ON IMPROVING THE ACCURACY OF THE HF LEACHING TECHNIQUE.

A method to modify the HF leaching technique is put forward. According to this modified method, the dissolution rate of mullite in hydrofluoric acid is measured for the sample to be analyzed, and the amount of mullite in the residue is calculated from the results of chemical analysis. With these, the amount of mullite dissolved in hydrofluoric acid can be calculated and subtracted from the weight loss of the sample, resulting in satisfactory accuracy of the quantitative analysis of the amount of glassy phase. A comparison of the accuracy of the modified HF leaching technique with those of the unmodified HF leaching technique shows that the accuracy of the modified technique is much higher than those of other techniques.