Bismuth preoxidation for preparing solutions of salts

Abstract

The oxidation of metal bismuth after the introduction of bismuth oxide, ammonium nitrate, sodium chloride or carbonate into its melt, as well as the effect of mechanochemical preactivation on the oxidation process have been studied by X-ray diffraction analysis and thermogravimetry. It has been established that the oxidation of metal bismuth occurs at the dispersion stage, and the mechanochemical pretreatment of metallic bismuth mixed with 10–30% of its oxide leads to a decrease in the temperature of the onset of bismuth oxidation from 350 to 200°C. An ecologically pure method for obtaining concentrated solutions of various bismuth salts from metal by its preconversion to oxide and dissolution in mineral acids has been shown to be useful.