SORPTION OF LITHIUM IONS FROM AQUEOUS SOLUTIONS ON TRANSCARPATIAN CLINOPTILOLITE

Abstract

The spectrophotometric method using thoron was optimized to determine the breakthrough point of lithium during its sorption on Transcarpathian clinoptilolite. The selectivity of this method towards zeolite cations was investigated. The results show that Na+, K+, Mg2+, Ca2+, Al3+, and Fe3+ ions which are present in clinoptilolite do not interfere with Li+ determination in the analyzed model solutions. The sorption properties of natural Transcarpathian clinoptilolite towards trace amounts of lithium in aqueous solutions were studied. The findings indicate that this natural aluminosilicate can be used as a sorbent in solid-phase extraction. The most effective sorption occurs from solutions at pH 6.5 using pre-fired at 350 °C clinoptilolite samples. Under optimal conditions, the sorption capacity of clinoptilolite towards lithium is 538 μg/g.