Papers by Keyword: Sericite

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Authors: Xia Xu, Hao Ding, Ning Liang, Yue Bo Wang, Wei Yan
Abstract: To activate the reactivity of sericite and make it have the abilities of ion exchange and intercalation between layers, the effects of heat treatment on crystal structure and reactivity of sericite were studied. The results, analyzed by XRD and Hall formula, indicate that sericite still retains its crystal characteristics after being activated by heat treatment at 500°C-800°C, but there are significant lattice distortions, and the maximum one occurred at 800°C. It can be seen from the SEM images that heat treatment reduces the order of sheets of sericite and makes the surfaces rough and the edges and corners smooth. The Al3+ dissolution amount from the sericite in HNO3 is 24.34 mg/g after heat treatment, which is increased significantly compared with the untreated one. It demonstrates that the reactivity of sericite is improved remarkably.
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Authors: Kyung Nam Kim, Dae Yong Shin, Hyun Park
Abstract: Sericite has the intermediate nature of the muscovite and illite, which has been used as the additive of the cosmetics, the ceramic industry, welding rods, and other various pigments and the paint. In this study, the characteristics of sericite were examined using XRD(X-ray diffractometer), XRF(X-ray fluorescence spectrometer), TG-DTA(Thermal Analyzer), SEM(Scanning Electron Microscope) and PSA(Particle Size Analyzer). The raw ore is composed of 60.90wt% SiO2, 7.88wt% K2O, 0.36wt% TiO2, 24.80wt% Al2O3, 1.64wt% Fe2O3, 2.39wt% CaO, and 0.83wt% MgO. After sericite was purified, the content of SiO2 decreased from 60.9wt% to 51.4wt%, and in the crystal phase the intensity of quartz decreased significantly. For the high grade purification of sericite, the removal of iron and separation of quartz for the raw ore (sericite), the hydrocyclone were used with the magnetic separator. The content of iron was reduced from 1.64wt% to 0.91wt%.
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Authors: Xia Xu, Hao Ding, Yue Bo Wang, Yu Liang, Wei Jiang
Abstract: The structure of sericite is stable, and it is hard to prepare polymer layered silicate nanocomposites (PLSN). Therefore, structural modification was employed to activate sericite to reduce the layer charger. The thermal treated sericite (S1) was prepared by thermal modification at 800 for one hour. Then, the resulting product was modified with sodium fluorosilicate, whose effect was characterized by X-ray diffraction (XRD) analysis. The dissolving-out amount of Al3+ of salt-treated product (S2) reached circa 2.55 mg/g at the optimal processing conditions. CEC of S2 was increased to 10.52 meq/100g compared with that of original sericite (4.94 meq/100g). The results of XRD analysis indicated that mica-type phase persisted after salt modification with sodium fluosilicate.
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Authors: Yue Bo Wang, Hao Ding, Le Fu Mei, Wei Jiang
Abstract: Although sericite belongs to 2:1 clay minerals, it hardly has intercalation properties because it has high layer charge density, which produces pretty strong electrostatic force. Therefore, the purpose of activation is to permanently reduce the layer charge of sericite and obtain numbers of exchangeable cations. The original sericite (S0) was sintered at 800 °C for 1 h. After that, thermal-treated sericite (S1) was activated with sodium fluosilicate and nitric acid, whose effects were characterized by X-ray diffraction (XRD) analysis, chemical analysis and zeta electric potential analysis. The dissolving-out amount of Al3+ of acid-treated product (S2) reached circa 65 mg/g at the optimal processing conditions. After sodium modification with NaCl, CEC of final resulting product (S3) was increased to 14.34 meq/100g compared with that of original sericite (4.94 meq/100g). The results of chemical analysis and zeta electric potential analysis indicated that acid activation with sodium fluosilicate and nitric acid decreased the layer charge of sericite.
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Authors: Yu Liang, Hao Ding, Fen Chen
Abstract: The structure of sericite is very stable, so it is hard to peel it directly using traditional methods. In this article, the sericite which was processed through thermal activation, acid treatment, Na-modification and CTAB intercalation was used as raw material to do the exfoliation. The mechanical exfoliation method and ultrasonic method were used respectively to exfoliate the modified sericite. The grain size of final product using mechanical exfoliation method reached 16.6nm and the grain size of final product using ultrasonic method reached 8.1nm. Alongside with the result of TEM images, the ultrasonic method is thought to be better.
184
Authors: Xi Feng Hou, Shou Ren Yu, Hao Ding, Can Ye
Abstract: Sericite-TiO2 composite particle material was prepared via mechano-chemical method. SEMEDS and XPS ananlysis indicates that the surface of the sericite were coated by the TiO2 layers and the Ti4+ cations were anchored by formation of SiOTi bonds. Otherwise, the TiO2-coated sericite powders have higher light scattering indexes and other more outstanding properties than the naked sericite powders. Especially, the whiteness, adsorbed value, and hiding power indexes of the rutile TiO2-coated sericite powders were higher than those of the anatase TiO2-coated sericite powders. Hence, rutile TiO2-coated sericite powders can be substitute for the titanium dioxide pigment.
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Authors: Hao Ding, Xia Xu, Ning Liang, Yue Bo Wang
Abstract: Sericite nanoflakes were prepared by exfoliating sericite layers by wet ultrafine grinding. Their appearance morphologies and main properties were characterized. Optimum conditions were studied with the purpose of forming shear stress which was beneficial to the exfoliation of mineral flakes. The results indicated that sericite nanoflakes could be prepared. Mass ratio of grinding media to materials, diameter ratio of grinding balls, solid content of powders and grinding time had significant effects on the preparation. The thicknesses of sericite nanoflakes were 20-80 nm, and the transmittances of ultraviolet ray with wavelength of 190-220 nm were only 0.1%-1%. This demonstrated that sericite nanoflakes had the function of shielding ultraviolet ray.
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Authors: Jun Fang Guan, Hui Qun Yang, Yan Qiang Yu, Yang Chen, Guo Bing Yang, Hui Min Gao, Ling Yan Zhang
Abstract: In the paper, ultrafine quartz, sericite and wollastonite modified with silane coupling agents KH-570 were incorporated into natural rubber(NR). The synergisitc effect on reinforcing NR caused by the three types of fillers was investigated under a same vulcanizing formulation and process. The mechanical properties and microstructure of the vulcanizates were conducted through mechanical testing and scanning electron microscopy(SEM). The results of mechanical properties tests showed that when one of these three fillers was loaded within NR alone, the tear strength and permanent set of NR vulcanizates filled with quartz could reach 27.61 kN m-1 and 16.0%, respectively, stress at 300% elongation of NR vulcanizates filled with sericite could attain 4.69 MPa, and the tensile strength and elongation at break of NR vulcanizates filled with wollastonite could get to16.64 MPa and 951.21%, respectively. Under the condition that the filler loadings were 40 parts per hundred parts of rubber(phr), and the mass ratio of quartz, sericite, wollastonite was 1:1:3, the tensile strength and tear strength could come up to 17.33MPa and 27.54 kN m-1. The mechanical properties of NR composites filled with mixtures were found to be complemented by those three types of minerals. SEM results revealed that the fillers are well dispersed in the rubber matrix in the parallel arrangement with a densest stack, and the synergistic reinforcment effect of the fillers on NR was obvious.
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Authors: Yi Miao Nie, Shao Bo Wei, Xiao Long Lu, Shu Xian Liu
Abstract: Based on the crystal structure research of sericite and muscovite in mineralogy, research of sericite was done by the analysis of XRD,IR ,SEM and microscope research in its color, chemical composition, gloss,and other properties. Applications were summarized in this paper and little difference was discussed between sericite and moscovite.
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