Experimental Study on Influence of Al2O3, CaO and SiO2 on Preparation of Zinc Ferrite

Gossan ore of sulfide zinc deposit contains abundant zinc, iron, and other metal elements, which is a significant resource with complex components and can be utilized. In this study, a new technology of preparing zinc ferrite from zinc sulfide deposit gossan was proposed. The effects of Al2O3, CaO, and SiO2 in gossan on the formation of zinc ferrite were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and specific surface area and pore size analysis (BET). The results show that the presence of Al2O3 and CaO could hinder the formation of zinc ferrite, while silica had no effect on the formation of zinc ferrite. Under the conditions of the molar ratio of ZnO and Fe2O3 to Al2O3, CaO, and SiO2 of 1:1:1, an activation time of 60 min, and a roasting temperature of 750 °C for 120 min, the products, which had good crystallinity, smooth particle surface, and uniform particle size could be obtained. In addition, compared to the roasted products with Al2O3 and CaO, the specific surface area, pore volume, and pore size of the products with SiO2 were the largest.

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Study on Microstructure Variation Laws of Al-Pillared Montmorillonite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.158.248 ◽

2010 ◽

Vol 158 ◽

pp. 248-255 ◽

Cited By ~ 2

Author(s):

Gui Fang Wang ◽

Xian Jun Lu ◽

Shuai Zhang ◽

Shao Jian Ma ◽

Jun Qiu ◽

...

Keyword(s):

Specific Surface ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

Interlayer Spacing ◽

Volume Distribution ◽

Pillared Montmorillonite ◽

Bet Specific Surface Area ◽

Pore Size Analysis ◽

Porous Volume

Al3+/clay ratio is one of the important factors influencing microstructure of Al-pillared montmorillonite. Microstructure variation laws of Al-pillared montmorillonite prepared under the condition of different Al3+/clay ratio are systematically studied by XRD, FTIR, specific surface area and pore size analysis. The results show that the interlayer spacing and BET specific surface area of Al-pillared montmorillonite are remarkably affected by the Al3+/clay ratio. The interlayer spacing d(001) value and BET specific surface area of Al-pillared montmorillonite increase firstly and then decrease with the increases of the Al3+/clay ratio, and they reach to maximum when the Al3+/clay ratio is 10mmol/g. Besides, the BJH porous volume distribution of Al-pillared montmorillonite is the most probable distribution, and the most probable pore size is about 2 nm, which is attributed to mesopore. The porous structure of hydroxy-Al pillared montmorillonite is characterized as parallel plate slit or “house-of-cards” wedge-shaped pore which is formed by novel meso-microporous delaminated structure and fragments. With the increase of the Al3+/clay ratio, BJH total porous volume and mesoporous volume of hydroxy-Al pillared montmorillonite decreases, while the proportion of microporous volume in the total porous volume increases. The proportion of microporous specific surface area of all the hydroxy-Al pillared montmorillonite samples is about 62% and is much larger than that of Na-M and those of mesopore and macropore, indicating the main action of intercalation of hydroxy-Al pillaring solution into montmorillonite interlayer is to increase the micropore amount.

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Preparation of Carbon-Covered Phosphorus-Modified Alumina with Large Pore Size and Adsorption of Rhodamine B

Nanomaterials ◽

10.3390/nano11030799 ◽

2021 ◽

Vol 11 (3) ◽

pp. 799

Author(s):

Shuaiqi Chen ◽

Xuhui Wang ◽

Weiyi Tong ◽

Jianchuan Sun ◽

Xiangyu Xu ◽

...

Keyword(s):

Specific Surface ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

Rhodamine B ◽

Molar Ratio ◽

Modified Alumina ◽

Alumina Sample ◽

Large Pore ◽

Large Pore Size

In this study, phosphorus-modified alumina with large pore size was synthesized through a coprecipitation method. The carbon-covered, phosphorus-modified alumina with large pores was prepared by impregnating with glucose and carbonizing to further improve the adsorption of organic dyes. The morphology and structure of these composites were characterized by various analysis methods, and Rhodamine B (RhB) adsorption was also examined in aqueous media. The results showed that the specific surface area and pore size of the phosphorus-modified alumina sample AP7 (prepared with a P/Al molar ratio of 0.07) reached 496.2 m2·g−1 and 21.9 nm, while the specific surface area and pore size of the carbon-covered phosphorus-modified alumina sample CAP7–27 (prepared by using AP7 as a carrier for glucose at a glucose/Al molar ratio of 0.27) reached 435.3 m2·g−1 and 21.2 nm. The adsorption experiment of RhB revealed that CAP7–27 had not only an equilibrium adsorption capacity of 198 mg·g−1, but also an adsorption rate of 162.5 mg·g−1 in 5 min. These superior adsorption effects can be attributed to the similar pore structures of CAP7–27 with those of alumina and the specific properties with those of carbon materials. Finally, the kinetic properties of these composites were also studied, which were found to be consistent with a pseudo-second-order kinetic model and Langmuir model for isothermal adsorption analysis. This study indicates that the prepared nanomaterials are expected to be promising candidates for efficient adsorption of toxic dyes.

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Low Temperature One-Pot Hydrothermal Carbonization of Corn Straw into Hydrochar for Adsorbing Cadmium (II) in Wastewater

Energies ◽

10.3390/en14248503 ◽

2021 ◽

Vol 14 (24) ◽

pp. 8503

Author(s):

Heng Li ◽

Yan Shi ◽

Li Bai ◽

Mingshu Chi ◽

Xiuling Xu ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Hydrothermal Reaction ◽

Agricultural Waste ◽

Hydrothermal Carbonization ◽

Size Analysis ◽

Order Kinetic ◽

Corn Straw ◽

Pore Size Analysis

Corn straw, a typical agricultural waste, was directly converted into hydrochar with a yield of 77.56% by hydrothermal carbonization at 140–230 °C for 2 h with a solid–liquid ratio of 1:20. The morphology and surface properties were characterized by elemental analysis, specific surface area and pore size analysis and Fourier transform infrared spectroscopy. The results showed that with the increase of hydrothermal reaction temperature, some physical and chemical properties such as the increase of hydrocarbon content, crystallinity, and specific surface area of hydrochar changed significantly. A series of chemical reactions such as dehydration, decarboxylation, and aromatization occurred in the hydrothermal carbonization process so that the prepared hydrochar had rich oxygen-containing functional groups (-HO, C-O-C, C=O) and unique porous structure made the hydrochar prepared at 170 °C had the best removal effect on Cd2+ in solution (5.84 mg/g). These specific conditions could remove Cd2+ and greatly improve the adsorption performance. The pseudo-second-order kinetic model and Freundlich isotherm model could better describe the adsorption behavior of Cd2+. Therefore, corn straw hydrochar as a potential adsorbent for removing Cd2+ from water.

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The relationship between geotechnical index properties and the pore-size distribution of compacted clayey silts

Science and Engineering of Composite Materials ◽

10.1515/secm-2013-0302 ◽

2015 ◽

Vol 22 (6) ◽

Author(s):

Nazile Ural

Keyword(s):

Specific Surface ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Surface Area ◽

Specific Surface Area ◽

Pore Volume ◽

Correlation Coefficients ◽

Liquid Limit ◽

Index Properties

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the

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The Influence of Fe/Al Molar Ratio on Microreactor-Based Catalyst Preparation and Carbon Nanotube Preparation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1036.130 ◽

2021 ◽

Vol 1036 ◽

pp. 130-136

Author(s):

Ting Qun Tan ◽

Lei Geng ◽

Yan Lin ◽

Yan He

Keyword(s):

Carbon Nanotubes ◽

Catalytic Activity ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Small Diameter ◽

High Specific Surface Area ◽

Detection Methods ◽

Molar Ratio ◽

High Catalytic Activity

In order to prepare carbon nanotubes with high specific surface area, small diameter, low resistivity, high purity and high catalytic activity, the Fe-Mo/Al2O3 catalyst was prepared based on the microreactor. The influence of different Fe/Al molar ratios on the catalyst and the carbon nanotubes prepared was studied through BET, SEM, TEM and other detection methods. Studies have shown that the pore structure of the catalyst is dominated by slit pores at a lower Fe/Al molar ratio. The catalytic activity is the highest when the Fe/Al molar ratio is 1:1, reaching 74.1%. When the Fe/Al molar ratio is 1:2, the catalyst has a higher specific surface area, the maximum pore size is 8.63 nm, and the four-probe resistivity and ash content of the corresponding carbon nanotubes are the lowest. The higher the proportion of aluminum, the higher the specific surface area of the catalyst and the carbon nanotubes, and the finer the diameter of the carbon nanotubes, which gradually tends to relax. The results show that when the Fe/Al molar ratio is 1:2, although the catalytic activity of the catalyst is not the highest, the carbon nanotubes prepared have the best performance.

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Mesoporous Activated Carbon Filaments

MRS Proceedings ◽

10.1557/proc-454-9 ◽

1996 ◽

Vol 454 ◽

Cited By ~ 3

Author(s):

Weiming Lu ◽

D. D. L. Chung

Keyword(s):

Activated Carbon ◽

Specific Surface ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

Mesoporous Activated Carbon ◽

Carbon Filaments

ABSTRACTActivated carbon filaments of diameter ∼0.1 μm, main pore size (BJH) 55 Å, specific surface area 1310 m2/g and yield 36.2% were obtained by activating carbon filaments of diameter ∼ 0.1 urn in C02 + N2 (1:1) at 970°C for 80 min. Prior to this activation, the filaments were surface oxidized by exposure to ozone.

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Chapter 13 Adsorption methods for the assessment of the specific surface area, the pore size distribution and the active sites of heterogeneous catalysts

Catalysis: An Integrated Approach - Studies in Surface Science and Catalysis ◽

10.1016/s0167-2991(99)80016-0 ◽

1999 ◽

pp. 543-566 ◽

Cited By ~ 4

Keyword(s):

Specific Surface ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Surface Area ◽

Specific Surface Area ◽

Active Sites ◽

Heterogeneous Catalysts

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High specific surface area ordered mesoporous silica COK-12 with tailored pore size

Microporous and Mesoporous Materials ◽

10.1016/j.micromeso.2019.01.050 ◽

2019 ◽

Vol 280 ◽

pp. 133-143 ◽

Cited By ~ 7

Author(s):

Laura M. Henning ◽

Diego Díaz Cubas ◽

Maria G. Colmenares ◽

Johannes Schmidt ◽

Maged F. Bekheet ◽

...

Keyword(s):

Mesoporous Silica ◽

Specific Surface ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

High Specific Surface Area ◽

Ordered Mesoporous Silica ◽

Ordered Mesoporous

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Preparation of Porous Wollastonite Ceramics for Filtration

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1102 ◽

2007 ◽

Vol 336-338 ◽

pp. 1102-1104 ◽

Cited By ~ 1

Author(s):

Ming Sheng He ◽

Jian Bao Li ◽

Bo Wen Li ◽

Hong Lin ◽

Xiao Zhan Yang ◽

...

Keyword(s):

Specific Surface ◽

Pore Size ◽

Surface Area ◽

Specific Surface Area ◽

Sintering Temperature ◽

Porous Ceramics ◽

Holding Time ◽

Starting Material ◽

Sintering Method

Wollastonite powder was selected as a starting material with carbonate as pore-forming agent and binder added. The porous ceramics were prepared at different temperature by sintering method. The process includes batching, granulating, pressing molding, drying and sintering. It is discussed the influence of sintering temperature, dosage of binder, dosage of pore-forming agent, pressure of molding and holding time on the performance of porous ceramics. According to the principle of particles stack, the porous wollastonite ceramics for filtration with various diameters, shapes and porosity were fabricated by serial experiments. These products have 1 to 10 microns in pore size, 30.04 to 66.15% in porosity, 2.82 m2/g in specific surface area.

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