scholarly journals Structural Characterization and Adsorption Capability of Carbonaceous Matters Extracted from Carbonaceous Gold Concentrate

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Huiqun Niu ◽  
Hongying Yang ◽  
Linlin Tong
Keyword(s):  
Particle Size ◽  
Humic Acid ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Mesoporous Structure ◽  
Average Pore Diameter ◽  
Average Pore ◽  
Complex Organic Compound

In this paper, the structures of element carbon and humic acid extracted from carbonaceous gold concentrate were characterized employing a variety of analytical methods. The extracted amounts of ECE (elemental carbon extract) and HAE (humic acid extract) were 14.84–38.50 and 11.55–28.05 mg g−1, respectively. SEM and porosity analysis indicated that ECE occurred mostly as irregular blocky particles with a mesoporous surface with the average pore diameter being 31.42 nm. The particle size of ECE was mainly ranged from 5.5 to 42 μm and the specific surface area was 20.35 m2 g−1. The physicochemical features and structure of ECE were close to activated carbon, and the crystallinity was slightly lower than graphite. The particle size distribution of HAE varied from 40 to 400 nm with the specific surface area of 42.84 m2 g−1, whereas the average pore diameter of HAE was 2.97 nm. FTIR and UV–VIS analyses indicated that HAE was a complex organic compound containing the enrichment of oxygen-containing structure. The results showed that the adsorption amounts of ECE and HAE under the acidic conditions were 470.46 and 357.60 mg g−1, respectively. In an alkaline environment, the amount of ECE was 449.02 mg g−1 and the value of HAE was 294.72 mg g−1. ECE mainly utilized the outer surface and mesoporous structure to adsorb gold, while the functional groups’ complexation or surface site adsorption was the leading approach for HAE to adsorb gold.

scholarly journals COMPARISON OF PORE FRACTAL CHARACTERISTICS BETWEEN MARINE AND CONTINENTAL SHALES

Fractals ◽  
2018 ◽  
Vol 26 (02) ◽  
pp. 1840016 ◽  
Author(s):  
JUN LIU ◽  
YANBIN YAO ◽  
DAMENG LIU ◽  
YIDONG CAI ◽  
JIANCHAO CAI
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Clay Minerals ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Fractal Dimensions ◽  
Average Pore Diameter ◽  
Average Pore ◽  
Dimension Formula ◽  
Marine Shale

Fractal characterization offers a quantitative evaluation on the heterogeneity of pore structure which greatly affects gas adsorption and transportation in shales. To compare the fractal characteristics between marine and continental shales, nine samples from the Lower Silurian Longmaxi formation in the Sichuan basin and nine from the Middle Jurassic Dameigou formation in the Qaidam basin were collected. Reservoir properties and fractal dimensions were characterized for all the collected samples. In this study, fractal dimensions were originated from the Frenkel–Halsey–Hill (FHH) model with N[Formula: see text] adsorption data. Compared to continental shale, marine shale has greater values of quartz content, porosity, specific surface area and total pore volume but lower level of clay minerals content, permeability, average pore diameter and methane adsorption capacity. The quartz in marine shale is mostly associated with biogenic origin, while that in continental shale is mainly due to terrigenous debris. The N[Formula: see text] adsorption–desorption isotherms exhibit that marine shale has fewer inkbottle-shaped pores but more plate-like and slit-shaped pores than continental shale. Two fractal dimensions ([Formula: see text] and [Formula: see text] were obtained at [Formula: see text] of 0–0.5 and 0.5–1. The dimension [Formula: see text] is commonly greater than [Formula: see text], suggesting that larger pores (diameter [Formula: see text][Formula: see text]nm) have more complex structures than small pores (diameter [Formula: see text][Formula: see text]nm). The fractal dimensions (both [Formula: see text] and [Formula: see text]) positively correlate to clay minerals content, specific surface area and methane adsorption capacity, but have negative relationships with porosity, permeability and average pore diameter. The fractal dimensions increase proportionally with the increasing quartz content in marine shale but have no obvious correlation with that in continental shale. The dimension [Formula: see text] is correlative to the TOC content and permeability of marine shale at a similar degree with dimension [Formula: see text], while the dimension [Formula: see text] is more sensitive to those of continental shale than dimension [Formula: see text]. Compared with dimension [Formula: see text], for two shales, dimension [Formula: see text] is better associated with the content of clay minerals but has worse correlations with the specific surface area and average pore diameter.

scholarly journals Soybean oil bleaching by Al-pillared montmorillonite

2002 ◽  
pp. 27-34 ◽  
Author(s):  
Erne Kis ◽  
Jonjana Ranogajec ◽  
Radmila Marinkovic-Neducin ◽  
Etelka Dimic ◽  
Tatjana Vulic
Keyword(s):  
Soybean Oil ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Textural Properties ◽  
Oil Industry ◽  
Average Pore Diameter ◽  
Average Pore ◽  
Pillared Montmorillonite

AI-pillared montmorillonite was synthesized from raw clay, mined at Sipovo Srpska Republic. Its textural properties and bleaching capacity were compared with some commercial adsorbents and filtration aid materials commonly used in domestic oil industry. The bleaching capacity of AI-pillared montmorillonite is lower than that of commercial Super Celite L748 (Johns Manville, USA) or Perfit PF-3 (Termika dd., Zrenjanin Yugoslavia), but somewhat is higher than the bleaching capacity of pure montmorillonite. The results suggest that the bleaching capacity of the investigated samples is primarily determined by average pore diameter and not by specific surface area.

Fuels Desulphurisation by Adsorbtion on Fe / Bentonite

2017 ◽  
Vol 68 (3) ◽  
pp. 483-486
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Gabriel Vasilievici ◽  
Dorin Bombos
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pore Diameter ◽  
Adsorption Process ◽  
Continuous System ◽  
Gas Oil ◽  
Average Pore ◽  
Atmospheric Distillation

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.

Nano/Micro Pore Structure and Fractal Characteristics of Baliancheng Coalfield in Hunchun Basin

2021 ◽  
Vol 21 (1) ◽  
pp. 682-692
Author(s):  
Youzhi Wang ◽  
Cui Mao
Keyword(s):  
Fractal Dimension ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Coal Reservoir

The pore structure characteristic is an important index to measure and evaluate the storage capacity and fracturing coal reservoir. The coal of Baliancheng coalfield in Hunchun Basin was selected for experiments including low temperature nitrogen adsorption method, Argon Ion milling Scanning Electron Microscopy (Ar-SEM), Nuclear Magnetic Resonance (NMR), X-ray diffraction method, quantitative mineral clay analysis method. The pore structure of coal was quantitatively characterized by means of fractal theory. Meanwhile, the influences of pores fractal dimension were discussed with experiment data. The results show that the organic pores in Baliancheng coalfield are mainly plant tissue pores, interparticle pores and gas pores, and the mineral pores are corrosion pores and clay mineral pores. There are mainly slit pore and wedge-shaped pore in curve I of Low temperature nitrogen adsorption. There are ink pores in curve II with characteristics of a large specific surface area and average pore diameter. The two peaks of NMR T2 spectrum indicate that the adsorption pores are relatively developed and their connectivity is poor. The three peaks show the seepage pores and cracks well developed, which are beneficial to improve the porosity and permeability of coal reservoir. When the pore diameter is 2–100 nm, the fractal dimensions D1 and D2 obtained by nitrogen adsorption experiment. there are positive correlations between water content and specific surface area and surface fractal dimension D1, The fractal dimension D2 was positively and negatively correlated with ash content and average pore diameters respectively. The fractal dimensions DN1 and DN2 were obtained by using the NMR in the range of 0.1 μm˜10 μm. DN1 are positively correlated with specific surface area of adsorption pores. DN2 are positively correlated volume of seepage pores. The fractal dimension DM and dissolution hole fractal dimension Dc were calculated by SEM image method, respectively controlled by clay mineral and feldspar content. There is a remarkable positive correlation between D1 and DN1 and Langmuir volume of coal, so fractal dimension can effectively quantify the adsorption capacity of coal.

Preparation of High Surface Area Anatase TiO2 by a Low Temperature Hydrothermal Process

2011 ◽  
Vol 299-300 ◽  
pp. 106-109
Author(s):  
Mei Zhen Gao ◽  
Zhi Rong Zhang ◽  
Wen Li ◽  
Wen Bao Liu ◽  
Bing Jun Yang
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Surface Area ◽  
Pore Diameter ◽  
High Surface ◽  
Hydrothermal Process ◽  
Mesoporous Structure ◽  
Average Pore Diameter ◽  
Average Pore ◽  
Adsorption Desorption

Pure anatase TiO2spheres with mesoporous structure were prepared by a simple urea assisted hydrothermal process at low temperature. The characterization of TiO2was examined by X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), N2adsorption-desorption and ultraviolet visible spectrophotometer (UV-VIS). The TEM and N2adsorption-desorption results confirmed that TiO2spheres has a mesoporous structure. The surface area of TiO2annealed at 400 °C is up to 302.3 m2/g with average pore diameter about 4.1 nm. While after annealed at 500 °C, the average pore diameter of TiO2is about 6.8 nm, but the surface area reduces to 142.6 m2/g

The Degradation and BMP Release Dynamics of Silica-Based Xerogels Modified by Adding Calcium and Magnesium or Sintering Process

2012 ◽  
Vol 151 ◽  
pp. 378-382 ◽  
Author(s):  
Xiao Sheng Li ◽  
Wei Lin ◽  
Feng Lan Xing
Keyword(s):  
Electron Microscope ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Silica Xerogel ◽  
Calcium And Magnesium

A new mesoporous silica xerogel used as biodegradable material was synthesized by improved sol-gel methods. The xerogel’s degradation character and property of releasing character for bone morphological protein (BMP)were modified by adding calcium (Ca) and phosphor (P) elements into pure silica xerogel, and uesing sintering processes, as well as adding magnesium (Mg) into silica xerogel. The differential thermal and thermogravimetric analysis (DTA-TG), X-Ray diffraction analysis(XRD), Fourier infrared spectrum analysis (FITR), N2 adsorption-desorption analysis, Scanning electron microscope(SEM) and Transmitting electron microscope (TEM) observation were used to measure the thermal effects, crystalline state, pore diameter and specific surface area, surface morphology and inner structure of the xerogels. The xerogel’s degradability and BMP release were studied by simulated body fluid (SBF) immersion. The results indicated that the synthesized xerogels were mesoporous structure with pore diameter around 3 nm and the big specific surface area about 1000 m2/g.They were non crystall with hydroxyl and micro-molecular silica-oxygen groups. Xerogels dried at low sintering temperature degraded completely in 42 days in bursting manner and degraded in linear curves with sintering temperature increased as well as adding calcium and magnesium into xerogels. The BMP release behaviour from the Mg-xerogel dried naturally was in controlled manner.

Activated Natural Zeolite Membrane for Separating Dissolved Impurities in Coconut Sap

2020 ◽  
Vol 1000 ◽  
pp. 293-302
Author(s):  
H. Aripin ◽  
Nundang Busaeri ◽  
Acep Irham Gufroni ◽  
Sliven Sabchevski
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Natural Zeolite ◽  
Pore Diameter ◽  
Ceramic Membrane ◽  
Applied Pressure ◽  
Zeolite Membrane ◽  
Separation Performance ◽  
Average Pore

A ceramic membrane has been produced from a natural zeolite. A series of samples has been sintered at range temperature from room temperaure to 900°C. The influence of the sintering temperature on the specific surface area, pore diameter, and surface roughness has been investigated. It has been found that a decrease for value of the specific surface area and average pore diameter from 300°C to 900°C was attributed to a change of the crystalline structure of tridimite from partially to fully crystallized samples. The fabricated membrane has been used successfully to evaluate the separation performance during the treatment of coconut sap. The membranes have a steady state flux from 0.12 to 0.22 mL/min.cm2 at an applied pressure of 1 bar.

scholarly journals Fractal characteristics of shale pore structure and its influence on seepage flow

2021 ◽  
Vol 8 (5) ◽  
pp. 202271
Author(s):  
Shengwei Wang ◽  
Xijian Li ◽  
Haiteng Xue ◽  
Zhonghui Shen ◽  
Liuyu Chen
Keyword(s):  
Fractal Dimension ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Average Pore ◽  
Bet Specific Surface Area ◽  
Niutitang Formation ◽  
Shale Permeability

The migration law of shale gas has a significant influence on the seepage characteristics of shale, and the flow of the gas is closely related to the pore structure. To explore the influence of shale pore parameters on permeability in different diffusion zones, the pore structure of the shale in the Niutitang Formation in Guizhou, China, was analysed based on liquid nitrogen adsorption experiments and nuclear magnetic resonance experiments. The relationship among fractal dimension, organic carbon content (TOC) and BET-specific surface area was analysed based on the fractal dimension of shale pores calculated using the Frenkel–Halsey–Hill model. Shale permeability was calculated using the Knudsen number ( Kn ) and permeability equation, and the influence of the fractal dimension and porosity in different diffusion zones on shale permeability was analysed. Previous studies have shown that: (i) the pores of shale in the Niutitang Formation, Guizhou are mainly distributed within 1–100 nm, with a small total pore volume per unit mass, average pore diameter, large BET specific surface area and porosity; (ii) fractal dimension has a negative correlation with average pore diameter and TOC content and a quadratic relationship with BET specific surface area; and (iii) permeability has a positive correlation with Kn , porosity and fractal dimension. In the transitional diffusion zone, fractal dimension and porosity have a significant impact on permeability. In the Knudsen diffusion zone, porosity has no obvious effect on permeability. The methodologies and results presented will enable more accurate characterization of the complexity of pore structures of porous media and allow further understanding of the seepage law of shale gas.

Variation of Conditions of ZrO2•nH2O Precipitation and Aging as a Method for Controlling the Phase Composition and Texture of ZrO2

2020 ◽  
Vol 20 (5) ◽  
pp. 335-343
Author(s):  
Sh. O. Omarov ◽  
N. A. Pakhomov
Keyword(s):  
Particle Size ◽  
Phase Composition ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Space ◽  
Mesoporous Structure ◽  
Precipitation Method ◽  
Porous Texture ◽  
Aging Conditions

The effect exerted by precipitation method, temperature and duration of ZrO2·nH2O aging on the porous texture, phase composition and thermal transformations of ZrO2·nH2O and ZrO2 has been studied. It was found that variation of precipitation method makes it possible to change the specific surface area, volume and mean pore size of ZrO2·nH2O and ZrO2, increase the contribution of mesopores to the pore space of ZrO2·nH2O, and alter the particle size of ZrO2. An increase in the aging temperature of ZrO2·nH2O led to a considerable development of the mesoporous structure, an increase in the specific surface area of ZrO2·nH2O and ZrO2, and a decrease in the ZrO2 particle size. However, the ratio of ZrO2 phases changed non-monotonically with extending the aging time. Selection of precipitation and aging conditions provided a twofold increase in the pore volume of ZrO2 as compared to the sulfated zirconia isomerization catalyst and allowed extending the surface area without the introduction of additional components. The best characteristics of the ZrO2 pore structure – Ssp = 140 m2/g and Vpore = 0.404 cm3/g – are achieved when precipitation is performed at a constant pH and is followed by ZrO2·nH2O aging at 90 °С for 12 h.

scholarly journals Investigation on the Deterioration Mechanism of Recycled Plaster

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Zhixin Li ◽  
Kaidong Xu ◽  
Jiahui Peng ◽  
Jina Wang ◽  
Xianwei Ma ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Nitrogen Adsorption ◽  
Water Requirement ◽  
Scanning Calorimetry ◽  
Average Pore ◽  
Preparation Temperature ◽  
Deterioration Mechanism

The deterioration mechanism of recycled plaster (R-P) was studied. The large specific surface area (SSA), improper preparation temperature, increased water requirement of R-P, and microstructure of its hardened body were analyzed by particle size distribution (PSD), Blaine method, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and nitrogen adsorption porosimetry. The results indicated that the properties of R-P were deteriorated, but its strength decreases from 50% at the same manufacturing process to 30%–40% at similar specific surface area. The analysis shows that the large SSA, poor morphology, narrow PSD, and increased internal detects give rise to increase of water requirement. In addition, the deterioration properties are caused by unsuitable temperature of preparation, loose structure, and large average pore diameter in hardened R-P as well.

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