EXTRACTION OF ZIRCONIUM(IV) FROM SULFURIC-ACID-SOLUTIONS WITH AMINES AND MATHEMATICAL SIMULATION OF EXTRACTION PROCESSES

The knowledge of extraction equilibrium and its mathematical description is basic information necessary for the design of separation process and equipment. The comparison of the extraction of zirconium sulfate in aqueous sulfuric acid solutions with high-molecular amines - tri-n-laurylamine, tri-n-octylamine, di-n-nonylamine, Primene JMT, p-dodecylaniline - in organic solvents has been investigated by varying the concentration of acid, solvent and aqueous zirconium. Stoichiometric equations for the extraction of zirconium(IV) at various acid concentrations were suggested. Taking into account these extraction equilibria, the presence of the various species of zirconium in the aqueous phase with known thermodynamic stability constants, mass balance equations and equation for electroneutrality, a model capable of predicting equilibrium compositions of the phases with great reliability and without restrictions on the composition of the aqueous phases is suggested.