OJSC Scientific and Industrial Complex “Supermetall”

I. V. Boryagina, Junior Researcher, Post Graduate Student, e-mail: IrinaBoryagina@mail.ru

M. V. Lomonosov Moscow State Academy of Fine Chemical Technology

E. V. Volchkova, Assistant Professor

T. M. Buslaeva, Professor

M. V. Vasilyeva, Specialist

M. V. Lomonosov Moscow State University

G. V. Ehrlich, Leading Researcher

Sorption of palladium (II), platinum (II) and platinum (IV) from the hydrochloric acid solutions of the chemically modified silica is studied, depending on the phase contact time, the pH of solutions, the metal concentrations and the temperature. The settling time constant values of the degree of extraction of Pt (II) and Pt (IV) is 20 minutes. The degree of extraction of Pd (II) is 5 minutes. The degree of metals extraction is reduced with the increasing acidity (from 0.1 to 10 mol/l HCl). On the basis of the studies, it is suggested the lead sorption from 0.1 mol/l hydrochloric acid solutions. Using the IR and electronic spectroscopy, there are established the types of complexes, formed in the sorbent phase – silica, which is modified by g-aminopropyl triet hoxysilane groups — depending on the acidity of the solution. Sorption of Pd (II) occurs mainly on the anion exchange mechanism as a result of protonation of the nitrogen atom of the functional group. In solutions with high concentration of palladium, there is probably the polymerization of adsorbed complexes. The Pt (IV) sorption occurs from the weakly acid solutions, primarily through the mechanism of complex formation, and from the acid solutions by anionexchange mechanism. The Pt (II) sorption is characterized by the occurrence of functional groups of the sorbent into the inner coordination sphere of the complex, which indicates the occurrence of sorption on the mechanism of complex formation. There is proposed to use the hydrochloric acid solutions of thiourea as the event. On the basis of the researchings, there is proposed the sorption separation scheme Pd (II) and Pt (IV). The results indicate the prospects of using the chemically modified silicas for the separation and isolation of ions of platinum (IV) and palladium (II) from hydrochloric acid solutions.

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