以廉价高岭土和硅藻土为原料合成方沸石分子筛膜

以廉价高岭土和硅藻土为主要原料,在管状莫来石支撑体上采用2次水热生长法合成了方沸石分子筛膜.通过气体渗透性能测试和XRD、SEM等对膜进行表征,重点考察了合成溶胶中的碱度、合成温度、晶化时间对膜层的晶体形貌和结构以及渗透性能的影响.结果表明:在n（ H2 O）: n（ Na2 O）为200的合成溶胶体系中,合成温度为150℃的条件下晶化反应6 h,可制备出结晶度好且渗透性能较高的纯相方沸石分子筛膜.室温下该膜的氢气渗透率为1.8×10-8 mol·m-2·s-1·Pa-1,H2/CO2气体分离因子为15,高于其努森扩散值（4.7）.     

雨水酸化条件对高岭土改性沥青路面腐蚀性能的试验模拟

在酸雨条件下,为提高路面抗腐蚀性能的最佳高岭土掺量,探究酸雨对高岭土改性沥青路面腐蚀性能的影响.在pH值为2.0, 4.0,5.6,7.0时,采用周期浸泡、加速腐蚀的试验方法,依次研究高岭土改性沥青混合料的变化情况.试验结果表明:不同pH值的酸雨对4种不同高岭土掺量的沥青混合料均有侵蚀作用,但掺加高岭土的马歇尔试件明显好于基质沥青试件;通过宏观实验及微观分析,当高岭土掺量为3%时,高岭土改性沥青混合料抗腐蚀性能最佳.     

煤系地层中高岭土矿床的主要成因类型及特征

沉积高岭土矿床,可分为煤层内高岭石夹矸和煤层间高岭土矿床二种类型。前者成分很纯、结晶很好。在煤系地层中,由于原始物质、地质构造、地形条件、水文地质等条件的具备,也发育风化矿床,它们多半为软质粘土或木节土。内蒙老石旦高岭土矿床是石炭系煤层及其夹矸的风化残余产物。甘肃安口高岭土矿床也是侏罗系煤层,夹矸及顶板泥质岩的风化残余产物。四川叙永高岭土矿床则为二迭系煤层及其底板风化淋滤的结果。由于煤层自燃,还存在高岭土经烧变而成的天然熟料,可以作为一种变质高岭土矿床。本文从具体矿床实例出发,提出了煤系地层中高岭土矿床存在的主要成因类型,在理论上,找矿和利用上,均具一定意义。     

用高岭土制备聚氯化铝铁-淀粉复合絮凝剂及性能研究

以高岭土、淀粉为原料合成聚氯化铝铁-淀粉复合絮凝剂。产品和市售PAC(以质量相同计)对废水进行处理,絮凝性能明显优于市售PAC。实验研究了酸浸高岭土的优化工艺条件,高岭土与盐酸质量比为1:3,盐酸浓度为6mol.L-1,温度为85～90℃,反应时间为4h,铝铁的浸取率分别达93%、95%。实验还研究了复合絮凝剂优化反应条件,酸浸液中铝与淀粉质量比为3.4:1,pH为1.5,温度为60℃,反应时间为6h时,产品絮凝效果佳。     

稻壳灰与高岭土掺料对再生细骨料混凝土 性能影响的研究

为了改善和提高再生细骨料混凝土的性能,加大再生细骨料混凝土的应用,本文通过配置不同比例的强化液对再生细骨料（取代率为20%）混凝土的强化效果进行了研究,研究表明：配置的5种化学浆液,即稻壳灰与高岭土的混合比例分别为：1:0、3:1、1:1、1:3、0:1,对再生细骨料混凝土强化效果均有提高,当稻壳灰与高岭土的混合比值为3:1时,强化效果最佳;抗压强度为32.4 MPa,较未强化前增加了1.5 MPa,增幅4.9%;抗折强度为4.54 MPa,较未强化前增加了0.18 MPa,增幅4.1%;磨损量最小为0.452 g?cm-2,耐磨性最好。该成果对再生细骨料混凝土的推广应用具有重要的社会效益和经济价值。     

纯培养铁还原菌去除高岭土中铁的研究

利用异养铁还原菌对含Fe2O3的高岭土进行除铁研究,考察了时间、碳源及其投加量、pH值、微生物接种量、温度6个因素对高岭土除铁的影响.研究结果表明,在厌氧条件下,每g高岭土蔗糖加入量为0.04 g、菌液加入量为0.5 mL、pH6.0、温度为30 ℃条件下,铁还原菌除铁效果最好,培养16 d后,矿浆质量浓度为100 g·L-1高岭土中的Fe2O3含量由原来的0.59%降低至0.52%,自然白度由原来的75提高为80.     

高岭土对准东高碱煤煤灰熔融特性影响的量子化学与实验研究

采用量子化学理论计算与实验表征相结合的方法,研究了高岭土对准东高碱煤煤灰熔融特性及其熔融过程中矿物质演变规律的影响,并从矿物质微观结构特性角度阐述了高岭土对改变准东煤煤灰熔融特性的影响机制。结果表明,准东高碱煤煤灰熔融温度随高岭土的添加呈现先快速升高后逐渐变缓的趋势,当高岭土添加比例大于10%时,其提高煤灰熔融温度的趋势变缓;准东高碱煤添加高岭土后,其在1 000-1200℃下的低熔融矿物钙长石、硬石膏等量明显减少,1 200-1 300℃下有一定量的莫来石生成,是其煤灰熔点升高的主要原因;高岭石分子结构中的O(26)、O(22)、Si(6)、Si(8)的反应活性较高,能够与灰中的Fe~(2+)等金属离子成键,促使高岭石的铝氧键断裂。煤中的碱金属或碱土金属(Na或Ca)氧化物中的的O2-,作为亲核试剂,与高岭石的Si(6)和Si(8)发生亲核反应,使桥氧键S-O-Si断裂。     

水溶性疏水缔合聚合物在高岭土/水界面的吸附

表面活性剂;水溶性疏水缔合聚合物在高岭土/水界面的吸附     

Surface Speciation Modeling of Heavy Metals in Kaolin: Implications for Electrokinetic Soil Remediation Processes

The driving mechanisms for flux occur at interface between the soil particles and solution during electrokinetic soil remediation and the nature of this interface affects the electrokinetic response of the system. The pH-dependent adsorption of heavy metal contaminants by kaolin and the sensitivity of kaolin zeta potential to the aqueous phase properties are two important aspects that complicate the metal movement during electrokinteic soil remediation. This paper addresses these aspects and presents an electrostatic adsorption model that describes the behavior of kaolin surface for Cr(VI), Cr(III), Ni(II), and Cd(II) under various chemical conditions. This study showed that the aqueous properties: pH, ionic strength and the presence of the heavy metals Cr(VI), Cr(III), Ni(II), and Cd(II) in the system affect the zeta potential of kaolin surface. The zeta potential of kaolin shifts to a more negative value if the system pH increases. However, it shifts to a more positive value if the system ionic strength or metal concentration increases. It was found that the amount of the heavy metal adsorbed by kaolin has a pronounced sensitivity to the pH. As a result of the adsorption modeling, the constant capacitance protonation-dissociation intrinsic constants of kaolin are: pK and . The ion-kaolin surface complexation constants (pK ) of Cr(VI), Cr(III), Ni(II), and Cd(II) are: −12.5± 0.5, −5.0± 1.0, 2.6± 0.6, and 3.3± 1.0, respectively.     

Effect of the Kaolin Particle Size on the Pozzolanic Behaviour of the Metakaolinite Produced

This paper reports an investigation of the effect of the particle size of kaolin on its transformation to metakaolinite. Kaolin from the island of Milos was either crushed or ground in order to produce four samples with different degrees of fineness (residue at 500 μm: 0–71.8%). The samples were treated thermally under different conditions in order to determine the optimum treatment conditions. The conversion of kaolinite to metakaolinite and the structural changes in the material during treatment were investigated by means of TG and XRD, respectively. Each sample was incorporated into a type I cement, at 20% by mass of cement, and the compressive strengths of the resulting blended cements were measured. It is concluded that the particle size of the raw kaolin does not affect the thermal conversion or the pozzolanic activity of the material. The use of crushed kaolin has many benefits since the furnace load can be increased, while the grinding process is needed only to reduce the size of the metakaolinite particles. This revised version was published online in August 2006 with corrections to the Cover Date.