Preparation of nanosized anatase TiO2-coated kaolin composites and their pigmentary properties

Nanosized anatase TiO₂-coated kaolin composites were prepared by the chemical deposition method starting from calcined kaolin and TiCl₄. The resultant TiO₂ nanoparticles on the kaolin surfaces existed in anatase phase after calcination at 200, 400, and 900 °C for 1 h, respectively. The surfaces of the kaolin powders were uniformly coated by a monolayer of TiO₂ nanoparticles. The higher calcination temperature was beneficial to formation of well crystallized anatase TiO₂ nanoparticles. The light scattering indexes of the TiO₂-coated calcined kaolin composites were two times higher than that of the kaolin substrate. XPS analysis shows that TiO₂ coating layers anchored at the kaolin surfaces via the Ti-O-Si and Ti-O-Al bonds.     

高岭土在FCC催化剂中的应用

介绍了高岭土在FCC催化剂应用中作用原理,以及国内外发展概况。论述了高岭土在半合成和全白土型催化剂合成中其原料的理化性质、产地以及酸碱改性等对产品的影响,并试图找到影响产品催化裂化性能的内在原因。     

广西北海市矿山地质特征及找矿潜力分析

针对广西北海市矿山矿产资源丰富,为此提出广西北海市矿山地质特征及找矿潜力分析。广西北海市矿产主要为岩体风化型高岭土,次为沉积型软质高岭土、石膏、钛铁砂矿、金等。其中,那车垌岩体风化型砂质高岭土已控制的矿石资源量多达8.42亿多吨,矿床储量居广西乃至全国首位。广西北海市矿山综合外部环境较好,经济效益明显,具有较好的找矿前景。     

我国玻纤用叶蜡石和高岭土开发现状

叶蜡石是我国E玻璃纤维生产的主要原料.主要矿区在东南沿海的浙江、福建两省、目前已有三家专有矿粉厂加工生产,另有桐乡巨石、泰山玻纤集团自己的石粉加工厂,足可满足全国玻纤用量,2005年再扩展到60万t玻纤产量也能保证供给,而且还有正在开发的高岭土粉准备为玻纤生产服务.关键是各矿粉厂、玻纤厂如何选择优质叶蜡石粉保证长期、稳定的供贷渠道,以及如何注意矿粉的合理搭配使用,保证池窑拉丝的正常进行.     

高岭土与氢氧化镁合成高性能堇青石材料

本研究采用高岭土和Mg(OH) 2 在常压氧化气氛 13 5 0℃～ 14 0 0℃合成高性能的堇青石陶瓷材料 ,热膨胀系数为 1.5 2× 10 -6/℃(10 0 0℃ )。     

低品位高岭土制备莫来石的研究

以苏州低品位高岭土为原料,分别研究了直接煅烧和添加氢氧化铝煅烧制备3∶2型莫来石。通过XRF、DTA、XRD、IR等测试手段,研究了样品分别经1 000~1 500℃煅烧1 h后的相转变过程。结果表明:高岭土直接煅烧在1 500℃可生成不含方石英的3∶2型莫来石产品。添加Al(OH)3可以降低3∶2型莫来石的合成温度至1 300℃,但结晶度较低,提高煅烧温度虽然可提高结晶度,但刚玉相的出现降低了莫来石的氧化铝含量。     

The membrane properties of alumina-coated alumina support layers and alumina-coated diatomite–kaolin composite support layers

ABSTRACT

Porous ceramic membranes are a current research focus because of their outstanding thermal and chemical stability. Recent research has utilised inexpensive natural materials such as diatomite to reduce the expense of these porous ceramic membranes. However, insufficient data exist for microfiltration applications using the diatomite-based membranes. The measured membrane properties of alumina-coated alumina support layers and alumina-coated diatomite–kaolin composite support layers have been compared. These experiments have been used to determine whether the average pore size could be reduced effectively by controlling the thickness of the alumina coating layer, while maintaining acceptable water permeability. The membrane properties of the alumina-coated alumina support layers and the alumina-coated diatomite–kaolin composite support layers were examined using the scanning electron microscopy, mercury porosimetry, and a dead-end microfiltration system.     

以低温固相碱熔活化高岭土为原料合成ZSM-5分子筛

以天然矿物高岭土为主要硅铝原料,经低温固相碱熔活化后,在常规水热条件下合成ZSM-5分子筛,考察m(高岭土)∶m(氢氧化钠)、碱熔温度及碱熔时间等因素对高岭土活化效果的影响。采用XRF、XRD、FT-IR和N2-吸脱附等对不同样品进行表征。结果表明,在m(高岭土)∶m(氢氧化钠)=1∶1.5、碱熔温度250℃和碱熔时间30 min条件下,可以实现高岭土完全活化。该活化方式不仅降低了活化温度,且能在极短时间内提高高岭土活性。以最适宜低温固相碱熔活化条件下所得活性硅铝物质为主要原料,硅溶胶为外加硅源,采用水热法合成高相对结晶度的纯相ZSM-5分子筛。与工业ZSM-5分子筛相比,合成ZSM-5分子筛具有更大的比表面积和孔容。     

xCeO_2/高岭土催化剂上丙烷氧化脱氢制丙烯

采用浸渍法制备不同CeO_2负载量的xCeO_2/高岭土催化剂,采用XRD、N_2吸附-脱附、H_2-TPR和XPS等对催化剂物化性质进行表征。将xCeO_2/高岭土催化剂应用于丙烷氧化脱氢反应中,考察CeO_2负载量对丙烷氧化脱氢反应的影响,同时对催化剂进行原位电导测试。结果表明,CeO_2负载质量分数8%时,CeO2/高岭土催化剂的催化性能最好,500℃时,丙烷转化率为17.92%。在氧-丙烷-氧+丙烷连续变化的不同气氛下均显示了氧化还原可逆性。