Abstract: The effects of original glass structure and composition, leaching temperature, time and the concentration of the acid solution on the purity of the drawn sodium-boro-silicate glass fibers without phase separated were systematically studied by using Nuclear Magnetis Resonance (NMR) and Ramanru-1000 Model Raman spectroscopy. The results show that tingh purity and ultrafine silica fibers can be obtained by acid leaching method. The low of leaching monsiliceous constituents was found to be the residual contents of nonsiliceous constituents in the fibers also decrease continually, as the leaching temperature and time increasing, and the decreasing speed gets slower and slower. A minimum point appears on the curve of the residual contents of nonsiliceous constituents vs the acid concentration with acid concentration increasing. Furthermort, leaching mechanism was discussed on the basis of experimental results, which can be considered as a process of ion exchange and diffusion.

Key words: acid leaching, silica glass fiber. nonsiliceous constituents, ion exchange, diffusion