, the main fluorine-containing compound of a man-made product of electrolytic aluminum production, as a mineralizing additive when burning clinker. A comparative assessment of the effectiveness of cryolite Na3AlF6, as a mineralizer, and calcium fluoride CaF2, a substance that has the most effective mineralizing effect, is provided. The influence of mineralizer additives on the processes of dissociation of calcium carbonate, assimilation of free calcium oxide with the formation of silicates, aluminates and calcium ferrites, liquid-phase sintering and clinker formation with the synthesis of basic clinker minerals is considered. The physical and chemical processes that occur when heating raw material mixtures without additives and with the addition of mineralizers – CaF2 and Na3AlF6 – to a clinker sintering temperature of 1450ºC are examined in detail. The dynamics of changes in the qualitative phase composition of firing products at various temperatures, ranging from 700ºC to the clinker sintering temperature of 1450ºC, as well as a quantitative characteristic of the intensity of formation of the main clinker minerals are presented. It has been determined that cryolite has a mineralizing effect and can be used as a mineralizer when burning clinker. The effectiveness of cryolite is comparable to the effectiveness of calcium fluoride, and the burning temperature of clinker can be reduced to 1400ºC

Optimizing the marketing of flexibility for a virtual battery in day-ahead and balancing markets: A rolling horizon case study

Industrial electricity consumers with flexible demand can profit from adjusting their load to short-term prices or by providing balancing services to the grid. Markets which support this kind of short-term position adjustment are the day-ahead market and balancing markets. We propose a formulation for a combined optimization model that computes an optimal distribution of flexibility between the balancing and day-ahead markets. The optimal solution also includes the specific bids for the day-ahead and balancing markets. Besides the expected profits of each market and their different rules for bidding, our model also takes their different roles in a continuous marketing of flexibility into account. To prevent overrating short-term profits we introduce a variable penalty term that adds a cost to unfavorable load schedules. We evaluate the optimization model in a rolling horizon case study based on the setting of a virtual battery at TRIMET Aluminum SE, which is derived from a flexible aluminum electrolysis process. For such a battery we compute a daily optimal split of flexibility and trading decisions based on data in the period 04/2021–03/2022. We show that the optimal split is more profitable than using only one market or a fixed split between the markets.

Effect of Nanopillars on the Wetting State and Adhesion Characteristics of Molten Aluminum Droplets.

To solve the adhesion problem between molten aluminum and vacuum ladle liner during the electrolytic aluminum production process, the wetting state and adhesion properties of molten aluminum droplets on substrate surfaces with different nanopillars are investigated based on molecular dynamics. The results show that the adhesion strength of molten aluminum droplets in different wetting states has the pattern Young state > Wenzel state > Cassie state. Effects of increasing nanopillar height or interval are poles apart in the wetting state and adhesion characteristics of aluminum molten droplets. The critical height and critical interval of the nanopillar where the wetting state transition occurs are obtained. The increase of the nanopillar width can induce the wetting state transition from the Cassie state to the Wenzel state. In addition, the phantom wall method is applied to study the variation of the separation force. It is found that a peak in the separation force curve occurs when the molten droplet separates from the bottom of the nanopillar interval or the top of the nanopillar. The separation force curves of the droplets in the Young state and the Cassie state have single peaks, while the droplets in the Wenzel state have double peaks.

Correlation between chemical composition, wettability and carbon anode performance: Exploration of high quality carbon anode preparation for aluminum electrolysis

The chemical composition of coal tar pitch has a significant effect on its wettability and the performance of carbon anode for aluminum electrolysis. This study aimed to reveal the correlation among chemical composition, wettability, and carbon anode performance, as well as provide strategies for reducing energy consumption, greenhouse gases, and hazardous waste emissions during aluminum electrolysis processes. First, the chemical composition of modified coal tar pitch was regulated by adding low-temperature coal tar pitch. The effects of low-temperature coal tar pitch mixing amount on the chemical composition, basic properties, contact angle, static wettability, functional groups, and coke microstructure were studied. In particular, electron paramagnetic resonance (EPR) and atomic force microscopy (AFM) were performed to qualitatively and quantitatively analyze radical emissions and surface structure of coal tar pitch at the microscopic scale. Subsequently, the correlation of chemical composition, wettability, and performance was discussed according to the effect of low-temperature coal tar pitch on the performance of carbon anode. Results showed that the incorporation of low-temperature coal tar pitch reduced the softening point and viscosity, and the increase in fluidity improved the contact angle and static wettability. Meanwhile, the increase in volatile content and the decrease in coking value, surface roughness, nanoscale adhesion, and free radical release concentration jointly weakened the bonding strength between coal tar pitch and calcined petroleum coke. The performance of the carbon anode prepared by blending low-temperature coal tar pitch weakened, except for the ash content. Consequently, the balance between the wettability and bonding strength of coal tar pitch is essential for the preparation of high-quality anode for aluminum electrolysis.

Enhanced sequestration of CO2 from simulated electrolytic aluminum flue gas by modified red mud

The aluminum industry is facing severe economic and environmental problems due to increasing carbon emissions and growing stockpiles of red mud (RM). RM is a strongly alkaline, high-emission solid waste from the alumina industry with potential for CO2 sequestration. However, the effectiveness of RM carbon sequestration is poor, and the mechanism behind it is not well understood. In this study, the effect of microwave and tube furnace activation of RM on CO2 sequestration in alumina was first investigated at different temperatures. The result showed that the CO2 sequestration capacity of unmodified RM (URM) was only 14.35 mg/g at ambient temperature and pressure, and the CO2 sequestration capacity could be increased to 52.89 mg/g after high-temperature activation and modification. Besides, high-temperature activation and modification will effectively improve the carbon sequestration capacity of RM. The carbonized RM was characterized by FT-IR, SEM, XRD, laser particle size, TG-DSC, and pH measurements. In addition, the mechanism of RM capturing CO2 was also proposed, which shows that CO2 was finally sequestered in the RM as CaCO3. The change in particle size distribution and the mineral phase in the RM indicated that high-temperature activation modification positively affects the application of RM to the sequestration of CO2. This study can provide a promising technology for the low-carbon and green development of the aluminum industry, as well as achieving the waste treatment and utilization objective.

Plasma electrolytic oxidation of aluminium in electrolytes containing various concentrations of carbon black nanoparticles

Incorporation of carbon-based nanoparticles into ceramic coatings during plasma electrolytic oxidation (PEO) is promising for the synthesis of new composite layers on lightweight metals. Specifically, the present study focuses on the incorporation of carbon black (CB) nanoparticles into PEO alumina layers. For this purpose, PEO of aluminium is performed in silicate-based electrolytes containing various concentrations of dispersed carbon black nanoparticles (from 0 to 6 g·L−1). The influence of this concentration on the microstructure of the achieved PEO coatings is investigated by combining complementary characterization techniques (scanning electron microscopy, X-ray diffraction and Raman spectroscopy). Results show that using concentrations up to 6 g·L−1 tend to limit the morphological inhomogeneity between the edges and the centre of the treated samples. Moreover, the addition of carbon black nanoparticles results in a sponge-like outermost sublayer covering larger areas of the surface with abilities to host a higher amount of these nanoparticles. It is also evidenced that CB nanoparticles do not suffer any further structural degradation during their incorporation. In addition, cross-checked results show that the presence of dispersed CB nanoparticles slightly affect the coating average growth rate. As for potential future applications, the electrical volume conductivity of grown carbon-alumina composite coatings is also measured.

Efficient lithium recovery from lithium-containing spent aluminium electrolyte via NaF fluorination roasting and Al2(SO4)3 leaching

Recently, there has been a growing interest in lithium-containing spent aluminium electrolyte (LSAE) as a potential new source of lithium. However, the current method of using strong inorganic acids for leaching lithium from LSAE has several drawbacks, which not only consume a lot of acids but raise safety and environmental concerns due to the release of HF. Herein, a novel process combining NaF fluorination roasting and Al2(SO4)3 leaching is proposed for the efficient extraction of lithium from LSAE. LSAE with NaF additive was first roasted at temperatures between 900 and 980 °C to convert Na2LiAlF6 into easily leachable LiF. Then, environmentally friendly Al2(SO4)3 solutions were used to selectively leach LiF from roasted LSAE. Gibbs free energy change calculated by DFT confirms the thermodynamic feasibility of the NaF fluorination roasting and Al2(SO4)3 leaching process, and it was found that Al2(SO4)3 could react more readily with LiF than with Na3AlF6. Under optimal process conditions, a lithium leaching rate of 94.05% was achieved. After leaching, 99.26% of Al and 97.21% of F in the leachate were recycled as AlF1.5(OH)1.5(H2O)0.375 precipitation by adding NaOH solution to adjust the pH to 6.6. Then, AlF3 and Al2O3 with metallurgical grade were obtained by roasting AlF1.5(OH)1.5(H2O)0.375 at temperatures between 500 and 600 °C. Lastly, Li2CO3, with a purity of 99.0%, was precipitated using Na2CO3 from lithium-containing leachate after purification and evaporation concentration. The overall Li recovery rate for the entire process is 86.2%. Collectively, this research proposes an efficient and environmentally friendly extraction process for lithium from LSAE.

Clean Process for Selective Recovery of Lithium Carbonate from Waste Lithium-Bearing Aluminum Electrolyte Slag

Clean Process for Selective Recovery of Lithium Carbonate from Waste Lithium-Bearing Aluminum Electrolyte Slag

Melting and Crystallization Behaviors of Mold Flux with the Addition of Waste Electrolyte

The influence of waste fluoride electrolyte addition on key properties of mold flux is investigated, with the aim to convert the hazardous waste in electrolytic aluminum industry into treasure in steel industry. The results show that the initial melting temperature of mold fluxes decreases from 1614.40 K (1341.40 °C) to 1564.67 K (1291.67 °C), and the complete melting temperature decreases from 1704.45 K (1431.45 °C) to 1674.34 K (1401.34 °C) with the addition of waste electrolyte from 10.08 to 24.89 wt%. The crystallization of mold flux is enhanced, and its crystallization mechanism transforms from “constant nucleation rate and 2D growth” into “constant nucleation number and 3D growth” with the addition of waste electrolyte. The main precipitated crystals in mold fluxes are grossular (Ca3Al2(SiO4)3) and CaF2, but the phase transforms into gehlenite (Ca2(Al(AlSi)O7) at higher temperature. In addition, the crystallization activation energy is 13.80, 12.40, 12.01, 11.03, and 10.27 kJ mol−1, respectively, which further confirms that the addition of waste electrolyte can reduce the energy barrier of crystallization and promote the crystallization ability of mold flux.

Developing a Comprehensive Mathematical Model for Aluminium Production in a Soderberg Electrolyser

The technological process of aluminium electrolysis is a complex scientific and technical task. This is due to a large number of internal, external and resultant factors. The aim of this work is to analyse these factors, assess them and their influence on the technological process of electrolysis and develop a comprehensive and mathematical model of aluminium production in the Soderberg electrolyser. The work analyses the technological process of primary aluminium production on the basis of the Bayer method and then on the basis of the Hall–Eru method. The existing methods and technologies for computer modelling of the technological process are analysed. The modern methods of analysis for thermal and electromagnetic fields in electrolysers are considered. On the basis of an in-depth analysis, a number of factors influencing the process of primary aluminium production are identified. Using the methods of system analysis to analyse the identified factors, a ranked list of factors according to the degree of influence is obtained. Using the Pareto diagram, we obtain a list of factors with maximum impact. A conceptual model of the technological process is derived. Based on the obtained conceptual model, the mathematical model of the technological process is derived. The conducted research may be useful to specialists in the field of metallurgy for the analysis of the technological processes of primary aluminium production.

Anodic Overpotential on Metallic Oxygen Evolving Anodes for Aluminum Electrolysis in Low Temperature Electrolyte of KF-Naf-AlF₃-Al₂O₃

To eliminate climate gas emissions from aluminum electrolysis, significant research and development efforts focus on non-consumable oxygen evolving anodes to replace the carbon anodes used in the Hall Héroult process. Modifying the cryolite-based electrolyte currently used, by partly replacing Na with K in the molten fluoride, opens up a range of metallic alloys as feasible materials for inert anodes. In this work, the performance of Cu-Ni-Fe anodes, with or without surface treatment, is benchmarked against Pt and the pure components of the alloy.Anodic overpotential using an inert anode with low-temperature electrolyte, 750–800 ⁰C, for aluminum reduction should be low to compensate for ~1.10 V higher reversible potential for O₂ evolution than in conventional Hall-Héroult process at 960 ⁰C. In this study, voltammetry methods were applied in a low-temperature electrolyte mixture of KF-NaF-AlF₃-Al₂O₃ at 800 ⁰C. Oxygen evolution overpotential on pure Pt anode was measured using steady-state polarization. Tafel plots were obtained, and kinetic parameters were derived in the form of Tafel coefficients and exchange current density. A theoretical treatment for anodic process on Pt electrode with a two-step electron transfer mechanism is developed.Some anodic polarization curves were obtained for pure metals of Cu, Ni, Fe, and alloy of Cu-Ni-Fe in KF-NaF-AlF₃-Al₂O₃ at 800 ⁰C. Prior to use, some anodes of Cu-Ni-Fe alloy were oxidized in air at 800 ⁰C for 8 h and found to perform relatively better than an untreated alloy of the same composition. Anodes following electrochemical measurements were characterized by scanning electron microscope (SEM) coupled energy dispersive spectroscopy (EDS).

(Invited) tamm Plasmon Resonance Sensors Based on Nanoporous Anodic Alumina Photonic Crystals

Nanoporous Anodic Alumina (NAA) is a material with growing interest in nanotechnology and for biological and medical applications. It is a cost-effective nanostructured material obtained by the electrochemical etching of aluminum in acidic electrolytes at the adequate conditions of applied voltage or current, temperature and electrolyte composition [1-4]. The precise control over the diameter of the nanopore allows to create periodic variations of nanopore’s diameter in deep and obtain different photonic crystals e.g.., Gradient-index filters, microcavities, Distributed Bragg Reflectors, etc [5-6]. The optical properties of NAA depend on its nanoporous structure and of its functionalized surface. NAA can be used to fabricate hybrid photonic structures by gold coating on nanoporous anodic alumina photonic crystals surface (NAA-PCs) [7]. In this metal-dielectric photonic structure, we can observe effects of an enhancement of the surface plasmon resonance due to absorption of the light at the interface of metallic layer and the NAA photonic crystal.Tamm plasmon resonance (TPR) can be tuned by engineering the properties and characteristics of the metal film and the porous photonic structure, providing new opportunities to achieve unique plasmonic−photonic structures for different applications (optical switching, lasing, light emission, surface-enhanced spectroscopy, and sensing). One interesting application of TPR is the use as a sensing platform taking advantage of its exceptional optical properties to confine/amplify the light-matter interactions [8-9]. The sensing performance of TPR-NAA−PCs is assessed by the infiltration of their structure with analytical solutions, producing a spectral shift in the Tamm plasmonic resonance. In this work, we evaluate the structural geometry and the optical properties of TPR-NAA-PCs and the assessment of TPR-NAA-PCs as a sensing platform.Figure 1a shows the reflectance spectrum for a TPR-NAA–PCs structure. The spectrum shows the photonic bandgap and the absorption narrow-line associated with the resonant recirculation of light within the plasmon-photonic system. Figure 1b shows the sensing performance of TPR-NAA-PCS. Red-shift on the position of the TPR-NAA-PCs is observed due to the refractive index variation when the nanopores are infiltrated of different analytical solutions (water- ethylene glycol)AcknowledgmentsThis work was supported by the Spanish Ministerio de Ciencia e Innovación (MICINN/FEDER) PDI2021- 128342OB-I00, by the Agency for Management of University and Research Grants (AGAUR) ref. 2017- SGR-1527, COST Action 20126 - NETPORE and by the Catalan Institution for Research and Advanced Studies (ICREA) under the ICREA Academia Award.

Plasma electrolytic oxidation of tantalum in an aluminate electrolyte: Effect of cathodic polarization and frequency

The effect of cathodic polarization on plasma electrolytic oxidation (PEO) of the refractory metal of tantalum is investigated in 10 g/l NaAlO2+2 g/l KOH under 1000 and 100 Hz. Ceramic coatings are formed under various cathodic-to-anodic current densities ratios (R = jc/ja) of 0, 0.6, 1.3 and 2.3. For PEO under 1000 Hz, the plasma discharges intensify with the increase of R from 0 to 1.3, with optical emission from Ta being detected at later stage of PEO under cathodic polarization. However, excessive R ratio of 2.3 has caused early extinguishment of the plasma discharges. Correspondingly, thicker coatings are formed as the R ratio increases from 0 to 1.3, and the coating under R = 1.3 exhibits a most porous outer layer. A thin and compact coating is formed under R = 2.3. It is also found that the application of cathodic polarization increases the Na content in the resultant coatings, with a new crystalline phase NaTaO3 being formed under R = 2.3. Cathodic polarization also decreases the corrosion resistance of the coatings. Surface wettability tests show that the coatings formed under R = 1.3 are the most hydrophilic. PEO under 100 Hz shows some differences in discharge and coating formation. Larger sized discharges are also observed at the later stage under R = 0.6, but Ta species are detected at a delayed time. For the R values of 1.3 and 2.3, patches of soft sparking occur on the sample surface, leading to non-uniform coatings. This study shows that both cathodic polarization and frequency significantly affect the PEO process. Moreover, compared with the PEO of Al, tantalum responds quite differently to cathodic polarization. Mechanisms of coating formation have been illustrated: Protons and other cations are attracted by cathodic electric field into the coatings, where they undergo a series of reactions to significantly affect the PEO behaviors.

Piggybacking on past problem for faster optimization in aluminum electrolysis process design

In process industry, it is a habitual phenomenon that the production efficiency is improved via replacing the obsolete devices with the advanced ones. To achieve an optimal performance, these devices are always required for heavily empirical adjustments, which is very time-consuming and inefficient. Though outdated, invaluable experiences for adjusting devices towards a more efficient industrial production have been accumulated by those replaced facilities. Thereby, new devices are expected to adapt to perform the industrial task without many modulations if the aforementioned experiences can be appropriately utilized. Inspired by the fact that evolutionary multitasking is capable of exploiting latent similarities and commonalities among multiple optimization tasks so as to improve the overall convergence of multi-task optimization, in this paper, we propose a novel framework to automatically search for the optimal settings for new devices based on the knowledge accumulated by the old. The framework, dubbed Piggybacking on Past Problem for Faster Optimization (PPPFO), is able to piggyback on the past optimization problem for a faster convergence of the targeted. By means of automatically transferring search experiences (i.e. genetic and cultural characteristics) from source task to the target, PPPFO can assist an engineering optimizer to improve its search exercises. PPPFO has been tested with a number of widely used benchmark functions and has been successfully adopted to an important real application, i.e., aluminum electrolysis process design. The remarkable results verify the efficacy and efficiency of the proposed framework.

Quasi-Solid-State Aluminum-Air Batteries with Ultra-high Energy Density and Uniform Aluminum Stripping Behavior.

Aqueous aluminum-air batteries are attracting considerable attention with high theoretical capacity, low-cost and high safety. However, lifespan and safety of the battery are still limited by the inevitable hydrogen evolution reaction on the metal aluminum anode and electrolyte leakage. Herein, for the first time, a clay-based quasi-solid-state electrolyte is proposed to address such issues, which has excellent compatibility and a liquid-like ionic conductivity. The clay with uniform pore channels facilitates aluminum ions uniform stripping and reduces the activity of free H2 O molecules by reconstructing hydrogen bonds network, thus suppressing the self-corrosion of aluminum anode. As a result, the fabricated aluminum-air battery achieves the highest energy density of 4.56 KWh kg-1 with liquid-like operating voltage of 1.65V and outstanding specific capacity of 2765 mAh g-1 , superior to those reported aluminum-air batteries. The principle of constructing quasi-solid-state electrolyte using low-cost clay may further promote the commercialization of aluminum-air batteries and provide a new insight into electrolyte design for aqueous energy storage system.

Robust fault detection for chemical processes based on dynamic low-rank matrix and optimized LSTM

The data collected by sensors in modern chemical process systems are always contaminated by industrial noise, so robust fault detection is an important technology to ensure process safety. However, the existing robust detection techniques have limitations in extracting dynamic and time series features of chemical process data. In this paper, a robust fault detection method based on dynamic low-rank matrix and optimized LSTM is proposed for dynamic chemical processes under noise background. First, a new low-rank matrix decomposition method, dynamic principal component pursuit (DPCP), is proposed for the dynamic characteristics of process data containing noise. The PCP is improved using the time delay excursion method, i.e., the DPCP is constructed by embedding an augmented dynamic matrix with a time lag factor on the PCP and solved using the alternating direction multiplier method. The purpose is to strip the useless noise from the useful detection information and extract the dynamic low-rank matrix. Second, an optimized LSTM (OPLSTM) is proposed for the time series features of dynamic low-rank matrix. vector factors for feature selection of memory cells in the LSTM are reweighted to balance the time series features of industrial processes and avoid heavy reliance on erroneous fault information. In addition, support vector data description (SVDD) is used to describe the hypersphere with clear boundary, and distance-based statistic is constructed to achieve fault detection with high fault detection rate and low false alarm rate. Finally, to assess the effectiveness of the proposed method, we performed extensive experiments on the Tennessee Eastman Process and the electrolytic aluminum process, and compared them with multiple methods. The experimental results show that the proposed method is effective and robust for chemical processes fault detection in the background of industrial noise.