Luo Jun, Jiang Tao, Li Guanghui, Peng Zhiwei, Rao Mingjun, Zhang Yuanbo
School of Minerals Processing & Bioengineering, Central South University, Changsha 410083, China.
Materials (Basel). 2017 Jun 12;10(6):647. doi: 10.3390/ma10060647.
In the present study, porous alumina/silica materials were prepared by selective leaching of silicon/aluminum constituents from thermal-activated kaolinite in inorganic acid or alkali liquor. The correlations between the characteristics of the prepared porous materials and the dissolution properties of activated kaolinite were also investigated. The results show that the specific surface area (SSA) of porous alumina/silica increases with silica/alumina dissolution, but without marked change of the BJH pore size. Furthermore, change in pore volume is more dependent on activation temperature. The porous alumina and silica obtained from alkali leaching of kaolinite activated at 1150 °C for 15 min and acid leaching of kaolinite activated at 850 °C for 15 min are mesoporous, with SSAs, BJH pore sizes and pore volumes of 55.8 m²/g and 280.3 m²/g, 6.06 nm and 3.06 nm, 0.1455 mL/g and 0.1945 mL/g, respectively. According to the adsorption tests, porous alumina has superior adsorption capacities for Cu, Pb and Cd compared with porous silica and activated carbon. The maximum capacities of porous alumina for Cu, Pb and Cd are 134 mg/g, 183 mg/g and 195 mg/g, respectively, at 30 °C.
在本研究中，通过在无机酸或碱液中对热活化高岭土中的硅/铝成分进行选择性浸出来制备多孔氧化铝/二氧化硅材料。还研究了所制备多孔材料的特性与活化高岭土溶解性能之间的相关性。结果表明，多孔氧化铝/二氧化硅的比表面积（SSA）随二氧化硅/氧化铝的溶解而增加，但BJH孔径无明显变化。此外，孔体积的变化更取决于活化温度。通过对在1150℃下活化15分钟的高岭土进行碱浸以及对在850℃下活化15分钟的高岭土进行酸浸所获得的多孔氧化铝和二氧化硅为介孔材料，其比表面积、BJH孔径和孔体积分别为55.8 m²/g和280.3 m²/g、6.06 nm和3.06 nm、0.1455 mL/g和0.1945 mL/g。根据吸附试验，与多孔二氧化硅和活性炭相比，多孔氧化铝对铜、铅和镉具有优异的吸附能力。在30℃时，多孔氧化铝对铜、铅和镉的最大吸附容量分别为134 mg/g、183 mg/g和195 mg/g。
