Abstract: Recovery of germanium from the effluent of optical fiber manufacturing processes depends on the realization that the germanium is to a substantial extent in gaseous form. Thus, to separate the germanium effectively appropriate measures are taken to separate not only particulate matter but also gaseous germanium compounds. This separation is done through among other steps an appropriate solvation and precipitation to remove the gaseous germanium material.

Abstract: A hydrolysis method of purifying silicon tetrachloride is shown that reduces losses in optical fibers made from silica produced therefrom. Water is added to impure liquid silicon tetrachloride, which forms a gel which is then separated from the remaining SiCl.sub.4. Metal impurities, OH-containing impurities, and SiHCl.sub.3 are removed by this process. In a preferred embodiment, the water is added by bubbling a wet gas through the SiCl.sub.4. A residual amount of OH containing impurities and HCl is left after the hydrolysis, which impurities may be further removed by a refluxing technique.