In order to obtain the optimal technique conditions for preparing the super clean coal,taking industry washing oil as solvent,super clean coal was prepared by heat extraction with 1 /3 coking coal from Xiaokang Village. The initial pressure,residence time,coal particle size,cold- hot filtering method,volume ratio of solvents and other factors were investigated on the properties of coal heat extraction and the industry washing oil recycling times was studied. The results showed that in an inert environment,e...