ギーセラー流動性の測定方法

抄録

Testing method for plastic properties of coal by the Gieseler Plastometer has beeng employed in the revised JIS M 8801-1972 (Testing methods for coal).
Therefore, we studied on the instrumental factors which would affect the data of the Gieseler Plastometer, one of the quite useful informations to Japanese coke industries in evaluating the quality of metallurgical coals.
Informations obtained are as follows:
1) The physical condition of a joining part between crucible and stirrer play very important role on plastic properties. Although their qualities do affect plasticities slightly.
2) The stirrer shall be replaced after wear to the extent that the diameter of rabble arms are reduced to 1.5 mm, because a maximum fluidity increases rapidly as soon as they are worn to less than 1.4 mm in their diameters.
3) With regard to the sample size, the significant difference of the maximum fluidity is observed between two samples of-35 mesh and-60 mesh. Overcrushing, therefore, must be avoided carefully in sample preparation.
4) As the decrease of the maximum fluidity can be recognized after about one month from sample preparation, the measurement should be done as soon as possible when a sample is prepared.
5) The repeatability in same laboratory obtained by the interlaboratory experiment was superior to the tolerance specified in ASTM D 1812-69, however, the reproducibility between different laboratories was an unsatisfactory result, probably due to the differences in the apparatus of each laboratory.