2017 年 63 巻 6 号 p. 191-195
Japan is one of the resource-rich countries in the world from the standpoint of “urban mine”, and the establishment of simple, low-cost and environment-friendly technology for noble metal recovery is the urgent issue to be solved. In this study, the nonwoven fabric which can adsorb gold ions selectively was developed using nanofiber with extremely high specific surface area as an adsorbent. The nanofiber material useful for gold ion adsorption was explored, and as a result, it was found out that nylon 6 has a great affinity for gold ions. The nanofiber nonwoven fabric was prepared by depositing nylon 6 nanofibers produced by electrospinning method. The mean diameters of nanofibers produced in this study were 143 and 206 nm at the nylon 6 concentrations of 10 and 20 wt%, respectively. The nonwoven fabric with thinner fibers has higher adsorption capacity due to larger specific surface area. The adsorption test of a mixture of Au3+, Cu2+, Al3+ and Fe3+ was also performed. As a result, only gold ions could be selectively adsorbed to the nylon 6 nanofiber nonwoven fabric. Moreover, the desorbability of gold ions adsorbed to the fabric was increased by shifting the immersion fluid to the higher pH environment.