Dynamic and mass-exchange parameters of scandium recovery by TVEX-TBP in column mode from the solution after salt chlorinator cake leaching

Abstract

The paper deals with scandium extraction with Levextrel-type resin named TVEX contained tributyl phosphate (TVEX-TBP) in the column mode from the clarified solution formed after leaching salt chlorinator cake formed at Zaporozhye Titanium & Magnesium Combine Ltd. It was found that TVEX-TBP featured high extraction parameters. Total dynamic exchange capacity was defined. Mass-exchange parameters were calculated for scandium extraction in the column mode taking into account the impact of external diffusion kinetics: time to form the equation concentration front, front parallel transfer time, concentration and kinetic recovery factors, kinetic factor of external diffusion, linear speeds of the solution in the column and the equilibrium concentration front motion. The calculated mass-exchange parameters may be used to design the column cascade for scandium extraction from the clarified leaching solution of the salt chlorination cake in column mode. There are the following advantages of scandium extraction with TVEX-TBF in the column mode in comparison with its recovery in a reactor cascade: simpler hardware design and process control, the possibility to better wash TVEX from impurities, getting a strippant higher Sc concentration, reduced TVEX abrasion.