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1.
粘土矿物的掺杂对沉积物吸持Cu、Zn能力的影响   总被引:3,自引:0,他引:3  
通过考察粘土矿物及掺杂粘土矿物前后沉积物的吸附/解吸特性,分析了伊利石与蒙脱石对重金属污染沉积物中Cu与Zn稳定固定化的可行性。结果表明:伊利石与蒙脱石的掺杂均降低了沉积物吸持Cu的能力(最大下降量分别为5.4%和3.8%),伊利石的掺杂同样降低了沉积物吸持Zn的能力(最大下降量为4.4%),但蒙脱石掺杂后沉积物吸持Zn的能力明显增强,最高增加5.7%。因此,蒙脱石具有固定污染沉积物中Zn的能力,但不能提高污染沉积物中Cu的稳定性。  相似文献   

2.
镉在蒙脱石等粘土矿物上的吸附行为研究   总被引:5,自引:0,他引:5  
研究了土壤中主要硅酸盐粘土矿物蒙脱石、伊利石、高岭石、海泡石对重金属镉的吸附行为.结果表明:硅酸盐粘土矿物吸附镉受酸度和离子强度的影响;吸附反应是快反应,能很好地符合Lagergren二级吸附速度方程;优化条件下的高岭石对镉吸附很弱,蒙脱石、伊利石、海泡石对镉的实验饱和吸附容量分别为2.88、1.08、2.82 mg/g,蒙脱石吸附镉更适合Freundlich拟合,伊利石、海泡石对镉的吸附结果更适合Langmuir拟合;相关性分析表明,硅酸盐粘土矿物对镉的饱和吸附容量大小与其理化性质有关,其中矿物中氧化锰含量高低与其对镉饱和吸附容量大小的相关性达到极显著水平.  相似文献   

3.
Pyrolysis experiments were carried out on Monterey formation kerogen and bitumen and Green River formation kerogen (Type II and I, respectively), in the presence and absence of montmorillonite, illite and calcite at 200 and 300°C for 2–2000 hours. The pyrolysis products were identified and quantified and the results of the measurements on the gas and condensate range are reported here.A significant catalytic effect was observed for the pyrolysis of kerogen with montmorillonite, whereas small or no effects were observed with illite and calcite, respectively. Catalytic activity was evident by the production of up to five times higher C1–C6 hydrocarbons for kerogen with montmorillonite than for kerogen alone, and by the dominance of branched hydrocarbons in the C4–C6 range (up to 90% of the total amount at any single carbon number). This latter effect in the presence of montmorillonite is attributed to cracking via a carbonium-ion [carbocation] intermediate which forms on the acidic sites of the clay. No catalytic effect, however, was observed for generation of methane and C2 hydrocarbons which form by thermal cracking. The catalysis of montmorillonite was significantly greater during pyrolysis of bitumen than for kerogen, which may point to the importance of the early formed bitumen as an intermediate in the production of low molecular weight hydrocarbons. Catalysis by minerals was also observed for the production of carbon dioxide.These results stress the importance of the mineral matrix in determining the type and amount of gases and condensates forming from the associated organic matter under thermal stress. The literature contains examples of gas distributions in the geologic column which can be accounted for by selective mineral catalysis, mainly during early stages of organic matter maturation.  相似文献   

4.
为了从深层次揭示控制黏土矿物天然气吸附能力的主要因素, 选择不同来源和成因的泥页岩中的常见黏土矿物进行了甲烷等温吸附实验.分析显示不同类型的黏土矿物气体吸附能力差异明显, 各种黏土矿物甲烷吸附容量次序为蒙脱石>>伊蒙混层>高岭石>绿泥石>伊利石>粉砂岩>石英岩.黏土矿物结晶结构决定了矿物片层之间的层间孔隙和聚合体颗粒之间粒间孔隙的形态和大小, 从而决定着其表面积和气体吸附性能.黏土矿物甲烷吸附能力与电镜扫描所反映的微孔隙发育程度密切相关.研究表明, 黏土矿物的气体吸附能力不仅与黏土类型有关, 而且明显受成岩演化程度和岩石成因的影响.此外, 随粒度减小孔隙连通性和内表面积的不断增加, 黏土矿物气体吸附能力有所升高.   相似文献   

5.
以皂石、高岭石、绿泥石和伊利石为原材料,分别与赖氨酸进行反应,研究赖氨酸在上述粘土矿物上的吸附行为, 并运用粉末X-射线衍射技术(XRD)、傅里叶变换红外吸收光谱术(FTIR)和热重(TG)等分析方法,表征反应前后粘土 矿物的变化。实验结果表明,不同粘土矿物对赖氨酸的吸附等温线均符合Freundlich等温方程,且不同粘土矿物对赖氨酸的 饱和吸附量大小顺序为:皂石>蒙脱石>绿泥石>高岭石>伊利石;XRD结果表明皂石对赖氨酸的吸附发生在矿物层间,而绿 泥石、高岭石和伊利石对赖氨酸的吸附主要在矿物表面进行;FTIR和TG结果表明赖氨酸主要取代粘土矿物层间吸附水,以 氢键的形式与Si-O-Si(IVAl)键合。实验结果将有助于进一步探明环境中粘土矿物对有机质的吸附机理。  相似文献   

6.
为揭示伦坡拉盆地渐新世—中新世之交黏土矿物蕴含的古气候信息,探讨其与青藏高原隆升及全球气候响应过程的关系,利用X射线衍射和荧光光谱分析对蒋日阿错剖面的黏土矿物特征进行了深入研究。结果表明:区内泥质岩中黏土矿物以伊/蒙混层矿物为主,伊利石次之,仅含有少量绿泥石和蒙脱石。黏土矿物的垂向组合特征显示伊利石和绿泥石含量在剖面下部低、上部高,伊/蒙混层含量与之相反,伊/蒙混层和伊利石在剖面中部呈明显波动变化,蒙脱石只出现在剖面中下部,可能为区域火山喷发产物在碱性环境中蚀变而成。伊利石结晶度变化于0.24°~0.48°,平均值为0.41°,表明样品未发生明显成岩蚀变,主微量元素比值指示研究区物源位置未发生较大改变,因此研究剖面黏土矿物特征可以有效反映伦坡拉盆地古气候演化过程。根据自生黏土矿物的习性指出伦坡拉盆地在渐新世—中新世之交出现了一次明显的降温事件,并且这次降温在青藏高原内部及周缘地区普遍存在,但造成这次降温事件的根本原因仍值得进一步探讨。  相似文献   

7.
巴州坳陷下白垩统—中侏罗统的粘土矿物特征   总被引:1,自引:1,他引:0  
根据岩石薄片、X衍射和扫描电镜分析资料,本文研究了巴州坳陷下白垩统—中侏罗统粘土矿物特征,发现粘土矿物分为伊利石、伊/蒙混层和绿泥石三种类型。粘土矿物的类型和含量随深度而变化,形成了伊/蒙混层带、混层迅速转化带和伊利石带。粘土矿物的转化和自生粘土矿物的形成是沉积地层非常重要的成岩变化。  相似文献   

8.
Kerogen has been artificially matured under “hydrous pyrolysis” conditions in the presence of various minerals in order to investigate the influence of the latter on the organic products. In addition to three clay minerals (montmorillonite, illite, kaolinite), calcium carbonate and limonite were also employed as inorganic substrates. Kerogen (Type II) isolated from the Kimmeridge Blackstone band was heated in the presence of water and a 20-fold excess of mineral phase at two different temperatures (280 and 330°C) for 72 hr. Control experiments were also carried out using kerogen and water only and kerogen under anhydrous conditions. This preliminary study describes the bulk composition of the pyrolysates with detailed analyses of the aliphatic hydrocarbon distributions being provided by gas chromatography and combined gas chromatography-mass spectrometry.In the 280°C experiments, considerably more organic-soluble pyrolysate (15% by weight of original kerogen) was produced when calcium carbonate was the inorganic phase. At 330°C, all samples generated much greater amounts of organic-soluble products with calcium carbonate again producing a large yield (40% wt/wt). Biomarker epimerisation reactions have also proceeded further in the 330°C pyrolysate formed in the presence of calcium carbonate than with other inorganic phases. Implications of these and other observations are discussed.  相似文献   

9.
 Adsorption/desorption and oxidation/reduction of arsenic at clay surfaces are very important to the natural attenuation of arsenic in the subsurface environment. Although numerous studies have concluded that iron oxides have high affinities for the adsorption of As(V), very little experimental work has addressed the arsenic attenuation capacities of different clay minerals and aging process affecting the transformation of arsenic. The abundance of clay minerals in a variety of geochemical environments and their influence on adsorption of contaminants suggests a need for more experimental work to characterize the adsorption desorption, and oxidation of arsenic on clay minerals. In this investigation three types of clay mineral were studied: the 1 : 1 layer clays [halloysite (IN), sedimentary M-kaolinite, and weathered EPK-kaolinite]; the 2 : 1 layer clays [illite (MT) and illite/montmorillonite (MT)]; the 2 :>: 1 layer clay [chlorite (CA)]. The halloysite and the chlorite had much greater As(V) adsorption (25–35 folds) than the other clay minerals. The clay minerals had lower As(III) adsorption than As(V) adsorption, and the adsorption was affected by pH. Desorption of arsenic from the clay minerals was significantly influenced by the aging process. The quantities of extractable As(III) and As(V) decreased with increasing aging time. The results demonstrated that oxidation of As(III) to As(V) occurred on the clay surfaces, whereas reduction of As(V) to As(III) was not found in any of the clay minerals studied. The oxidation of As(III) was affected by the types of clay and aging time. Received: 22 March 1999 · Accepted: 15 April 1999  相似文献   

10.
Certain factors influencing the incorporation, transport and release of fatty acids by clay minerals, calcite and marine sediments have been investigated.Salinity was found to be an important factor. The adsorption of heptadecanoic acid by bentonite clay at 4%. was nearly triple that at 0%.. However, from 4%. to 35%., only a minor adsorption increase occurred. This behavior is believed to be related to flocculation of the clay at the lower salinity range. The pH over the range of 6.0–8.5 has a small influence on fatty acid-clay association, depressing it somewhat as the basicity increases.When the temperature of the fatty acid solution was increased from 0°C to 50°C, a decrease in adsorption on to clay was found. This effect may be due to increased water solubility of the acid at higher temperatures, since solubility is very important in controlling the degree of fatty acid-mineral interaction. Furthermore, apparent solubilization of fatty acids by indigenous dissolved organic matter in sea water reduces adsorption on to clay minerals.Based upon the heat of adsorption of ?14.6 kcal/mole, fatty acids are physically bound to clay minerals by weak van der Waals forces and hydrogen bonds.Bentonite and kaolinite were found to be the most adsorptive minerals investigated, followed in order by illite, montmorillonite and calcite. Sediments from Narragansett Bay were found to lie between illite and montmorillonite in adsorptive capacity after indigenous sediment organic matter had been removed. Sediment organic matter reduced fatty acid uptake by a factor of 1.6.  相似文献   

11.
在X射线衍射和扫描电镜观测的基础上,结合区域沉积演化分析,探讨了晋城矿区粘土类型、组合特征、微观结构与沉积-成岩作用的关系。结果表明,晋城矿区粘土矿物以高岭石为主,其次为伊利石和伊利石/蒙脱石混层,还有少量的绿泥石和蒙脱石;山西组粘土矿物颗粒排列定向性优于太原组,多呈带状或平叠状产出,而太原组多为蜂巢状、花朵状或凝絮状;由于太原期频繁的海侵海退致使煤层顶底板处于pH值较高的碱性环境,使成岩过程中高岭石向伊利石转化,造成太原组粘土矿物的伊利石含量明显高于山西组,而高岭石含量相对较低。  相似文献   

12.
颗石藻是海洋中广泛分布的超微型浮游藻,经生物矿化作用形成的碳酸钙质颗石,在古海洋学研究中具有重要意义。海洋粘土矿物与有机质的有机-无机相互作用在全球碳循环中扮演着重要角色。本文选取广泛分布于海洋的赫氏颗石藻Emiliania huxleyi与海洋粘土矿物中具有代表性的伊利石和蒙脱石共培养。通过对颗石藻生长曲线和Sr/Ca、Mg/Ca元素比值、颗石藻与粘土矿物样品的紫外可见光吸收光谱、红外吸收光谱和矿物物相等分析,研究海洋粘土矿物与颗石藻的相互作用规律。通过研究表明伊利石对颗石藻的影响较小,蒙脱石因对营养元素的吸附和颗石藻的絮凝作用对颗石藻的生长和Sr/Ca、Mg/Ca元素比值影响较大。颗石藻代谢分泌的生物分子未能通过层间插层作用进入伊利石层间,颗石藻分泌的生物分子可通过插层作用进入并储存于蒙脱石层间,海洋粘土矿物中的蒙脱石与海洋微生物的相互作用值得地球微生物家关注,可能有助于对古海洋环境的认识。  相似文献   

13.
本文提出粘土矿物(特别是含伊/蒙不规则混层粘土矿物)混合物相的X射线定量分析方法——模拟定量法。着重解决在蒙脱石-不规则伊/蒙混层粘土矿物-伊利石组合中,伊/蒙混层粘土矿物的定量分析计算。模拟定量法是对以前的各种粘土矿物X射线定量分析方法的补充。用纯净的蒙脱石、伊利石、高岭石、绿泥石及各种伊/蒙混层比的伊/蒙混层粘土矿物,配制了各种不同组合的粘土矿物混合样品,制成定向薄膜片,进行了X射线分析,讨论了各种组合的粘土矿物混合物相X射线衍射图谱的特征,并在此基础上提出了粘土混合物相定量分析的方法。  相似文献   

14.
滇黔桂地区卡林型金矿热液矿物地球化学   总被引:2,自引:0,他引:2  
肖荣阁  范军 《矿物学报》1997,17(4):478-482
滇黔桂卡林型金矿是产于热水沉积岩及碎屑岩系的热液矿床,载金矿物为黄铁矿、毒砂等热液矿物,而石英、碳酸盐、萤石及粘土等矿物则是主要的热液蚀变矿物。矿化产于蒙脱石、高岭石粘土到伊利石、绿泥石粘土矿物的转变带,成矿深度在2000m以上,成矿热液来源于粘土矿物脱水产生的异常高压流体或沿断裂带天水循环形成的成矿流体。这种流体形成的热液矿物稀土元素分配显示中稀土富集的分配模式,并明显富元素钇,这种流体中形成的黄铁矿中Co/Ni值显示沉积到热液成因的过渡类型,因此与砂岩铜矿中热液矿物的稀土分布模式有某些一致性。  相似文献   

15.
The adsorption of pentachlorophenol (PCP) onto quartz, kaolinite, illite, montmorillonite and iron oxides has been investigated by batch equilibrium techniques. The pH-dependent isotherms are curves with peak values, the position of which is at about pH = 5-6 depending on the mineral species. Based on distribution of both speciation of surface hydroxyls on minerals and PCP in solution a surface reaction model involving surface complexation and surface electrostatic attraction is presented to fit the pH-dependent isotherms, and both reaction constants are calculated. The results show that on quartz and phyllosilicate minerals the predominant adsorption reaction is surface complexation, meanwhile both of surface electrostatic attraction and surface complexation are involved on the iron oxide minerals. The reaction constants of surface electrostatic adsorption are usually one to three orders in magnitude, larger than that of surface complexation. The concentration-dependent isotherms can be well fitted by Langmnir equation with the correlation coefficient R〉0.93 for kaolinite and iron oxides. The maximum adsorption is found in the order: hematite 〉 lepidocrocite 〉 goethite 〉 kaolinite 〉 quartz 〉 montmorillonite ≈ illite, which can be interpreted by consideration of both reaction mechanism and surface hydroxyl density. The significant adsorption of PCP onto mineral surfaces suggests that clay and iron oxide minerals will play an important role as HIOCs are adsorbed in laterite or latertoid soil, which is widespread in South China.  相似文献   

16.
始新世—渐新世是新生代气候从“温室”向“冰室”转变的重要节点,也是青藏高原及邻区气候格局发生重大变革的关键时期。为了重建高原中部腹地始新世—渐新世的古气候演变特征,探讨古气候变化的控制因素,利用X射线衍射分析对高原中部伦坡拉盆地382道班剖面的黏土矿物特征进行了综合研究,结果显示,伦坡拉盆地在始新世—渐新世牛堡组二段沉积的黏土矿物主要以伊利石为主,伊/蒙混层次之,高岭石与绿泥石含量极少,蒙脱石仅出现在极少样品中。黏土矿物类型及组合特征指示伦坡拉盆地在该时期整体处于寒冷干旱的气候条件,但在长周期趋势下伊利石相对含量逐渐减少,伊/蒙混层逐渐增多,显示出青藏高原中部地区的气候系统在晚始新世—早渐新世时期存在向更加湿润的气候条件转变,这种气候系统的改变可能与南亚季风在晚始新世的演化所带来的更多水汽条件和青藏高原中部中央分水岭的形成有关,但在始新世与渐新世之交,伊利石含量陡然增多,而伊/蒙混层含量则减少,且两者频繁波动,这反映了该盆地在EOT时期受到全球降温的影响。  相似文献   

17.
对川东华蓥山二叠系/三叠系界线附近粘土层中的粘土矿物进行野外采样和室内X射线衍射分析,结果表明,这些粘土矿物主要由规则混层伊利石-蒙脱石组成,其中1个样品可能舍有少量不规则混层绿泥石-蒙脱石等粘土矿物。总地看来.该界线粘土层中的规则混层伊利石-蒙脱石中伊利石层的含量自下而上呈现减少的趋势,平均含量约83%,所经历的最大古地温在125-150℃之间。这些粘土矿物的构成和特征与前人在华南其他地区相同层位取得的成果总体上具有较好的一致性.显示了该粘土层成因的相同性及所具有的等时意义。不同地区粘土矿物构成的差异性(如高岭石的存在与含量)可能与二叠系/三叠系界线不整合的存在与否或间断时间有关,规则混层伊利石-蒙脱石的混层比则与埋藏历史和沉积-沉积期后的流体介质有关。  相似文献   

18.
山东车镇凹陷东部古近系沙河街组成岩作用   总被引:6,自引:4,他引:6       下载免费PDF全文
车镇凹陷沙河街组的沉积体系受控于盆地内的构造、物源供给以及沉积时的气候环境。以岩石学特征为基础,描述了成岩过程中压实与压溶作用、胶结作用、溶解作用与次生孔隙的特征,以及次生孔隙带在本区的分布。论述了碳酸盐胶结物与粘土矿物胶结作用的特点。粘土矿物蒙脱石-伊利石转变具有明显的渐变与突变交替的演化程式,其演化经历了蒙脱石带、渐变带、迅速转化带和伊利石带以及蒙脱石向伊利石的转变带。沙河街组的成岩作用划分为早期成岩阶段(A期、B期)和晚期成岩阶段(A期、B期、C期),并提出了成岩阶段的划分标志。  相似文献   

19.
蒙脱石等粘土矿物对重金属离子吸附选择性的实验研究   总被引:71,自引:6,他引:65  
矿物质与重金属离子间的相互作用已是当今环境科学、矿物学,土壤化学等学科领域研究的热点。通过蒙脱石,伊利石和高龄石在一定的介质条件下对Cu^2+、Pb^2+、Zn^2+、Cd^2+、Cr^3+五种重金属离子的竞争吸附实验研究,阐明了三种粘土矿物对五种重金属离子的吸附选择性。  相似文献   

20.
The synthesis of illite mixed-layer minerals at surface conditions is possible through precipitation of Al hydroxides from Si-, Mg- and K-containing solutions. It has been shown that amorphous hydroxides of Al, Fe, etc. are capable of coprecipitating silica even from very dilute solutions. By aging of these X-ray amorphous hydroxide—silica precipitates under certain conditions, clay minerals can be synthesized at low temperatures. The presence of Mg particularly favors the formation of three-layer clay minerals. Mg-rich Al hydroxide—silica precipitates permit formation of tri- and di-octahedral smectite, illite and chlorite. The formation of three-layer clay minerals is only possible when the precipitates contain at least 6% MgO. The precipitates stay amorphous if the Mg content is lower. The adsorption of Mg and K on the hydroxide—silica precipitate controls the illite or montmorillonite portion in the mixture of the three-layer silicates. There is a competition for K and Mg adsorption on the hydroxide—silica precipitates. Higher K concentration inhibits the three-layer mineral formation through the lowering of the Mg content in the precipitates. Illite mineral formation is favored under certain K/Mg ratios. Higher NaCl contents do not favor the three-layer mineral formation.The enrichment of Mg and K in the precipitates is not as large as the enrichment of Si in the hydroxides. This means that the illite mineral formation is only possible from solutions with a high-salt content like seawater.  相似文献   

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