Hydrothermal synthesis of boehmite and α-alumina from Bayer’s alumina trihydrate

Panda, P. K.; Jaleel, VA; Devi, S. Usha

doi:10.1007/s10853-006-0771-7

Cited by 25 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…(xerogel/aerogel (106), emulsión-evaporación (107-109), tratamiento termal (90,110,111) , microondas (112), secado por atomización (113), liofilización (114), spray-pirólisis (115)) o basadas en procesos electroquímicos, como el anodizado de aluminio (116,117).…”

Section: Obtención De Alúminaunclassified

Alúminas porosas: El método de bio-réplica para la síntesis de alúminas estables de alta superficie específica

Guerrero¹,

Maqueda²,

Castro³

et al. 2013

Bol. Soc. Esp. Ceram. Vidr.

View full text Add to dashboard Cite

INTRODUCCIÓNEn general, la síntesis de estructuras cerámicas porosas con una alta estabilidad térmica y de elevada resistencia, tanto física como química, atraen cada vez una mayor atención en multitud de áreas, especialmente en tecnologías relacionadas con la energía y medioambiente, como separadores gas/líquido, filtros, electrodos porosos para celdas de combustible de óxido sólido (SOFCs), soportes de catalizadores, membranas de micro y ultrafiltración, sensores químicos, así como también en sistemas de aireación de líquidos, sistemas de intercambio iónico, diálisis, separación cromatográfica, sistemas optoelectrónicos, liberación controlada de fármacos y biomateriales para implantes (1-4).En concreto, las cerámicas porosas de alúmina, por sus excelentes propiedades intrínsecas (bajo peso específico, elevada superficie específica, alta permeabilidad y estabilidad térmica, resistencia a la corrosión) y su bajo coste de producción, presentan un gran interés tecnológico en diversos campos. Destaca su empleo como refractarios, como membranas de separación (5-7) usadas por ejemplo en componentes de filtros de metales fundidos (8) y de gases de alta temperatura (9), y como membranas catalíticas (10) encontrando utilidad tanto en la eliminación de compuestos contaminantes de efluentes gaseosos (11-13) como del agua En las últimas décadas el desarrollo de alúminas porosas viene siendo objeto de numerosas investigaciones por las propiedades intrínsecas que tiene el óxido de aluminio, como elevado punto de fusión, baja conductividad térmica, inercia química y resistencia a la corrosión, a las que se unen una elevada superficie específica y permeabilidad, que hacen que encuentren aplicación en multitud de sectores industriales y técnicos. En aquellos procesos en los que intervengan temperaturas altas, la estabilidad cristalográfica y textural de las alúminas adquiere una importancia significativa; sin embargo, la mayoría de los métodos de preparación conducen hacia la generación de óxidos metaestables, que no encuentran aplicabilidad en procesos de elevada temperatura debido a su transformación hacia la fase alfa, con la consiguiente reducción de superficie. El presente artículo realiza una revisión de distintas vías de obtención de alúmina porosa de elevada superficie específica, incluyendo los métodos y estrategias que han tenido por objeto la síntesis de alfa-alúmina de alta superficie. Dentro de este marco, el trabajo analiza los resultados obtenidos hasta el momento a través de la bio-réplica de lignocelulósicos, tecnología que permite mimetizar con exactitud la compleja jerarquía estructural de las máscaras hasta diferentes niveles. Porous Aluminas: The biotemplate method for the synthesis of stable high surface area aluminas Development of porous alumina has been the objective of numerous studies in recent decades, due to the intrinsic properties of aluminium oxide, such as high melting point, low thermal conductivity, chemical inertness and corrosion resistance which, in addition to a high surface area and perme...

show abstract

Section: Obtención De Alúminaunclassified

Alúminas porosas: El método de bio-réplica para la síntesis de alúminas estables de alta superficie específica

Guerrero¹,

Maqueda²,

Castro³

et al. 2013

Bol. Soc. Esp. Ceram. Vidr.

View full text Add to dashboard Cite

show abstract

“…Hydrothermal synthesis has advantages such as direct powder formation, particle size and particle shape can be controlled with different feed sizes and conditions, high reactivity of the resulting powder [16]. Boehmite can be synthesized from several kinds of materials, such as Aluminum nitrat (Al(NO3)3) [17], Aluminum clorida (AlCl3) [18], Aluminum tri-sec-butoxide (ATB) [19] and Aluminum trihydrate (ATH) [20][21] [22]. Boehmite produced by hydrothermal conversion of ATH for the first time, while ATH is an inexpensive and readily available raw material, because the yearly world production of gibbsite is millions of tons [9] According to Panda, et al [20] boehmite can be formed from ATH with particle size 80-100 μm under hydrothermal conditions at higher temperature (≥ 350 °C) and pressure .…”

Section: Introductionmentioning

confidence: 99%

“…Boehmite can be synthesized from several kinds of materials, such as Aluminum nitrat (Al(NO3)3) [17], Aluminum clorida (AlCl3) [18], Aluminum tri-sec-butoxide (ATB) [19] and Aluminum trihydrate (ATH) [20][21] [22]. Boehmite produced by hydrothermal conversion of ATH for the first time, while ATH is an inexpensive and readily available raw material, because the yearly world production of gibbsite is millions of tons [9] According to Panda, et al [20] boehmite can be formed from ATH with particle size 80-100 μm under hydrothermal conditions at higher temperature (≥ 350 °C) and pressure . Al'myasheva et al [21] used hydrothermal to produced boehmite from amorphous ATH at higher temperatures (350 -450°C) and pressure (2-70 MPa).…”

Section: Introductionmentioning

confidence: 99%

Synthesis of boehmite from aluminum trihydrate through facile hydrothermal method

Chamida

Rois

Widiyastuti

et al. 2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Boehmite (g-AlOOH) has demonstrated to have superior performance as coating material for battery separator, especially lithium-ion battery, due to its excellent wetting ability and thermal stability. The products of Bayer process from bauxite are typically in the form of aluminum trihydrate (ATH). Observing the phase diagram of Al2O3-H2O, it was assumed that the ATH might be converted into boehmite by controlling the pressure and temperature under hydrothermal condition. Therefore, the purpose of this work is to investigate the effect of operating conditions on the conversion of ATH to boehmite in a hydrothermal reactor. The experiments were carried out in a 100-mL hydrothermal reactor with a liquid filling volume of 30% and 50%. The reaction time was varied from 2 to 8 h. The hydrothermally treated ATH particles were characterized by an X-ray diffraction (XRD) and a scanning electron microscopy (SEM). The XRD patterns exhibited that the ATH has not been converted yet into boehmite at a reaction time of 2 h for all conditions. When the reaction time was prolonged to 4 h, ATH was transformed into boehmite at filling volume of 30% and 50%. It appears that liquid filling volume influences the transformation of ATH into boehmite. As observed by the SEM images, the morphology of particles also changed by the change of the crystalline phase. The particles changed from nearly spherical-shaped to cube and the particle size was typically larger

show abstract

“…α-alümina sentezinde mekanik öğütme, buhar fazı reaksiyonu, çöktürme, sol-jel, hidrotermal sentez ve yakma metodu gibi çeşitli yöntemler bilinmektedir [11][12][13][14][15][16][17]. Bu yöntemlerin hemen hepsinde kendine has sınırlayıcı özellikler bulunmaktadır.…”

Section: Gi̇ri̇ş (Introduction)unclassified

“…Literatürde faz dönüşüm sıcaklıkları ile ilgili çeşitli sıcaklıklar verilmekle birlikte genel kabul: Bohmit→ γ (300°C); γ →δ (850°C); δ → θ (1100°C); θ → α (≥1200°C) şeklinde gösterilebilir [7][8][9][10]. α-alümina sentezinde mekanik öğütme, buhar fazı reaksiyonu, çöktürme, sol-jel, hidrotermal sentez ve yakma metodu gibi çeşitli yöntemler bilinmektedir [11][12][13][14][15][16][17]. Bu yöntemlerin hemen hepsinde kendine has sınırlayıcı özellikler bulunmaktadır.…”

Section: Gi̇ri̇ş (Introduction)unclassified

PEG-400 Destekli Alumina Sentezi, Karakterizasyonu ve Morfolojik Özelliklerin İncelenmesi

Vural

Sarı²

2018

Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım Ve Teknoloji

View full text Add to dashboard Cite

ÖzBu çalışmada hidrotermal sentez yöntemi kullanılarak PEG-400 destekli α-alümina (α-Al 2 O 3 ) sentezi başarılı şekilde gerçekleştirilmiştir. Yapı düzenleyici ajan olarak kullanılan PEG-400'ün parçacık boyutuna etkileri araştırılmıştır. Sentezlenen tozların yapısal karakterizasyonu XRD, Raman ve FTIR yöntemleri kullanılarak gerçekleştirilmiştir. Termal özelliklerin araştırılmasında TGA yöntemi kullanılmıştır. Morfolojik özellikler ise SEM yöntemi kullanılarak araştırılmıştır. Çalışmanın sonuçları yapı düzenleyici ajan kullanılmadan gerçekleştirilen deneyle karşılaştırıldığında daha küçük boyutlarda saf α-Al 2 O 3 elde edildiğini göstermektedir. AbstractIn this study, α-alümina structures are successfully prepared via hydrothermal synthesis supported with PEG-400. The effect of the PEG-400 as structure directing agent on the particle size is investigated. The structural characterization of the prepared powders is carried out using XRD, Raman and FTIR techniques. TGA analysis technique is used for the investigation of the thermal properties of the powders. Morphological properties are investigated using SEM technique. Obtained results show that comparing with the experiment without the use of the structure directing agent, pure α-Al2O3 was obtained in smaller size.

show abstract

Hydrothermal synthesis of boehmite and α-alumina from Bayer’s alumina trihydrate

Cited by 25 publications

References 20 publications

Alúminas porosas: El método de bio-réplica para la síntesis de alúminas estables de alta superficie específica

Alúminas porosas: El método de bio-réplica para la síntesis de alúminas estables de alta superficie específica

Synthesis of boehmite from aluminum trihydrate through facile hydrothermal method

PEG-400 Destekli Alumina Sentezi, Karakterizasyonu ve Morfolojik Özelliklerin İncelenmesi

Contact Info

Product

Resources

About