Investigation of the forms of occurrence of nonferrous metals in oxyhydroxides from the process of nitration of chloride solutions

Abstract

Using the methods of X-ray photoelectron spectroscopy (XPES), X-ray phase analysis, gamma-resonance (Mossbauer) spectroscopy, thermogravimetry of solid samples and atomic absorption, and atomic emission spectroscopy for solutions, the forms of occurrence of nonferrous metals in oxyhydroxide sediments (nitration hydroxides, NH) from nitration of refining of rhodium, iridium, and ruthenium are investigated. According to the XPES data, nitration hydroxides involve oxidized and unoxidized (selenium) transition metals, namely, Fe(III), Sn(II), Te(IV), Cu(I), Cu(II), Ni(II), Pb(II), As(III), Se(0), and Se(IV), as well as nonmetals O, Cl, and C. All nitration hydroxides are formed mainly by an X-ray amorphous phase (>90%). During heating of nitration hydroxides up to t = 900°C in an inert atmosphere, dehydration of hydroxides and crystallization of certain phases take place, but the X-ray amorphous phase amounts to more than 50%. Purely oxide phases or mixed oxide phases Fe3O4, SnO2, CuIFeIIIO2, and Pb2O3 (NH-1); Ni0.4Fe2.6O4, CuIFeIIIO2, and CuNiSnO4 (NH-2); and Fe3O4, Fe2O3, and SnO2 (NH-3) are formed in this case.