Internal surface area and porosity of kaolinitic glaebules

Soil Research ◽  
1975 ◽  
Vol 13 (2) ◽  
pp. 235
Author(s):  
ID Sills

Specific surface areas, cation exchange capacities and pore size distributions have been determined on sieved fractions of a sandy loam from Merredin, W.A., certain horizons of which contain significant proportions of kaolinitic glaebules. The sand-sized glaebules are resistant to breakdown by normal dispersion techniques, and so remain in the sand fraction during particle size analysis. However, certain of their physicochemical characteristics are consistent with those of soil colloids. For instance, the 250-500 �m fraction of the 155-190 cm horizon has a specific surface area of 16.3 m2/g, an average pore size of some 6 nm plate separation and a surface charge density of 3.8 x 104 esu/cm2. In soils containing significant proportions of such glaebules, the physicochemical properties will differ markedly from those inferred from particle size analysis.

2012 ◽  
Vol 39 (12) ◽  
pp. 1274-1284 ◽  
Author(s):  
Erhan Güneyisi ◽  
Mehmet Gesoǧlu ◽  
Turan Özturan ◽  
Kasım Mermerdaş

In this study, the utilization of unprocessed kaolins calcined at various temperatures as supplementary cementing material was investigated experimentally. The current work deals with four kaolin deposits existing in the western region of Turkey that have not yet been investigated for this purpose. Thermal properties of the unprocessed kaolins were examined by means of differential thermal and thermo gravimetric analysis. After determination of the thermal behavior, pozzolanic activity indices of the kaolins were determined according to ASTM C311. Based on the pozzolanic activity test results, calcination temperatures were assigned for kaolins and the changes in the mineralogical composition and the formation of amorphous structures were examined by X-ray diffraction analysis. The changes in particle size and specific surface area of the calcined kaolin minerals were observed through, particle size analysis with laser diffractometer, Scanning electron microscopy image analysis, and Brunauer-Emmett-Teller specific surface area measurement. The results showed that a complete kaolinite to metakaolinite conversion was achieved by the calcination procedure adopted.


Soil Research ◽  
1974 ◽  
Vol 12 (2) ◽  
pp. 107 ◽  
Author(s):  
ID Sills ◽  
LAG Aylmore ◽  
JP Quirk

Pore size distributions using mercury injection and nitrogen sorption techniques were determined on a number of soils classified as clays on the basis of particle size analysis. Some of these soils exhibit markedly different consistencies during texturing and undergo changes in texture during prolonged manipulation, e.g. subplastic, superplastic and self-mulching soils. The pore size distributions for these soils do not differ significantly from those obtained for the normal labile clay soil in the pore size range 2 nm to 50 �m. The clay soils examined, with the exception of the krasnozem, have the majority of their pore volume within pores smaller than 10 nm with the predominant pore size centred around 3 nm plate separation. In the case of the krasnozem, the particle size analysis does not correspond to the texture assessment as a clay loam. Surface and subsoil samples of the krasnozem have high porosities and predominant plate separations of 6 nm. They consequently possess significantly different pore size distributions from the other clays. In the case of the surface sample, only a small proportion of its total pore volume is in pores smaller than 10 nm. These differences in pore structure observed between the krasnozem and the other soils examined may result from differences in mineralogy, and in particular from the high sesquioxide content of the krasnozem.


2017 ◽  
Vol 898 ◽  
pp. 1929-1934
Author(s):  
Ye Kai Zhu ◽  
Da Jun Chen

Attapulgite (AT)-based nanofibrous membranes (NFMs) were fabricated via a facile papermaking procedure, and the AT-based NFMs were sintered at three different temperatures (240 °C, 400 °C, and 600 °C). The effect of sintering temperature on the structure and properties, such as specific surface area, pore size distribution, porosity, mechanical property, pure water fluxes of AT-based NFMs, were investigated. The results showed that average pore size, total pore volume, and porosity of AT-based NFMs increased with increasing of the sintering temperature, while specific surface area and flexural strength of AT-based NFMs decreased. The optimal sintering temperature for AT-based NFMs was 400 °C. In addition, it was also found that the swelling degree of AT-based NFMs in aqueous solutions was suppressed and the pure water fluxes of AT-based NFMs were improved by sintering process.


2002 ◽  
Vol 740 ◽  
Author(s):  
Gopinath Mani ◽  
Qinguo Fan ◽  
Samuel C. Ugbolue ◽  
Isabelle M. Eiff

ABSTRACTThis research work focuses on combining ball milling and ultrasonication to produce nano-size clay particles. Our work also emphasizes on increasing the specific surface area of montmorillonite clay particles by reducing the particle size to nanometer dimensions. We have characterized the as-received clay particles by using particle size analysis based on laser diffraction and found that the size of the clay particles is not consistent and the particle size distribution is very broad. However, after the unique treatment and processing, the clay particles were obtained in nanometer dimensions with narrowed particle size distribution.


2018 ◽  
Vol 16 ◽  
Author(s):  
Siti Asmahani Saad ◽  
Nasir Shafiq ◽  
Maisarah Ali

Rice husk ash (RHA) contains high amount of amorphous silica that is ubiquitous in the pozzolanic reaction of SCM in concrete. However, usage of conventional RHA is currently unfavourable in concrete industry due to its properties inconsistency. In this regard, improvement on the RHA properties by introduction of thermochemical pre-treatment prior to burning procedure is seen as an excellent way to reach the goal. In this paper, raw rice husk was pre-treated using 0.1N hydrochloric acid (HCl) and heated at 80oC. It was then mechanically activated by high energy planetary ball mill for 15 minutes at speed of 300rpmand ball-to-powder ratio (BPR) of 15:1. The chemical composition, mineralogical properties, particle size analysis, specific surface area as well as microstructure properties of ultrafine treated rice husk ash (UFTRHA) were determined accordingly. As for amorphous silica content of the optimum sample was recorded as 98.60% incinerated at 600oC with four hours of pre-treatment soaking duration. In terms of particle size and specific surface, it was also observed that, burning temperature of 600oC, pre-treated at four hours were recorded to produce finest size of UFTRHA where d(0.1), d(0.5) and d(0.9) were obtained as 1.416?m, 4.364 ?m and 14.043 ?m respectively. Largest specific surface area value was obtained at 219.58 m2/g with the similar pre-treatment conditions. Meanwhile, the strength activity of UFTRHA from the optimum pre-treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.17MPa with 3% UFTRHA replacement at 28 days.


2019 ◽  
Vol 19 (6) ◽  
pp. 3205-3209 ◽  
Author(s):  
Shangqing Lu ◽  
Qirui Lin ◽  
Sufang Wu

This study focuses on the synergy effect of pore size and specific surface area (SSA) on the carbon dioxide sorption performance. Nano CaO-based CO2 sorbents with various pore size (15–55 nm) under similar SSA, and different SSA (14.50–48.90 m2/g) under similar pore size are prepared using selected organic templates. Results indicate that increasing the proportion of macropore in 47–96 nm could significantly improve sorbent’s sorption rate and corresponding sorption capacity. Besides, sorption capacity could be also by SSA. Moreover, partial correlation analysis reveals that sorption capacity is slightly more dependent on average pore size than SSA.


2018 ◽  
Vol 16 (6) ◽  
Author(s):  
Siti Asmahani Saad ◽  
Nasir Shafiq ◽  
Maisarah Ali

Rice husk ash (RHA) contains high amount of amorphous silica that is ubiquitous in the pozzolanic reaction of SCM in concrete. However, usage of conventional RHA is currently unfavourable in concrete industry due to its properties inconsistency. In this regard, improvement on the RHA properties by introduction of thermochemical pre-treatment prior to burning procedure is seen as an excellent way to reach the goal. In this paper, raw rice husk was pre-treated using 0.1N hydrochloric acid (HCl) and heated at 80oC. It was then mechanically activated by high energy planetary ball mill for 15 minutes at speed of 300rpmand ball-to-powder ratio (BPR) of 15:1. The chemical composition, mineralogical properties, particle size analysis, specific surface area as well as microstructure properties of ultrafine treated rice husk ash (UFTRHA) were determined accordingly. As for amorphous silica content of the optimum sample was recorded as 98.60% incinerated at 600oC with four hours of pre-treatment soaking duration. In terms of particle size and specific surface, it was also observed that, burning temperature of 600oC, pre-treated at four hours were recorded to produce finest size of UFTRHA where d(0.1), d(0.5) and d(0.9) were obtained as 1.416?m, 4.364 ?m and 14.043 ?m respectively. Largest specific surface area value was obtained at 219.58 m2/g with the similar pre-treatment conditions. Meanwhile, the strength activity of UFTRHA from the optimum pre-treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.17MPa with 3% UFTRHA replacement at 28 days.


2011 ◽  
Vol 382 ◽  
pp. 427-430
Author(s):  
E. Dong ◽  
Long Guan

Since coal gangue can destroy the environment, we aim at improving coal gangue to absorbing material by changing it in different temperature and chemical liquor. Base on the microstructure and the adsorption experiment, we detect microstructure and absorption property of improved coal gangue. The microstructure experiment shows that the average pore size and specific surface area of improved coal gangue appear distinguish obviously as the increasing of chemical liquor pH value and temperature. Absorption experiment shows that the absorption capacity of improved coal gangue decrease as the chemical liquor pH value increase, increase as the temperature increase. The adsorption capacity of improved coal gangue increases with an increase of average pore size and specific surface area.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Wei Xin ◽  
Duanwei Zhu ◽  
Guanglong Liu ◽  
Yumei Hua ◽  
Wenbing Zhou

Novel visible-light-active Mn–C–TiO2nanoparticles were synthesized by modified sol-gel method based on the self-assembly technique using polyoxyethylenes orbitan monooleate (Tween 80) as template and carbon precursor and manganese acetate as manganese precursor. The samples were characterized by XRD, FTIR, UV-vis diffuse reflectance, XPS, and laser particle size analysis. The XRD results showed that Mn–C–TiO2sample exhibited anatase phase and no other crystal phase was identified. High specific surface area, small crystallite size, and small particle size distribution could be obtained by manganese and carbon codoped and Mn–C–TiO2exhibited greater red shift in absorption edge of samples in visible region than that of C–TiO2and pure TiO2. The photocatalytic activity of synthesized catalyst was evaluated by photocatalytic oxidation of methyl orange (MO) solution under the sunlight irradiation. The results showed that Mn–C–TiO2nanoparticles have higher activity than other samples under sunlight, which could be attributed to the high specific surface area, smaller particle size, and lower band gap energy.


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