Improved Coal Pulverization Method Using the Embrittlement due to Cracks Generated in Pores of Coal [Translated]<sup>†</sup>

Abstract

Pulverized coals produced by a rounding method have a wide range of particle sizes. Even though the coals have the same Hardgrove Grindability Index (HGI), some coals are difficult to pulverize by the rounding method.There are many pores in the coal. When pore pressure is rapidly reduced, cracks are generated in the pores by the expansion of air and the coal becomes brittle. The purpose of the present work is to investigate the performance of coal pulverization by an improved rounding method specifically by the embrittlement of coal due to the cracks generated in the pores.The experimental results show that pulverized coals for CWM which have a wide range of particle size can be easily produced by the improved rounding method. Furthermore, a discharge pressure at the embrittlement treatment can control the particle size of the pulverized coals.† This report was originally printed in J. Soc. Powder Technology, Japan, 38(9), 607-611 (2001) in Japanese, before being translated into English by KONA Editorial Committee with the permission of the editorial committee of the Soc. Powder Technology, Japan.