共查询到19条相似文献，搜索用时 140 毫秒
1.
利用离子交换方法可以制备出K-型、Na-型和Ca-型斜发沸石。斜发沸石所含的阳离子类型不同,其物理化学性能有明显的差异。本文就不同类型的阳离子对斜发沸石的某些物理化学性能的影响进行了研究。 相似文献
2.
中国科学院地质研究所矿物组 《地质科学》1977,12(3):284-288
斜发沸石是天然沸石中较常见和具有实际应用价值的一种。其化学分子式为:Ca（Na·K）4Al6Si30O72·24H2O。关于斜发沸石的吸附、阳离子交换等性能,国外已有很多研究,并已将天然的斜发沸石、丝光沸石应用于从空气中富集氧、石油化工、原子能放射性废水和工业污水的处理、干燥剂,土壤改良剂、造纸充填剂等许多方面。 相似文献
3.
采用NaOH对围场地区天然沸石进行处理,采用X射线衍射仪、红外光谱仪、N_2吸附-脱附技术、扫描电子显微镜等对材料进行表征分析,采用水蒸气吸附法评价材料的亲水性,采用Cr~(3+)和Mn~(2+)评价材料的离子交换性能,探讨了碱处理对天然沸石的结构、亲水性和离子交换性能的影响及其机理。实验结果表明,围场地区天然沸石中主要含有斜发沸石、石英和伊利石;碱处理可降低天然沸石的硅铝比,且沸石的硅铝比随着碱处理浓度的提高而不断降低;碱处理对斜发沸石结构的影响较石英和伊利石更大;高浓度碱处理导致天然沸石的结构发生破坏,比表面积降低,孔体积提高;伴随着天然沸石硅铝比的降低,其亲水性和离子交换性能不断提高。 相似文献
4.
本文收集了我国一些地区的斜发沸石、片沸石和丝光沸石样品,进行了矿物分离、提纯和化学分析,测定了沸石的晶胞参数,将其结果与国外资料进行了对比,指出了我国目前所发现的一些斜发沸石和丝光沸石的特点。 相似文献
5.
本文系对IMA CNMMN批准的沸石命名法的修改建议。其中扩展了沸石类矿物的定义 ,今后凡具有沸石的性质 ,但其结构中含有四面体格架者则可视为沸石 ;亦允许非硅和铝的元素在格架内的完全替换。在具特定结构的组成系列中 ,格架外的不同阳离子中的原子比值最大者可确定为独立的矿物种 ,命名时采用相应的元素符号作为后缀 ,用连字符加在系列名称之后 [钙十字沸石类 (philipsite)和方沸石 (analcime)系列中的交沸石 (harmotome)、铯沸石 (pollucite)和斜钙沸石 (wairakite)除外 ]。具有相同结构格架的沸石中空间群对称和有序—无序关系的差异一般不作为建立独立矿物种的根据。除片沸石 (heulandite) (Si∶Al<4 .0 )和斜发沸石(clinoptilolite) (Si∶Al>4 .0 )外 ,沸石的矿物种不能只靠Si∶Al值来区分。失水、部分水化和过量水化不能作为区别沸石独立矿物种的根据。在涉及到沸石的简化分子式或平均分子式时 ,应当避免使用“理想分子式”这一术语。在不同的组成系列中最近确定的矿物种有 :brewsterite Sr、 Ba(锶沸石 Sr、 Ba)、chabazite Ca、 Na、 K(菱沸石 Ca、 Na、 K)、clinoptilolite K、 Na、 Ca(斜发沸石 K、 Na、 Ca)、dachiardite Ca、 Na(环晶沸石 Ca、 Na)、erionite Na、 K、 Ca(毛沸石 Na、 K 相似文献
6.
河北省赤城县独石口沸石岩矿物学特征及其性能研究 总被引：2，自引：0，他引：2
独石口沸石岩共生矿物组合为斜发沸石、蒙脱石、α-方石英和少量丝光沸石。斜发沸石呈微晶产于玻璃质岩屑和火山尘中,也呈板状产于玻屑和珍珠岩溶解形成的孔洞中,沸石总量大于70％;化学成分显示高Si、高Al、富K、富Ca、贫Na的特征;阳离子交换容量高,交换性阳离子以Ca为主,其次为K,Na,Mg;阳离子选择交换顺序为NH_4~+>K~+>Ca~(2+)>Na~+>Mg~(2+);不同阳离子类型的沸石岩其热稳定性和吸附性有差异,K型和Na型沸石岩可稳定至700℃,而Ca型沸石岩在500℃时结构被破坏;Ca型沸石岩吸附性好,而K型差。 相似文献
7.
8.
9.
关于沸石类矿物命名法的建议(Ⅰ) 总被引：1，自引：0，他引：1
《矿物岩石地球化学通报》2001,20(3):149-155
本文系对IMA-CNMMN批准的沸石命名法的修改建议.其中扩展了沸石类矿物的定义,今后凡具有沸石的性质,但其结构中含有四面体格架者则可视为沸石;亦允许非硅和铝的元素在格架内的完全替换.在具特定结构的组成系列中,格架外的不同阳离子中的原子比值最大者可确定为独立的矿物种,命名时采用相应的元素符号作为后缀,用连字符加在系列名称之后[钙十字沸石类(philipsite)和方沸石(analcime)系列中的交沸石(harmotome)、铯沸石(pollucite)和斜钙沸石(wairakite)除外].具有相同结构格架的沸石中空间群对称和有序-无序关系的差异一般不作为建立独立矿物种的根据.除片沸石(heulandite)(Si∶Al＜4.0)和斜发沸石(clinoptilolite)(Si∶Al＞4.0)外,沸石的矿物种不能只靠Si∶Al值来区分.失水、部分水化和过量水化不能作为区别沸石独立矿物种的根据.在涉及到沸石的简化分子式或平均分子式时,应当避免使用"理想分子式”这一术语.在不同的组成系列中最近确定的矿物种有brewsterite-Sr、-Ba(锶沸石-Sr、-Ba)、chabazite-Ca、-Na、-K(菱沸石-Ca、-Na、-K)、clinoptilolite-K、-Na、-Ca(斜发沸石-K、-Na、-Ca)、dachiardite-Ca、-Na(环晶沸石-Ca、-Na)、erionite-Na、-K、-Ca(毛沸石-Na、-K、-Ca)、faujasite-Na、-Ca、-Mg(八面沸石-Na、-Ca、-Mg)、ferrierite-Mg、-K、-Na(镁碱沸石-Mg、-K、-Na)、gmelinite-Na、-Ca、-K(钠菱沸石-Na、-Ca、-K)、heulandite-Ca、-Na、-K、-Sr(毛沸石-Ca、-Na、-K、-Sr)、levyne-Ca、-Na(插晶菱沸石-Ca、-Na)、paulingite-K、-Ca(勃林沸石-K、-Ca)、phillipsite-Na、-Ca、-K(钙十字沸石-Na、-Ca、-K)和stilbite-Ca、-Na(辉沸石-Ca、-Na).原文对于包括13个组成系列在内的总计82种沸石矿物和3个存疑的物相列出了主要参考文献、典型产地、名称来源、化学数据、IZA结构类型符号、空间群对称、晶胞参数和关于结构的简要论述(由于篇幅所限,将另文刊出--编译者注).herschelite(碱菱沸石)、leonhardite(黄浊沸石)和svetlozarite(钾丝光沸石)已确定为无效矿物种名称. 相似文献
10.
11.
E. Passaglia 《Contributions to Mineralogy and Petrology》1975,50(1):65-77
Mordenite is a zeolite whose approximate composition is (Na2, K2,Ca)4[Al8Si40O96] 28 H2O. Unit cell dimensions, determined by X-ray powder diffractometry for 35 natural samples, fell within the following ranges: a=18.052–18.168, b=20.404–20.527, c=7.501–7.537 Å. The indexed powder pattern of a typical sample is reported. Complete wet chemical analyses of 12 samples, partial analyses of three others, and 6 analyses from the literature reveal that mordenites vary only slightly in chemical composition. Si occupies 80 to 85% of the tetrahedra, and the exchangeable cations are mainly Na and Ca, with minor K. The lattice constant b is negatively correlated to the ratio Si/(Si+Al+Fe?). 相似文献
12.
The crystal structure of Bi2Al4−x
Fe
x
O9 compounds (x = 0–4) has striking similarities with the crystal structure of mullite. A complete substitution of Al by Fe3+ in both octahedral and tetrahedral sites is a particular structural feature. The infrared (IR) spectra of the Bi2M4O9 compounds (M = Al, Fe3+) are characterised by three band groups with band maxima in the 900–800, 800–600 and 600–400 cm−1 region. Based on the spectroscopic results obtained from mullite-type phases, the present study focuses on the composition-dependent analysis of the 900–800 cm−1 band group, which is assigned to Al(Fe3+)–O stretching vibrations of the corner-sharing MO4 tetrahedra. The Bi2Al4O9 and Bi2Fe4O9 endmembers display single bands with maxima centred at 922 and 812 cm−1, respectively. Intermediate Bi2Al4−x
Fe
x
O9 compounds exhibit a distinct splitting into three relatively sharp bands, which is interpreted in terms of ordering effects within the tetrahedral pairs. Thereby the high-energy component band of the band triplet relates to Al–O–Al conjunctions and the low-energy component band to Fe–O–Fe conjunctions. The intermediate band is assigned to stretching vibrations of Al–O–Fe or Fe–O–Al configurations of the corner-sharing tetrahedral pairs. Bands in the 800–600 cm−1 range are assigned to low-energy stretching vibrations of the MO4 tetrahedra and to M–O–M bending vibrations of the tetrahedral pairs. Absorptions in the 600–400 cm−1 range are essentially determined by M–O stretching modes of the M cations in octahedral coordination. 相似文献
13.
Results are reported of an experimental study which examined the effect of solution composition on the composition, structure, and crystallization path of phillipsite and merlinoite in the system Na2OK2O-Al2O3-SiO2H2O at 80°C and .At a fixed 3.5 M total dissolved silica concentration, zeolite Si/Al ratio was found to be a linear function of pH within the pH range of the experiments.29Si NMR spectra of the initial solutions show that pH determines the distribution of aqueous aluminosilicate species and, as a result, the precipitated zeolite Si/Al ratio. SEM observations reveal that zeolites may precipitate with or without the presence of an intermediary gel phase, depending on solution composition. The growth rate of the zeolites was found to be dependent upon solution pH and total dissolved aluminum concentration. These observations are discussed in terms of their possible applications to natural zeolite paragenesis and serve to delineate the framework of a comprehensive theory for the mechanism of zeolite crystallization from highly alkaline solutions. 相似文献
14.
1974年在一水晶矿石英脉晶洞中,发现了一种含Ba、Li的硅酸盐新矿物--纤钡锂石。我们对纤钡锂石进行了光性研究、比重测定、差热及热失重分析、红外光谱分析、X射线单晶结构分析等工作,现分述如下。 相似文献
15.
Experiments carried out in the system granite-H2O-HF at 0.1 GPa show that the crystal-liquid equilibrium temperature of quartz rises and that of alkali-feldspar goes down with increasing F content. The calculated results of quartz and alkali feldspar crystal-liquid equilibrium show that the activity of SiO2 in melt increases and the activities of NaAlSi3O8(Ab) and KAlSi3O8(Or) decrease, with a greater decreasing extent for a Ab L than a Or L . These systematic changes are believed to be caused by F complexing with Al, Na, K, but not Si in the melt, and are consistent with F decomposing AlO 2 ? tetrahedra and more preferentially forming complexes with Na than K. The comparison between effects of F and H2O on phase equilibrium suggests that the maximum difference affecting melt structure between F and OH is F complexing without Si and OH complexing with Si in granitic melt. 相似文献
16.
Derek Taylor 《Contributions to Mineralogy and Petrology》1975,51(1):39-47
Cell parameters, ranging from 8.447 to 9.331 Å, are given for 13 synthetic aluminosilicate-sodalites. Correlations between the cell edge of aluminosilicate-sodalites and the sizes of the cavity ions are established and discussed. The principal infrared absorption bands for 6 synthetic and 4 natural aluminosilicate-sodalites are also correlated with the cell edge and discussed in terms of the bonding theory of linked TO4 tetrahedra (T=Si, Al). 相似文献
17.
Silicon K-edge x-ray absorption near-edge structure (XANES) spectra of a selection of silicate and aluminosilicate minerals have been measured using synchrotron radiation (SR). The spectra are qualitatively interpreted based on MO calculation of the tetrahedral SiO 4 4? cluster. The Si K-edge generally shifts to higher energy with increased polymerization of silicates by about 1.3 eV, but with considerable overlap for silicates of different polymerization types. The substitution of Al for Si shifts the Si K-edge to lower energy. The chemical shift of Si K-edge is also sensitive to cations in more distant atom shells; for example, the Si K-edge shifts to lower energy with the substitution of Al for Mg in octahedral sites. The shifts of the Si K-edge show weak correlation with average Si-O bond distance (dSi-O), Si-O bond valence (sSi-O) and distortion of SiO4 tetrahedra, due to the crystal structure complexity of silicate minerals and multiple factors effecting the x-ray absorption processes. 相似文献
18.
Deyi Wu Bohua Zhang Li Yan Hainan Kong Xinze Wang 《International Journal of Mineral Processing》2006,80(2-4):266-272
Hydrothermal conversion of fly ash into zeolites was conducted and the effects of the addition of sodium halide and waste solutions produced after zeolitization of fly ash, as well as the adjustment of the Si/Al ratio prior to synthesis process on the formation and cation exchange capacity (CEC) of zeolite product were evaluated. Both the addition of NaCl and NaF ameliorated the crystallinity and CEC of synthesized zeolite, but NaF had a better improvement effect. Na+ was considered to enhance the crystallization of zeolite, while F− favored the dissolution of fly ash. The type of zeolite formed depended on the Si/Al ratio of the starting material prior to the nucleation and crystallization of zeolite. The adjustment of the Si/Al ratio of fly ash by addition of Na2SiO4 and Al(OH)3 changed the type and CEC of zeolite. Waste solutions contained large amount of Si and little Al due to the formation of a zeolite named NaP1 in zeolite terminology with the Joint Committee of Powder Diffraction Standard (JCPDS) code of 39-0219. The alkalinity decreased largely. As a result, the CEC value of zeolite products synthesized with waste solution as alkali source decreased. The supplementation of new alkali to adjust the alkalinity of waste solution could enhance the CEC of synthesized product. It was concluded that: (1) addition of sodium halide and adjustment of the Si/Al ratio prior to synthesis can improve the quality of zeolite; (2) waste solutions produced following the zeolitization of fly ash can be reused as an alkali source in the activation of fly ash; zero-emission of waste solution in the synthesis of zeolite from fly ash is possible. 相似文献
19.
Silicon-29 “magic angle spinning” nuclear magnetic resonance (NMR) spectroscopy has been used to study the changes in local Si environment during Al, Si ordering in synthetic cordierite, Mg2Al4Si5O18. In the most disordered form, crystallized from a glass, eight distinct tetrahedral sites for silicon can be identified and assigned, while there are only two distinguishable Si sites in the well-annealed ordered form. This allows the changes in the Si site environments to be determined as a function of annealing time for the transformation from the disordered to the ordered form. The first crystallized state has a considerable degree of partitioning between T1 and T2 sites with the following site occupancies: T1 ? Al:Si=0.80:0.20, T2?Al:Si=0.27:0.73 The changes in Si environment are approximately linear with log time. The measured values of 29Si isotropic chemical shift do not fit well to previously determined correlations of shift with various structural parameters. 相似文献