Abstract: An economical method for liquefying low rank coal is proposed.

Abstract: Method of processing low rank coals which comprises steps of classifying crushed low rank coals into middle sized lumps and minute particles, subjecting the middle sized lumps to a non-evaporating dehydration treatment to produce low moisture content coals, separating ash content from the minute particles and then at least partly liquefying the minute particles to produce liquefied oil, and mixing the liquefied oil with the low moisture content coals to thereby produce low moisture coal-oil slurry. The method makes it possible to utilize even small sized particles of coal in a practical manner.