关于JG／T193—2006（《钠基膨润土防水毯》有关问题的讨论

对建材行业标准JG／T193—2006《钠基膨润土防水毯》中有关膨润土的诸如标准的制定、标准的命名、膨润土吸蓝量、钠基膨润土、人工钠基膨润土的变质以及膨润土的耐久性等一些有争议的问题进行了讨论,并就有关膨润土防水毯国家标准的编制提出了一些建议。     

信阳天然膨润土提纯试验研究

根据信阳膨润土的特性,采用湿法对其进行提纯。分别考察了六偏磷酸钠用量、液固比、沉降时间、搅拌时间对提纯效果的影响,并用吸蓝（MB）法和X-射线衍射对提纯效果进行检验。结果表明,信阳膨润土最佳提纯条件：分散剂用量0.125%、最佳液固比12、搅拌时间80min、沉降时间120min。膨润土的蒙脱石含量从61%提高到90%以上。     

常见外加剂对水泥砂浆性能的影响研究

本文研究了减水剂、憎水剂、引气剂、硅灰、膨润土和膨胀剂等6种外加剂对水泥砂浆抗渗性能、吸水量和抗压强度的影响.结果表明:在相同流动性下,适量减水剂可以全面提高水泥砂浆的各项性能,其最佳掺量为0.3％;憎水剂和引气剂能够降低水泥砂浆的吸水量,但也会大幅降低抗压强度;硅灰掺量超过5％对砂浆的抗渗性能有明显帮助;膨润土和膨胀...     

有机膨润土的应用

有机膨润土是钠基膨润土与有机阳离子表面活性剂反应生成的一种复合产品。一、有机膨润土在油漆行业的应用油漆的种类很多,有机膨润土主要用在环氧树脂,醇酸树脂,沥青,氨基树脂等合成树脂中,另外还应用在含铁、锌、铅等系列颜料     

聚丙烯酰胺改性膨润土防渗材料的制备及其表征

以吉林省刘房子地区天然膨润土为主要原料,采用水溶液聚合法,在室温条件下,首次通过改性聚丙烯酰胺对膨润土进行直接插层改性,制备了一种新型聚丙烯酰胺改性膨润土防渗材料。结合表征结果讨论了不同改性聚丙烯酰胺加入量对改性膨润土材料结构的影响,结果表明,聚丙烯酰胺加入量为30%的改性膨润土比表面积较原土增大,粒径分布较好;XRD表征结果说明,聚丙烯酰胺插层使膨润土的层间距变化不大,对膨润土的其它部分的结构及形貌等未产生影响,d001的峰比较尖锐,说明聚丙烯酰胺在膨润土中分散性较好;SEM表征显示改性膨润土表面的不规整程度明显增加;IR分析结果说明膨润土层间存在聚丙烯酰胺。     

我国膨润土行业的发展现状、主要问题及合理建议

该文详细介绍了当前我国膨润土资源分布、生产消费、国际贸易、市场趋势等方面的情况,分析了我国膨润土行业发展中存在的主要问题,并提出了具体建议。     

预筛分细料-膨润土渗透性能研究

以建筑垃圾预筛分细料、膨润土为研究对象,研究膨润土掺量、种类对其渗透系数的影响,从而为建筑垃圾预筛分细料作为土-膨润土材料可行性提供理论依据。结果表明,相同膨润土掺量下,随固结压力增大,预筛分细料-膨润土渗透系数随之减小,因此当膨润土膨胀性能较差或者母土颗粒粒径较大可通过增加膨润土掺量大大降低预筛分细料-膨润土渗透系数,从而满足竖向隔离墙设计标准要求;膨润土掺量相同时,由于蒙脱石含量不同,相同固结压力下怀俄明膨润土的渗透系数明显比高庙子膨润土小,渗透性能优于高庙子的;试验为建筑垃圾预筛分细料以及质量较差膨润土的综合利用提供了可行性和新思路。     

纳米膨润土加固黏土强度的试验研究

纳米膨润土是一种新型的土体加固材料,能有效提高土体的物理力学性质。掌握纳米膨润土加固土体的特性对于该技术的推广应用具有重要的意义。本文开展了10组无侧限抗压强度试验,研究了掺加纳米膨润土后黏土土样的力学性质,以及纳米膨润土掺量、土的含水率和干密度三个因素对土体无侧限抗压强度的影响。结果表明,纳米膨润土的掺加能有效提高黏土的抗压性能,且抗压强度随纳米膨润土掺量、土干密度的增加呈非线性增加;随土含水率的增加,抗压强度先减少后增加。黏土内掺入纳米膨润土后,由于土的孔隙会被填充,形成密集结构,纳米膨润土-黏土颗粒界面的有效接触面积增加,使黏土体的强度显著增加。同时,水分会在纳米膨润土-黏土界面起到润滑作用。本研究表明,这一土体加固技术能有效提高地基土的承载力和变形性能,因此具有巨大的应用潜力。     

科技新干线

钙基膨润土改性为锂基膨润土我国膨润土资源丰富,预测储量有70亿t,保有储量24.6亿t,居世界首位,占世界量的60%。但绝大多数为钙基膨润土,若不改性便难以应用。改性目前主要有两种改性:一是钠化改性,二是有机包覆改性。最近信阳师范学院用河南信阳上天梯的钙基膨润土,通过改性剂制备出锂基膨润土。锂基膨润土,既有钠基膨润土的特性,又有有机膨润土的功能,而且在很多应用领域可以代替有机膨润土,因此具有较高的价值。用钙基膨润土制备锂基膨润土的工艺流程如下:钙基膨润土→加H2O崩解浆化→粗滤(滤出沙石)→静置(滤出上清液)→干燥→破碎→加…     

膨润土掺量对自密实混凝土强度及变形能力的影响

基于混凝土的抗压试验,研究了膨润土掺量对自密实混凝土抗压强度和弹性模量的影响。试验中膨润土掺量分别为胶凝材料总体积的0%、2. 5%、5%、10%、15%、20%、30%、40%和50%。结果表明:当膨润土掺量不超过5%时,抗压强度随着掺量的增加而增大;膨润土掺量超过5%时,抗压强度随着掺量的增加而减小。当膨润土掺量超过2. 5%时,随着掺量的增加,弹性模量逐渐降低。此外,当膨润土掺量不超过10%时,模强比随着掺量的增加而减小;当掺量超过10%时,模强比开始逐渐增大。自密实混凝土中膨润土掺量宜控制在胶凝材料总体积的5%～15%。     

基于晶层水化模型确定膨润土的相对密度

 根据蒙脱石晶层间水化模型,建立采用脱气纯水作为溶剂的蒙脱石相对密度计算公式,该式表明蒙脱石总比表面积和吸附水膜厚度越大,其相对密度也越大。同时对乙二醇饱和不同初始含水率膨润土,用X射线衍射仪测试了蒙脱石的晶层间距,发现其晶层厚度大致相同。对福建标准砂和高庙子钙基膨润土分别用煤油和脱气纯水2种溶剂进行相对密度试验,通过实测和计算相对密度值的比较,得到膨润土的相对密度值与溶剂的种类有关的结论,以脱气纯水作为溶剂,比用煤油测得的膨润土相对密度要大,验证了蒙脱石相对密度计算公式的合理性。     

Microwave- and acid-treated bentonite as adsorbents of methylene blue from a simulated dye wastewater

Batch adsorption tests for removal of methylene blue dye (MBD) from aqueous solutions onto bentonite was investigated using natural chemically treated (sulphuric acid) and physically treated (microwaved) bentonite. In batch sorption tests for MBD removal by the developed sorbents, the time needed to reach equilibrium was less than 30 min. The uptake of MBD by the microwave-treated bentonite was the highest, followed by the acid-treated and finally the untreated bentonite. The uptake of MBD increased with an increase in the dye concentration or the solution temperature. Three kinetic models were used for elucidation of the probable mechanisms of MBD uptake by the three sorbents. The rates of MBD uptake followed the pseudo second-order model with a high correlation. Intraparticle diffusion was involved in the sorption process but was not the rate-controlling factor. The Freundlich and Langmuir isotherm models were employed and well represented the experimental data.      

聚多巴胺 / 膨润土吸附剂的制备及对铬（Ⅵ）的吸附性能研究

本文以膨润土为基体,盐酸多巴胺为原料,采用聚合物改性技术制备聚多巴胺-膨润土吸附剂(PDA/SDS-BT)。通过红外光谱仪(FT-IR),X射线衍射仪(XRD)、透射电镜(TEM)对制备的吸附剂进行了结构表征,并考察了PH、吸附剂投加量、吸附时间和吸附温度对吸附性能的影响。结果表明:适当提高温度有利于吸附,PH=3,反应温度313K,达到吸附平衡时,吸附量可达81.10mg/g。     

Investigating factors influencing polymer elution and the mechanism controlling the chemical compatibility of GCLs containing linear polymers

A study was conducted to investigate (1) physicochemical factors that influence polymer elution from GCLs containing a blend of bentonite and linear (water-soluble) polymer (LPB GCLs) and (2) the mechanism that controls the chemical compatibility of LPB GCLs when polymer elutes. A series of hydraulic conductivity (k), free swell and viscosity tests were performed on a commercial LPB GCL using DI water, varying concentrations of NaCl and CaCl?. Comparable tests were also performed on a conventional bentonite (CB) GCL containing the same untreated bentonite and the same physical properties as the LPB GCL. The LPB GCL showed improved swelling and hydraulic performance compared to the CB GCL when permeated with salt solutions. Total organic carbon analysis of the effluents showed that polymer eluted from the LPB GCL regardless of the permeant solution. However, the rate at which polymer eluted increased as the concentration and valence of the dominant cation increased. The rate at which polymer eluted also increased with hydraulic gradient. The mass of polymer retained inside the GCL matrix did not correlate with the k of the LPB GCL. Free swell tests coupled with chemical analysis suggest that, the improved chemical compatibility of the LPB GCL was due to the ability of the polymer to scavenge cations from the solution which allows the bentonite to undergo adequate swelling during the initial hydration period. Analogous to water-prehydrated CB GCLs, the dispersed structure of the bentonite fabric and increased adsorbed water molecules attained during initial swelling controls the k of the LPB GCL when polymer elutes.     

Adsorption of Cu(II) from industrial liquid waste on Na-bentonite and Al-PILC following a full factorial design

The paper reports a study of the performance of Maghnia bentonite in a purified and modified state for the removal of Cu(II) from industrial liquid waste in the region of Oran (North West Algeria). Bentonite was firstly treated to produce a Na-bentonite, then modified with an aluminum solution containing molar ratio OH/Al of 1.8 and finally calcined at 450 °C. The polymer [AlO₄Al₁₂(OH)₂₄(H₂O)₁₂]⁷⁺ formed in solution was adsorbed by surface complexation on the bentonite, which is known to have a high capacity to fix metal cations. The prepared materials were characterized by DRX, BET and EDX. In order to find the optimum conditions, a full factorial design of 2⁴ allowed us to determine the main effects and interactions of the factors studied: pH, mass of materials, contact time and temperature. The results obtained show that the best rate of adsorption of copper requires a pH = 10, a mass = 0.8 g, a stirring time = 80 min, and a temperature = 25 °C. The adsorption capacity of treated bentonite increased considerably from 4.147 mg/g for Na-bentonite to 7.173 mg/g for pillared aluminum bentonite. This shows the strong adsorption of copper compared with Na-bentonite, caused by its high surface area.     

Determination of full-scale pore size distribution of Gaomiaozi bentonite and its permeability prediction

Gaomiaozi(GMZ)bentonite is a potential buffer/backfill material for a deep geological disposal of highlevel radioactive waste.It has a wide pore size distribution(PSD)with sizes ranging from several nanometers to more than one hundred microns.Thus,properly characterizing the pore structures of GMZ bentonite is a challenging issue.In this study,pressure-controlled porosimetry(PCP),ratecontrolled porosimetry(RCP),and scanning electron microscopy(SEM)were used to investigate the PSD of GMZ bentonite,The results indicate that each method has its limitation,and a combined use of PCP and RCP is suitable to obtain the full-scale PSD of GMZ bentonite.Moreover,we also compared the full-scale PSD with nuclear magnetic resonance(NMR)result.It is found that there is no significant difference in the range of PSD characterization between NMR and mercury intrusion method(PCP and RCP).However,in a ce rtain range,the detection accuracy of NMR is higher than that of mercury injection method.Finally,permeability prediction based on PCP and SEM data was conducted,and both of the two methods were found to be able to predict the permeability.The combined method is effective to obtain the full-scale PSD of GMZ bentonite,which is the key to estimation of the sealing ability of bentonite buffer.     

膨润土吸水率测试方法的对比及讨论

吸水率是球团用膨润土必检的重要指标之一,也是衡量膨润土性能的重要指标。精确的测试方法对判定球团用膨润土的质量至关重要。本文对两种吸水率测试方法进行三组对比实验,结果发现：新实施国标GB／T20973—2007膨润土吸水率测试方法在正确度、准确度上均优于建材行业标准JC／T593—1995的吸水率测试方法。     

新疆阿尔泰膨润土土水特征的室内试验研究

在介绍渗析(液相)法与气相法的基础上,对新疆阿尔泰膨润土在自由状态下的土水特征进行了室内实验研究,荻取了相应的土水特征曲线,并对所得的土水特征曲线的基本特征进行了分析研究,最后提出了土水特征曲线的几种表达方式,分析了新疆阿尔泰膨润土的体积变化特性及其对土水特征曲线形状的影响.结果表明:实验室中渗析(液相)法与气相法的结...