Тип публикации: статья из журнала
Год издания: 2021
Идентификатор DOI: 10.3103/S1067821221060043
Ключевые слова: platinum metals, autoclaves, hydrothermal conditions, dissolution, hydrochloric acid media
Аннотация: The results of a study of the features of the dissolution processes of metallic platinum, rhodium, and iridium in hydrochloric acid solutions under hydrothermal autoclave conditions are presented. Hydrogen peroxide is used as an oxidizing agent. Solid and liquid phases are brought into contact after reaching a predetermined temperaПоказать полностьюture, which is critically important in the study of the kinetics of dissolution of rhodium black and platinum plate due to the high rates of these processes. The concentrations of the metals in solutions are determined by atomic absorption spectroscopy and inductively coupled plasma mass spectrometry. The forms of chlorocomplexes of rhodium, iridium, and platinum in solutions are determined with a spectrophotometric method. As a result of the experiments, the modes of quantitative dissolution of a platinum plate and rhodium (in the form of affined powder and a plate) are determined and it is shown that, at 210 degrees C in a medium of 6M hydrochloric acid with the addition of 5 vol % hydrogen peroxide, iridium taken in the form of affined powder dissolved by 50% in over 50 h, while the platinum plate dissolved completely at 130 degrees C in about 120 min. An analysis of kinetic data using the shrinking core model showed that the rate determining the steps of the dissolution of rhodium black and affined rhodium and iridium powders under autoclave conditions were the chemical reactions. These results can be used both in analytical chemistry for quantitatively determining inert platinum metals and in refining production to improve the technology for processing raw materials containing platinum group metals (PGMs) and to optimize approaches to the synthesis of pure chlorocomplex compounds of PGMs.
Журнал: RUSSIAN JOURNAL OF NON-FERROUS METALS
Выпуск журнала: Vol. 62, Is. 6
Номера страниц: 668-674
Место издания: PLEIADES PUBLISHING INC
Издатель: 0