Radiochemical Investigation of the Coprecipitation of Microamounts of Hydrolysing Elements with Metal Hydroxides and -Oxides. Pt. 6. Coprecipitation of Chromium (III)

摘要

The coprecipitation of different amounts of chromium (III) (between 1 mu g and 3.26 mg) with hydroxides of Sn (IV) Fe (III), Th, Be, Cd, and Mg was investigated in dependence of the pH of the solution. It was shown that the acido-basic reaction process of the micro- and macrocomponents is determined by their different acidic properties. The most important coprecipitated type of chromium (III) is the neutral hydroxocomplex Cr(OH) exp 03 . In the pH range of the solution where the microcomponent under investigation does not have a neutral hydrolytic form, its coprecipitation with the precipitate is due to the fact that it appears to react with the collector if there are no positively charged hydroxocomplexes of the macrocomponent in the solution. It is assumed that the reaction of chromium (III) with better hydrolysing elements, e.g. tin (IV) and iron (III) enhances its hydrolysis while reaction with a less well hydrolysing element, e.g. beryllium, hinders its hydrolysis. (Atomindex citation 11:530689)