화학공학소재연구정보센터
Separation Science and Technology, Vol.41, No.3, 549-572, 2006
Extraction and separation of germanium using Cyanex 301/Cyanex 923. Its recovery from transistor waste
The extraction of Ge(IV) from HCl, HNO3 and H2SO4 media in toluene solution of Cyanex 301 and Cyanex 923 is investigated. It is almost quantitatively extracted (similar to 95%) in Cyanex 301 and Cyanex 923 at 8 molL(-1) HCl but the extractions from H 2 SO 4 and HNO3 are poor in the entire investigated range of acid molarity. Detailed investigations were carried out from HCl medium. Based on the slope analysis data the extracting species is identified as GeCl 4 center dot 2R (R=Cyanex 301/Cyanex 923). The extraction of Ge(IV) is higher and comparable in diluents like toluene, n-hexane and kerosene (160-200 degrees C) and there is no correlation between the dielectric constant and the percent extraction. The extractants are stable towards prolonged acid contact and there is negligible loss in their extraction efficiency even after recycling them for several cycles. The extraction behavior of commonly associated metal ions namely As(V)/(III), Sn(IV), Tl(III), In(III), Ga(III), Fe(III), Al(III), Hg(II), and Cu(II) has also been investigated. Based on the partition data conditions for attaining some binary and ternary separations involving Ge(IV) have been optimized. The separation data have been fused to develop a scheme for the recovery (93%) of pure germanium (similar to 99%) from semi conductor waste.