Method for forming basalt fibers with improved tensile strength

摘要

A method of improving the tensile strength of drawn fibers produced from molten basalt rock. Strength is increased by reducing the ferric iron content of the final fibers below that which would be present in the fibers if drawn under normal atmospheric and operational conditions. This is accomplished by either adding a reducing agent to the melt, by drawing the fibers in an inert or reducing atmosphere, or by a combination of both methods.