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吉林露水河硅藻土在煅烧中的结构及性能的变化 总被引：1，自引：0，他引：1
应用X射线衍射、红外光谱分析、扫描电镜及化学分析方法对吉林露水河硅藻土在煅烧中的结构及性能的变化进行研究，结果表明：高温时蛋白石转变成方英石，激烈的相变温度为1160℃左右；当温度在1100℃～1200℃时，硅藻的微孔开始阻塞或消失，并出现开裂现象，硅藻的结构变得模糊，但硅藻仍保持其外形；室温～600℃，比表面积逐渐增加，600℃～1200℃比表面积则减少；室温～700℃时，pH值逐渐减小，700℃～1200℃时，pH值则逐渐增加。 相似文献
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吉林露水河硅藻土质量评价 总被引：1，自引：0，他引：1
露水河硅藻土矿是第四纪形成的沉积矿床，具有直链硅藻土和圆环硅藻土两种类型矿层。硅藻土矿的物质组成以硅藻为主，可含少量粘土矿物。SiO2主要由硅藻贡献。Al2O3主要由粘物贡献，Fe主要以Fe2O3形成被吸附在粘土矿物颗粒表面和粒间。直链硅藻土矿层厚度稳定，主要是Ⅱ级土，含Fe较高；圆环硅藻土矿层厚度有变化，大多为Ⅰ级土，含Fe低，但局部见硅藻严重破碎现象。利用SiO2-密度相关图解，可适时监测硅藻土品质。 相似文献
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分布于雷州半岛南部火山湖盆及火山岩洼地内的田洋组,是第四纪中更新世晚期至晚更新世早-中期沉积的一套内陆湖相地层体,以富含硅藻为主要特征.其岩性组合下部由粘土质硅藻土、含粘土硅藻土和硅藻土组成,中部以含硅藻粘土和硅藻质粘土为主,上部为粘土质硅藻土和硅藻土.就单个湖盆而言,其岩性组合变化不大,不同的湖盆,岩性组合略有差异.沉积厚度以湖盆或洼地中心最厚,往边缘逐渐变薄.岩相变化自下而上由深湖亚相→浅湖亚相→滨湖亚相转变.由于田洋组在沉积过程中所具备的特殊地理地质环境,大量硅藻在湖泊富营养的水环境中生存、繁殖和死亡,从而形成了大厚度由硅藻遗骸堆积而成的硅藻土矿,其硅藻含量一般为60%～80%,最高达90%,总储量约215.8×106t,具有良好的开发利用前景. 相似文献
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基于矿床地质特征,初步分析了江西广昌头陂硅藻土矿床的成因,提出了下一步勘查方向。头陂硅藻土矿赋存于新近系头陂组上段,呈层状和似层状,平面上呈面型展布并延伸至矿段外。上部矿层以圆筛藻属硅藻为主,下部矿层以羽纹目硅藻为优势。新近纪以来,头陂淡水湖泊盆地在温暖、湿润气候条件下,硅藻快速繁殖生长;中新世中晚期以来,盆地外围大面积的铝硅酸盐岩化学风化作用和少量火山灰飘落于水体中为硅藻土形成提供物质条件;硅藻死亡后,其硅质骨骸则保存下来形成硅藻淤泥,经过初步成岩后,便形成了硅藻土层。头陂地区硅藻土矿找矿标志为新近纪新地层和水平层理发育的浅色沉积岩。 相似文献
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雷州半岛硅藻土中的硅藻及其化学成分 总被引：4，自引：5，他引：4
本文论述雷州半岛各硅藻土矿床中的硅藻形态和种属。九斗洋和田洋钻孔样品中硅藻种属随深度而变化，由直链藻到了冠盘藻，直到小环藻。总结了对不同种属硅藻的硅质硬过峭同部位的Ｘ射线能谱成分分析和研究结果。 相似文献
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先锋盆地系第三纪时期构造成因的拉分盆地,盆地内沉积了褐煤和硅藻士,均具有工业价值。本文分析了盆地的成因,探讨了煤与硅藻土的聚积条件和分布规律。煤与硅藻土的聚积和分布是受当时的地质构造、基岩岩性、地理环境、气候与植物条件的制约。(1)沉积盆地的东部,为平缓开阔的斜坡带,由于水较浅,水动力条件较弱,利于泥炭沼泽的富集和硅藻的繁殖,故成为褐煤与硅藻土的主要聚积分布区。(2)盆地的南部,为一陡坡,因水深,边缘中的冲、洪积扇发育,粗粒碎屑沉积灌度快,水动力条件强,不利于煤和硅藻土的形成。(3)盆地的中心,长期处于湖水较深,湖底光线较暗,为一弱还原环境,它可以溶解硅藻,而不利于硅藻的大量繁殖及其残骸的保存,因而也不利于煤与硅藻土的形成。最后,就先锋盆地的成矿地质条件,分析了在省内寻找硅藻土矿的地质前提。 相似文献
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A Mineralogical Study of Diatomite in Leizhou Peninsula 总被引：5，自引：0，他引：5
In this paper diatomite samples taken from the Leizhou Peninsula have been studied by chemical analysis, DTA, TG, XRD, IR ,SEM and X-ray Energy Spectroscopy.The study shows that the diatomaceous genera and species and their organic contents are variable with buried depth ,from Melosira to Stephanodiscus and then to Cyclotella. Various impurities in the samples, such as quartz, kaolinite and montmorillonite indicate different sedimentary environments. When heated, the diatom would change in shape due to the phase transformation in which amorphous silica crystallized from disordered opal to ordered cristobalite. The temperatures of phase transformation are different for various diatoms due to the presence of different impurities and constituents of diatomaceous genera and species. 相似文献
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Jean Gaudant Jean-Paul Saint-Martin Mostefa Bessedik Bouhameur Mansour Pierre Moissette Jean-Marie Rouchy 《Journal of African Earth Sciences》1997,24(4):511-529
A new locality of Messinian fossil fish has been found in the diatomite outcropping in the surroundings of the former “Ferme Giraud”, in the Murdjadjo Massif (near Oran, Algeria). It has yielded an oligospecific fish fauna, including five species indicative of a littoral marine environment that may have occurred in a gulf bottom. This was probably linked to a brackish lagoon, as indicated by the diatom flora. 相似文献
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《矿物学报》2013,(Z1)
Diatomite, a type of biogenic mineral, is sourced from deposition and accumulation of diatom shell. Diatom shells are mainly composed of amorphous hydrated silica, which is categorized as non-crystalline opal-A according to the mineralogical classification. Diatomite has a characteristic macro/mesoporous structure and unique physical and chemical capabilities, such as high thermal stability, strong acid resistance, and high adsorption capacity, and thus is widely used as the filter aid, catalytic support, and adsorbent. However, the low surface area of diatomite shows disadvantage in adsorption. Moreover, the hydrophilic surface which contains abundant silanols is usually covered by adsorbed water, resulting in that the adsorption sites of diatomite were occupied and the adsorption capacity of hydrophobic guests decreased. In previous reports, zeolitization was employed to increase the specific surface area (SBET) and porosity of diatomite. However, the hydrophilic property of diatomite was not changed after zeolitization. It is due to that the zeolite formed on the surface area of diatomite contained some aluminum in its structure, which was highly hydrophilic. Therefore, it is significantly interesting to prepare the zeolitized diatomite with both large SBET and high hydrophobicity. 相似文献
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This paper describes the geological-depositional and environmental characteristics of diatomite. The diatomite deposit is situated in the southern part of the Alayunt (Kutahya) Basin. Samples of 18 diatomites and 12 host rocks were collected from four sedimentary profiles in the spring season. Basement rocks are Paleozoic-aged metamorphic rocks (schist, phyllite, quartzite, etc.) and Mesozoic-aged ophiolitic and complex rocks. Host rocks are rhyodacitic–rhyolitic tuffite, volcanic glass. Diatomite is composed of Upper Miocene–Upper Pliocene-aged diatom species. Diatomite shows layer morphology and lies on volcanic glass layer. XRD characteristic peaks of diatomite show that it comprises dominantly of Opal-A silica, whereas volcanic glass has Opal-CT constituent. SEM and NPM photomicrographs indicate that diatomites are dominantly composed of benthic freshwater diatom species, such as Pinnularia microstauron, Pinnularia lundii, Pinnularia subrostrata, Pinnularia brevicostata, Pinnularia tenuis, Pinnularia sp., Navicula eligensis, Fragilaria construens, Mastogloia braunii Grunow, Melosira varians Agardh, Surirella capronii Brébisson, Cymbella lanceoloata, Amphora venata, Gomphonema germainii, Gomphonema angustatum and Rhapalodia gibba. These species are general indicators of shallow paleolake environment and cool climate conditions. Due to the fluvial currents and climatic conditions; lake water levels, temperature and nutrient content fluctuated through the time. Chemical data obtained from 18 diatomite samples show that while silica is the bodybuilding material for diatomite (over 89 % SiO2), Al, Mg and Fe contents of diatomite samples might be derived from clastic materials. The concentration of Al, Mg and Fe decreases toward the lake center. Diatom genera, sedimentary profile sections and mineralogic data suggest that diatomite deposited in lacustrine-type freshwater shallow lake is associated with Upper Miocene-aged extension tectonics. Physical and filtration tests along with environmental characteristics of diatomite suggest that calcined diatomite can be used for waste treatment processes in the filter aid industry. 相似文献
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Ioanna K. Ilia Michael G. Stamatakis Theodora S. Perraki 《Central European Journal of Geosciences》2009,1(4):393-403
Two bulk samples of clayey diatomite of Upper Miocene age originated from Western Macedonia, northern Greece and Thessaly central Greece were examined for their efficiency to be used as industrial absorbents. The samples were characterized using X-Ray Diffraction, Thermo-Gravimetric and Fourier Transform Spectroscopy, Scanning Electron Microscopy and ICP-MS analytical methods. The absorption capability of the clayey samples in oil and water were also examined. The mineralogy of both samples is predominated by the presence of clay minerals and amorphous silica. The clay minerals prevailed in the Klidi (KL) bulk sample, with muscovite being the dominant phase, and kaolinite and chlorite occurring in minor amounts. In the Drimos (DR) bulk sample, vermiculite was the predominant clay phase. Smectite was not found in either sample, whereas detrital quartz and feldspars were present in significant amounts. The amorphous silica phase (opal-A) occurs mainly with the form of disck-shaped diatom frustules. The chemistry of the samples is characterized by the predominance of silica, alumina, and iron, whereas all the other major and the trace elements are in low concentrations. Both clayey diatomite rocks exhibited sufficiently good oil and water absorption capacity, ranging between 70 to 79% in the clay-rich sample KL and 64 to 70% in the opal-A-rich sample DR. Comparing the properties of the rocks studied with other commercial absorbents, it is concluded that they may find applications as absorbents in industrial uses. 相似文献
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GUNVER KRARUP PEDERSEN 《Sedimentology》1981,28(4):487-504
A diatomite, about 60 m thick, of late Palaeocene-early Eocene age crops out in northern Jutland, Denmark. The diatomite is locally termed ‘Moler’. Frustules of marine diatoms constitute c. 65% (by weight) of the diatomite, and clay minerals, chiefly montmorillonite, make up the remainder. Slight variations in the relative supply of diatom frustules and clay minerals are preserved undisturbed in laminated diatomite, while lamination is partly destroyed by burrowing organisms in weakly laminated diatomite and obliterated by total bioturbation in structureless diatomite; these three facies alternate throughout the sequence. The presence or absence of infaunal burrowing organisms is interpreted as a record of the content of dissolved oxygen in the water above the sediment-water interface and hence of the position of the redox potential discontinuity. Interspaced in the diatomite are 179 identifiable layers of volcanic ash. These ash layers provide a means of precise lateral correlation. They show that levels of laminated diatomite may be followed throughout the basin and therefore that changes between anoxic and oxic conditions occurred simultaneously across the area. The laminated diatomites may consequently be interpreted as representing short-term anoxic events, of which twelve have been recognized. 相似文献
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硅藻土开发应用及其进展 总被引：19，自引：0，他引：19
利用硅藻土的微米级形体、天然纳米孔和主要成分为非晶质硅藻壳等特殊构造与性质,开发多用途的纳米材料、微孔材料、改性剂及合成白炭黑等,应用于污水处理、环保建材、无机分离膜、杀虫剂、橡胶补强等领域,取得了良好的效果,其应用前景十分可观。 相似文献
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《Russian Geology and Geophysics》2015,56(6):947-958
Three Far East diatomites, Puzanov (Kunashir Island, Kuril Islands), Sergeevskii, and Terekhovka (Southern Primorye) are characterized in detail. Rock-forming taxa are identified (Puzanov—Aulacoseira subarctica (O. Mull.) Hawort and Stephanodiscus niagarae var. pusanovae Genkal et Cherepanova; Sergeevskii—Staurosira construens var. venter (Ehr.) Gran., Aulacoseira italica (Ehr.) Sim., and representatives of the genus Cymbella with large valves (up to 175 Jim in length); Terekhovka—Aulacoseira praegranulata var. praeislandica f. praeislandica (Sim.) Moiss.). Morphometric analysis of valves of the dominant taxa showed a low variability of valve parameters for the Puzanov diatomite and a high one for the Sergeevskii and Terekhovka diatomites. The lake environments of the diatoms forming the diatomites were reconstructed based on the elemental composition of diatom valves and the ecological structure of diatom paleocommunities. The high oxygen and low silicon concentrations in valves of the Puzanov diatomite, most likely, indicate that the diatoms were part of plankton communities formed in a large deep freshwater lake. Significant concentrations of silicon in valves of the Terekhovka diatomite, in contrast, suggest that the diatoms occurred in benthic ecotopes in a shallow lake. The age of the deposits was refined by detailed studies of Aulacoseira valves, using light and scanning electron microscopes. For example, the presence of Aulacoseira taxa of the “prae” group in the Terekhovka diatomite confirms its Pliocene age, and the presence of valves of the present species A. italica in the Sergeevskii diatomite points to its Late Pliocene age. The identified features of the diatomites permit their use in practice. 相似文献