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通过密度泛函理论模拟了H_2O_2和SO_2气体在矿物氧化物(α-Fe_2O_3)表面上的非均相反应,研究了H_2O_2和SO_2在α-Fe_2O_3(001)表面的吸附机制和氧化机制。研究结果表明,SO_2、H_2O_2均在α-Fe_2O_3(001)表面通过Fe原子进行吸附,H_2O_2相比于SO_2优先吸附在α-Fe_2O_3(001)表面,且H_2O_2在表面的赋存形式趋向于两个·OH形式吸附。通过二者共吸附的局域态密度、差分电荷密度、Mulliken电荷布局分析结果发现,SO_2和H_2O_2的共吸附形式是通过H_2O_2产生的·OH吸附在α-Fe_2O_3(001)表面,同时SO_2被H_2O_2产生的·OH氧化[S(SO_2)-电荷布局:0. 79 e→1. 32 e; O(H_2O_2)-电荷布局:-0. 77 e→-1. 11 e]形成·OH+SO_2团簇。模拟结果表明大气微量气体H_2O_2能够在矿物氧化物表面介导SO_2吸附并促进SO_2的转化,为理解H_2O_2在大气中非均相氧化SO_2的反应过程提供了理论依据。 相似文献
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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
6.
纤钡锂石产于湖南临武香花岭地区一水晶矿锂云母石英脉晶洞中,与锂云母、石英等矿物共生。矿物为浅黄白色,丝绢光泽,呈针状、纤维状、放射状或平行束状集合体,纤维长达1厘米。经X射线单晶及粉晶衍射测定:该矿物属斜方晶系,空间群Ccca,晶胞参数:a=13.60(?),b=20.24(?),e=5.16(?)。最强衍射线为:10.12(?)(100) 4.05(?)(78) 3.39(?)(91) 2.605(?)(31)2.390(?)(28)。 相似文献
7.
N. V. Chukanov R. K. Rastsvetaeva I. V. Pekov A. E. Zadov R. Allori N. V. Zubkova G. Giester D. Yu. Puscharovsky K. V. Van 《Geology of Ore Deposits》2009,51(7):588-594
Biachellaite, a new mineral species of the cancrinite group, has been found in a volcanic ejecta in the Biachella Valley,
Sacrofano Caldera, Latium region, Italy, as colorless isometric hexagonal bipyramidal-pinacoidal crystals up to 1 cm in size
overgrowing the walls of cavities in a rock sample composed of sanidine, diopside, andradite, leucite and hauyne. The mineral
is brittle, with perfect cleavage parallel to {10$
\bar 1
$
\bar 1
0} and imperfect cleavage or parting (?) parallel to {0001}. The Mohs hardness is 5. Dmeas = 2.51(1) g/cm3 (by equilibration with heavy liquids). The densities calculated from single-crystal X-ray data and from X-ray powder data
are 2.515 g/cm3 and 2.520 g/cm3, respectively. The IR spectrum demonstrates the presence of SO42−, H2O, and absence of CO32−. Biachellaite is uniaxial, positive, ω = 1.512(1), ɛ = 1.514(1). The weight loss on ignition (vacuum, 800°C, 1 h) is 1.6(1)%.
The chemical composition determined by electron microprobe is as follows, wt %: 10.06 Na2O, 5.85 K2O, 12.13 CaO, 26.17 Al2O3, 31.46 SiO2, 12.71 SO3, 0.45 Cl, 1.6 H2O (by TG data), −0.10 −O=Cl2, total is 100.33. The empirical formula (Z = 15) is (Na3.76Ca2.50K1.44)Σ7.70(Si6.06Al5.94O24)(SO4)1.84Cl0.15(OH)0.43 · 0.81H2O. The simplified formula is as follows: (Na,Ca,K)8(Si6Al6O24)(SO4)2(OH)0.5 · H2O. Biachellaite is trigonal, space group P3, a =12.913(1), c = 79.605(5) ?; V = 11495(1) ?3. The crystal structure of biachellaite is characterized by the 30-layer stacking sequence (ABCABCACACBACBACBCACBACBACBABC)∞. The tetrahedral framework contains three types of channels composed of cages of four varieties: cancrinite, sodalite, bystrite
(losod) and liottite. The strongest lines of the X-ray powder diffraction pattern [d, ? (I, %) (hkl)] are as follows: 11.07 (19) (100, 101), 6.45 (18) (110, 111), 3.720 (100) (2.1.10, 300, 301, 2.0.16, 302), 3.576 (18) (1.0.21,
2.0.17, 306), 3.300 (47) (1.0.23, 2.1.15), 3.220 (16) (2.1.16, 222). The type material of biachellaite has been deposited
at the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, registration number 3642/1. 相似文献
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Steeve Gréaux Yoshio Kono Norimasa Nishiyama Takehiro Kunimoto Kouhei Wada Tetsuo Irifune 《Physics and Chemistry of Minerals》2011,38(2):85-94
The thermoelastic parameters of synthetic Ca3Al2Si3O12 grossular garnet were examined in situ at high-pressure and high-temperature by energy dispersive X-ray diffraction, using
a Kawai-type multi-anvil press apparatus coupled with synchrotron radiation. Measurements have been conducted at pressures
up to 20 GPa and temperatures up to 1,650 K: this P, T range covered the entire high-P, T stability field of grossular garnet. The analysis of room temperature data yielded V
0,300 = 1,664 ± 2 ?3 and K
0 = 166 ± 3 GPa for K￠0 K^{\prime}_{0} fixed to 4.0. Fitting of our P–V–T data by means of the high-temperature third order Birch–Murnaghan or the Mie–Grüneisen–Debye thermal equations of state,
gives the thermoelastic parameters: (∂K
0,T
/∂T)
P
= −0.019 ± 0.001 GPa K−1 and α
0,T
= 2.62 ± 0.23 × 10−5 K−1, or γ
0 = 1.21 for fixed values q
0 = 1.0 and θ
0 = 823 (Isaak et al. Phys Chem Min19:106–120, 1992). From the comparison of fits from two different approaches, we propose to constrain the bulk modulus of grossular garnet
and its pressure derivative to K
T0 = 166 GPa and K￠T0 K^{\prime}_{T0} = 4.03–4.35. Present results are compared with previously determined thermoelastic properties of grossular-rich garnets. 相似文献
9.
采用CO碳化SiO2和Al3O4负载的Co(NO3)2的方法制备了SiO2和Al3O4负载的Co2C催化剂,采用N2物理吸附、X射线衍射和H2-程序升温还原技术对催化剂进行了表征,并用于催化费托合成反应中.结果显示,需要较长碳化时间才可合成负载的Co2C催化剂;所制催化剂表现出CO加氢生成高碳醇的催化性能,其原因可能在于催化剂表面存在的金属Co物种使CO解离,表面Co物种有利于CO插入,从而导致醇的生成,但体相Co2C则不具有催化活性. 相似文献
10.
Thermodynamic analysis of the system Na2O-K2O-CaO-Al2O3-SiO2-H2O-F2O–1 provides phase equilibria and solidus compatibilities of rock-forming silicates and fluorides in evolved granitic systems and associated hydrothermal processes. The interaction of fluorine with aluminosilicate melts and solids corresponds to progressive fluorination of their constituent oxides by the thermodynamic component F2O–1. The chemical potential (F2O–1) buffered by reaction of the type: MOn/2 (s)+n/2 [F2O–1]=MFn (s, g) where M=K, Na, Ca, Al, Si, explains the sequential formation of fluorides: carobbiite, villiaumite, fluorite, AlF3, SiF4 as well as the common coexistence of alkali- and alkali-earth fluorides with rock-forming aluminosilicates. Formation of fluorine-bearing minerals first starts in peralkaline silica-undersaturated, proceeds in peraluminous silica-oversaturated compositions and causes progressive destabilization of nepheline, albite and quartz, in favour of villiaumite, cryolite, topaz, chiolite. Additionally, it implies the increase of buffered fluorine solubilities in silicate melts or aqueous fluids from peralkaline silica-undersaturated to peraluminous silica-oversaturated environments. Subsolidus equilibria reveal several incompatibilities: (i) topaz is unstable with nepheline or villiaumite; (ii) chiolite is not compatible with albite because it only occurs only at very high F2O–1 levels. The stability of topaz, fluorite, cryolite and villiaumite in natural felsic systems is related to their peralkalinity (peraluminosity), calcia and silica activity, and linked by corresponding chemical potentials to rock-forming mineral buffers. Villiaumite is stable in strongly peralkaline and Ca-poor compositions (An<0.001). Similarly, cryolite stability requires coexistence with nearly-pure albite (An<2). Granitic rocks with Ca-bearing plagioclase (An>5) saturate with topaz or fluorite. Crystallization of topaz is restricted to peraluminous conditions, consistent with the presence of Li-micas or anhydrous aluminosilicates (cordierite, garnet, andalusite). Fluorite is predicted to be stable in peraluminous biotite granites, amphibole-, clinopyroxene- or titanite-bearing calc-alkaline suites as well as in peralkaline granitic and syenitic rocks. Fluorine concentrations in felsic melts buffered by the coexistence of F-bearing minerals and feldspars increase from peralkaline through metaluminous to mildly peraluminous compositions. At low-temperature conditions, the hydrothermal evolution of peraluminous granitic and greisen systems is controlled by white mica-feldspar-fluoride equilibria. With decreasing temperature, topaz gradually breaks down via: (i) (OH)F–1 substitution and fluorine transfer to fluorite by decalcification of plagioclase below 600 °C, (ii) formation of muscovite and additional fluorite at 475–315 °C, and (iii) formation of paragonite and cryolite, consuming F-rich topaz and albite below 315 °C. These equilibria explain the absence of magmatic fluorite in Ca-bearing topaz granitic rocks; its abundance in hydrothermal rocks is due to: (i) closed-system defluorination of topaz, (ii) open-system decalcification of plagioclase or (iii) hydrolytic alteration. These results provide a complete framework for the investigation of fluorine-bearing mineral stabilities in felsic igneous suites.Electronic Supplementary Material Supplementary material is available in the online version of this article at . A link in the frame on the left on that page takes you directly to the supplementary material.Editorial responsibility: T.L. Grove 相似文献
11.
N. V. Chukanov R. K. Rastsvetaeva S. N. Britvin A. A. Virus D. I. Belakovskiy I. V. Pekov S. M. Aksenov B. Ternes 《Geology of Ore Deposits》2011,53(8):767-774
A new heterophyllosilicate mineral schüllerite was found in the L?hley basalt quarry in the Eifel volcanic region, Germany,
as a member of the late mineral assemblage comprising nepheline, leucite, augite, phlogopite, magnetite, titanite, fresnoite,
barytolamprophyllite, fluorapatite, perovskite, and pyrochlore. Flattened brown crystals of schüllerite up to 0.5 × 1 × 2
mm in size and their aggregates occur in miarolic cavities of alkali basalt. The mineral is brittle, with a Mohs hardness
3–4 and perfect cleavage parallel to (001). D
calc = 3.974 g/cm3. Its IR spectrum is individual and does not contain bands of OH−, CO32− or H2O. Schüllerite is biaxial (−), α = 1.756(3), β = 1.773(4), γ = 1.780(4), 2V
meas = 40(20)°. Dispersion is weak, r < ν. Pleochroism is medium X > Y > Z, brown to dark brown. Chemical composition (electron microprobe, mean of five-point analyses, Fe2+/Fe3+ ratio determined by the X-ray emission spectroscopic data, wt %): 3.55 Na2O, 0.55 K2O, 3.89 MgO, 2.62 CaO, 1.99 ArO, 28.09 BaO, 3.43 FeO, 8.89 Fe2O3, 1.33 Al2O3, 11.17 TiO2, 2.45 Nb2O5, 26.12 SiO2, 2.12 F, −0.89 -O=F2, 98.98 in total. The empirical formula is (Ba1.68Sr0.18K0.11Na1.05Ca0.43Mn0.47Mg0.88Fe0.442+Fe1.023+Ti1.28Nb0.17Al0.24)Σ7.95Si3.98O16.98F1.02. The crystal structure was refined on a single crystal. Schüllerite is triclinic, space group P1, unit cell parameters: a = 5.4027(1), b = 7.066(4), c = 10.2178(1)?, α = 99.816(1), β = 99.624(1), γ = 90.084(1)°, V = 378.75(2) ?3, Z = 1. The strongest lines of the X-ray powder diffraction pattern [d, ?, (I, %)]: 9.96(29), 3.308(45), 3.203(29), 2.867(29), 2.791(100), 2.664(46), 2.609(36), 2.144(52). The mineral was named in honor
of Willi Schüller (born 1953), an enthusiastic, prominent amateur mineral collector, and a specialist in the mineralogy of
Eifel. Type specimens have been deposited at the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow,
registration no. 3995/1,2. 相似文献
12.
四川地质局二O七地质队物探组 《物探与化探》1979,3(2):33-38
本文介绍根据井中磷矿天然伽玛强度利用回归分析方法计算P2O5品位,顺便也谈谈在钙芒硝矿上的应用效果,以此说明统计分析方法应用在物探测井工作中的必要性和有效性。 相似文献
13.
N. V. Chukanov R. K. Rastsvetaeva I. V. Pekov A. E. Zadov 《Geology of Ore Deposits》2007,49(8):752-757
Alloriite, a new mineral species, has been found in volcanic ejecta at Mt. Cavalluccio (Campagnano municipality, Roma province,
Latium region, Italy) together with sanidine, biotite, andradite, and apatite. The mineral is named in honor of Roberto Allori
(b. 1933), an amateur mineralogist and prominent mineral collector who carried out extensive and detailed field mineralogical
investigations of volcanoes in the Latium region. Alloriite occurs as short prismatic and tabular crystals up to 1.5 × 2 mm
in size. The mineral is colorless, transparent, with a white streak and vitreous luster. Alloriite is not fluorescent and
brittle; the Mohs’ hardness is 5. The cleavage is imperfect parallel to {10
0}. The density measured with equilibration in heavy liquids is 2.35g/cm3 and calculated density (D
calc) is 2.358 g/cm3 (on the basis of X-ray single-crystal data) and 2.333 g/cm3 (from X-ray powder data). Alloriite is optically uniaxial, positive, ω = 1.497(2), and ɛ = 1.499(2). The infrared spectrum
is given. The chemical composition (electron microprobe, H2O determined using the Penfield method, CO2, with selective sorption, wt %) is: 13.55 Na2O, 6.67 K2O, 6.23 CaO, 26.45 Al2O3, 34.64 SiO2, 8.92 SO3, 0.37 Cl, 2.1 H2O, 0.7 CO2, 0.08-O = Cl2, where the total is 99.55. The empirical formula (Z = 1) is Na19.16K6.21Ca4.87(Si25.26Al22.74O96)(SO4)4.88(CO3)0.70Cl0.46(OH)0.76 · 4.73H2O. The simplified formula (taking into account the structural data, Z = 4) is: [Na(H2O)][Na4K1.5(SO4)] · [Ca(OH,Cl)0.5](Si6Al6O24). The crystal structure has been studied (R = 0.052). Alloriite is trigonal, the space group is P31c; the unit-cell dimensions are a = 12.892(3), c = 21.340(5) ?, and V = 3071.6(15) ?3. The crystal structure of alloriite is based on the same tetrahedral framework as that of afghanite. In contrast to afghanite
containing clusters [Ca-Cl]+ and chains ...Ca-Cl-Ca-Cl..., the new mineral contains clusters [Na-H2O]+ and chains ...Na-H2O-Na-H2O.... The strongest reflections in the X-ray powder diffraction pattern [d, ? (I, %)(hkl)] are: 11.3(70)(100), 4.85(90)(104), 3.76(80)(300), 3.68(70)(301), 3.33(100)(214), and 2.694(70)(314, 008). The type material
of alloriite is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow. The registration number
is 3459/1.
Original Russian Text ? N.V. Chukanov, R.K. Rastsvetaeva, I.V. Pekov, A.E. Zadov, 2007, published in Zapiski Rossiiskogo Mineralogicheskogo
Obshchestva, 2007, No. 1, pp. 82–89.
A new mineral alloriite and its name were accepted by the Commission on New Minerals and Mineral Names, Russian Mineralogical
Society, May 8, 2006. Approved by the Commission on New Minerals and Mineral Names, International Mineralogical Association,
August 2, 2006. 相似文献
14.
根据X射线衍射(XRD)分析发现: A Fe3(SO4)2(OH)6(A=K+、H3O+)系列铁钒的XRD数据十分相近,难以用XRD区别,需通过能谱(EDS)辅助分析,才能区分此类铁矾。另外,此类铁矾的003和107面网间距d随K+含量增大而增大,且呈一元三次方程的关系;而033和220面网间距d随K+含量增大而减小,呈一元二次方程的关系。对该现象从铁矾晶体结构方面进行解释:K+、H3O+离子位于较大空隙中,且沿着Z轴方向排列,当K+、H3O+离子之间相互替换时,会导致该铁矾晶体结构在Z轴方向有较明显的变化。 相似文献
15.
采用等温溶解平衡法开展了三元体系K+,Mg2+∥B4O72--H2O 348K的稳定相平衡研究,获得溶解度数据及平衡液相的密度,折光率,pH值。根据溶解度数据绘制了三元体系稳定相图。该三元体系在348K时的稳定相图含有一个共饱点E、两条单变量曲线AE,BE和两个结晶相区MgB4O7.9H2O(AECA)和K2B4O7·4H2O(BEDB)。共饱点的平衡固相组成为MgB4O7·9H2O和K2B4O7·4H2O,对应的平衡液相组成为w(K2B4O7)=42.28%、w(MgB4O7)=8.11%。研究结果表明,该三元体系属于简单共饱和型,无复盐和固溶体形成。K2B4O7·4H2O和MgB4O7·9H2O互相存在盐溶作用,使得这两种盐的溶解度明显增大。平衡液相的密度、折光率均随溶液中K2B4O7质量分数的增大而增大。 相似文献
16.
M. N. Taran K. Langer I. Abs-Wurmbach D. J. Frost A. N. Platonov 《Physics and Chemistry of Minerals》2004,31(9):650-657
Pyrope-knorringite garnets, Mg3(Al1-X Cr3+X)2Si3O12 with X=0.25, 0.50, and 1.00, were synthesized between 9 and 16 GPa and 1300 and 1600 °C, using multianvil high-pressure techniques. The garnets with X=0.25 and 0.50 are fine-grained, pink and violet in color. The end-member knorringites with X=1.00 are black when compact and gray when coarse-grained. The fine powder is greenish gray in natural light and pale pink under a tungsten lamp. Powder remission spectra in the wavenumber range 30 000–10 000 cm–1 on finely powdered crystals were measured by two different methods: (I.) by the use of a small integrating sphere for small samples or (II.) microscope-spectrometric measurement using diffusely reflected radiation from a 45° illuminated microsample. Both methods yielded similar diffuse reflectance spectra. The following crystal-field parameters of [6]Cr3+ were determined for garnets with X=0.25, 0.50, 1.00: 10 Dq=17 856, 17 596, 17 286 cm–1; and B=654, 677, 706 cm–1; nephelauxetic ratio =(Bfield/Bfree)= 0.71, 0.74, 0.77. The -values indicate decreasing covalency of the Cr–O bond with increasing Cr content. The 10 Dq value for together with the mean Cr–O distance in end-member knorringite, 1.96 Å (Novak and Gibbs 1971), were used to calculate from the spectral data, local mean Cr–O distances (Langer 2001a) as a function of composition. The results indicate relatively strong local site relaxation with a value of =0.77. 相似文献
17.
西大别造山带红安高压榴辉岩主要矿物为石榴石、绿辉石、冻蓝闪石、石英和绿帘石,有时可见蓝闪石、多硅白云母和钠云母。石榴石具有生长环带且边缘成分变化大,可分为代表峰期的Ⅰ型边（XMg高、Grs低）和受退变质改造的Ⅱ型边（XMg低、Grs高）。石榴石内蓝闪石包体发育冻蓝闪石退变边,说明包体不能完全反映进变质条件。基质绿辉石比包体绿辉石Jd含量低,在一个晶体内成分有明显变化和沿解理缝发育冻蓝闪石,显示峰后绿辉石有成分变化和退变质改造。基质中冻蓝闪石晶体较大,核部见有蓝闪石残留,说明二者有成因联系。冻蓝闪石和绿辉石都发育后成合晶结构,石榴石有韭闪石的反应冠状体。在THERMOCALC程序计算的P-T视剖面图中,石榴石Ⅰ型边反映的峰期P-T条件为2.4~2.6GPa、570~585℃,和基质中多硅白云母Si含量等值线限定范围一致,对应硬柱石蓝闪石榴辉岩组合。石榴石Ⅱ型边P-T范围为1.9~2.4GPa、530~570℃,低于峰期条件。在可能的峰后降压过程中,岩石先后主要经历了硬柱石脱水生成绿帘石和蓝闪石、绿辉石退变为冻蓝闪石的反应阶段。绿辉石、冻蓝闪石发育的后成合晶说明晚期退变过程缺乏流体,石榴石的韭闪石冠状体也可能在该阶段产生,都受局部成分域控制。红安高压榴辉岩中各矿物与成分代表不同变质阶段,称其为冻蓝闪石榴辉岩只是对现有主要组成矿物的描述,不是基于共生关系的严格岩石学命名。 相似文献
18.
磷矿矿石沒有标誌性的物理性質,因此在一般情形下很难凭它的外貌来确定它是否磷矿石。我国的磷矿石既有呈致密块状的也有呈礫石狀的,顏色也是各种各样的。所以寻找磷矿必須借助于化学試剂。目前所用的最广泛的也是最简便的方法,是用鉬酸銨的飽和水溶液与濃硝酸混合溶液作試剂,滴在岩石上,如果岩石含磷达万分之几就岀現黄色沉淀。 相似文献
19.
The pyrite-type FeO2and FeO2H were synthesized at the pressure-temperature conditions relevant to Earth’s deep lower mantle.Through the water-iron reaction,the pyrite-phase is a good candidate to explain the chemical heterogeneities and seismological anomalies at the bottom of the mantle.The solid solution of pyrite-type FeO2and FeO2H,namely the FeO2Hx(0≤x≤1),is particularly interesting and introduces puzzling chemical states for both the O and H atoms in the deep mantle.While the role of H in the FeO2–FeO2H system has been primarily investigated,discrepancies remain.In this work,we summarize recent progress on the pyrite-phase,including FeO2,FeO2H,and FeO2Hx,which is critical for understanding the water cycling,redox equilibria,and compositional heterogenicities in the deep lower mantle. 相似文献
20.
为研究亚硝酸(HONO)在γ-Al_2O_3(110)表面非均相氧化SO_2的机理,基于密度泛函理论(density functional theory,DFT)的第一性原理计算了SO_2和HONO在γ-Al_2O_3(110)表面的吸附机制和氧化机制。结果表明,SO_2以分子的形式吸附在完整或缺陷的γ-Al_2O_3(110)表面,而HONO仅在完整表面上以分子的形式存在。表面氧缺陷的存在不仅会增强SO_2和HONO的吸附强度,而且能诱导HONO在含氧缺陷表面的分解(HONO→NO+·OH)。通过局域态密度(partial density of states,PDOS)和Mulliken电荷布局分析表明,HONO的分解遵循Haber-Weiss机制。当SO_2和HONO共同吸附在氧缺陷表面时,HONO分解产生·OH,氧化SO_2形成HOSO_2团簇分子。该研究不仅有助于理解HONO在矿物氧化物表面氧化SO_2的作用,而且为解释大气硫酸盐气溶胶的形成提供了理论依据。 相似文献