Recently, needs for reduction of raw material usage and use of low-quality raw materials have been growing in each steelworks. When the time has been ripe for prevention of global warming, the introduction of energy-saving equipment is also required investments in the iron- and steelmaking industry. In response to these needs, a coal moisture control system (hereafter referred to as “CMC”) has been introduced to produce coking coal for environmental preservation and energy conservation purposes. CMC is a preliminary coal treatment process in which charge coal for a coke oven is dried and is expected to bring about the advantages of “reduced carbonization heat value of coke ovens,” “improved coke quality,” and “increased coke production.” Since the introduction of the steam tube dryer (STD) type CMC of the 1st generation in 1983, Nippon Steel Corporation (NSC) has pursued the improvement of equipment and processes, and succeeded in developing the fluidized bed (FB) type CMC of the 3rd generation in 1996. Currently, NSC has been constructing the FB type CMC in Maanshan Iron & Steel Co., Ltd. As the New Energy and Industrial Technology Development Organization (NEDO) project between China and Japan. The FB type CMC of Nippon Steel Engineering Co., Ltd. (NSEC) makes use of coke oven exhaust gas for fluidization gas and is a process with the higher effect of energy conservation than that of STD type CMC that uses steam as a drying heat source, etc. Furthermore, in China an FB type CMC that dries coking coal before pulverization has been running, but NSEC FB type CNC is a process that dries coking coal after pulverization. NSC conducted experiment on the drying efficiency of these two types of fluidized bed (FB) dryers and has conformed that the smaller the grain size would be, the higher the drying efficiency would be, which enables a fluidized bed to be formed without partial excess drying and overheat.