Селективное выделение благородных металлов из водных растворов с помощью дитиооксамидированного полисилоксана

Шакирова Екатерина Андреевна

Аннотация


Shakirova Ekaterina Andreevna's master's thesis on the topic «Selective extraction of precious metals from aqueous solutions using dithiooxamidated polysiloxane», which includes 59 pages of printed text, 16 tables, 18 figures and 89 bibliographic references.
In this work, the conditions of sorption of silver (I), palladium (II) and gold (III) from individual solutions on dithiooxamidated polysiloxane (DTOAPS) in the dynamic mode are investigated. The output exchange curves calculated the dynamic exchange capacity of the polysiloxane. Comparing it with the literature data, they found that DTOAPS has a high sorption capacity.
The influence of the method of synthesis of dithiooxamidated polysiloxane on its sorption properties is estimated. It was established that the sorbent obtained in two stages has the advantage in the sorption parameters before the sorbent, which was synthesized in one stage.
The selective properties of DTOAPS with respect to ions of noble metals depending on the acidity of the medium were studied. It has been established that in an acidic environment, the ions of the gold (III) and palladium (II) are jointly extracted from multicomponent systems in a dynamic mode. The dependence of the sorption of silver (I) and gold (III) from a multicomponent solution was studied. It was shown that at pH=8 on dithiooxamidated polysiloxane, silver (I) and copper (II) are extracted together with gold (III) and accompanying alkaline earth and transition metals. And in an acidic medium (1.5 M HCl), there is a selective separation of gold (III) from silver (I) and non-precious metal ions. The effect of the acidity of the medium on the selective properties of dithiooxamidated polysiloxane with respect to silver (I) and palladium (II) ions was studied in a dynamic mode. It was established that sorption of palladium (II) prevails in an acidic medium (1.5 M HCl), and silver (I) dominates in alkaline (pH=8). The possibility of applicability of dithiooxamidated polysiloxane for the extraction of noble metal ions on real objects has been studied.
In addition, it was found that the sorption of palladium (II), gold (III) and silver (I) under dynamic conditions is reversible; quantitative desorption is possible when the sorbent is treated with hydrochloric acid and sulphate of thiourea.
On the basis of all the experimental data obtained, a method for the sorption of silver (I) and palladium (II) was proposed, which makes it possible to separate and extract these metal ions.