Эвдиалит Кольского полуострова — перспективный источник получения композиционных Zr – Ti – SiO2 сорбентов цветных металлов и радионуклидов

Abstract

Based on the products of hydrochloric acid decomposition of eudialyte concentrate, composite zirconium-titanium-silica sorbents with a SiO2 content of 10 – 30 wt.% were synthesized and their surface was modified into H+ and Na+-form. All samples were studied by chemical, X-ray phase, BET and BJH assays. It is shown that all the obtained samples of silica-containing Zr – Ti – SiO2 sorbents are mesoporous. At the same time, the pores have a predominantly wedge-shaped shape with open ends, and the maximum pore volume has pores with a diameter lying in the range of 10 – 50 nm (∼ 50 % of the total pore volume). Based on the obtained values of the specific capacity of the adsorption monolayer of the surface of the SiO2 samples and the value of the Gibbs energy change (ΔGo) during nitrogen sorption, it is concluded that the modification of the surface of the synthesized Zr – Ti – SiO2 sorbents does not affect the physicochemical properties of their surfaces and the mechanism of nitrogen sorption. The sorption activity of synthesized samples with respect to Cu2+, Co2+ and Sr2+ ions was studied in batch experiments. It was found that the modification of the obtained samples into the H+-form has less effect on their sorption capacity than their conversion to the Na+-form, does not depend on the content of SiO2 in them in the range of 10 – 30 % and decreases in the range of Cu2+ − Co2+ − Sr2+.