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1.
首先研究了大同高岭石的矿物学特征,结果表明大同高岭石晶粒粗大,主要由高岭石组成,样品的有序度高,Hinckley指数为1.12。在此基础上,用二甲基亚砜对大同高岭石进行插层,采用XRD、IR和TG-DSC研究插层复合物的结构。XRD结果表明DMSO已插入高岭石层间,d001由原来的0.717nm增至1.13nm,插层率达96.01%;红外光谱证明DMSO中的S=O基团与高岭石的外羟基发生了化学键合作用;热分析结果显示插层复合物于120℃~240℃发生DMSO的脱嵌作用,高岭石的脱羟基温度在400℃~750℃。 相似文献
2.
金洋、蒙西和雪纳高岭土化学成分以SiO2和Al2O3为主,K、Na、Ca、Mg含量低,而Fe、Ti含量较高;矿物成分以高岭石为主,还含有少量一水软铝石、石英、蒙脱石等。XRD和IR分析结果表明,金洋和蒙西高岭石的有序度较高,HI结晶指数分别为1.19和1.23,而雪纳高岭石的衍射峰峰形弥散,对称程度差,HI结晶指数仅有0.56。二甲基亚砜和甲酰胺与煤系高岭土相互作用后均能进入高岭石层间并撑大其晶面间距,其中金洋高岭土的插层率最高,雪纳次之,蒙西高岭土的插层效果最差。 相似文献
3.
高岭石/醋酸钾插层复合物的制备及其影响因素 总被引：1，自引：0，他引：1
利用浸泡法制备了高岭石/醋酸钾插层复合物,进行X射线衍射分析,探讨了影响插层的因素。结果表明,醋酸钾对高岭石的插层作用与高岭石的结晶度、插层剂浓度、pH值密切相关。高岭石结晶度越高,越有利于插层作用的进行;高浓度的插层剂(≥30%)可以在较短的时间(12 h)内完成插层作用,而低浓度的插层溶液则需要非常长的时间(≥144 h)才能完成,且获得的插层率较低;pH=10的弱碱性条件最有利于插层的进行;温度对高岭石的插层作用影响不大,在室温就可获得较好的插层效果。 相似文献
4.
插层高岭石层间醋酸钾的作用和取向 总被引：9，自引：1，他引：9
利用X粉晶衍射和激光拉曼光谱实验分析高岭石及其醋酸钾插层物的结构。通过实验表明醋酸钾对结晶指数(HI)为0．9的高岭石进行插层．插层率为73％，使高岭石的d(001)由0．72075nm增加到1．42093nm。进入高岭石层间的醋酸根利用其羧基上的两个氧同时和高岭石的面内羟基形成氢键，在高岭石层间直立取向，而对其内羟基基本无影响。当温度升高时，与面内羟基伸缩振动有关的峰(3698cm^-1,3684cm^-1，3672cm^-1等)发生红移，且强度增加；而与内羟基伸缩振动有关的峰(3621cm^-1)则发生蓝移。温度升高到100C以上，开始发生去插层过程；直到250C，插层分子还不能完全从高岭石层间脱去。 相似文献
5.
利用化学分析、XRD、IR、SEM、TGA/DSC等技术,从矿物学角度对淮北煤系高岭土和苏州高岭土的性能差异进行了分析。分别以淮北煤系高岭土和苏州土为载体合成了FCC催化剂,并对催化剂的性能进行了对比研究。结果表明,淮北煤系高岭土相对于苏州土具有Fe2O3、TiO2等杂质含量高,结晶有序度低,粒度分布范围较宽,微观形貌以片状为主等特点;以淮北煤系高岭土为载体制备的催化剂(HC-1)的理化性能及石油裂化性能与对比样(SC-1)相当,可以满足FCC催化剂质量指标的要求。 相似文献
6.
粘土矿物高岭石的有序化程度与其成因关系密切，而又受诸因素的作用和影响，通过对我国沉积岩中高岭石的大量研究和资料收集，获得新的发现和认识。无序高岭石一般在常温常压下通过结晶八面体中离子交换而形成，并可在较稳定的地质条件下长期保存，或因相领晶层错动而无序等。但总的说，在地热与高温热水作用或水岩作用中它常由无序向有序化固相发展。过去国内一般认为高度有序化高岭石系受成脉岩或喷出岩热液蚀变而成。这种情况在国内外都是存在的。然而研究后发现大范围更高度有序化高岭石则是煤系紫压（高岭石软质粘土）受后生阶段区域岩浆上升热水进入粒间空隙叠加于地温等作用之上而形成的。 相似文献
7.
我国球粘土应成为独立矿种,湖沼球粘土中含“内胶体”的自生高岭石是生物有机质作用造成,水云母、I-M间层粘土矿物及有机质会增加可塑性、粘结性及干燥强度,钾、钠的增加可降低烧结温度。沉积球粘土与残积成因高岭石为无序或较无序,古生代煤系高岭石为有序和高度有序,岩浆热液成因的高岭石常为有序或高度有序;北方古生代软质粘土（紫矸）为规模较大、较为均匀稳定的高度有序高岭石,应积极开发。硬水铝石岩溶铝土矿应属于生物有机质成矿作用的沉积型铝土矿。 相似文献
8.
高岭石插层复合物作为新型矿物材料现已被广泛应用。然而,插层复合物热稳定性较难控制使其在聚合物中的应用一直受到限制。本文应用热分析、X射线衍射、质谱及发射红外光谱等表征技术对煤系高岭石/醋酸钾插层复合物受热分解产物及微结构变化进行了研究。结果表明,煤系高岭石/醋酸钾插层复合物热相变主要经历以下几个阶段:插层水脱嵌(约350℃),插层剂醋酸钾脱嵌(约400℃),脱羟基(约450℃),偏高岭石形成(450~550℃),KHCO3出现(约600℃),KHCO3热分解形成K2CO3和KAl Si O4出现(约700℃),热解产品K2Al2Si O4出现(约800℃),K4Al2Si2O3出现(900~1000℃),大量K3Al O3形成阶段(1100℃及以上)。此外,还发现通过控制插层率和加热温度,可实现高岭石插层复合物的可控分解、新物相合成与转变,从而有利于新材料的合成。 相似文献
9.
醋酸钾/偏高岭石插层复合材料的制备及机理研究 总被引：1，自引：1，他引：0
采用机械研磨法,成功制备了醋酸钾/偏高岭石插层复合材料.通过XRD、FTIR和TEM研究了插层前后偏高岭石结构的变化,提出了该复合材料的插层机理和结构模型:首先醋酸钾与水分子以配位键结合,然后通过机械研磨作用进入偏高岭石层间,并将偏高岭石片层撑开.当进行热处理时,水的挥发也会对偏高岭石片层起到撑开作用.最终导致偏高岭石被撑开、剥离.在插层复合材料中,醋酸根与偏高岭石的铝氧层通过水分子桥接方式连接,钾离子水合物为保持电中性,位于带负电的硅氧层附近. 相似文献
10.
高岭石矿物缺陷结构研究——以晋北晚古生代煤系地层高岭岩为例 总被引：2，自引：0，他引：2
本文主要根据ＸＲＤ分析和ＩＲ光谱分析的有关参数，对山西境内产部晚古生代煤系夹矸高岭岩的矿物结构特征进行了详细研究，认为高岭石矿物结晶度与其显微结构有关，隐晶质高岭岩比碎屑团粒状和蠕虫状高岭岩结晶指数高。高岭石的无序度主要反映于（ａ，ｂ）面上的随机层错，同时与样品中低缺陷相的比率有关。动荡的水介质环境可能导致其无序度的增加。 相似文献
11.
A. Anandarajah 《Engineering Geology》1997,47(4):491-323
In an assembly of clay particles placed in a fluid, each particle is typically subjected to: (1) double-layer repulsive forces; (2) van der Waals attractive forces; and (3) contact mechanical forces. The study presented here concerns an approximate, quantitative analysis of clay suspensions, with considerations to the first two - the physico-chemical forces. Using recent theories to calculate the physico-chemical forces between two clay particles in an approximate model of an assembly, the equilibrium void ratio of a clay suspension is computed. The mechanical forces are ignored in the analysis. The results serve to verify the validity of physico-chemical theories employed and help interpret experimental data more fundamentally in terms of the system variables. 相似文献
12.
R. L. Frost J. Kristof G. N. Paroz J. T. Kloprogge 《Physics and Chemistry of Minerals》1999,26(3):257-263
Upon intercalation of both ordered (low defect) and disordered (high defect) kaolinites with acetamide, two types of interaction
are observed. Firstly, hydrogen bonding between the NH2 groups of the acetamide with the siloxane oxygens is formed, as evidenced by the formation of two new bands at 3400 and 3509
cm–1. Secondly, the appearance of additional bands at ∼3600 cm–1 in both the infrared and Raman spectra of the acetamide intercalates is attributed to a second type of hydrogen bonding by
the interaction of the C=O group and the inner surface hydroxyls. Changes in the intensity of the hydroxyl deformation modes
in the 895 to 940 cm–1 region are attributed to the changes in the hydrogen bonding of the kaolinite surfaces. It is proposed that the hydrogen
bonding between the adjacent kaolinite layers is replaced with hydrogen bonding between both kaolinite surfaces and the acetamide
molecule. Changes in the molecular structure of acetamide are observed upon intercalation. The amide 1 band is lost and replaced
with a well-defined NH2 deformation vibration. The loss of the amide 1 band is attributed the hydrogen bond formation between the amide hydrogens
and the siloxane surface. The bands of the C=O group at 1680 and 1740 cm–1 become a single band at 1680 cm–1. The amide 2 band remains unchanged. The lack of intensity of the 1740 cm–1 band is attributed to the formation of hydrogen bonding between the inner surface hydroxyl groups and the carbonyl group.
Received: 4 February 1998/ Revised, accepted: 30 June 1998 相似文献
13.
Dehydration-induced luminescence (DIL), the emission of light from a clay paste upon dehydration, was characterized experimentally for a colloidal kaolinite. The relationship between total photon count of the emitted light and film thickness is linear up to a thickness of 30 micrometers. The photon emission was obtained over a critical range of water contents (25-60%) of the oven-dry clay, and the kinetics of photon emission was presumed to be closely associated with the kinetics of film dehydration. Whether drying proceeded throughout the bulk or via a moving front was undetermined, but in either mode it was preceded by the formation of a thin dry film at the interface with the atmosphere. Grinding of the kaolinite for several minutes by mortar and pestle before paste preparations resulted in an overall increase of photon emission compared to unground kaolinite and in the formation of more than one emission peak, as well as a prolongation of the light emission. This effect on the kinetics of light emittance was observed for about two months after the application of the mechanical stress and suggests a means of detecting the mechanical stress history of a clay. An estimate was made of the spectral characteristics of the emitted light using optical filters and by incorporating tryptophan and salicylic acid into the kaolinite paste where they acted as fluorescent probes. The latter technique shifted the frequency of the light emitted by the kaolinite from the ultraviolet to the visible range where it was less effectively reabsorbed. The first method showed that the wavelengths of 97% of the emitted light was <460 nm and that 75% of the light had wavelengths < 410 nm. The second method showed that the total intensity of DIL increased in the presence of fluorescence molecules, suggesting that the emittance was in the ultraviolet range. 相似文献
14.
Blandine Clozel Jean-Marie Gaite Jean-Pierre Muller 《Physics and Chemistry of Minerals》1995,22(6):351-356
Trapped holes located on Al-O-Al bonds in kaolinite were studied by electron paramagnetic resonance spectroscopy (EPR) at 9.3 and 35 GHz applied to well-crystallized, X-ray irradiated and oriented samples. The Q-band EPR spectrum is characterized by three clearly separated groups of 11 quasi-equidistant superhyperfine lines centered at gxx=2.040±0.0005, gyy=2.020±0.0005 and gzz=2.002±0.001. In each of these groups, the 11 superhyperfine lines exhibit intensities according to the ratios 12345654321. An angular dependence of the Q-band EPR spectrum with respect to the magnetic field is demonstrated by measurements on oriented films of kaolinite. An appropriate numerical treatment of the EPR spectra is described, which allowed extraction of the SuperHyperfine Structures (SHFS). X-and Q-band spectra have also been simulated. It is concluded from these experiments that only one type of center is present. This center, labelled the B-center in the literature, is very probably a hole trapped on oxygen (O- center) atoms coupled to two octahedral aluminium. 相似文献
15.
16.
Long-term behavior of lime-stabilized kaolinite clay 总被引：1，自引：1，他引：0
Clay soils create many problems for highway construction and they have to be replaced or improved by stabilization for satisfactory performance. Lime stabilization is a well-established technique to improve the performance of clays. Cementitious minerals form upon mixing of clay with lime causing an improvement in strength and durability. In the study, the changes in the microfabric of long-term cured lime-stabilized kaolinite clay using X-ray diffraction pattern, scanning electron microscope and unconfined compressive strength (UCS) is presented. Unconfined compression test samples at two different lime contents (4 and 12% by weight) were prepared and cured in a humidity room for long time curing. The UCS of pure kaolinite was originally 125 kPa, which increased to 1,015 kPa after 1 month and to 2,640 kPa (21 times the initial value) after 10 years for cured lime-stabilized kaolinite samples. Similar long-term strength increases were also observed for stabilized kaolinite with 12% lime. Calcium aluminate silicate hydrate minerals were detected in the structure of the kaolinite. This suggests pozzolanic reactions with lime stabilization may continue in the long-term for up to 10 years. 相似文献
17.
Sorption of lanthanides on smectite and kaolinite 总被引：2，自引：0，他引：2
Frédéric Coppin Gilles BergerAndreas Bauer Sylvie CastetMichel Loubet 《Chemical Geology》2002,182(1):57-68
Experiments were carried out to investigate the sorption of the complete lanthanide series (Ln or rare earth elements, REE) on a kaolinite and an a Na-montmorillonite at 22°C over a wide range of pH (3-9). Experiments were conducted at two ionic strengths, 0.025 and 0.5 M, using two different background electrolytes (NaNO3 or NaClO4) under atmospheric conditions or N2 flow (glove box). The REE sorption does not depend on the background electrolyte or the presence of dissolved CO2, but is controlled by the nature of the clay minerals, the pH and the ionic strength. At 0.5 M, both clay minerals exhibit the same pH dependence for the Ln sorption edge, with a large increase in the sorption coefficient (KD) above pH 5.5. At 0.025 M, the measured KD is influenced by the Cation Exchange Capacity (CEC) of the minerals. Two different behaviours are observed for smectite: between pH 3 and 6, the KD is weakly pH-dependent, while above pH 6, there is a slight decrease in log KD. This can be explained by a particular arrangement of the particles. For kaolinite, the sorption coefficient exhibits a linear increase with increasing pH over the studied pH range. A fractionation is observed that due to the selective sorption between the HREEs and the LREEs at high ionic strength, the heavy REE is being more sorbed than the light REE. These results can be interpreted in terms of the surface chemistry of clay minerals, where two types of surface charge are able to coexist: the permanent structural charge and the variable pH-dependent charge. The fractionation due to sorption observed at high ionic strength can be interpreted either because of a competition with sodium or because of the formation of inner-sphere complexes. Both processes could favour the sorption of HREEs according to the lanthanide contraction. 相似文献
18.
高岭石水溶液的界面反应特征 总被引：2，自引：1，他引：1
高岭石的表面荷电性、溶解及其对 Cu2 、 Pb2 的吸附等实验结果表明, 高岭石的零净质子电荷点 pHPZNPC=5.2,但端面 >AlOH的 pHPZNPC在 6.5～ 7.0之间,而 >SiOH的 pHPZNPC < 2.3;然而,在 pH 2～ 10范围,ζ电位均为负值,即电动电荷等于零对应的 pH (pHIEP) < 2;且在 pH < 4溶解时, Al溶出率比 Si高,表明高岭石表层形成富 Si贫 Al层.随着溶液 pH由酸性往碱性的变化,重金属离子的吸附表现为离子交换与表面配位模式并存,并发生规律性的变化:在 pH < 6.5时主要表现为离子交换吸附,在 pH < 4时由于受到高岭石 Al的高溶出及较高的离子强度影响,高岭石对 Cu2 、 Pb2 的吸附率较低,但在 pH 5～ 6附近吸附率有明显的提升,并且有个吸附平台;在 pH > 6.5时,主要表现为离子交换和表面配位均为重要的吸附机制,若 pH再升高或重金属离子浓度过高时甚至发生表面沉淀.研究还表明,溶液 pH与离子强度影响高岭石水界面反应过程,表面溶解与质子化反应改变高岭石的表面性质,包括表面荷电性和表面位化合形态,因而调控 Cu2 、 Pb2 的界面吸附行为. 相似文献
19.
Toshihiko Ohnuki Takahiro Yoshida Takuo Ozaki Mohamad Samadfam Naofumi Kozai Kunio Yubuta Toshiaki Mitsugashira Takeshi Kasama Arokiasamy J. Francis 《Chemical Geology》2005,220(3-4):237-243
We assessed the accumulation of uranium (VI) by a bacterium, Bacillus subtilis, suspended in a slurry of kaolinite clay, to elucidate the role of microbes on the mobility of U(VI). Various mixtures of bacteria and the koalinite were exposed to solutions of 8 × 10− 6 M- and 4 × 10− 4 M-U(VI) in 0.01 M NaCl at pH 4.7. After 48 h, the mixtures were separated from the solutions by centrifugation, and treated with a 1 M CH3COOK for 24 h to determine the associations of U within the mixture. The mixture exposed to 4 × 10− 4 M U was analyzed by transmission electron microscope (TEM) equipped with EDS. The accumulation of U by the mixture increased with an increase in the amount of B. subtilis cells present at both U concentrations. Treatment of kaolinite with CH3COOK, removed approximately 80% of the associated uranium. However, in the presence of B. subtilis the amount of U removed was much less. TEM–EDS analysis confirmed that most of the U removed from solution was associated with B. subtilis. XANES analysis of the oxidation state of uranium associated with B. subtilis, kaolinite, and with the mixture containing both revealed that it was present as U(VI). These results suggest that the bacteria have a higher affinity for U than the kaolinite clay mineral under the experimental conditions tested, and that they can immobilize significant amount of uranium. 相似文献
20.
Centrifuge tests were carried out to confirm and determine the effect of different pure alcohols, methyl t-butyl ether (MTBE) and mixtures of alcohols with gasoline and diesel on a thin disc of consolidated clay. The evolution of changes in the clay hydraulic conductivity with time was investigated and other structural changes due to chemical attack were monitored. The findings presented here demonstrate that the hydraulic conductivity of the clay appear to be generally related to the polarity of the chemicals and the dielectric constant. The cracking effect of butanol and MTBE on consolidated clay at low flow rate and low stress level was observed. The addition of ethanol or MTBE to diesel increased the clay permeability and the migration of organic chemical. The addition of ethanol to gasoline also caused an increase in the clay hydraulic conductivity. The effect of the association of alcohols with gasoline or diesel on the clay hydraulic conductivity is discussed, with a view to improving current pollution remediation techniques. 相似文献