Method for making mullite whiskers using hydrofluoric acid

摘要

A method for making mullite whiskers includes the steps of: P Ppreparing a mullite-intensive sol by mixing an alumina sol with a silica sol at a molar Al.sub.2 O.sub.3 /SiO.sub.2 ratio of 1.37-1. 76, PPgelating said mullite-intensive sol by adding HF thereto at a molar HF/3Al.sub.2 O.sub.3 ·2SiO.sub.2 ratio of 0. 01- 0.1,PPdrying the gel at a temperature lower than 120. degree. C.; andPPcalcining the dried product in an open system at a temperature up to 1000° C. and in a closed system at a temperature from 1200°-1600° C.