To obtain accurate contents of specific fiber particles of titanate products with an industrially practical method, conventional SEM observation and computer-aided dynamic image analysis (DIA) method were compared for newly developed sodium hexatitanate with extremely low fiber particle content. Measurements with the two methods are highly consistent with each other in the small powder size range. Most conspicuous difference between the two is the number of particles measured (population), which strongly affects the fiber content values. The fiber content obtained by the DIA method represents the whole product while that obtained by the SEM method represents the only small powder size range. However, the fiber content values obtained by the DIA method can be easily reduced by adding some large sized heavy particles, indicating that the upper limit of the fiber content in the commercial products should be regulated together with a particle size range to be measured. Scatter of the data obtained by the DIA method which deals with a large number of particles in a very short time is very small compared to the SEM method, and the DIA method is recommended as one of the convenient measurement methods for fiber contents in titanate from viewpoints of statistical accuracy and practicality.
Daisuke Taki, Toho Titanium Co., Ltd., Japan; Hideki Sakai,, Hideki Fujii