Features of the Microstructure and Chemical Compositions of Vanadium-Containing Slags Including Determination of Vanadium Oxidation Degrees

Abstract

Metallurgical vanadium-containing converter slag could be used as an alternative vanadium source. The development of a physico-chemical basis for the comprehensive processing of industrial vanadium-containing debris requires information about their elemental composition as well as the oxidation degrees of the elements and forms of compounds in order to solve two key problems: a better utilization of industrial wastes and a lowering of environment impact. This research was aimed at the development of methods to determine the fractions of elements and their oxidation degrees in vanadium-containing industrial debris exemplified by basic oxygen converter vanadium slags. A set of bulk and surface analysis methods (X-ray fluorescence analysis (XRF), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS)) was used for this purpose: based on results of elemental analysis, SEM detects the oxide phases of metals, while an analysis of the XPS lines’ fine structures provides fractions of corresponding elements with definite oxidation degrees. In this way, one can determine the fractions of vanadium in multiple oxidation degrees in slags and can properly select the chemicals and parameters of chemical processes for its fullest extraction.

Study of Forms of Compounds of Vanadium and Other Elements in Samples of Pyrometallurgical Enrichment of Ash from Burning Oil Combustion at Thermal Power Plants

“…In previous works, we have shown the influence of the degree of oxidation and forms of compounds of elements on the manufacturability of processing the corresponding raw materials [ 41 , 42 , 43 ]. To study the mineral composition and the degree of oxidation of elements in vanadium raw materials, the following methods are described: X-ray phase analysis [ 44 , 45 , 46 ], X-ray photoelectron spectrometry [ 45 , 47 , 48 ], titrimetric [ 44 , 45 , 49 ], electrochemical methods [ 44 ], mass spectral [ 50 ], thermal analysis [ 48 ], infrared spectrometry [ 48 ], electron microscopy [ 46 , 47 ], study of the fine structure of the X-ray absorption spectrum (XAFS) [ 17 ], and nuclear magnetic resonance method [ 27 ].…”

Determination of Composition of Raw Materials for Porcelain Fabrication by XRF, TOF-SIMS, and XPS Methods for Further Porcelain Art Items Characterisation and Detection of Modern Counterfeits

“…In accordance with the traditions of analytical chemistry compositions of complex oxide systems such as ores, ceramics and so on is listed for most elements in terms of oxides where oxides of polyvalent metals are given in maximal oxidation degrees. So, XRF data for vanadium compounds in slags was given for V2O5 oxide while XPS has demonstrated that it was presented only in V 2+ and V 3+ states [18]. One can see from Table 1 that XRF is enough sensitive to detect small impurities with content down to 0.003 %mass.…”