Hydrothermal synthesis of AlPO4-5 type zeolitic materials by using aluminum dross as a raw material

The hydrothermal synthesis of AIPO(4)-5, which is one of the large pore size aluminum phosphate condensates like zeolitie materials. was carried out by using aluminum dross as a raw material. Triethylamine (TEA) was used as a structure directing agent (SDA) for AIPO(4)-5 synthesis. Various physical properties such as crystal structure, surface texture and specific surface area were investigated for the obtained reaction product. AIPO(4)-5 can be synthesized from aluminum dross under hydrothermal conditions at 453-473 K for 3 h. AIPO(4) salt as a by-product, which is a non-porous material, is formed at the same time. The crystal of the obtained AIPO(4)-5 is hexagonal as observed by SEM photographs. It is desirable to heat-treat the reaction product at the temperature around 823 K to remove TEA. The crystal structure of AIPO(4)-5 changes to non-porous aluminum phosphate in case of a heat treatment exceeding 973 K. The specific surface areas of the reaction product before and after heat treatment at 823 K are 18 and 360 m(2)/g, respectively. (c) 2005 Elsevier Ltd. All rights reserved.