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1.
牦牛坪矿床中钙稀土氟碳酸盐多体矿物,经扫描电镜观察和电子探针分析,表明氟碳铈矿可由矿液直接结晶或通过多体矿物的分解反应形成。与多体矿物相比较,氟碳铈矿的稀土配分模式以富La为特点。多体矿物的CaO/REE2O3(重量比)的平均值为0.131(测试值)和0.141(计算值),低于氟碳钙铈矿的理论值0.171。根据多体系列化学计量的线性关系,证明多体矿物形成于Ca^2 和CO3^2-活度较低的矿液中。这种矿液不利于典型氟碳钙铈矿的形成。  相似文献   

2.
用选区电子衍射和高分辨电子显微术研究钙稀土氟碳酸盐矿物及其衍生物多晶体结构,发现三种不同的氟碳铈矿与直氟碳钙铈矿具8:6新规则混层结构,确定了各自的晶体结构类型,晶胞参数,堆垛模式及晶体化学式等。高分辨像的观察分析,揭示出了三种B8S6规则混层结构中的Ce-F离子层以及两个Ce-F离子层之间的CO3离子组具有不同的排列方式,观察和讨论了上述规则支结构中的无序夹层及堆垛层错等非均匀结构现象。  相似文献   

3.
四川冕宁钙-铈氟碳酸盐矿物中的晶畴结构   总被引:1,自引:1,他引:0  
用透射电子显微技术研究了四川冕宁霓石碱性花岗岩中的钙-铈氟碳酸盐矿物系列的晶畴结构,发现该系列矿物中的相畴。反相畴是由于晶格沿「0001」方向产生0.471nm的位移,即沿「0001」面的层错引起。在混层结构的畴区内确定了B4S2型规则混层结构匠3R新多型并观察到有序混层结构中存在无序结构微畴及在无序结构中的有昆层结构微畴。  相似文献   

4.
碳酸盐类矿物的物相分析对研究与碳酸盐矿物有关的矿床成矿规律中极为重要。本文讨论了方解石族碳酸盐矿物中钙、镁和铁的碳酸盐矿物相分析的化学分析法。根据碳酸盐矿物有一定的组成:利用不同的碳酸盐矿物溶解性能的差别和在一定条件下被溶下的钙、镁和铁(Ⅱ)量的比例关系,判断是类质同象系还是独立矿物并确定类质同象矿物中各原子间的比例关系,可以测定较为富集的碳酸盐矿物中的方解石、白云石、镁铁白云石、菱铁矿、菱镁矿和菱镁菱铁矿系列等矿物物量。方法简易、快速,曾与X射线分析互为对照,结果基本一致。  相似文献   

5.
用选区电子衍射(SAED)和高分辨电子显微术(HREM)研究钙稀土氟碳酸盐矿物及其衍生多晶体结构,发现三种不同的氟碳铈矿(B)与直氟碳钙铈矿(S)具8:6新规则混层结构(B_6S_6-Ⅰ、B_8S_6-Ⅱ和S_8S_6-Ⅲ),确定了各自的晶体结构类型、晶胞参数、堆垛模式及晶体化学式等。高分辨像的观察分析,揭示出三种B_8S_6规则混层结构中的Ce-F离子层以及两个Ce-F离子层之间的CO_3离子组具有不同的排列方式,观察和讨论了上述规则混层结构中的无序夹层及堆垛层错等非均匀结构现象  相似文献   

6.
氟碳酸盐是重要的稀土矿物,本研究利用增量模式讨论其氧同位素分馏性质,计算的氧同位素富集顺序为:氟碳铈矿>Ca0.5BaCe2(CO3)4F>白云鄂博矿>黄河矿>氟碳铈钡矿。结合白云鄂博矿床氟碳酸盐矿物氧同位素分析数据,可看出理论预测的分馏顺序与实际相一致,计算的成矿温度与矿区地质相吻合。由于钡系列氟碳酸盐矿物可看成是CeCO3F与BaCO3层状堆垛衍生的结果,故对矿物体衍生过程中氧同位素分馏的变化进行了讨论,并由此预测了中华铈矿和氟碳钡铈矿的氧同位素分馏曲线。  相似文献   

7.
萤石是简单氟化物的主要矿物。氟化物在自然界中分布不多,与氟组成化合物的元素数目虽可达15种左右,但其中只以钙起着独特的作用,形成较为常见的萤石CaF2。萤石由于其低熔点,大部分用于冶金工业作为熔剂;在化学工业,萤石是制取氢氟酸等氟的化合物的原料;无色的萤石晶体用于制作光学仪器;另外,在制陶工业萤石也有广泛应用。  相似文献   

8.
钡矿石的物相分析   总被引:1,自引:0,他引:1  
关于钡的物相分析,仅见到龚美菱等制定的测定钡碳酸盐、重晶石和钡长石的物相分析方法。为配合某矿区物质成分研究,我们进行了钡矿石的化学物相分析研究,拟定了分析钡的碳酸盐、氟碳酸盐、重晶石、钡铁钛石、包头矿等五相的分析方法,经生产实践表明本方法基本上满足了地质及矿物物质成分研究的要求,比地质上原来用的颗粒矿物定量法,精  相似文献   

9.
针对微山稀土矿不同品位的稀土精矿,采用化学分析、配分分析、X射线衍射分析、扫描电镜能谱分析、偏光显微镜等分析方法对微山稀土矿的化学成分、稀土元素分布、矿物组成、矿物嵌布特征等进行了研究,结果表明:不同品位的微山稀土精矿中稀土矿物主要由氟碳铈矿、氟碳钙铈矿、碳铈钠石、碳酸锶铈矿组成,主要杂质矿物是方解石、重晶石、天青石和菱锶矿,这是区别于其他氟碳铈矿的典型特征;轻稀土元素占稀土总量的98.5%以上,典型富铈低钇型轻稀土,矿中的钙、锶、钡等杂质较多;40%品位的稀土精矿是微山稀土企业主流产品,稀土矿物的解离度较高,单体矿物均在66%以上,稀土矿物与碳酸盐矿物、重晶石、天青石、硫化矿物、磷灰石连生。通过对微山稀土矿特性研究,为稀土矿的加工提供矿物学依据。  相似文献   

10.
火星表面有含碳酸盐岩石的新证据表明,该星球上至少有某些远古的水域并不像先前所认为的酸性那样强。Beth-any Ehlmann及其同事应用在Mars Reconnaissance Orbiter上的一个光谱仪在一个叫做Nili Fossae的谷地区域探测到了某些碳酸盐矿物。这些矿物可能存在于被水侵蚀的火山岩中,而这些水的pH值是相对中性的。尽管火星具有形成碳酸盐的原材料成分(如水、玄武岩以及一个含有二氧化钛的大气),但科学家们在此之前一直没能在火星上找到大面积的碳酸盐。对这一神秘现象的一种主要的解释之一是:酸性的水要么已经将碳酸盐溶解,要么妨碍了碳酸盐的形成。特别是在火星的中时代,即西方纪时期,人们一直认为这是一个酸性侵蚀很常见的时期。这些新发现的碳酸盐出现在小面积的岩石接触面中(小于10平方公里),它们还伴有黏土矿物。这表明,在这些矿物质形成的时候,该局部地区的水是中性的,甚或是碱性的。(中国化工仪器网)光谱仪在火星上探测到寻觅已久的碳酸盐  相似文献   

11.
稀土离子对溶液体系中碳酸钙生成的影响   总被引:1,自引:0,他引:1  
用X射线粉末衍射、XPS光电子能谱、红外光谱以及ICP-MS等技术研究不同浓度的Ce3+,Nd3+,Tb3+,Gd3+,Lu3+对碳酸钙结晶状况的影响.稀土离子的加入有利于热力学稳定态的方解石型碳酸钙的生成,并且稀土离子能够部分的取代晶格中的钙离子,改变碳酸钙的结晶习性,在宏观上形成有序规则的排列.  相似文献   

12.
Moalla SM 《Talanta》1997,45(1):213-221
The distribution of major, trace and rare earth elements in bulk, different particle sized and strongly magnetic fractions of Lake Nasser sediments has been investigated. The elements were determined using neutron activation analysis. Statistical data processing indicates good correlation between Th, La and Ce, suggesting that accessory minerals such as monazite may play a role in controlling rare earth elements (REE) in the lake sediments. The highly significant relationship between Al and light-REE accounts for the capability of clay minerals to host these elements. In addition, principle components analysis reflects that there are only four factors which could explain about 90% of the total variance in the lake sediments. The results show also that Al, Th and REE have low contents in the sediment magnetic fraction relative to the corresponding values in the bulk sediments, whereas Fe, Mn, Ti, Co, Cr, Hf, V and Zn have higher concentrations in the same fraction than the corresponding values in the bulk sediments. This may be attributed to their incorporation in Fe-Mn minerals.  相似文献   

13.
FT-IR study of rare earth 4-aminobenzenesulfonate complexes   总被引:1,自引:0,他引:1  
The crystal structure of lanthanum 4-amino-benzenesulfonate complex has been determined by X-ray diffraction. The crystal data indicate that lanthanum and neodymium 4-amino-benzenesulfonates are isomorphous. The FT-IR spectroscopic study of rare earth 4-amino-benzenesulfonate complexes showed that the spectra of light rare earth (La, Nd, Sm, Eu) complexes are similar and so are the spectra of heavy rare earth (Dy, Er, Y) complexes. There are remarkable differences between the spectra of light rare earth and heavy rare earth complexes. Based on above results, we infer that light rare earth (La, Nd, Sm, Eu) complexes are isomorphous and three heavy rare earth (Dy, Er, Y) complexes are of a different structure but also isomorphous.  相似文献   

14.
Synthesis of rare earth compound nanosheets with uniform thickness is of potential interest to the luminescent materials. Herein, whole series of rare earth hydrates and oxides nanosheets have been synthesized by using lamellar liquid crystal as a template, except Ce and Pm. Polarizing microscope images and transmission electron microscopy images show that the lamellar liquid crystal can prevent the rare earth hydrate nanosheets from curving to nanotubes in the processes of synthesis. The synthesized nanosheets have a uniform thickness of 10–15 nm and can retain morphology after being calcined at 650 °C. After facile chemical treatment, the functionalized rare earth compounds were obtained, which have unique luminescent property.  相似文献   

15.
运用化学分析、场发射扫描电镜、X射线能谱仪及AMICS自动矿物分析系统等分析方法对白云鄂博中深部矿石弱磁尾矿中稀土的赋存状态进行研究,研究结果表明:中深部弱磁尾矿中稀土品位为9.66%,稀土矿物主要是氟碳铈矿和独居石,且二者的比例随着开采深度的增加由原来的7∶3~6∶4逐渐变化为3∶1,氟碳铈矿的比例明显增大。元素含量种类较多,矿物的组成非常复杂,嵌布粒度很细,稀土矿物在38μm粒度以下累积量超过了90%。稀土矿物主要是与铁矿物、萤石连生,解离度较高,利于稀土矿物分选。氟碳铈矿和独居石主要以单体存在,呈微细粒状、断续或者连续条带状分布于石英、闪石、铁矿物、萤石、磷灰石、霓石、方解石中。此研究结果对白云鄂博矿中深部弱磁尾矿中稀土的高效综合利用具有重要的指导意义。  相似文献   

16.
Rare‐earth halides may be reduced by rare‐earth metals (conproportionation) and, as an alternative, by unlike metals such as alkali or alkaline‐earth metals, a route first established for the production of rare‐earth metals. It has great power for exploratory research subject to enhanced reactivity at lower temperatures and the formation of alkali halide flux for crystal growth. A large number of new compounds, ternary and higher, salt‐like and (semi‐)metallic including interstitially stabilized cluster compounds has been synthesized and characterized during the last decades.  相似文献   

17.
Major, trace and rare earth elements have been measured in sediments of different layers to determine the controls of constituent minerals on the distribution of elements and sediment deposition environment in the Meghna river delta. The geochemical composition of sediments was enriched in SiO2, Ca, Mg and Ba and depleted in Al, Fe, Ti, Mn, and Sr relative to PAAS (Post-Archaen Average Shale) value. The X-ray diffraction and elemental analyses demonstrate the dominant presence of quartz, micas, feldspar, chlorite, amphibole and clay minerals in sediments. The very low contents of trace elements suggest that the oxic condition was more prevalent during sediment deposition of Pleistocene-Holocene period and reflect the massive chemical weathering by biogeochemical reactions. The enrichment of light rare earth elements and La/Yb ratio reflect the intense silicate weathering of crustal materials and the high sediment depositional rate in the Meghna river delta.  相似文献   

18.
稀土氧化物对聚丙烯等温结晶动力学的影响   总被引:4,自引:0,他引:4  
本文用差示扫描量热法测定了3种稀土氧化物对聚丙烯等温结晶行为的影响。结果表明,Avrami方程指数n、成核机理、晶体生长方式以及结晶晶型基本上不受稀土氧化物的影响。少量稀土氧化物可使结晶晶格垂直于分子链方向单位面积的界面自由能降低,结晶速率加大,其中Y_2O_3的效果最为显著,La_2O_3效果最低,混合稀土的作用效果与Y_2O_3相似。填加1wt%的Y_2O_3可使聚丙烯的结晶速度常数增大一个数量级。  相似文献   

19.
This work deals with the crystal-structure deduction of new structural types of Bi3+-M2+ oxyphosphates (M is a transition element) from HREM images. Previous studies showed the unequivocal attribution of particular HREM contrasts to the corresponding Bi/M/O-based polycationic species in similar materials. On this basis, the examination of isolated crystallites of polyphased samples led to new HREM contrasts assigned to new polycationic species in three new structural types. This helped us to solve one crystal structure, and the two other forms have been deduced through HREM image decoding. It helped to model the investigated materials from the structural point of view as well as the chemical one. The three assumed crystal structures are formed by polycationic ribbons, n tetrahedra wide, surrounded by PO4 groups, as already encountered in these series of oxyphosphates. However, here we deal with the original n= 4-6 cases, whereas, up to this work, only the n= 1-3 ribbons have been reported. The greater size of ribbons is associated with particular structural modifications responsible for complex HREM contrasts. The validity of the proposed models is verified in Part 2 of this work.  相似文献   

20.
桦甸油页岩中稀土元素赋存状态研究   总被引:3,自引:0,他引:3  
以吉林省桦甸油页岩为研究对象,采用电感耦合等离子质谱( ICP-MS)和化学逐级提取方法相结合,对油页岩中稀土元素的分布特征以及油页岩中稀土元素的赋存状态进行研究.结果表明,相对于中国煤,桦甸油页岩表现为轻稀土元素富集程度高于重稀土元素.油页岩中稀土元素与陆源碎屑岩关系密切,且陆源物质的供应相对比较稳定.轻重稀土间分馏...  相似文献   

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