Na2CO3活化煤系高岭土吸附生活污水中磷的研究（Ⅰ）

考察了Na2CO3活化煤系高岭土对城市生活污水中磷的吸附。结果表明：当焙烧温度在700～750℃时吸附率达到最大，且在相同条件下，先活化后焙烧比先焙烧后活化的煤系高岭土对污水中磷的吸附率明显要低。当Na2CO3的浓度为2mol／L、固液比为10g/L时，吸附率都各自能达到其相同条件下的最大值。液膜扩散是煤系高岭土对磷吸附的主控步骤。     

活化煤系高岭土吸附城市生活污水中磷的研究

分别考察了焙烧温度、硫酸浓度和煤系高岭土用量对城市生活污水中磷的吸附率的影响,在此条件下又考察了吸附等温线、吸附动力学和吸附热力学.结果表明,当焙烧温度为700 ℃,硫酸浓度为70%,煤系高岭土用量为0.75g(每50 mL污水)时,煤系高岭土对城市生活污水中磷元素的吸附率分别达到最大.通过对吸附等温线、吸附动力学曲线和吸附热力学曲线的处理,得出硫酸活化煤系高岭土对磷的吸附行为更符合Freundlich模型,液膜扩散是其对磷吸附的主控步骤,且吸附是一个放热过程.     

焙烧条件对煤系高岭土吸附城市生活污水中有机物的影响

利用L16(45)正交试验考察了焙烧温度、焙烧时间、颗粒大小和硫酸浓度对煤系高岭土吸附城市生活污水中有机物的影响。结果表明当焙烧温度为700℃,焙烧时间为30 min,颗粒粒径为0.106 mm(150目)和硫酸质量分数为80%时,煤系高岭土对城市生活污水中有机物的吸附率达到最大值。     

碱改性处理高岭土的性能研究

以高岭土为原料,通过高温焙烧、碱处理的方法,制备多孔的基质材料,采用气相色谱仪和自 动吸附仪对碱处理前后的焙烧高岭土进行比表面、孔体积和孔分布的测定,结果表明,碱处理后的焙烧高岭土孔体积明显增加,且具有明显的中孔特征,平均孔径在55埃米左右,且随着碱液浓度的增加,孔体积和比表面也有明显的提高.     

固定床颗粒填料的制备及其处理三乙胺废水的研究

以粉煤灰、膨润土、高岭土为原料,经研磨、混合、造粒、焙烧等工艺,研制了一种颗粒吸附剂填料,并应用于农药行业三乙胺类废水的脱色。讨论了原料配比、焙烧温度、焙烧时间,对吸附剂颗粒空隙率、机械强度、吸附性等物理化学性能的影响。将吸附颗粒填充至实验室模拟固定吸附床装置中,应用于三乙胺废水的吸附处理,并与粉末状填料进行吸附对比。结果表明,高岭土的含量需大于15%,膨润土含量的范围为25%~50%,粉煤灰含量的范围为29%~60%,焙烧温度需600℃以上,且时间不低于1 h,可满足机械强度大于30 N。以高岭土、膨润土、粉煤灰配比为15.0∶42.5∶42.5,焙烧温度和时间分别为600℃和1 h,所制得颗粒填料进行吸附实验,结果表明,颗粒填料对三乙胺废水的脱色效果可将其色度从500将至50以下,COD去除率达30%以上,可与粉状填料相比媲。     

高岭土矿超细粉体制备及表面改性

以江西宜春某矿山的高岭土为原料，研究超细高岭土粉体的制备方法和表面有机改性的较佳工艺条件。试验证明，所制得的改性高岭土粉体的有效活性指数达86．4，经X衍射等分析，表明铝酸酯、钛酸酯复配偶联剂对高岭土表面不仅有较强键能的化学吸附。同开寸还存在一定的物理吸附。     

水华蓝藻胞外聚合物对高岭土吸附罗丹明B行为的影响

蓝藻水华爆发时期会在水中产生大量的蓝藻胞外聚合物（EPS），然而蓝藻水华EPS对于有机染料在水体与沉积物界面之间的影响尚不明确。在实验室条件下利用提取的微囊藻EPS，研究其对高岭土吸附罗丹明Ｂ的影响。试验证明，EPS能促进高岭土对罗丹明Ｂ的吸附，吸附动力学与伪一级动力学拟合，高岭土与高岭土EPS复合体的拟合相关系数R2分别为0.846 7和0.950 1。等温吸附以Langmuir和Freundlich拟合，结果更符合Freundlich吸附模型。不同pH条件下的吸附试验结果表明，罗丹明B在酸性条件下更容易被吸附。     

焙烧高岭土催化剂对催化甲醇制二甲醚性能的影响

为了考察高岭土焙烧前后性能的变化,将高岭土分别在200℃、400℃、600℃、和800℃进行焙烧,得到焙烧高岭土催化剂样品,并对催化剂进行TG-DTA、XRD和SEM等的分析及活性测试。结果表明,高岭土经过高温焙烧后转变为偏高岭土,高岭土的特征峰消失,同时孔道明显增多,甲醇转化率、二甲醚选择性和收率均提高。     

高岭土尾矿对亚甲基蓝的吸附行为的研究

文章探索了高岭土尾矿对亚甲基蓝溶液的吸附性行为,测定了高岭土尾矿的粒度与用量、亚甲基蓝溶液的pH与浓度、吸附时间及吸附温度等因素对亚甲基蓝吸附性能的影响。结果表明：在碱性条件下,高岭土尾矿对亚甲基蓝溶液有较好的吸附能力,亚甲基蓝浓度增加,高岭土尾矿对其脱色率减小,而随着高岭土尾矿用量的增加,则脱色率不断提高。高岭土尾矿对亚甲基蓝的等温吸附服从Freundlich方程式。高岭土尾矿对亚甲基蓝吸附的随时间的增加、温度的升高而增加。通过对这些参数的探索和测定,高岭土尾矿的吸附能力可以达到98%以上,高岭土尾矿能有效除去溶液中的亚甲基蓝。     

堇青石合成过程的研究

采用高岭土滑石和氧化铝作原料合成堇青石，通过对高岭土和滑石的ＤＴＡ分析，并结合前人所做的工作对高岭土和滑石在１０００℃以前的加热变化过程进行了阐述，同时通过对不同烧成温度下的试样做ＸＲＤ分析及ＳＥＭ观察，重点研究了堇青石的合成过程。     

高岭土原位合成Y型沸石过程中的吸附研究

采用N2静态吸附法和IR光谱法研究了高岭土原位晶化合成Y型沸石过程中的孔结构和沸石的形成过程。结果显示，在原位晶化过程中，从天然高岭土到晶化产物，孔结构发生了很大的变化，从大孔到中孔发达的过程，焙烧微球在碱溶液的作用下，形成了发达的孔道结构，进而在孔道的可接近表面上均匀地生长出了Y型沸石；原位晶化过程是焙烧微球在液相组分中先转变为硅铝酸钠凝胶，随后硅铝酸钠凝胶逐步地转变为Y型沸石。     

石棉尾渣和粉煤灰制备堇青石多孔陶瓷及其理化性能

低成本制备堇青石多孔陶瓷一直是专家学者们研究的热点,本文以石棉尾渣、粉煤灰、高岭土为原料,在不添加发泡剂的情况下,采用直接烧结法成功制备了堇青石多孔陶瓷,系统研究了堇青石多孔陶瓷的物相演化、显微结构及理化性能。结果表明:烧结温度的升高和配方中高岭土含量的增加有助于样品中堇青石的合成,高岭土的添加可以有效降低样品发泡的温度和提高样品的孔隙率;当烧结温度为1 240 ℃,焙烧后的石棉尾渣、焙烧后的粉煤灰和高岭土质量比为5∶5∶3时,制备的堇青石多孔陶瓷的体积密度仅为0.6 g/cm³,孔隙率高达76.94%;当烧结温度为1 220 ℃,焙烧后的石棉尾渣、焙烧后的粉煤灰和高岭土质量比为5∶5∶5时,制备的堇青石多孔陶瓷吸水率达到最大值34.57%;此外,制备的堇青石多孔陶瓷还表现出良好的耐碱性能。     

改性高岭土捕集CdCl2、PbCl2蒸气

针对两种重金属氯化物PbCl₂、CdCl₂，探究高岭土表面羟基对吸附重金属的作用。对高岭土进行煅烧及水热改性，并在两段式管式炉上进行高岭土捕集重金属氯化物蒸气实验，并使用原子吸收分光光度计（AAS）测量吸附剂中的重金属氯化物含量。吸附数据表明对于PbCl₂及600～700℃的CdCl₂吸附，高岭土经过煅烧吸附效率大幅降低，水热重新赋予羟基后吸附效率有所提升，但仍低于原高岭土。结合热重（DTG）及红外谱图（FTIR）分析可知，高岭土经800℃煅烧脱除全部羟基，经水热重新获得部分羟基，且所获数量随水热程度的加深而增多，结合XRD谱图可知羟基促进了高岭土与重金属氯化物的吸附反应；800℃以上高温下原高岭土吸附效率逐渐低于煅烧高岭土和水热高岭土，结合核磁共振谱图（NMR）分析可知其原因在于，高岭土经煅烧改性及水热改性，Al原子配位数降低，活性增强，更易与重金属氯化物蒸气结合。     

Adsorption of Hydroxypropyl Methyl Cellulose in an Aqueous System Containing Multicomponent Oxide Particles

The adsorption behavior of a hydroxypropyl methyl cellulose (HPMC) polymer in aqueous suspensions of alumina, silica, kaolin, and talc powders, two-component combinations, and one three-component combination was determined. Powders were well characterized by chemical analysis, XRD, DRIFT, SEM, particle size, surface area, and density analyses. The zeta-potential of each powder in aqueous suspension was determined over a range of pH to determine particle charging and the isoelectric point for each material. Alumina and silica powders having heavily hydroxylated surfaces were observed not to adsorb the HPMC polymer over a range of pH. The layer-type minerals talc, which was noticeably hydrophobic, and kaolin, which had differently hydrated basal planes, adsorbed the HPMC polymer but in different amounts per unit of surface area. In the two-component systems, HPMC polymer adsorption for systems of dispersed particles of like electrical charge (kaolin + silica, talc + silica or alumina, and kaolin + talc) was proportionate to the sum of the fraction x specific surface area x adsorption capacity for each particle type. In systems where particles had an opposite electrical charge (kaolin + alumina, kaolin + talc + alumina), the HPMC polymer adsorption was significantly lower than that calculated for a dispersed system. SEM analysis showed very fine, nonadsorbing alumina particles predominantly on the faces of the adsorbing kaolin particles that apparently masked polymer adsorption. Results suggested a hydrophobic mechanism for the HPMC polymer adsorption and adsorption on only one face of the kaolin particles.     

水分子在高岭土中吸附特性的蒙特卡罗模拟研究(英文)

利用巨正则系综蒙特卡罗方法模拟高岭土对水分子的吸附特性。通过数值计算和实验分析,表征不同温度、压强及阳离子交换条件下高岭土的吸附机理。研究表明数值分析与实验结果吻合较好。温度和压强对高岭土的吸附性质有着明显影响。铝置换硅使得高岭土的活性有了大幅度提高。此外,不同阳离子的引入,不仅能平衡体系的电价,还能不同程度地改变高岭土的吸附特性。     

高岭土高温吸附重金属和碱金属的研究进展

高岭土在高温下对碱金属和重金属具有吸附能力,可以解决煤、生物质和垃圾等在燃烧、气化等过程中产生的结渣、积灰、腐蚀以及重金属和超细颗粒物排放等问题。国内外学者已对此进行了长期研究,但仍存在相关的难度和问题,因此本文从高岭土高温结构特征、研究方法、高温吸附机理、高温吸附技术应用效果以及高岭土改性等5个方面介绍了相关重要成果,并结合前人研究成果和作者自身的研究经验,提出了本领域研究的展望。指出缺乏简便而准确的金属蒸气定量发生装置和在线检测装置严重阻碍了高岭土高温吸附的试验研究,亟待开发出对应的新方法或新设备;高岭土高温吸附的同时其结构因为高温也在发生畸变,掌握其中的关联是理解高温吸附行为的关键之一;烟气组分对吸附的影响研究仍不充分,因此目前无法形成复杂烟气组分下的高岭土高温吸附行为规律和数学描述;技术应用过程中,高岭土添加量较大（通常大于3%）,可能对燃烧或气化工艺产生不良影响,抑制了其工业应用;高岭土改性是提升吸附效率、降低高岭土用量的有效方法,改性工艺仍有待深入研究,但因为吸附后高岭土难以分离回收和循环再生,改性成本必须低。     

高岭土尾矿对苯胺吸附性能研究

研究了高岭土尾矿用量、苯胺初始浓度、溶液pH值、吸附时间、温度等因素对苯胺吸附性能的影响。结果表明：在酸性条件下,高岭土尾矿对苯胺有较好的吸附能力,其吸附率随着尾矿用量的增加而增加,随苯胺初始浓度增加而减小,且随温度的升高吸附平衡时间缩短,其等温吸附过程服从Freund lich方程式。用2.5 g高岭土尾矿吸附20 mg/L苯胺溶液,在35℃、pH=2.3时,苯胺的吸附率可达94.8%。     

Asphaltene adsorption on clay

Asphaltene adsorption measurements with a well crystallized kaolin, a poorly crystallized kaolin, and a montmorillonite under anhydrous conditions and in the presence of water showed that the adsorption varied depending on the properties of the clay and the amount of water. The presence of presorbed water on the clays reduced asphaltene adsorption. Adsorption experiments made at elevated temperatures did not substantially alter adsorption data.     

Flocculation properties and adsorption kinetics of cationic starches in kaolin suspensions

The flocculation characteristics of cationic starches with degree of substitution (DS 0.32–0.63) have been evaluated in 1.0 wt % kaolin suspension by spectrophotometry and colloid titration. Cationic starch is found to be an effective flocculant for removal of anionic suspension particles. Changes in the electrokinetics of kaolin as a function of pH were investigated in the absence of flocculant. The results show that kaolin in water exhibits a negative surface charge at pH > 2.5. The negative hydrophilic surface sites of kaolin are responsible for the adsorption of cationic starch molecules. The experimental data of the adsorption of cationic starch (DS 0.51) follow a Langmuir isotherm with maximum adsorption capacities of 16.89 mg/g. For the adsorption of cationic starch, chemical reaction seems significant in the rate‐controlling step and the pseudosecond‐order chemical reaction kinetics provides the best correlation for the experimental data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Adsorption and desorption behaviour of Pb(II) on a natural kaolin: equilibrium,kinetic and thermodynamic studies

BACKGROUND: Pb(II) is common in both waste‐waters and gas emissions. In developing countries, public health problems have been reported concerning Pb(II) pollution, so that stringent measures are required to deal with it. MAJOR RESULTS: The adsorption and desorption behaviour of Pb(II) has been investigated on a natural Chinese kaolin. Several factors, including initial concentration, pH, equilibration time, dosage and temperature correlated positively with Pb(II) adsorption. The Pb(II) adsorption capacity of natural kaolin was 165.117 mg g^?1. A kinetic study shows that Pb(II) adsorption on purified kaolin equilibrates within 35 min. The enthalpy changes of Pb(II) adsorption on purified kaolin were 63.683, 20.488 and 21.371 kJ mol^?1 with entropy changes 262.250, 112.210 and 105.120 J mol^?1 K^?1 for solutions containing 50, 100 and 200 mg L^?1 Pb(II) respectively, indicating an endothermic and spontaneous adsorption process. The desorption of Pb(II) from kaolin was difficult with more than 85% Pb(II) removal. Based on X‐ray diffraction (XRD) analysis, the Pb(II) adsorption on natural and purified kaolin was attributed mainly to the magnesite component and complexation with the mineral surface. CONCLUSIONS: Natural kaolin exhibits a satisfactory performance for adsorption of Pb(II) from aqueous solution. The optimum conditions for adsorption were: ionic strength = 0.01 mol L^?1; pH ≥ 7.2; dosage = 10 g L^?1; temperature = 25 °C; duration ≥ 16 h (C_i = 80 mg L^?1); and the optimum conditions for desorption were ionic strength = 0.1 mol L^?1 and pH ≤ 5.0. Copyright © 2009 Society of Chemical Industry