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为了研究γ辐射和热同时作用对膨润土的影响,以高庙子改性钠基膨润土为研究对象,开展了90℃热作用下、不同剂量率和不同累积剂量的γ辐射老化试验。结果表明:γ辐射和90℃热同时作用引起了膨润土物理化学性质和微观结构的变化。在老化作用后,膨润土的吸水率、pH值、阳离子交换容量、层荷以及蒙脱石001晶面方向的微晶尺寸均减小,比参考样分别降低了(最大减幅)18.4%、7.8%、3.4%、2.9%和15.6%,且表现出剂量率效应;老化作用对膨润土的矿物成分及含量影响较小。在高放废物地质处置的工程屏障设计和安全评价中,应考虑膨润土性质变化的影响因素。 相似文献
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以内蒙古兴和县高庙子钠基膨润土和甘肃北山BS05号钻孔地下水为研究对象,依托低氧手套箱,在常温低氧条件下开展膨润土与地下水长期作用试验研究,获得了1年内膨润土 北山地下水体系pH和Eh值随时间的变化特征;得到了作用前后体系液相关键离子成分以及固相可交换阳离子、化学成分,依托拉曼光谱仪测定了作用前后膨润土的结构。结果表明,膨润土 北山地下水体系在本试验条件和时间范围内可以保持相对稳定的状态。 相似文献
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导热性能是高放废物地质处置库缓冲/回填材料的重要性能之一。采用瞬变平面热源法,研究了我国高放废物地质处置首选缓冲/回填材料高庙子膨润土,及以其为主料,添加不同含量石英砂、北山花岗岩碎屑组成的混合材料的导热性能。分析了添加剂种类和含量、干密度、饱和度等因素对导热系数的影响。研究结果表明:高庙子膨润土及其混合材料的导热系数、热扩散系数都随干密度和含水量的增大而增大;石英砂、北山花岗岩碎屑能够不同程度提高膨润土的导热系数,石英砂的作用优于北山花岗岩碎屑;饱和度对添加剂发挥其提高缓冲/回填材料导热性能的作用影响明显,饱和度越高,添加剂的作用越显著。 相似文献
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Based on the results of one-dimensional free swelling tests, the coupled effects of NaCl-Na2SO4 solutions and temperature on the swelling deformation property of compacted GMZ bentonite-sand mixtures were analyzed. The concentrations of the NaCl-Na2SO4 solutions were 0, 0.008, 0.04, 0.08 and 0.16 mol/L, the temperatures were 20 °C, 40 °C, 60 °C, 80 °C and 90 °C and the sand contents were 0, 30 and 50%. X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP) tests were also performed to find the influences of the temperature, solution concentration and sand content on the mineral composition and microstructure. The results showed that the maximum swelling strain of the specimens increased with an elevated temperature, while it decreased with increases in the solution concentration and sand content. The swelling process was accelerated by the rising temperature. The XRD tests indicated that the combined effect of a high temperature and a high solution concentration may have caused more Na+ from the saline solutions to enter the interlayer, partly displacing the divalent cations. The MIP tests demonstrated that adding sand to the bentonite could reduce the amount of inter-granular pores and increase the intra-aggregate pores. These findings are advantageous to the transfer of heat and pour fluid in the specimens; and thus, the swelling deformation capacity of the bentonite-sand mixtures was higher than that of pure bentonite under the same conditions. 相似文献
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Soil-water characteristics of Gaomiaozi(GMZ)Ca-bentonite at high suctions(3–287MPa)are measured by vapour equilibrium technique.The soil-water retention curve(SWRC)of samples with the same initial compaction states is obtained in drying and wetting process.At high suctions,the hysteresis behaviour is not obvious in relationship between water content and suction,while the opposite holds between degree of saturation and suction.The suction variation can change its water retention behaviour and void ratio.Moreover,changes of void ratio can bring about changes in degree of saturation.Therefore,the total change in degree of saturation includes changes caused by suction and that by void ratio.In the space of degree of saturation and suction,the SWRC at constant void ratio shifts to the direction of higher suctions with decreasing void ratio.However,the relationship between water content and suction is less affected by changes of void ratio.The degree of saturation decreases approximately linearly with increasing void ratio at a constant suction.Moreover,the slope of the line decreases with increasing suction and they show an approximately linear relationship in semi-logarithmical scale.From this linear relationship,the variation of degree of saturation caused by the change in void ratio can be obtained.Correspondingly,SWRC at a constant void ratio can be determined from SWRC at different void ratios. 相似文献
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振荡时间、离子强度、温度和pH值对GMZ膨润土中Cr(Ⅲ解)吸特性的影响 总被引:2,自引:0,他引:2
对吸附在高庙子(GMZ)膨润土上的Cr(III)进行解吸实验,研究振荡时间、解吸溶液离子强度、温度和pH值等因素对解吸特性的影响规律。结果表明:高庙子膨润土上Cr(III)的解吸过程较易发生;Cr(III)的解吸动力学过程较吸附过程慢,实验条件下解吸过程在3 h后达到平衡;当使用0.1 mol/L HCl、1 mol/L NaCl和1 mol/L CaCl 2作为解吸液时,Cr(III)的最终解吸率分别达89.4%,56.5%和77.2%;增大解吸溶液的离子浓度能够促进解吸过程的发生;pH值对Cr(III)解吸过程有重要影响;吸附/解吸过程较符合Freundlich等温模型。GMZ膨润土在处理Cr(III)废水时具有较好的再生能力,可以多次重复利用。 相似文献
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以莱西钙基膨润土为原料,经二次湿法提纯-2μm的膨润土,钠化改型,制备了高纯度的钠基膨润土,在此基础上,探索了无机凝胶的制备工艺,考察了不同磷化剂和胶化剂对无机凝胶的影响。提出了以0.7%焦磷酸钠为磷化改性剂,1.5%CaO为胶化剂制备无机凝胶的新工艺。希望能代替进口的VEEGUM系列应用于日化工业。 相似文献