The determination of zirconium in mineral rutile with Alizarin red S

Abstract

A colorimetric procedure has been developed for the determination of the zirconium oxide content of rutile. A fusion with potassium hydrogen difluoride enables the rutile to be brought into solution rapidly and eliminates the task of filtering off silica. The zirconium is separated from the titanium by a phosphate precipitation, but the interference of tin inherent in the method involving phosphate precipitation followed by ignition to oxide, is eliminated by dissolving the zirconium phosphate and applying a colorimetric finish, with Alizarin red S. Calibration is effected by making additions of zircon to titanium oxide and carrying each through the entire procedure, thus eliminating reagent-blank difficulties. It has been used in the range of 0 to 1 per cent. of zirconium oxide. Good agreement with independent determinations by X-ray fluorescence has been obtained.