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Optimization of chemical precipitation for valuable metal recovery from spent lithium nickel manganese cobalt oxide batteries
(2026-05-01)
Morawan, Nattaya
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Kruthun, Orathai
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Katers, John F.
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Attaphong, Chodchanok
This study investigated the optimized conditions for chemical precipitation to recover nickel manganese cobalt hydroxide (NiCoMn-OH) and lithium carbonate (Li<inf>2</inf>CO<inf>3</inf>) from spent lithium nickel manganese cobalt oxide (sLi-NMC) batteries. The research focused on establishing optimized conditions to maximize recovery efficiency and product purity. The process involved dismantling and incinerating the batteries to produce black powder, followed by acid leaching using H<inf>2</inf>SO<inf>4</inf> and H<inf>2</inf>O<inf>2</inf>, and a two-step precipitation to recover NiCoMn-OH and Li<inf>2</inf>CO<inf>3</inf>. Results indicated that the optimized incineration conditions for efficient black powder production were 600 °C for 30 min. During the leaching process, the optimized extraction of lithium, nickel, cobalt, and manganese was achieved using 1 M H<inf>2</inf>SO<inf>4</inf> with 2% H<inf>2</inf>O<inf>2</inf> at a liquid-to-solid ratio of 30:1 mL/g. In the first precipitation stage, the optimized conditions for co-precipitating the solid NiCoMn-OH using saturated NaOH were identified as pH 10, 25 °C, and a contact time of 90 min. The results showed that nickel, manganese, and cobalt were precipitated at 92.04%, 90.35%, and 86.78%, respectively (a purity of 98.67%). Finally, lithium was successfully recovered as Li<inf>2</inf>CO<inf>3</inf> using saturated Na<inf>2</inf>CO<inf>3</inf>, at pH 12, 100 °C, and a contact time of 120 min up to 96.51% (a purity of 98.98%). Ultimately, the optimized conditions obtained from this study can provide valuable data for waste management and serve as a comparative baseline for environmental impact assessment of conventional metal recovery, enabling direct comparisons with optimized alternative methods in future research.
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Multi-temporal scale of urban rainfall in the Eastern Northeast based on observed data and gridded products: physiographic factors and changes in land use and occupation
(2026-02-01)
da Silva, Luis Felipe Francisco Ferreira
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de Oliveira Romão, William Max
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Lyra, Gustavo Bastos
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da Silva, Elania Barros
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da Silva Costa, Micejane
Rainfall is one of the most important meteorological variables in the daily lives of urban populations. The city of Maceió, the capital of Alagoas, located in the eastern part of the Northeast of Brazil (ENEB), has 50 neighborhoods and a population of approximately one million people, with few studies on the subject. The objectives were: (i) to validate the CHIRPS product; (ii) to identify the preferential rainfall periods in Maceió via GIS; (iii) to map areas for the installation of in situ stations in the city with the aim of supporting the prevention of hydrometeorological disasters; and (iv) creation of a theoretical-conceptual rainfall model. The statistical indicators (R², ρ, BIAS, MAPE and RMSE) were used to validate the gridded precipitation product CHIRPS from 11 CEMADEN rain gauge stations. Monthly rain occurrence maps via Spline tension were developed by QGIS (Quantum GIS) software. The HAND model was applied at neighborhood level for the assessment of urban floods. Waterborne disease data were obtained from SINAN, Natural Disaster data via S2iD from the period 2000 to 2023, and the NDVI and EVI indices in the years 2015 and 2022 were evaluated in the study. All stations were monotonically positive (ρ > 0.65) and significant (p-value < 0.001), indicating that CHIRPS is able to capture rainfall variability despite the influences of the coast, Lagoa Mundaú, and topography. Most stations showed underestimation (negative BIAS) and lower errors (MAE and RMSE). Spatially, the increase in rainfall on the coastal plateau is due to the interaction of the wind regime with the relief, driven by the circulation of breezes and the influence of trade winds. The preferential rainfall period occurs between 04:00 am and 07:00 am. The HAND model identified very high and high susceptibility, mainly on the coast, in areas adjacent to Lagoa Mundaú, and in neighborhoods crossed by rivers and urban canals, and low susceptibility in densely populated neighborhoods. Waterborne diseases together with transformations via NDVI and EVI indicated that rainfall amplifies risk scenarios for the most vulnerable and densely populated populations. In light of this, it is perceived that the rainfall patterns in Maceió are due to the interaction of physiographic and/or anthropogenic factors and meteorological systems – theoretical-conceptual model – which requires improvements in infrastructure and an active monitoring system.
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Rainfall variability, land use and land cover dynamics, and implications for climate risk through a theoretical-conceptual model for the Eastern Northeast of Brazil
(2025-06-01)
da Silva Costa, Micejane
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Francisco de Oliveira Júnior, José
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Godoy de Barros, Bárbara
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Francisco Ferreira da Silva, Luís Felipe
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Alencar Cardoso, Kelvy Rosalvo
The study assessed the variability of rainfall, land use and land cover (LULC), the influence of meteorological systems and their interactions, followed by the increase in climate risks in Maceió – Alagoas – ENEB. Monthly rainfall data were obtained from the 64-year historical series (1958–2022) of the TerraClimate platform. The TerraClimate precipitation data were validated ANA and SEMARH data, resulting in R2 = 0.72 and r = 0.85. Spatially, the highest rainfall accumulations occurred from April to July (rainy season), with May and June being the wettest months (>800 mm). In contrast, the months from October to February (dry season) and March, August, and September (transition season) recorded lower rainfall, with November and December being the driest months (150–201 mm). The seasonal occurrence of rainfall and the relief in Maceió were associated with areas of climate risk. Maceió is a region vulnerable to extreme rainfall events due to its geographical location, the influence of the Atlantic Ocean and the Mundaú/Manguaba Lagoons, and the interaction with multi-scale meteorological systems. With LULC, there was an expansion of forest areas in rural areas and a reduction of agricultural areas, followed by increased urbanization in neighborhoods in the western part of the city (coastal plateau). The theoretical-conceptual model of climate risk provides essential information for planning and supports decision-making for public policies. The ability to assess the impacts of extreme rainfall underscores the importance of adaptive responses by local communities through the management of public policies and strategies for adapting to climate risk.
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Precipitation hardening and structure evolution in hypereutectic Al-6 % Fe-Zr alloys subjected to ultrasonic melt processing
(2024-01-05)
Chankitmunkong, S.
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Wang, F.
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Pandee, P.
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Limmaneevichitr, C.
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Eskin, D. G.
The objective of this research was to study the influence of Zr concentration and ultrasonic melt processing (USP) on the microstructure and precipitation hardening of a hypereutectic Al-6% Fe alloy. Such alloys have a good potential in high-temperature, wear-resistant, and conducting applications but suffer from coarse structure and low strength/ductility, which prevents their processing. The microstructure of the studied alloys consisted of primary Al<inf>13</inf>Fe<inf>4</inf> intermetallics and (Al)+Al<inf>13</inf>Fe<inf>4</inf> eutectic colonies, which were successfully refined by adding Zr and performing USP. The mechanisms of USP and Zr were confirmed for the Al-6 % Fe alloys with a range of Zr additions. The structure refinement led to improved hardness and tensile properties of the alloys. All studied alloys demonstrated strong precipitation hardening effect with hardness increasing 4–5 times, reaching 170 HV for the alloy with 0.4 % Zr after annealing at 400 ℃ for 20 hrs. The electrical conductivity increased from 25 % IACS in the as-cast alloy to 40% IACS in the annealed Al-6% Fe-0.4 % Zr alloy. The prime novelty of this work is a considerable increase of hardness upon annealing, i.e. more than 100 HV, in the Al-6 % Fe alloy with only minute traces of Zr (<0.01 %). The precipitation phenomena were investigated by transmission electron microscopy. The precipitation of the semi-coherent Al<inf>13</inf>Fe<inf>4</inf> phase with Zr segregated to its surface was observed for the first time. All studied alloys (with minute and larger Zr additions) showed the precipitation of this phase, while the alloys with the larger amount of Zr also demonstrated the precipitation of the metastable L1<inf>2</inf> Al<inf>3</inf>Zr phase. Therefore, the properties improvement was attributed to the structure refinement and the formation of Zr-modified Al<inf>13</inf>Fe<inf>4</inf> and Al<inf>3</inf>Zr precipitates in the microstructure.
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Electrical mechanisms of bi-stable memory devices based on an Al/PVK:ZnO NPs/ITO structure with different ZnO NPs annealing temperatures
(2016-10-01)
Onlaor, Korakot
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Chaithanatkun, Natpasit
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Tunhoo, Benchapol
We reported on the influence of the structural properties of zinc oxide nanoparticles (ZnO NPs) on electrical bi-stable device based on an aluminum/poly(9-vinylcarbazole):ZnO NPs/indium-tin oxide structure. ZnO NPs were synthesized by simple precipitation method with different annealing temperatures. When annealing temperature was increased, the ZnO NPs crystallite increased and the ZnO NPs gradually changed shape from nanostar-like to nanospherical. The structural parameters, such as the crystallite size of ZnO NPs and dislocation density, can be calculated from the XRD spectra. The effect of ZnO NPs annealing temperature on memory properties can be measured by current-voltage characteristics and retention time measurements. The maximum ON/OFF current ratio for the memory devices was about 103 and the devices exhibited the Write-Once, Read-Many (WORM) memory type. The operating mechanisms of the memory device were analyzed using theoretical models, in which electrons trapping in the ZnO NPs and electrons tunneling among a PVK matrix by direct tunneling process were discussed.
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Low-temperature preparation of BaCeO3 through ultrasonic-assisted precipitation for application in solid oxide electrolysis cell
(2015-06-20)
Kim-Lohsoontorn, P.
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Paichitra, C.
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Vorathamthongdee, S.
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Seeharaj, P.
Barium cerate (BaCeO<inf>3</inf>) was synthesized using conventional precipitation and ultrasonic-assisted precipitation. The effect of precipitation parameters (precipitation precursor, precipitation agent, agent concentration and temperature) significantly affected %perovskite formation and crystallite size of the product. Precipitation with 1 M (NH<inf>4</inf>)<inf>2</inf>C<inf>2</inf>O<inf>4</inf> induced the formation of a single-phase BaCeO<inf>3</inf> while precipitation with 5-20 M NaOH provided a mixed phase of BaCeO<inf>3</inf> and CeO<inf>2</inf>. The %perovskite increased as increasing precipitation temperature; however, the crystallite size of the product also increased. Increasing ultrasonic intensity (30 and 150 W cm-2) during precipitation was found to increase the %perovskite and to reduce crystallite size. The precipitation with 1 M (NH<inf>4</inf>)<inf>2</inf>C<inf>2</inf>O<inf>4</inf> agent, using ultrasonic intensity at 150 W cm-2, provided single phase BaCeO<inf>3</inf> with crystallite size of 18.4 nm after calcination at 900 °C for 4 h. The electrochemical performance of the BaCeO<inf>3</inf> cell under steam electrolysis condition (controlled voltage from OCV to 1.5 V; 20% H<inf>2</inf>O, 40% H<inf>2</inf>, and 40% N<inf>2</inf>) was measured (600-800 °C) and the activation energy of conduction was calculated to be 0.78 eV.
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Sb-doped SnO2 nanoparticles synthesized by sonochemical-assisted precipitation process
(2015-02-01)
Noonuruk, Russameeruk
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Vittayakorn, Naratip
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Mekprasart, Wanichaya
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Sritharathikhun, Jaran
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Pecharapa, Wisanu
Sb-doped SnO<inf>2</inf> nanopowders were synthesized by sonochemical-assisted precipitation process using stannic chloride pentahydrate (SnCl<inf>4</inf> · 5H<inf>2</inf>O) and antimony chloride (SbCl<inf>3</inf>) as starting precursors. Effect of sonication and Sb doping concentrations on physical structures and electrical properties of Sb-doped SnO<inf>2</inf> nanoparticles were investigated by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Raman spectroscopy and two-point probe method. The results indicated that the good dispersion with less agglomeration of particles in SnO<inf>2</inf> phase can be obtained by single step sonochemical-assisted process. Moreover, XRD results indicated that the crystallinity of Sb-doped SnO<inf>2</inf> nanopowders deteriorated with increasing Sb content, suggesting that Sb dopant significantly prevent SnO<inf>2</inf> crystallite growth. The XPS spectra of Sb-doped SnO<inf>2</inf> obviously confirmed the existence of Sb ion incorporated into SnO<inf>2</inf> matrix. These results revealed that incorporation of Sb ions into SnO<inf>2</inf> lattice with specific concentration has significant influence on formation and crystallization and can dramatically enhance the conductivity of tin oxide.
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Precipitation above cloud point in palm oil based biodiesel during production and storage
(2014-04-15)
Na-Ranong, Duangkamol
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Kitchaiya, Prakob
Precipitation of a white solid in palm oil based biodiesel (PO-B100) can be found even in PO-B100 that contains minor contaminants (i.e. mono-, di- and triglycerides) within the limitation according to EN-14214 and Thailand's regulation. To identify compounds causing this precipitation, the precipitates collected at the temperature near cloud point and at room temperature were characterized using a gas chromatograph-flame ionization detector, gas chromatograph-mass spectrometry and fourier transform-infrared. The result indicated that the compounds causing the precipitation were steryl glucosides, not glycerides, regardless of temperature. Therefore, effect of steryl glucosides on precipitation time was further investigated using PO-B100s with different amounts of steryl glucosides, mono-, di- and triglycerides. The result revealed that precipitation time of the PO-B100 with high concentration of steryl glucosides was much less than the one without steryl glucosides and decreasing steryl glucosides concentration to 20 ppm significantly improved storage stability of PO-B100. In addition, the precipitation time was not influenced by concentration of mono-, di- and triglycerides. © 2014 Elsevier Ltd. All rights reserved.
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SnO2 nanoparticle synthesized by ultrasonic-assisted process
(2013-10-08)
Noonuruk, Russameeruk
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Mekprasart, Wanichaya
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Wongpisutpaisan, Narongdet
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Vittayakorn, Naratip
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Pecharapa, Wisanu
SnO<inf>2</inf> nanoparticles were synthesized by ultrasonic-assisted precipitation process using stannic chloride pentahydrate (SnCl<inf>4</inf>·5H<inf>2</inf>O) as a precursor. The stannic chloride aqueous solution was precipitated by ammonia under sonication. The as-synthesized precipitates were dried at 80 °C and then calcined at 400 °C for 2 h. The physical properties of nanoparticles with/without sonication were characterized by thermogravimetic and differential thermal analysis, X-ray diffraction, and transmission electron microscope. The results reveal that ultrasonic radiation has significant influence on phase transformation mechanism from Sn(OH)<inf>4</inf> to SnO<inf>2</inf>, grain size and uniformity of SnO<inf>2</inf> nanoparticles. © (2013) Trans Tech Publications, Switzerland.

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