PRODUCTION OF FUNCTIONAL INORGANIC MATERIALS, ALPO4-5, FROM WASTES IN ALUMINUM REGENERATION INDUSTRY

摘要

Hydrothermal synthesis of AIPO4-5, which is one of the aluminum phosphate condensates like zeolitic materials and has large pore size, was carried out using aluminum dross as a raw material. Triethylamine (TEA) was used as a structure directing agent (SDA) for AIPO4-5 synthesis. Various physical properties such as crystal structure, surface texture and specific surface area were investigated for the obtained reaction product. AlPO4-5 can be synthesized from aluminum dross in the hydrothermal condition of 453 K-473 K and 3h. At the same time, AlPO4-34 and AlPO4 are formed as by-products. The crystal of the obtained AlPO4-5 has a hexagonal structure from SEM photographs. It is desirable to heat the reaction product at the temperature around 823K to remove TEA. The crystal structure of AlPO4-5 changes to aluminum phosphate, which is non-porous material, in case of the heat treatment over 973 K. The specific surface areas of the reaction product before and after heat treatment at 823 K are 17.9 m2/g and 358.2 m2/g, respectively