Chemistry, Vol 13, No 3 (2020)

Extraction of scandium halides with mixtures of tributylphosphate and molecular iodine

Vladimir Ivanovich Kuzmin, Anna Alekseevna Kuzmina, Sergey Nikolaevich Kalyakin, Marina Aleksandrovna Mulagaleeva

Abstract


The extraction of scandium chlorides, bromides and iodides from aqueous solutions with mixtures of tributyl phosphate (TBP) and molecular iodine was studied. Extraction of scandium halides using TBP with the addition of iodine increases by more than 100 times. Salt distribution coefficients increase in the series ScCl3 3 3. The composition of the complexes was determined by isotherms of extraction and electrical conductivity of the organic phase. For chloride and bromide systems, compounds are formed with the ratio ScX3: I2 = 1:1 or 1:2, depending on the iodine concentration; for iodide systems, the formation of a solvate with the ratio ScI3:I2 = 1:4is established. The recovered compounds decompose into ions in the organic phase. When iodine is added to TBP, the extraction of all metal halides also increases with a predominant increase in the extraction of low charged alkali metal cations.