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中化地质矿山总局地质研究院涿州助剂厂研制开发的涿州皂土被酿酒专家誉为果酒浑浊的克星.它是以膨润土(Bentonite,主要含蒙脱石的粘土岩)为主原料,经过提纯、改性调整等许多复杂工序,配制加工而成的高附加值矿产品.皂土吸水膨胀分散于水中,形成稳定的胶体悬浮液. 相似文献
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新型高分子材料固沙抗冻性能试验研究 总被引:6,自引:0,他引:6
抗冻性反映固沙剂在低温环境下固沙的耐久性能。以新型高分子材料SH进行固沙,就其固沙后固沙体的抗冻、融特性进行了室内两种不同周期的冻、融循环试验。结果表明,冻、融循环对SH固沙性能均有劣化趋势。但冻、融速率较慢时,抗冻性较稳定。SH抗冻性优于其它同类化学固沙剂,显示其抗冻性良好。有机材料在冻、融过程中一段时间内出现强度增加的机理尚不清楚,建议进一步研究。 相似文献
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锂镁皂土——一种稀缺矿种的形成机理和用途 总被引:7,自引:0,他引:7
介绍了稀缺且具有极大经济价值的特殊粘土类矿产资源-锂镁皂土(汉克托石,hectorite)的基本概念、形成机理,特性及开发利用概况。 相似文献
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碎石桩技术自1950年代引进我国后,在工业、交通、水利等建设工程中得到了广泛应用。通过沉管碎石桩在砂性土地基中应用一例,闸明其在提高砂性土地基的承载力、减少地基变形和增强抗液化性能方面有着显著效果。 相似文献
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Owing to its favourable physical, chemical and rheological properties, densely compacted bentonite or bentonite-sand mix is considered as a suitable buffer material in deep geological repositories to store high level nuclear waste. Iodine-129 is one of the significant nuclides in the high level waste owing to its long half life and poor sorption onto most geologic media. Bentonite by virtue of negatively charged surface has negligible affinity to retain iodide ions. As organo-bentonites are known to retain iodide ions, the present study characterizes hexadecylpyridinium chloride (HDPyCl.H2O) treated bentonite from Barmer India (referred as HDPy+B) for physico-chemical properties, engineering properties and the iodide adsorption behavior of the organo clay. Batch experiments revealed that HDPy+ ions are largely retained (94 % retention) via cation exchange; the ion-exchange process neutralizes the negative surface charge and bridges clay particles leading to reduction in Atterberg limits, clay content and sediment volume. The organo clay retains iodide by Coulombic attraction (at primary sites) and anion exchange (at secondary sites). The free-energy change (ΔG o = ?25.5 kJ/mol) value indicated that iodide retention by organo clay is favored physical adsorption process. Iodide adsorption capacity of organo clay decreased significantly (85–100 %) on dilution with 50–80 % bentonite. On the other hand, dilution of bentonite with 50 % organo clay caused 58 % reduction in swell potential and 21 % reduction in swell pressure. 相似文献
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本矿床赋存于晚侏罗世仇山火山断陷盆地中劳村期的火山碎屑流沉积相底部地层内,矿体呈层状,多层产出,具稳定的层位及明显的标志层。矿体围岩的蒙脱石化、硅化、滞石化、高岭石化等蚀变较普遍,尤其是顶板的硅化。矿石结构、构造反映了火山碎屑沉积的特点。矿石是自生的粘土矿物富集体,没有或很少有碎屑物质混杂。矿体厚度和品位变化系数较小,属厚度稳定型—较稳定型和质量均匀的矿体。根据仇山矿区的矿床地质特征,我们认为该矿床属于陆相火山沉积型。 相似文献
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Jiang-feng Liu Yu Wu Cheng-Zheng Cai Hong-yang Ni Xu-lou Cao Hai Pu Shuai-bing Song Sheng-yan Pu Frédéric Skoczylas 《Environmental Earth Sciences》2018,77(5):213
Opalinus clay (OPA) is currently being investigated as a potential host rock for radioactive waste repository. The construction of this repository will lead to an excavation-damaged zone (EDZ) in the surrounding. Its sealing ability is crucial for the safety assessment of the geological repository. The sealing ability of OPA has a close relationship with its water retention and gas permeability behaviours. For this purpose, the water retention and gas permeability of OPA and its comparison with the artificial barrier (i.e. bentonite) were investigated in this study. The results show that OPA absorbed less water than granular bentonite material with equal suction. Compared with the other two similar materials (Boom clay and COx argillite), which were selected as natural engineering barriers for nuclear waste storage in Belgium and France, the suction behaviours of OPA are similar to those of COx argillite but notably different from those of Boom clay. The gas permeability tests show that OPA sample is quite sensitive to the changes in confining pressures but is less sensitive to applied gas pressures. Further, it is found that the OPA is more permeable than bentonite barrier after 10.5 years of hydration. Then, the OPA samples were artificially water-saturated. We find that the sealing ability can be recovered after long-time water saturation. However, when comparing with bentonite barrier, it is still a weak zone. This indicates that the EDZ should be paid more attention for the assessment the performance of the nuclear repository. 相似文献
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Swelling behavior of expansive soil has always created problems in the field of geotechnical engineering. Generally, the method used to assess the swelling potential of expansive soil from its plasticity index, shrinkage limit and colloidal content. Alternative way to evaluate swelling behavior is from its expansive index (EI) and swelling pressure value. The present study investigates the reduction of EI and swelling pressure for kaolinite and bentonite clay when mixed with various percentages of Ottawa sand and Class C fly ash. The percentages of Ottawa sand and Class C fly ash used were 0–50 % by weight. The results show that there is a significant reduction in the swelling properties of expansive soil with the addition of Ottawa sand and Class C fly ash. The reduction in EI ranged approximately from 10 to 50 and 4 to 49 % for kaolinite and bentonite clay, respectively. Also the maximum swelling pressure of kaolinite and bentonite clay decreased approximately 93 and 64 %, respectively with the addition of various percentages of Ottawa sand and Class C fly ash. Standard index properties test viz., liquid limit, plastic limit and linear shrinkage test were conducted to see the characteristics of expansive soil when mixed with less expansive sand and fly ash. Also, for these expansive soils one dimensional consolidation test have been conducted with sand and fly ash mixtures and the results were compared with pure kaolinite and bentonite clay. 相似文献
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河南信阳上天梯膨润土制备高效活性白土试验研究 总被引:6,自引:0,他引:6
上天梯膨润土属于钙基膨润土,主要矿物成分是钙质蒙脱石。矿石的胶体分散性较差,阳离子交换总量较低,主要的可交换阳离子是钙、镁离子。蒙脱石的晶体化学结构研究表明,蒙脱石有较高的有序度和较大的层电荷,因此,上天梯膨润土适合于制备高效活性白土。试验讨论了酸性活化、固液比及活化时间对产品质量的影响,确定了最佳工艺条件。对原矿进行捣浆提纯后,用16%~20%的硫酸溶液对膨润土进行活化,活化时间 6~8小时,固液比1∶2。制得的活性白土的脱色力达156~218,活性度大于222m.mol/100g ,其质量达到和超过了国家行业标准和同行业该产品的指标,脱色效果良好。 相似文献
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Research on the longevity of potential bentonite-based barrier materials is an important part of the Canadian Nuclear Fuel Waste Management Program. Valuable information on the longterm effectiveness of bentonitic barriers can be obtained by examining the properties of unprocessed bentonites from natural deposits. This study compares the swelling capacity (Ps) and hydraulic conductivity (K) of an unprocessed (clay that has not been ground and dried by the supplier) and a processed bentonite from south-central Saskatchewan, Canada. The clay deposit is 75 to 85 Ma old. At a given clay density, the processed bentonite exhibits a greater P3 and a lower K than the unprocessed clay. This can be at least partially attributed to the partial cementation of the unprocessed bentonite particles; this cementation is likely ruptured when the clay is ground during processing. Even though K for the unprocessed clay is higher than that of the processed clay, it is still low enough (< 1011m/s) to meet the permeability requirements of a barrier material in a nuclear fuel waste disposal vault. The unprocessed clay also has the has the ability to self seal: exposure to water, the normalized flow rate of water through some samples was as high as 10-5 m3/s, but the rate rapidly decreased to < 10-10m3/s the clay absorbed water and swelled. The data indicate that the unprocessed bentonite clay maintains anacceptably high swelling capacity and low permeability millions of years after deposition. 相似文献
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Summary The use of bentonite/crushed rock mixtures to form hydraulic barriers has greatly increased in recent years. To obtain an appropriate composition for such mixture sealants generally requires extensive laboratory work. Bentonite content and gradation of the crushed rock component are two key parameters in the seal design. This study investigates the effect of crushed rock gradation on the bulk porosity and permeability of systems of crushed tuff particles. Five different gradations are selected from the literature. The bulk porosity of systems of crushed tuff in the presence of bentonite is examined. The Fuller-Thompson gradations yield denser particle arrangements. For mixture samples containing 15% bentonite by weight, the amount of clay accounts for only 45 to 56% of the weight required to fill the interparticle pore space. The bentonite occupancy percentage amounts to 65 to 80% and 75 to 86.5% for samples having 25 and 35% bentonite by weight, respectively. The water content of bentonite at saturation is reduced and the resistance to piping and flow of bentonite is enhanced by the addition of clay. To reduce the bulk porosities of the mixtures containing 25% or more bentonite, a compaction energy higher than the standard Proctor compaction is necessary. 相似文献
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Muawia A. Dafalla 《Geotechnical and Geological Engineering》2012,30(6):1311-1321
The swelling of clay when it is subjected to moisture increase is a complicated process found to be influenced by several factors. The clay??s level of response is highly dependent on its mineralogical composition and structure. Practicing geotechnical engineers use the placement state and general index properties to forecast the swelling behavior of the soils. The purpose of this study was to investigate the influence of placement conditions on various clays and to demonstrate that the swelling of a particular clay type should not be predicted using information and trends obtained for other clays with different origins. Clay from Saudi Arabia was used to investigate the influence of initial moisture content and initial dry density on swelling. The prediction models created by other researchers were compared to the measured values in this study. The swelling behavior of both initially dry and wet prepared bentonite was examined, and the rate at which swelling developed in the bentonite clay was studied. The role of clay content in the volume change of sand?Cbentonite mixtures was also investigated. It was concluded that the prediction of clay-swelling parameters should not be based on the properties of other clays with different origins and mineralogical compositions. The trends published in the literature should be taken as a general guide only, and the influence of moisture content and dry density on swelling should be verified for individual sites. Because clay content significantly influences the overall volume change, it should be carefully assessed in each case. 相似文献