| abstract |
A solid compound having a volume average particle diameter of not more than 5 νm, for example, silicon dioxide, aluminum oxide, calcium carbonate, or silicon carbide, is deposited on a dry pulverized coal obtained from a feed coal having an average HGI of not less than 30 in such a manner that the value of α falls within the following range to improve the conveyability of the pulverized coal: K1.r0.59 « α « 10 (volume %) wherein K¿1? = 10?-1.42¿ and r represents the volume average particle diameter (νm) of the solid compound added. As a result, the pulverized coal is improved in fluidity and thus can be used as an injection fuel for blast furnaces or pulverized coal firing boilers. Further, it is possible to prevent hanging and changing within hoppers and clogging of piping. |