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沸石是一族含水的碱或碱土金属铝硅酸盐矿物 ,是当今世界各国十分重视的无机微孔材料 .天然沸石有很大的应用前途 ,但目前与人工合成分子筛比较 ,它的工业应用仍处于初级阶段 .真正得到广泛应用的是具有纯度高、孔径均一、比表面积大、离子交换和吸附性能强等特点的合成沸石 .尽管目前已合成了各种各样的沸石分子筛 ,但均是利用了纯的化工原料 .随着其他行业对高活性原料的需求增加 ,制备分子筛所需的硅、含铝原料和碱的供应日趋紧张 ,价格不断上涨 ,使得合成分子筛的成本较高 ;另外工艺复杂、能耗高 ,特别是大孔径的分子筛 ,其合成常常需要… 相似文献
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为了实现纳米TiO2的固定化负载,提高材料对污染物的光催化效率,采用静电自组装方法制备了天然斜发沸石负载纳米TiO2光催化材料。采用硅烷偶联剂(OCH3)3Si(CH2)3SH干法改性斜发沸石,采用30%H2O2/HOAc氧化剂将偶联剂巯基基团(—SH)氧化为易电离的磺酸基基团(—SO3H),带负电荷的沸石与钛聚合阳离子在静电引力的作用下自发地组装在一起,经一定温度的焙烧得到斜发沸石负载纳米TiO2光催化材料。采用XRD和SEM对材料进行分析和表征,采用甲基橙染料评价材料的吸附和光催化性能,结果表明:沸石负载纳米TiO2对甲基橙染料具有吸附与光催化的协同作用,静电自组装方法制备的材料的光催化性能较传统方法有所提高。 相似文献
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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
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《矿物学报》2016,(3)
采用天然斜发沸石吸附去除水中氨氮,利用X射线衍射(XRD)和X荧光光谱(XRF)分析沸石的物相组成和化学成分。通过批试验考察p H、氨氮初始浓度和温度对沸石吸附氨氮的影响,通过吸附等温线、吸附热力学和吸附动力学的研究探讨天然斜发沸石吸附氨氮的机理。溶液p H=8时沸石对氨氮的吸附效果最佳。Freundlich吸附等温线较Langmuir能更准确描述天然斜发沸石吸附氨氮的过程,该吸附过程属优惠吸附。对吸附热力学参数计算得到吉布斯自由能变ΔG~00,熵变ΔH~00,说明天然斜发沸石吸附氨氮是自发的吸热过程;熵变ΔS~00说明氨氮在沸石上的分布较在水溶液中的分布倾向无序。吸附动力学符合准二级动力学方程,且随着氨氮初始浓度的增大,吸附反应的优惠程度降低。运用颗粒内扩散模型对实验数据的拟合结果表明吸附过程分为两个阶段:前30分钟主要是外表面吸附,30分钟后主要是颗粒内扩散。 相似文献
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天然丝光沸石表面重构改性及其在水中去除重金属的应用 总被引：2，自引：1，他引：1
天然丝光沸石作为一种绿色廉价多孔材料广泛应用于环境治理中去除重金属,目前报道的天然沸石对重金属的去除率多在60%～90%,提升其去除效率已成为研究热点。本文采用正硅酸乙酯对天然丝光沸石进行表面重构改性,通过TEM、XRD、BET等手段表征其形貌和结构。结果表明:正硅酸乙酯水解生成的SiO_2可与天然丝光沸石复合形成新颖的"SiO_2/丝光沸石",原沸石表面包覆了新生纳米SiO_2孔结构,同时没有损坏原始沸石的多孔结构,使改性沸石材料兼具了天然丝光沸石和纳米SiO_2孔结构优点,增强了对重金属离子的吸附能力。该改性材料对水中Pb~(2+)、Cd~(2+)、Zn~(2+)和Mn~(2+)的最高吸附率为99. 3%、97. 1%、98. 3%和97. 0%,且极少解吸,性能稳定。考虑经济成本并保证合适吸附率的情况下选择吸附效率最佳的投加量,得到改性材料对初始浓度10 mg/L的Pb~(2+)、Cd~(2+)、Zn~(2+)、Mn~(2+)溶液的最佳投加量分别为0. 5 g/L、2 g/L、2 g/L、5 g/L,可为中试和规模应用提供参考。较之焙烧、酸、碱、盐和有机改性,本改性方式对多种重金属均有高的吸附率,并显现出操作简便、成本低和环境友好等优势,具有较好应用前景。 相似文献
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沸石类矿物因具有阳离子交换作用、催化作用及分子筛作用.它作为工业原料、农业原料、以及公害处理材料有多方面利用价值,很值得注意,还有这种矿物在比较低温条件下脱水,产生“沸石水”,这种热的特性也使人深感兴趣.本研究是想通过用差热分析,研究日本国内产斜发涕石(Clinop-tilotite)的热特性,作为探索天然沸石生成状态的一个线索.实验方法将日本岛根县产斜发沸石选纯.在IN、KCI、NaCI、CaCI_2水溶液中进行离子交换,作成K型、Na型、Ca型沸石,然后通过加热使结构发生变化,经化学分析确认已成为所要求的沸石.然后使用“岛津制作所的A30型热分析装置”以至少33毫升/分钟的N_2进行热矢量分析、差热分析,从沸石中存在的U~+、Na~+”、Ca~(2+)的离子比率中求出 相似文献
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Water／Rock Interactions and Changes in Chemical Composition During Zeolite Mineralization 总被引：2，自引：0，他引：2
Systematic analysis and comparative study of the chemical compositons of rocks and ores from the main types of zeolite deposits in the surroundings of the Songliao Basic have shown that the process of formation of zeolite from volcanic and pyroclastic rocks is generally characterized by the relative purification of SiO2,i.e.,SiO2/Al2O3 ratios tend to increase,alkali eart elements (CaO MgO)and H2O are relatively enriched,and the alkali metals(K2O Na2O)are depleted in their total amount.The alkali metals K and Na follow different rules of migration and enrichment during the formation of mordenite and clinoptilolite.In the process of formation of mordenite more Na^ will be imported and K^ will be lost remarkably.On the contrary,in the process of formation clinoptilolite more K^ will be incorporated and Na^ will become obviously depleted. 相似文献
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为了探讨有关天然沸石降低水溶液中氟含量方面实际应用的可能性及其机理,笔者自1979年春到1982年冬断断续续开展了些试验。实验中也用雪硅钙石(建筑上加气砖废料)对笔者的观点作了进一步验证。 相似文献
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Al_2O_3和Ti在风化和热液蚀变等地球化学过程中通常被认为是不活动元素,两者的比值Al_2O_3/Ti常被用来指示地球化学作用过程。通过对中国157件火成岩样品元素含量平均值的统计发现,火成岩样品中Al_2O_3/Ti与SiO_2含量值之间存在着较好的幂函数关系:ln(Al_2O_3/Ti)=0.073×SiO_2-0.89,式中Al_2O_3和SiO_2和Ti含量单位均为%。本文基于得到的经验方程和TAS图解构建了一个新的判别岩石类型的图解——Al_2O_3-Ti图解。该图解可以区分酸性岩、中酸性岩、中性岩、中基性岩-基性岩四类岩性。通过对三个火成岩风化剖面的研究发现,花岗岩风化剖面从新鲜基岩到风化形成的土壤在Al_2O_3-Ti图解中均落在酸性岩区,花岗闪长岩风化剖面从新鲜基岩到风化形成的土壤样品均落在中酸性岩区,玄武质安山岩风化剖面从新鲜基岩到风化形成的土壤样品均落在中基性岩-基性岩区。不同风化程度的风化产物与其母岩在Al_2O_3-Ti图解中所在的区域一致,即Al_2O_3-Ti图解可以用来追溯火成岩风化产物的母岩岩性。通过对胶东焦家金矿和豫西牛头沟金矿两个矿区岩石的研究发现,黑云母花岗岩从新鲜岩石到其蚀变岩及其形成矿石的样品在Al_2O_3-Ti图解中均落在酸性岩区。玄武质安山岩从新鲜岩石到其蚀变岩及其形成矿石的样品在Al_2O_3-Ti图解中均落在中基性岩-基性岩区。即不同蚀变程度的蚀变产物与其原岩在Al_2O_3-Ti图解中所在的区域一致,这表明新构建的Al_2O_3-Ti图解可以用来示踪蚀变岩的原岩性质。 相似文献
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Ismael S. Ismael Ahmed Melegy Tomas Kratochvíl 《Geotechnical and Geological Engineering》2012,30(1):253-262
Hazardous metal cations enter water through the natural geochemical route or from the industrial wastes. Their separation
and removal can be achieved by adsorptive accumulation of the cations on a suitable adsorbent. In the present work, toxic
Pb(II) ions are removed from water by accumulating it on the surface of natural zeolite in three different forms; one untreated
and two treated samples, one sample treated with 2 M HCI solution and other is treated with 3 M NaOH solution. Natural zeolite
is mainly composed of clinoptilolite, and mordenite, with amount of non-zeolite phase (smectite and illite) and C and CT opal.
The adsorption experiments are carried out using a batch process in environments of different pH, initial Pb(II) concentration,
interaction time and amount of zeolites. Treated zeolite samples show high exchange capacity for Pb(II) compared to untreated
sample, however, acid-treated sample shows an exceedingly good exchange capacity. Equilibrium data fitted well with the Langmuir
isotherm model with maximum adsorption capacity of 115, 126, and 132 mg g−1 of untreated natural zeolites, alkali-treated zeolites and acid-treated zeolites respectively. The rates of adsorption were
found to confirm to pseudo-first order kinetic with good correlation and the overall rate of lead ions uptake. 相似文献
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A consistent arrangement of solidus curves for reactions involving white mica, alkali feldspar, Al2SiO5, quartz and H2O, as expressed by the components KAlO2-NaAlO2-Al2O3-SiO2-H2O, provides a generally accurate and useful model for the origin of migmatites and peraluminous granites through partial melting
of pelitic rocks. The complexities of the univariant (Na-K) reactions may be easily seen on the projection from SiO2 and H2O onto the Ab-Or-Al2O3 plane. Alternative topologies for the appearance of muscovite, paragonite and Al2SiO5 on the quartz and H2O-saturated liquidus may be eliminated by a consideration of possible compositions of liquid and solid phases and Schreinemakers'
analysis around (Na-K) invariant points. Paragonite is not likely to be an important phase on the liquidus for most melting
paths. Melting paths for natural assemblages may be easily constructed appropriate to P-T-aH2O paths in the model system. Such paths are consistent with observed textures in natural assemblages. Although general models
can be developed for decreased aH2O, it is difficult to separate such effects from those involving participation of a calcic component without careful examination
of natural assemblages and experimental calibration of appropriate reactions. 相似文献
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27Al,29Si MAS NMR studies of kaolinite and its thermal transformation products show that in the kaolinite-mullite reaction series
there is an extensive segregation of Al2O3 and SiO2 and the reaction of Al2O3 with SiO2 to form mullite is the main path of mullite formation. At about 850° C, the peak intensity of A1(V) reaches its maximum and
with the further rise of temperature the A1(V) signal completely disappears. At about 950°C, γ-Al2O3 accounts for about 71% of the material phases containing Al atoms. In the series there is no obvious presence of Al-Si spinel.
The27Al and29Si MAS NMR spectra show that there is an obvious difference between the temperature points for Al-O2(OH)4 octahedral sheet collapsing and Si-O4 tetrahedral sheet breaking down. 相似文献
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Ray Macdonald Bogus?aw Bagiński Fiorenzo Ronga Piotr Dzier?anowski Michele Lustrino Andrea Marzoli Leone Melluso 《Mineralogy and Petrology》2012,104(3-4):163-175
Matrix glass and melt inclusions in phenocrysts from pantellerite lavas of the Boseti volcanic complex, Ethiopia, record extreme fractionation of peralkaline silicic magma, with Al2O3 contents as low as 2.3?wt.%, FeO* contents up to 17?wt.% and SiO2 contents ~65?wt.%. The new data, and published data for natural and experimental glasses, suggest that the effective minimum composition for peralkaline silicic magmas has ~5?wt.% Al2O3, 13?wt.% FeO* and 66?±?2?wt.% SiO2. The dominant fractionating assemblage is alkali feldspar?+?fayalite?+?hedenbergite?+?oxides?±?quartz. Feldspar – melt relationships indicate that the feldspar is close to the minimum on the albite-orthoclase solid solution loop through the entire crystallization history. There is petrographic, mineralogical and geochemical evidence that magma mixing may have been a common process in the Boseti rhyolites. 相似文献
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Gilbert Kuepouo Hiroaki Sato Jean-Pierre Tchouankoue Mamoru Murata 《Resource Geology》2009,59(1):69-86
FeO*‐Al2O3‐TiO2‐rich rocks are found associated with transitional tholeiitic lava flows in the Tertiary Bana plutono‐volcanic complex in the continental sector of the Cameroon Line. These peculiar rocks consist principally of iron‐titanium oxides, aluminosilicates and phosphates, and occur as layers 1–3 m thick occupying the upper part of lava flows on the southwest (site 1) and northwest (site 2) sites of the complex. Mineral constituents of the rocks include magnetite, ilmenite, hematite, rutile, corundum, andalusite, sillimanite, cordierite, quartz, plagioclase, alkali feldspar, apatite, Fe‐Mn phosphate, Al phosphate, micas and fine mixtures of sericite and silica. Texturally and compositionally, the rocks can be subdivided into globular type, banded type, and Al‐rich fine‐gained massive type. The first two types consist of dark globule or band enriched in Fe‐Ti oxides and apatite and lighter colored groundmass or bands enriched in aluminosilicates and quartz, respectively. The occurrence of andalusite and sillimanite and the compositional relations of magnetite and ilmenite in the FeO*‐Al2O3‐TiO2‐rich rocks suggest temperatures of crystallization in a range of 690–830°C at low pressures. The Bana FeO*‐Al2O3‐TiO2‐rich rocks are characterized by low concentrations of SiO2 (25–54.2 wt%), Na2O + K2O (0–1%), CaO (0–2%) and MgO (0–0.5%), and high concentrations of FeO* (total iron as FeO, 20–42%), Al2O3 (20–42%), TiO2 (3–9.2%), and P2O5 (0.26–1.30%). TiO2 is positively correlated with Al2O3 and inversely correlated with FeO*. The bulk rock compositions cannot be derived from the associated basaltic magma by crystal fractionation or by partial melting of the mantle or lower crustal materials. In ternary diagrams of (Al2O3)?(CaO + Na2O + K2O)?(FeO*+ MnO + MgO) and (SiO2)?(FeO*)?(Al2O3), the compositional field of the rocks is close to that of laterite and is distinct from the common volcanic rocks, suggesting that the rocks are derived from lateritic materials by recrystallization when the materials are heated by the basaltic magmas. A hydrothermal origin is discounted because the rocks contain high‐temperature mineral assemblages and lack sulfide minerals. It is proposed that the FeO*‐Al2O3‐TiO2‐rich rocks of the Bana complex were formed by pyrometamorphism of laterite by the heat of basaltic magmas. 相似文献
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Binoy K. Saikia Banashree Mahanta Upendra N. Gupta Om P. Sahu Prasenjit Saikia Bimala P. Baruah 《Journal of the Geological Society of India》2016,88(3):339-349
Coal is one of the most available energy sources on earth. The mineralogical and geo-chemical aspects of coals are of prime importance for their utilization. The mineralogical composition, ash chemistry, and ash fusion temperature (AFT) ranges of raw and beneficiated coals are investigated in this paper. Further, the mineral matter transformation during the beneficiation processes viz. by oxidative desulfurization; alkali extraction and ultrasonication along with the relationship of the ash fusion temperature (AFT) ranges with the ash components in the coal are discussed. The major oxides present in the coal and beneficiated coal ashes include Fe2O3, Al2O3, SiO2, CaO, and MgO, which significantly affect the ash fusion temperature ranges. Initial deformation temperature (IDT) changes with the ash components and, increases with the increase in the Fe2O3 content in coal ash. With increasing concentrations of both Al2O3 and SiO2, the initial deformation temperature (IDT) also increases. The increasing and decreasing nature of the initial deformation temperature (IDT) observed is also dependent upon the CaO and MgO contents. XRD analysis of the coal samples revealed significant changes in mineral matter contents with the types of beneficiation processes adopted for coal. The minerals like chlorite, illite, montmorillonite, pyrite, calcite, aragonite, and alumina have been removed during the beneficiation processes. The FTIR spectra also indicate the presence of minerals like gypsum (G), calcite (C) aragonite (Ar), quartz (Q) and kaolinite (K) in the raw coal and their subsequent removal after the beneficiation processes. 相似文献
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Wenjun Yong E. Dachs A. C. Withers E. J. Essene 《Physics and Chemistry of Minerals》2006,33(3):167-177
The low-temperature heat capacity (C
p
) of KAlSi3O8 with a hollandite structure was measured over the range of 5–303 K with a physical properties measurement system. The standard entropy of KAlSi3O8 hollandite is 166.2±0.2 J mol−1 K−1, including an 18.7 J mol−1 K−1 contribution from the configurational entropy due to disorder of Al and Si in the octahedral sites. The entropy of K2Si4O9 with a wadeite structure (Si-wadeite) was also estimated to facilitate calculation of phase equilibria in the system K2O–Al2O3–SiO2. The calculated phase equilibria obtained using Perple_x are in general agreement with experimental studies. Calculated phase relations in the system K2O–Al2O3–SiO2 confirm a substantial stability field for kyanite–stishovite/coesite–Si-wadeite intervening between KAlSi3O8 hollandite and sanidine. The upper stability of kyanite is bounded by the reaction kyanite (Al2SiO5) = corundum (Al2O3) + stishovite (SiO2), which is located at 13–14 GPa for 1,100–1,400 K. The entropy and enthalpy of formation for K-cymrite (KAlSi3O8·H2O) were modified to better fit global best-fit compilations of thermodynamic data and experimental studies. Thermodynamic calculations were undertaken on the reaction of K-cymrite to KAlSi3O8 hollandite + H2O, which is located at 8.3–10.0 GPa for the temperature range 800–1,600 K, well inside the stability field of stishovite. The reaction of muscovite to KAlSi3O8 hollandite + corundum + H2O is placed at 10.0–10.6 GPa for the temperature range 900–1,500 K, in reasonable agreement with some but not all experiments on this reaction. 相似文献