Inorganic Phosphate Crystal Na_(15-n)[al(po_4)_2f_2]_(3-n)[ti(po_4)_2f_2]_n (0 ≤ N < 1): A Novel Cation Exchanger With High Exchange Selectivity For Li~+ And Pb~(2+) Ions

摘要

A series of inorganic phosphate crystals have been hydrothermally synthesized, which have high chemical stability and can keep their crystal structure after acid/base treatments. Its cation-exchange properties have been investigated and the results show that it is an excellent ion exchanger with high exchange capacities for H~+, Li~+ and Pb~(2+) ions (12.74, 6.98 and 3.92 mequiv./g, respectively). Selective extractions of Li~+ and Pb~(2+) from the synthetic mixtures containing (Li~+, Sr~+, K~+, Mg~(2+), Ca~(2+) and Ba~(2+)) and (Pb~(2+), Ca~(2+), Ba~(2+), Co~(2+), Ni~(2+), Zn~(2+) and Mg~(2+)) have been observed. The reasons of the high exchange selection of NATP for Li~+ and Pb~(2+) ions have been discussed.