METHOD OF PREPARING THALLIUM (III) OXIDE Russian patent published in 2001 - IPC

FIELD: recovery and purification of thallium including isotope enriched thallium prepared by electromagnetic separation method. SUBSTANCE: pure metallic thallium is dissolved in concentrated nitric acid by addition of concentrated hydrochloric acid at ratio of 3:1, and solution is maintained at 80-90 C till it becomes disclosed. Thallium (I) is oxidized to thallium (III). Thallium hydroxide is deposited by addition of ammonia. After washing and filtration, Tl₂O₃×H₂O dehydration is carried out at 200-300 C. Method makes it possible to recover 99.6-99.8 of thallium in the form of oxide. Method uses standard equipment, inexpensive reactants and insignificant amount of electric energy. EFFECT: more efficient preparation method. 6 ex