Stripping Process Research Articles

Analisis Penyisihan Kandungan Amonia dengan Stripper di Pabrik Ammonia

Ammonia industrial waste treatment is part of the final process in the industry. Wastewater containing high ammonia content needs to be treated using a stripping process. This study to analysis the stripping process for ammonia waste treatment in the industry to obtain appropriate operating conditions and meet the wastewater standards issued by the Minister of the Environment. Data obtained during 10 days of operation were compared with the standards and analyzed for column efficiency. The results of the analysis showed that the waste output with a concentration of 13.9 - 49 ppm, a pH range of 8.7 - 9 and most of the waste discharge had met the standards, namely a maximum of 50 ppm and pH 6-9. The best gas-liquid ratio at the stripper inlet is 0.25 V / V and pressure has no significant effect on stripper efficiency.

Stripping process of TiAlN/TiSiN coating on WC-Co cemented carbide substrate by using the dry-electropolishing technique

Physical Vapor Deposition hard protective coatings are frequently applied to hardmetal cutting tools to extend their lifespan under service-like working conditions. However, these coatings may experience damage during their performance, such as wear. In addition, defective coatings during the production process can occur, requiring reconditioning. In this sense, provided that the coating has not chipped off, removing and recoating the tools is a crucial process for their reuse, ultimately reducing costs. This study investigates the stripping process of an industrial ternary system (TiAlN/TiSiN) coating deposited on WC-Co cemented carbide using the dry-electropolishing technique. X-ray photoelectron spectroscopy was used to analyze the electrochemical surface changes. Chemical analysis reveals that a layer of oxide is created during the stripping process, mainly composed of SiO2, TiO2, and Al2O3, as well as organic compounds (e.g.: pyrrodic group in aromatics C-(NH)-C) and nitrogen oxides (e.g.: pyrinidic O=N-C). The stripping process successfully removed the coating without damaging the WC-Co substrate or leaching metallic Co binder. Additionally, the process follows a linear trend, establishing a correlation between the time of dry-electropolishing applied and the remaining coating thickness.

Regulating Sodium Deposition Behavior by a Triple-Gradient Framework for High-Performance Sodium Metal Batteries.

An efficient method for the synthesis of a self-supporting carbon framework (denoted Gra-GC-MoSe2) is proposed with a triple-gradient structure-in sodiophilic sites, pore volume, and electrical conductivity-which facilitates the highly efficient regulation of Na deposition. In situ and ex situ measurements, together with theoretical calculations, reveal that the gradient distribution of Se heteroatoms in MoSe2, and its derivatives tailor the sodiophilicity, while the gradient distribution of porous nanostructures homogenizes the Na+ diffusion. Therefore, Na deposition occurs from the bottom to the top of the Gra-GC-MoSe2 framework without dendrite formation. In addition, the gradient in electrical conductivity ensures the stripping process does not lead to dead Na. As a result, a Gra-GC-MoSe2 modified Na anode (Na@Gra-GC-MoSe2) shows impressive cycling stability with a high average Coulombic efficiency in an asymmetric cell. In symmetric cells, it also exhibits a long cycling life of 2000h with a low polarization voltage and works stably even under a large capacity of 10mAhcm-2. Moreover, a Na@Gra-GC-MoSe2|| Na3V2(PO4)3 full cell delivers a high energy density with an excellent cycling performance.

Oriented Metal Stripping for Highly Reversible Zinc Anode.

Aqueous zinc metal batteries are a viable candidate for next-generation energy storage systems, but suffer from poor cycling efficiency of the Zn anode. Emerging approaches aim to regulate zinc plating behavior to suppress uncontrolled dendrites, while the stripping process is seldom considered. Herein, an oriented metal stripping strategy is demonstrated to stabilize the Zn anode by removing high-index facets for exposing the (002) plane through the addition of anionic additive sodium citrate (SC). Consequently, high-index facets that coordinate strongly with SC are preferentially stripped out due to a reduced stripping barrier, rendering stable (002) facet preponderant in epitaxial plating. After repeat stripping/plating, the ultra-high proportion of 93% for (002) and large-size grains of ≈100µm (six times larger than before) can be obtained. Zn anode shows continuous 25 000 cycles with low overpotential at 100mA cm-2 in symmetric cells and more than 70 h of stable operation even at an ultra-high depth of discharge of 92.3%. Moreover, an extremely long lifespan of 12 000 cycles at 10 A g-1 with a high capacity retention of 89% is achieved by the assembled Zn//I2 battery. This work provides a distinctive approach to improving the stripping process to design highly efficient zinc anodes for promising aqueous zinc metal batteries.

Selective recovery of transition metals from spent lithium-ion batteries leachate with Ni synergistic extraction system

Recycling spent lithium-ion batteries (LIBs) can not only generate ecological benefits but also realize low-carbon energy transition. Here, comprehensive recovery of transition metals from spent LIBs leachate using nickel (Ni) synergistic extraction system has been proposed. It was discovered that the combination of HEH(EH)P and Cyanex301 showed a strong synergistic extraction effect on Ni2+ and could also achieve the co-extraction of Ni2+, Co2+, Mn2+ after examining the extraction effects of single and mixed extractants of HEH(EH)P and Cyanex301. The mechanism of synergistic extraction of Ni2+ with mixed extractants was elucidate according to the slope analysis, FT-IR spectrometry and NMR spectrometry results. Then through a three stages of counter-current extraction process with 1.5 mol/L mixed extractant (XHEH(EH)P = 0.7, HEH(EH)P saponification degree of 60 %) and two stages of scrubbing process with 0.05 mol/L H2SO4, 99.18 % of Ni2+, 99.02 % of Co2+ and 99.93 % of Mn2+ were comprehensively recovered, while only 0.27 % of Li+ were lost. The Ni2+, Co2+, and Mn2+ loaded in the organic phase were entirely removed by a three stages of counter-current stripping process with HCl under O/A = 2.5/1. The synergistic extraction system still demonstrated outstanding reusability even after five cycles.

Magnesium Transfer between Atomic Force Microscopy Probes and Metal Electrodes in Aqueous Alginate Electrolytes.

The upcoming energy transition requires not only renewable energy sources but also novel electricity storage systems such as batteries. Despite Li-ion batteries being the main storage systems, other batteries have been proposed to fulfil the requirements on safety, costs, and resource availability. Moving away from lithium, materials such as sodium, magnesium, zinc, and calcium are being considered. Water-based electrolytes are known for their improved safety, environmentally friendliness, and affordability. The key, however, is how to utilize the negative metal electrode, as using water-based electrolytes with these metals becomes an issue with respect to oxidation and/or dendrite formation. This work studied magnesium, where we aimed to determine if it can be electrochemically deposited in aqueous solutions with alginate-based additives to protect the magnesium. In order to do so, atomic force microscopy was used to research the morphological structure of magnesium deposition at the local scale by using a probe-the tip of a cantilever-as the active electrode, during charging and discharging. The second goal of using the AFM probe technology for magnesium deposition and stripping was an extension of our previous study in which we investigated, for lithium, whether it is possible to measure ion current and perform nonfaradaic impedance measurements at the local scale. The work presented here shows that this is possible in a relatively simple way because, with magnesium, no dendrite formation occurs, which hinders the stripping process.

One-neutron stripping process in the 209Bi(6Li, 5Li)210Bi* reaction reaction

One-neutron stripping process in the 209Bi(6Li, 5Li)210Bi* reaction reaction

Microstructural Evolution and Mechanical Behavior of Pure Aluminum Ultra-Thin Strip under Roller Vibration

As the demand for lithium-ion batteries increases, higher quality requirements are being placed on pure aluminum ultra-thin strips, one of the main materials used in lithium-ion battery current collectors. Roller vibration during the rolling process of pure aluminum ultra-thin strips is unavoidable and significantly affects the quality of the strips. This paper uses 1A99 pure aluminum ultra-thin strips as raw materials and employs a controlled vibration method during the rolling process to obtain products under two conditions: stable rolling and vibrational rolling. The surface and cross-section of the aluminum strips were characterized using scanning electron microscopy (SEM), and the microstructure of the surface and cross-section was studied using electron backscatter diffraction (EBSD) technology. The results show that, during stable rolling, the surface quality of the aluminum strip is good without defects. Under vibration, obvious vibration marks appear on the surface of the aluminum strip, showing characteristics of peaks and troughs. With the increase in strain at the trough position, there is a transition from low-angle grain boundaries to high-angle grain boundaries, and the grain size is uneven at the peak and trough positions, with noticeable grain refinement at the troughs. At the same time, under the influence of vibration, the aluminum strip induces a different texture morphology from conventional rolling. Due to the different plastic strains at the peak and trough positions, a texture alternation phenomenon occurs at these positions. The tensile test results indicate that aluminum strips exhibit poor mechanical properties under roller vibration, with the reduction in mechanical performance primarily attributed to the uneven microstructure distribution caused by roller vibration.

Fusion and one-neutron stripping process for 6Li + 94Zr system around the Coulomb Barrier* *This research is supported by the National Nature Science Foundation of China (U2167204, 11975040, 1832130, 12375130), the Director's Foundation of Department of Nuclear Physics, China Institute of Atomic Energy 12SZJJ-202305. The Brazilian authors are grateful to the partial support from financial agencies FAPERJ, CNPq, and INTC-FNA

The complete and incomplete fusion cross section as well as one-neutron stripping process of 6Li + 94Zr system were measured at the energies around the Coulomb barrier by online γ-ray method. In addition to a 30% suppression factor when compared with the measured total fusion process, the complete fusion cross section in 6Li + 94Zr system was observed to be significantly lower than those in the nearby 6Li + 90, 96Zr system. The new experimental result implies that the coupling with breakup channel in the 6Li-induced fusion processes can be affected by the inner structure of the target, which is still not clear in any available model calculation. For the one-neutron stripping process, the direct production cross sections for each level in 95Zr were extracted and compared with the coupled reaction channel calculation, offering a unique opportunity to examine the single-particle nature of the produced excited states. Given the fact that an overall overestimation of the production cross section for 954-keV and 1618-keV levels was observed in the comparison, further investigation is highly demanded in order to understand the full reaction mechanism for the one-neutron stripping process induced by 6Li.

Analysis of the Asymmetrical Rolling of Ultra-Thin Strips Considering Elastic Deformation of the Strips.

In normal cold rolling, the elastic deformation of the strip is typically ignored because of the dominant plastic deformation. However, this neglect may introduce additional errors when the strip is very thin. The aim of this study is to investigate the characteristics of the deformation region and thickness reduction in the asymmetrical rolling of ultra-thin strips. Mathematical models were developed based on the slab method, with consideration of the elastic deformation of the strips, and employed in the simulation calculation. The percentage of the three zones and the thickness reduction were analyzed using the simulation results. An increase in the speed ratio results in an increase in the reduction ratio, which is influenced by parameters, such as front tension, back tension, friction coefficient, and entry thickness. The elastic deformation of the strip reduces the tension and the roll pressure and causes the reduction ratio to decrease. The findings and conclusions of this study may be helpful to the mill operating in the asymmetrical rolling process of ultra-thin strips.

Q-learning based scheduling method for continuous pickling process of titanium strips

This article addresses the energy consumption optimization problems of the pickling process for titanium strip manufacturing. The hybrid flow shop scheduling schemes for the pickling process of titanium strips are designed, and a novel shop scheduling method based on reinforcement learning is proposed for the pickling process of titanium strips. In the scheduling scheme, the pickling chemical treatment process of titanium strips are described as an asymmetric hybrid flow shop scheduling problem (AHFSP), and a mathematical model containing a temperature structure is established with the optimization objectives of minimizing pickling time and energy consumption. Based on the proposed scheduling scheme, a novel shop scheduling method based on reinforcement learning for the titanium strip pickling process is proposed. First, a mixed integer linear programing model for the mixed flow shop scheduling problem is established. Second, the flow shop scheduling problem with sequential energy consumption decisions is approximated as an asymmetric traveling sales-man problem (ATSP). Finally, the ATSP is described as a Markov decision processes (MDP), and a Q-learning based scheduling method for titanium strip pickling shops is proposed. Finally, the effectiveness of the proposed method is verified by examples, and the scheduling scheme can reduce the energy consumption by 16.61% on average while maintaining the schedule, which improves the productivity and economic efficiency.

Pulsed current-assisted twelve-roll precision rolling deformation of SUS304 ultra-thin strips with exceptional mechanical properties

Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips. The results show that in the first rolling pass, the rolling reduction rate of a conventionally rolled sample (at room temperature) is 33.8%, which can be increased to 41.5% by pulsed current-assisted rolling, enabling the formation of an ultra-thin strip with a size of 67.3 μm in only one rolling pass. After three passes of pulsed current-assisted rolling, the thickness of the ultra-thin strip can be further reduced to 51.7 μm. To clearly compare the effects of a pulsed current on the microstructure and mechanical response of the ultra-thin strip, ultra-thin strips with nearly the same thickness reduction were analyzed. It was found that pulsed current can reduce the degree of work-hardening of the rolled samples by promoting dislocation detachment, reducing the density of stacking faults, inhibiting martensitic phase transformation, and shortening the total length of grain boundaries. As a result, the ductility of ultra-thin strips can be effectively restored to approximately 16.3% while maintaining a high tensile strength of 1118 MPa.Therefore, pulsed current-assisted rolling deformation shows great potential for the formation of ultra-thin strips with a combination of high strength and ductility.

Optimization of Ammonia Nitrogen Removal and Recovery from Raw Liquid Dairy Manure Using Vacuum Thermal Stripping and Acid Absorption Process: A Modeling Approach Using Response Surface Methodology

Dairy manure adds a substantial amount of nitrogen to wastewater due to its high levels of associated nutrients. Removal and recovery of ammonia nitrogen (NH3-N) from raw liquid dairy manure (RLDM) is greatly valued. This study was focused on the vacuum thermal stripping–acid absorption (VTS-AA) process for NH3-N from RLDM, followed by modeling and optimization. Using the response surface methodology (RSM)-based central composite design (CCD) approach, the critical operational parameters of the vacuum thermal stripping process, including temperature (50–70 °C), pH (9–11), vacuum pressure (35–55 kPa), and treatment time (60–90 min), were optimized. With the specified parameters set at temperature 69.9 °C, pH 10.5, vacuum pressure 53.5 kPa, and treatment time 64.2 min, the NH3-N removal efficiency attained was 98.58 ± 1.05%, aligning closely with the model prediction. Furthermore, the recovered ammonium sulfate ((NH4)2SO4) closely matched their commercial counterparts, confirming the effectiveness of the VTS-AA process in recovering NH3-N from RLDM. The distinct advantage of the employed technology lies in the concurrent energy demand reduction achieved by introducing a vacuum system. These findings contribute valuable insights into the practical implementation of the VTS-AA process for treating raw dairy manure, particularly in large-scale operational contexts.

Towards reusable 3D-printed graphite framework for zinc anode in aqueous zinc battery

Aqueous zinc ion batteries (AZIBs) are an increasingly popular high-safety and eco-friendly energy storage solution. However, the development of high-performance zinc (Zn) anodes remains a formidable challenge, primarily due to dendrite formation and poor reversibility. To address these challenges, this study harnesses the potential of digital light process (DLP) 3D printing technology to fabricate reduced graphite oxide-based 3D gyroid structure (3DP-rGG) as zinc anode frameworks for aqueous zinc batteries. The 3D-printed structure effectively regulates local current density distribution, offering ample nucleation sites and free space for inducing uniform zinc deposition and accommodating diminutive zinc nodules. Consequently, the 3D-printed graphite framework demonstrates remarkable reversibility in zinc plating and stripping processes, resulting in commendable coulombic efficiency and low voltage hysteresis. The full battery with a 3D-printed zinc anode, incorporating a polyaniline-intercalated vanadium oxide cathode (PVO), exhibits high specific capacity and superior long-term cycling stability. Remarkably, the robust 3DP-rGG structure can be reused over ten times without any discernible impact on its electrochemical performance, thereby underscoring the potential of this controllable and efficient fabrication of 3D graphite current collectors as a promising solution to develop reusable 3D frameworks for high-performance metal batteries.

Recovery of vanadium from high-iron chlorination titanium-white waste acid using D2EHPA/iso-octanol: From laboratory to pilot test

The D2EHPA extraction − H2O2 stripping process offers a significant advantage over traditional methods for recovering vanadium (V) by eliminating the generation of ammonia-containing wastewater. However, the main challenge in industrial settings is the rapid decline in stripping efficiency due to the instability of peroxides. For instance, the efficiency can decrease from 80 % to 40 % within 4 min. To address this issue, the iso-octanol was added to the organic phase as a modifier to reduce the coordination ability of P = O in interacting with V, thereby lowering the decomposition rate of VO(O2)2- and lengthening the duration of peak stripping efficiency. A novel method of organic phase pre-oxidation and stepwise addition of H2O2 was introduced to further stabilize the stripping process. In optimal conditions, the V stripping efficiency can reach 98.16 % through a 3-stage counter-current process, while reducing the amount of H2O2 by approximately 50 % compared to a single-time addition. Furthermore, the organic phase was successfully regenerated with 6 mol/L HCl after stripping. The main impurity Fe was removed with an efficiency of 92 %, allowing for the organic phase recycling. The process produced the end-product V2O5 (>99 %) by heating hydrolysis of the stripping liquor and roasting of the hydrolysis precipitate. Overall, this method provides a complete recovery process for V from high-iron chlorination titanium-white waste acid (CTWA), which is characterized by its efficiency, environmental friendliness, and short process. These results could serve as a valuable reference for the industrialization of the H2O2 stripping process.

Quasi In Situ Study on the Slipping Behavior and Residual Stress of Copper Strip

The preparation method of integrated circuit lead frames has transitioned from stamping to etching, rendering them more sensitive to residual stress. Consequently, the dimensional deviations caused by residual stress become more pronounced, necessitating a thorough investigation into the copper strip processing process, particularly considering the high-precision requirements of the lead frame. A quasi in situ method was employed to monitor the deformation process, and quantitative analyses and graphical reconstructions of the residual stress were conducted. The results indicated that the orientation evolution did not exhibit a significant correlation with grain size or grain aspect ratio. However, the stored energy of the different grains was related to their orientations. Further analysis of slip traces revealed that single or multiple slipping may be activated in grain subdivisions, and the Schmid factor difference ratio (SFDR) value proved to be an effective tool for analyzing this deformation mode. An even more interesting finding was that the deformation mode directly affected the residual stress distribution in local regions. The relationship between residual stress, Schmid factor, and SFDR was further analyzed, and a clear correlation between SFDR and residual stress was found in this study.

Calculation method and analysis of residual stress in the strip bending roller straightening process

Taking thin gauge strip as an example, the deformation process of metal strip in bending roll straightening was studied. Based on the theory of discrete, curvature integral and elastic–plastic mechanics, the strip travel trajectory of the bending roll straightening process is analyzed, and the numerical analytical calculation method of the continuous straightening process of the strip bending roll is established. The results are verified by establishing MARC finite element simulation and designing straightening experiment. The effects of yield strength, plastic rate and bending amount on residual stress after straightening were studied. In the straightening process, with the increase of the amount of bending roll, the residual strain converges to the region Γ, and with the increase of the yield strength, the region Γ decreases. With the increase of the yield strength, the amount of bending roll and the plastic rate, the wave height increases. The results of the calculation of residual stress, finite element simulation and experiment are close and the trend is consistent. The results show that the logic of the calculation method is reasonable, and the prediction error is within the scope of engineering application, which is helpful to the realization of process intelligence in the process of bending roller straightening.

Experimental study on the mechanism and thermodynamics of extraction of Fe3+ from phosphoric acid solution

The new extractant (P12) was used to remove Fe3+ from the simulated liquid of wet process phosphoric acid in this work. The solubility of P12 in white oil under the action of P204(Di-(2-ethylhexyl) phosphate) and n-octanol is discussed in detail. Then, the effects of reaction temperature, reaction time, the volume ratio of extraction phase and aqueous phase (O: A), pH of the phosphoric acid solution(simulated solution) and various anions on the extraction process were discussed. The extraction efficiency increases with the increase of extractant P12, the decrease of pH and the increase of O: A. Under the condition of pH=0.2, O: A= 1:1, the extraction efficiency of P12=5 %, 7 % and 9 % can be up to 70.86 %, 81.84 % and 90.93 % respectively. The extraction mechanism and extract composition were determined by slope method, FTIR and SEM. The ΔH< 0, ΔG< 0, ΔS < 0 in the extraction process proves that the extraction process was a spontaneous and exothermic process. The extraction mechanism proves that the extraction process involves both cation exchange and complexation of extractant. The composition of the extract may be [Fe(H2PO4)2.4A0.6(HA)0.84(H2O)](o), [Fe(H2PO4)2.2A0.8(HA)1.12(H2O)](o). And stripping efficiency of 5.5 M HCl can reach 100 % at A: O=4:1, ΔH=38.9357 kJ/mol in stripping process prove that it is endothermic.

Prediction and control of profile for silicon steel strip in the whole tandem cold rolling based on PSO-BP algorithm

In the rolling process of silicon steel strip of the five-stand UCMW tandem cold rolling line, the quality of finished profile is the result of cooperative control of five stands, the exit profiles of the first four stands jointly decide the exit profile of the fifth stand, so it is necessary to accurately control the strip profile in the rolling process. However, the shapemeter is only typically equipped at the exit of fifth stand, making it impossible to obtain the strip profile of the first four stands. A profile prediction model for the whole tandem cold rolling based on PSO-BP algorithm is established, compared with the finite element method, this model can satisfy the demand for fast prediction of strip profile and quickly analyzing the profile change characteristics for five stands according to the adjustment of profile control parameters in the industrial field. Firstly, a 3D elastic-plastic finite element model of rolls and strip for five stands is built, and a large number of profile calculation data are as the training sample sets to build the PSO-BP model. Through the transfer calculation of strip profile between adjacent stands, the PSO-BP model of five stands is established, and the validity is verified by comparing with the actual measured data. Secondly, to improve the quality of product profile, focusing on the unreasonable setting of production parameters, many improvement schemes of WRB and WRS for five stands are designed, and the PSO-BP model is used to quickly calculate the strip profile, then comparing the result of each scheme, the optimum improvement scheme is selected, which is furtherly carried out rolling experiments in the industrial field, and the quality of strip profile is well improved. At present, the new scheme has been successfully applied to industrial production.

Characterization of a two-step laser paint stripping process on CFRP

This work presents a two-step non-destructive method for cleaning the surface paint of CFRP. The method combines ablation and vibration, using a pulsed laser with a wavelength of 1064 nm. The effects of laser power, beam and path overlap rate on the removal of paints are investigated. The analysis focuses on the cleaning and the damage threshold of the paints and fibers. Additionally, the study analyzed the thermal accumulation effect and fiber damage resulting from various laser parameters. The cleaned samples were analyzed for micro-morphology, elemental composition, surface roughness, three-dimensional morphology, and contact angle to demonstrate the modulation of derivatization phenomena of CFRP surface paints under different cleaning states using this method. This points to the reliability and feasibility of the relevant treatment parameters and provides a reference for the subsequent research on the practical application of laser cleaning.