STUDIES ON THE APPLICABILITY OF DIFFERENT TYPE EXTRACTANTS FOR REMOVAL OF SILVER (I) FROM SULFATE SYSTEMS

Silver (I) extraction was examined and the conditions of silver remova l from 1-9 M H2SO4, 0.2-1.2 M CuSO4 as well as 0.5- 2.0 M ZnSO4 soluti ons were determined. The solutions of Cyanex 471X, Cyanex 921 and Host arex F-3541 in petroleum or toluene with the addition of a modifier we re used as extractants. The best extractant for selective removal of s ilver (I) from the sulphate system proved to be Cyanex 471X - triisobu tylpbosphine sulphide. For Cyanex 471X the optimum conditions were det ermined for silver (I) removal depending on sulphuric acid and purifie d salt concentrations, the kind of solvent and the phase modifier as w ell as the time of a phase contact. It was shown that with the use of the mentioned extractant, it is possible to decrease the silver conten t below 10(-5)% in the purified copper and zinc sulphate solutions.