煤矸石制备堇青石微晶玻璃的研究

以煤矸石、工业氧化铝、菱镁矿、SiO2为原料,以TiO2为晶核剂,采用粉末烧结法制备了堇青石微晶玻璃.主要工艺过程是制定基础玻璃配方、玻璃的熔融和基础玻璃的不同热处理工艺.采用X射线衍射仪(XRD)、扫描电镜(SEM)分析了材料的物相组成和显微结构.800℃下核化时间对物相的形成没有明显影响,最佳的热处理工艺为:核化时间3h,核化温度800 ℃;晶化时间4h,晶化温度1200℃.     

Densification and Phase Development of Spodumene–Cordierite Glass Powder Mixtures

The sintering and crystallization of spodumene-cordierite glass-ceramics that are made from mixtures of Li₂O-Al₂O₃-SiO₂ (LAS) and MgO-Al₂O₃-SiO₂(MAS) glass powders were investigated. Pure LAS and MAS powders have good sinterability. However, the densification of LAS was drastically reduced when small amounts of MAS were added. When larger amounts of MAS were added, the amount of densification further increased. The decrease in the Li₂O content in the LAS glass promoted the densification of the mixed glass samples. The above-mentioned results can be explained by examining the crystallization temperature, which is influenced by the interactions between the LAS and MAS glass particles. The lower the temperature of crystallization, the less sintering occurred. For the sintered samples, the phase that crystallized from the MAS glass was alpha-cordierite, and that which crystallized from the LAS glass was ß-spodumene or high-quartz solid solution, depending on the Li₂O content in the LAS glass.     

烧结法堇青石微晶玻璃的研制

实验利用廉价的工业原料氧化铝、滑石、粘土等,加入少量添加剂和晶核剂TiO2,采用粉末烧结法制备出了具有低的介电常数、低的热膨胀系数和高的抗折强度等优良性能的MgO-A l2O3-SiO2系堇青石微晶玻璃。样品最佳热处理制度为:核化780℃,保温2h,晶化990℃,保温2h,升温速率3℃/m in。样品析出主晶相为α-堇青石,伴有少量镁橄榄石(Mg2SiO4)、镁铝钛酸盐(MAT)和金红石(TiO2)次晶相。     

用激光粒度分析仪检测细粒径SiO2基相变调湿复合材料的粒度分布

以SiO2为载体、棕榈醇-棕榈酸-月桂酸为相变材料,采用溶胶-凝胶法制备细粒径SiO2基相变调湿复合材料,以中位径(d50)为评价指标,采用激光粒度分析仪研究了溶液溶质浓度、超声时间、超声频率及分散介质对材料粒度的影响. 结果表明,激光粒度分析仪可用于检测SiO2基相变调湿复合材料的粒度分布,水对材料的分散效果比乙醇好,以水为分散介质,材料最佳溶质浓度为5~10 g/L,最佳超声时间为15 min以上,最佳超声功率大于400 W.     

乳液聚合瞬时乳胶粒大小和分布及其控制策略

乳液聚合中瞬时乳胶粒大小及分布与乳胶粒的形成和增长紧密相关,本文在苯乙烯,醋酸乙烯酯乳液聚合中考察了瞬时乳胶粒大小及分布。结果表明,在成核和稳定期乳胶粒增长速率较高,是控制乳胶粒大小及分布的关键阶段,由此提出了对于单体不同水溶性体系控制乳胶粒大小分布的策略,并以实验考核这些策略的合理性。     

以酸解TEOS为硅源合成可控孔径和粒径NaP分子筛

利用盐酸预处理TEOS得到的硅凝胶为硅源,铝酸钠为铝源,通过水热合成法制备了一种晶粒尺寸和孔径大小可控的NaP分子筛.利用不同时间酸解TEOS得到的硅凝胶合成NaP分子筛,但合成的样品杂晶较多且形貌不规整;采用正交试验,通过调节晶化时间、晶化温度、溶液pH值和水硅比,以达到样品提纯、形貌规整的目的.对样品进行SEM、XRD、N2物理吸附等表征,分析样品的形貌、结晶度和孔径分布等.并对样品进行铜离子吸附性能测试,得到NaP分子筛对Cu2+的有效去除率为98.9％.利用预先酸解TEOS得到的硅凝胶合成NaP分子筛的方法,为工业污水净化提供一定的理论依据及指导.     

Transparent Nano Crystalline Glass-Ceramics by Interface Controlled Crystallization

A prerequisite for the preparation of nano glass-ceramics is an increase in viscosity of the residual glassy matrix phase during the course of the crystallization process. This results in a deceleration of the crystal growth process due to increasing stresses, which finally may lead to a total freezing of the crystallization process. In principle, two routes for the preparation of nano glass-ceramics exist: in one of these routes, the first step is a phase separation in which a droplet phase is formed. Inside this droplet phase, the crystals are precipitated. In the other route, a preceding phase separation does not occur and the nucleation takes place in a homogeneous glassy phase. In both cases, the crystal growth velocity is high until the crystals reach a size of some nanometers or some ten nanometers, then the crystal growth velocity decreases strongly.     

锂辉石在中性硼硅玻璃中的应用研究

以锂辉石中的Li2O等量替代中性硼硅玻璃(简称5.0医药玻璃)化学组成中的Na2O和B2O3,研究Li2O对工艺性能和节能减排的影响。研究结果表明:Li2O具有较好的助熔效果,可以显著降低玻璃高、低温黏度特征点所对应的温度;当0.20%～0.30%(质量分数)Li2O替代Na2O时,5.0医药玻璃拉管工艺性能达到最好,0.20%Li2O替代B2O3时,其拉管工艺性能最好。因此,锂辉石对中性硼硅玻璃具有显著的节能减排效果,并能显著提高其拉管工艺性能。     

二氧化钛微晶物相及粒度分析

以钛酸丁酯为原料,无水乙醇为溶剂,在酸性条件下,采用溶胶-凝胶法制备了TiO2微晶。通过X-射线衍射仪(XRD)、激光粒度仪对样品的物相组成和颗粒粒径进行表征。研究了不同的反应条件对粉末颗粒粒径大小的影响。结果表明:钛酸丁酯∶冰醋酸为10∶3.5时,在600℃煅烧下制备的粉体颗粒粒径最佳;在400℃下煅烧样品呈现锐钛矿相,晶粒大小为13.4nm;样品在500℃、600℃煅烧后得到锐钛矿和金红石相的混合相;在700℃下煅烧样品完全转变为金红石相,晶粒大小为91.9nm。     

纯碱颗粒级配对平板玻璃熔制质量的影响

纯碱是平板玻璃生产中的一种重要原料 ,其粒度大小对玻璃的熔制存在明显的影响。通过大量的熔化、澄清实验研究纯碱的不同粒度以及颗粒级配对玻璃熔化、澄清质量的影响 ,从而确定符合生产需要的纯碱颗粒级配的优化范围 ,并从理论上加以探讨。过粗的纯碱颗粒不利于玻璃的熔制 ,其上限应控制在 2 6目左右 ,而纯碱细粉的含量则应控制在合适的范围内。     

叶蜡石粒度对玻璃熔制的影响

通过实验研究了叶蜡石粒度对玻璃熔制的影响。研究结果表明:在无法控制超细粉质量分数的生产工艺下,叶蜡石粒度并非越细越好,当粒度做到325目全通时反而会导致玻璃熔化和澄清质量变差。叶蜡石超细粉的质量分数应控制在合理的范围内,大量超细粉的存在不利于玻璃的熔化和澄清,但少量超细粉的存在并不损害玻璃的熔制。     

相反转工艺制备巴西棕榈蜡乳液的粒径调控

分别采用经过相反转过程的水入蜡乳化法和直接将蜡加入水中进行乳化的蜡入水乳化法2种工艺制备蜡乳液,测试所得蜡乳液粒径及分布等性能,分析乳化剂选择及复配、乳化剂用量、蜡水质量比、搅拌速度、乳化温度和时间等因素对蜡乳液粒径及其分布的影响。试验结果显示:采用相反转工艺,以乳化剂Span-80、Tween-80和助乳化剂十二烷基硫酸钠组成乳化剂体系,在乳化剂的用量为蜡质量的20%、蜡水质量比为1∶5、乳化温度为90℃、搅拌速度大于1 500 r/min,乳化时间为40 min条件下,能够得到平均粒径小于100 nm的蜡乳液。透射电镜照片显示蜡乳液粒子形状为球形。     

三组份锂质瓷烧成中的物相变化

本文研究了三组份锂质烧烧成过程中的物相变化。试验证明：１０００℃以β－锂辉石与Ａｌ－Ｓｉ尖晶石，石英反应生成β－锂辉石固体，随温度升高，β－锂辉石固溶体中ＳｉＯ２量增加，其ｄ（２０１）值变小；降温过程中，β－锂辉石固溶体从液相中析出，析晶速度较快时，其ｄ（２０１）值较小。     

Influence of Particle Size on Nonisothermal Crystallization in a Lithium Disilicate Glass

In this study, lithium disilicate (LS₂) glass samples with different particle sizes ranging from less than 105 to 850 μm were prepared. These specimens were inserted in a Pt‐Rh DSC crucible and heated to 850°C at different rates (? = 0.5–30 K/min) to identify their crystallization peaks. The activation energies for the overall crystallization (E) and the Avrami coefficient (n) were evaluated using different nonisothermal models. Specifically, n was evaluated using the Augis–Benett model and the Ozawa method, and E was evaluated using the Kissinger and Ligero methods. As expected, the coarse particles mainly crystallized in the volume, while surface crystallization was predominant in the samples with particle sizes of less than 350 μm. This result was confirmed through SEM analysis of the double stage heat‐treated samples. In contrast with previous studies, our results demonstrated that the activation energy decreased as the particle size increased. In addition, no clear correlation between the peak intensity (δT_p) and the particle size was observed.     

玻璃粉粒度对复合胶凝材料性能的影响

用激光粒度分析仪测定不同细度的玻璃粉粒度分布,以灰色关联方法( GIA)和扫描电子显微镜( SEM)研究了玻璃粉粒度对复合胶凝材料性能的影响。研究结果表明,玻璃粉中10μm以下的颗粒关联性均为正,说明这些颗粒对复合胶凝材料强度发展有积极贡献,其中以5~10μm的关联度为最大;而?45μm的颗粒呈负关联,其火山灰活性没有得到充分发挥;玻璃粉经适当物理磨细(35 min)后,能更有效地分散到复合胶凝材料的孔隙中,使复合胶凝材料的结构更加密实,从而提高了复合胶凝材料的抗压强度。     

激光粒度仪法测定HDPE粉末粒度及粒度分布的研究

将HDPE粉末分散在乙醇-水介质中,用激光粒度仪动态测定其粒度及粒度分布。     

锂辉石的成矿及在陶瓷和玻璃工业中的应用

锂辉石为典型的伟晶岩矿物，主要生成于花岗伟晶岩脉中。由地其独特的化学性质，使之在陶瓷和玻璃工业中的应用越来越普遍。并以其熔剂效应强，膨胀系数低，而提高烷融效果及显著改善制品的热稳定性，化学稳定性和机械性能。     

Controlled Crystallization and Properties of Zirconium Fluoride-Based Glass-Ceramics

51ZrF₄16BaF₂, 5LaF₃.3AlF₂,.20Li.F5PbF₂, glasses were pre-pared with CdF, additions of 0, 2, 5, and 7.5 mol%. The glasses with 2 and 5 mol% exhibited controllable nucleation upon heat treatment above the glass transformation tem-perature. The nucleation and crystallization of glasses with 5 mol% CdF, were characterized using bulk heat treat-ments, differential scanning calorimetry, and scanning elec-tron microscopy. The isothermal crystallization of nucleated glasses resulted in the formation of a glass-ceramic that was transparent in the infrared (>70% transmission) and more resistant to fracture than typical fluoride glasses.