Tritium redistribution between water and clay minerals

Hydrogen-isotope exchange between clay minerals and tritiated water was studied with kaolinite, montmorillonite and palygorskite. At all possible positions, tritium accumulated most intensively during the initial stage (10 to 20 days) but further increase of tritium concentration in experimental systems was much less intensive. Interaction of tritiated water with clay minerals decreased in a similar manner. In all samples, the highest amounts of tritium atoms and the maximum accumulation rates (V) were observed in the surface-adsorbed water (V_surf) over the complete study period. The modes of tritium accumulation in the interlayer space (montmorillonite) and in the channels (palygorskite) (V_inter) are quite similar and both types of structures are very suitable for hydrogen-isotope exchange. Availability of well-developed paths for the access of T⁺ ions to structural OH-groups (V_struct) enables intense tritium accumulation at these positions in montmorillonite and palygorskite (V_inter  V_struct). In kaolinite the access of T⁺ ions to structural OH-groups is more difficult, in spite of the considerable number of potential exchange positions in its structure, therefore resulting in lower tritium adsorption in comparison with the other two clay minerals.     

Bleaching of alkali-refined vegetable oils with clay minerals

Bleaching efficiencies of bentonites, montmorillonites and sepiolites for alkali-refined rapesseed, soybean, wheatgerm, safflower, corn, cottonseed and sunflower oils were investigated by a batch method at 110°C. The sepiolites with more acid sites at −5.6 < H_o ≥ −3.0 were the most effective in bleaching of each alkali-refined oil. Surface area and acidity at −5.6>H_o ≥ −3.0 were highly significant with bleaching efficiency. The sepiolites (numbers 2 and 3) were more suitable than standard activated clay because they were more effective both in retaining tocopherols and in reducing free fatty acids after bleaching.     

黏土矿物的防膨技术研究进展

在分析了黏土矿物主要膨胀类型和稳定性的基础上,根据黏土矿物的膨胀类型和防膨机理,对黏土矿物的防膨技术进行了研究性综述,介绍了防膨的评价标准,并对无机盐类、无机盐聚合物类、有机阳离子聚合物类、阳离子表面活性剂类、阴离子表面活性剂类、非离子型表面活性剂类、淀粉及木质素类、糖苷类、酸类防膨剂、微生物类防膨、胶质沥青类防膨剂,进行了防膨原理简述与客观评价。展望了未来的防膨剂及防膨类型,不但可研发出多种类型防膨剂,还可对防膨剂的多元复配及微生物防膨、环保型防膨剂进行研究。     

Catalytic synthesis of carbon nanotubes on clay minerals

Novel clay-carbon tube composites were synthesized by catalytic decomposition of acetylene over iron-catalyst centers supported on montmorillonite surfaces by ion-exchange. TEM and SEM micrographs show the growth of carbon tubes rooted to the clay surfaces, while the iron-nanoparticles (which catalyze the formation of carbon-nanotubes) are detected and characterized by Mössbauer spectroscopy, mainly as ferromagnetic cementite (Fe₃C). In the hybrid materials the clay retains its exchange properties making possible the preparation of clay-carbon nanotube derivatives that are valuable for various technological applications.     

甘肃凹凸棒矿石的分离与纯化研究

对甘肃临泽出产的凹凸棒矿石进行了纯化、分离实验,确定了高速剪切结合超声波分散的提纯方案,提纯率可达99%以上,且矿浆的悬浮性能大幅提高,并对原矿和提纯矿进行了XRD、FT-IR、SEM、TEM等分析,结果表明经过适当的方法纯化,甘肃凹凸棒矿石的纯度和性能大幅度提高,应用领域和应用价值提高,具备工业化生产的可行性.     

矿物填料改性工艺研究

通过偶联剂用量、改性温度、时间、搅拌速度等工艺条件试验,评价了矿物填料改性效果,优化了改性工艺条件。     

黏土类矿物合成多孔分子筛的研究进展

综述了以黏土类矿物合成沸石分子筛的特点,分别介绍了高岭土、膨润土、海泡石的组成、结构及其在合成沸石分子筛时对以上3种黏土的处理改性,并阐述黏土类矿物制备多孔分子筛的应用前景.     

Adsorption and intercalation of tetracycline by swelling clay minerals

Many of commonly used pharmaceuticals are hydrophilic. In aqueous solutions, these molecules will have strong interaction with swelling clay minerals, resulting in intercalation of these compounds in the interlayer of the minerals and retention by these minerals. In this research, we studied the intercalation of tetracycline (TC) into swelling clay minerals as represented by montmorillonite and rectorite of different surface charges and different charge densities. The maximum interlayer expansion was seen at a higher pH when the TC molecules adopted an extended conformation, even though, the amount of TC intercalated at higher pH is lower. Under pH 4–5, the intercalated TC produced an interlayer gallery height of 9.2 Å compared to 10.3 Å produced at pH 8.7 in the interlayer space of rectorite. Due to TC intercalation, the full width at half maximum (FWHM) becomes much broader, suggesting that the number of fundamental layers stacking along c axis decreased to 2–3. Depending upon the nature of the swelling clay minerals and the TC concentration, the intercalation process can be transitional, involving in the occurrence of mechanical mixtures, materials of intermediate layer thicknesses, and/or mixed layering of different ordering states.     

页岩中黏土矿物吸附特性分子模拟

页岩的吸附解吸特性对页岩气资源开发具有重要意义。为深入了解页岩中黏土矿物微观吸附机理, 利用Material Studio 分子模拟软件构建了伊利石、蒙脱石和高岭石3种黏土矿物分子模型, 采用巨正则Monte Carlo(GCMC)方法对3种模型的等温吸附量和吸附热进行了模拟计算。研究表明, 在相同温度和压力条件下3种黏土矿物对CH₄分子的吸附量大小顺序是伊利石>蒙脱石>高岭石;随压力增大3种黏土矿物对CH₄分子的吸附量均有所增加, 而且伊利石和蒙脱石对CH₄分子的吸附量对压力变化更为敏感;3种黏土矿物的等量吸附热均小于42 kJ·mol^-1, 对CH₄的吸附为物理吸附;随着温度的升高, CH₄分子的吸附热和吸附量均减小。     

黏土矿物基无机杂化颜料研究进展

近年来,无机杂化颜料成为无机颜料领域的研究热点之一.黏土矿物是储量丰富、廉价且易得的天然纳米物质,因具有独特的纳米片状、棒状和管状结构,成为构筑各种无机杂化颜料的理想基体材料.介绍了黏土矿物的结构特点,综述了黏土矿物基钴蓝、铋黄、铁红和其他色系杂化颜料的研究和应用进展,展望了黏土矿物基无机杂化颜料的未来发展方向.     

Synthesis and characterization of low-charge sodium fluorophlogopite mica-type clay minerals

This work reports a solid-state synthesis of low-charge mica-type clay minerals using a fluoride flux method. Synthesized mica-type clay samples yielded hydrated phases with d-spacings in the range of 12.1–12.5 Å as revealed by powder X-ray diffraction (XRD). ²⁹Si and ²⁷Al magic angle spinning nuclear magnetic resonance (MASNMR) spectroscopy revealed the Si and Al nearest neighbor environments as well as the presence of impurities such as amorphous silica and forsterite in these samples.     

Identification of clay minerals in coal by selective cation saturation

The accurate identification of clay minerals in coal is important because of their high relative abudance and because they give an indication of the environment of coal deposition. In addition, there is evidence that clay minerals may act catalytically in several coal liquefaction processes. Current methods used for identification of clay minerals in coal are shown to be subject to errors because the method of separation of the clay fraction leaves the clay partially or totally saturated with sodium. The sodium-saturated clay makes identification of smectite, vermiculite, and interstratified clay minerals very difficult, especially where one or more co-exist in the clay fraction. A method based upon selective cation saturation with potassium and magnesium is shown to allow identification of several additional clay species in the low-temperature ash of coal not detectable using the sodium-saturated clay.     

橡胶表面改性的方法

综述橡胶表面改性的方法，包括化学技术改性和物理技术改性。化学技术改性包括表面卤化（氟化、氯化、溴化和碘化）、表面氧化和共价功能化改性；物理技术改性包括表面涂层、等离子处理与等离子聚合改性、辐射（等离子、γ-射线、紫外线和电子束等）引发表面接枝聚合等。指出橡胶表面改性还需从橡胶表面分子的微观结构人手，不断探索新的改性手段。从而达到适应不同环境的目的。     

Prediction of asphaltene adsorption capacity of clay minerals using machine learning

A thorough understanding of asphaltene adsorption on clay minerals is particularly important in oil production and contaminated soil remediation using clay-based adsorbents. In this paper, we introduced a machine learning approach as a reliable alternative for commonly used adsorption isotherms that suffer from inherent limitations in the prediction of asphaltene adsorption onto clay minerals. Machine learning (ML) models, namely multilayer perceptron (MLP), support vector machine (SVM), decision tree (DT), random forest (RF), and committee machine intelligent system (CMIS) combined with two optimizers were used. Experimental data (142 data points for six different clay minerals) was used for the modelling. To improve the accuracy of the smart models, a comprehensive data preparation such as outlier removal and feature selection was carried out. The results showed that relatively all the proposed models predict asphaltene adsorption on clay minerals with acceptable precision. Nevertheless, the MLP model showed superior performance compared with other models in which the overall root mean square error (RMSE) and coefficient of determination (R²) values of 6.72 and 0.93 were obtained, respectively. Finally, the developed MLP model was compared with the well-known adsorption isotherms of Langmuir and Freundlich and exhibited superior performance.     

黏土矿物对化学驱提高采收率的影响

以当前各大油田储层矿物组成情况为基础,研究了油田常见4种黏土矿物(高岭石、蒙脱石、绿泥石、伊利石)对化学驱提高采收率的影响。通过在石英砂中添加相同含量的不同黏土,进行了室内填砂管模拟实验研究。结果表明,黏土矿物的存在对化学驱提高采收率有很大的影响,含有黏土矿物的模型化学驱提高采收率明显要低于纯石英砂模型;在相同含量的黏土中,蒙脱石矿物对化学驱提高采收率影响最大;绿泥石的存在对聚合物注入压力有很大影响。     

Complex mining of refractory clay and kaolin deposits using associated minerals

Conclusions In order to exploit mineral deposits more thoroughly, the Chasov-Yar and Veselovskoye refractory clay deposits and the Vladimirovke kaolin deposit should be developed on a composite basis, utilizing the associated minerals.The Donets and other interested Sovnarkhozes should deal with the problem of utilizing the associated minerals.For complex development of the Chasov-Yar, Veselovskoye and Vladimirovskoye deposits we recommend the combined system of stripping with the use of continuous-action mining and conveying equipment, with a productivity of 500 – 1000 m³/hour, and ESh-4/40 walking excavators.     

浅析宁夏中生代煤系粘土矿物与煤变质关系

在概述粘土矿物组合、电子显微形态和结晶度等矿物学特征的基础上,探讨了宁破地区中生代煤系粘土矿物与煤变质的关系。     

Thermodynamics of the chemical reactions between clay minerals and iron oxides

The thermodynamics of chemical reactions between clay minerals and iron oxides is considered within the framework of phase diagrams for multicomponent systems. Dominant reactions are identified featuring a thermodynamic probability higher than that of clay mineral dehydration.Translated from Steklo i Keramika, No. 12, pp. 21–23, December, 1996.     

The influence of ultrasound on the thermal behaviour of clay minerals

The aim of this work is to compare the influence of sonication on the thermal behaviour of kaolinites (KGa-1, KGa-2), pyrophyllite, talc and muscovite. Sonication produces a significant increase of the specific surface area due to particle size reduction. As sonication time increases and the particle size decreases, the thermal behaviour of these clay minerals is strongly modified. Thus, there is a significant increase of the weight loss at low temperature which is related to the loss of some outer hydroxyl groups and protonated hydroxyls whose proportion in the minerals increase as the new surface generated increases. Additionally, the original endothermic dehydroxylation effects of all these minerals shift to lower temperatures. Disordered kaolinite shows the smallest shift (9 °C) while muscovite presents the largest (184 °C). A linear relation has been established between the temperature shift of the dehydroxylation and the percentage of increase in the specific surface area. The influence of sonication on the high temperature DTA effects of kaolinite, pyrophyllite, and muscovite is also studied.     

黏土矿物基无机杂化颜料研究进展

近年来,无机杂化颜料成为无机颜料领域的研究热点之一。黏土矿物是储量丰富、廉价易得的天然纳米物质,因具有独特的纳米片状、棒状和管状结构,成为构筑各种无机杂化颜料的理想基体材料。本文介绍了黏土矿物的结构特点,综述了黏土矿物基钴蓝、铋黄、铁红和其它色系杂化颜料的研究和应用进展,展望了黏土矿物基无机杂化颜料的未来发展方向。