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The work is devoted to the study of the possibilities of minimizing the release of nitrogen oxides during the dissolution of silver in nitric acid solutions during refining of the gold and silver alloy. Using a rotating disk, the maximum concentration of nitric acid is determined, at which the oxidation potential of the system is insufficient for the oxidation of silver. It has been established that at a temperature of 363 K and a concentration of HNO3 = 50 g/dm3, the dissolution rate of silver does not exceed 0,00022∙10-5 mol/(cm2 ∙ s) and such conditions can be considered as background for an environmentally friendly process. To initiate dissolution, hydrogen peroxide was used as an alternative oxidizing agent. As a criterion for the rational use of the oxidant and the ecological purity of the process, the excess pressure over the solution was evaluated. The influence of the initial and current composition of the solution, temperature, and conditions of oxidant supply to the reactor on the kinetics of the target process was studied. It is shown that at a silver dissolution rate of 2,7∙10-6 mol/(cm2 ∙ s), no release of nitrogen oxides was observed.
Translated title of the contributionTo the Problem of Reducing the Amount of Harmful Emissions when Refining Silver
Original languageRussian
Title of host publicationАктуальные проблемы развития технических наук : сборник статей участников XXII Областного конкурса научно-исследовательских работ «Научный Олимп» по направлению «Технические науки»
Subtitle of host publicationсборник статей
Place of PublicationЕкатеринбург
PublisherФедеральное государственное автономное образовательное учреждение высшего профессионального образования "Уральский федеральный университет им. первого Президента России Б.Н. Ельцина"
Pages18-25
Number of pages8
ISBN (Print)978-5-91256-495-6
Publication statusPublished - 2020

    GRNTI

  • 81.09.00

ID: 13627836