Abstract: This work studied caking index of Shendong Coal (SDC) mixed with different proportions direct coal liquefaction residue (DCLR) and the caking strength of mixture pyrolysis semi-coke. The results indicated that the caking index of the mixture increases with increasing DCLR proportion and decreasing DCLR particle size. With increasing DCLR proportion the caking strength of the mixture pyrolysis semi-coke increases first and then decreases. The caking strength of the semi-coke increased when the pyrolysis temperature increases and the DCLR particle size decreases. Scanning electron microscopy (SEM) showed that as DCLR proportion increases, the number of pores on the semi-coke surface increases, the size of pore became larger and stronger bonding is developed among coal particles.

Key words: shendong coal, direct coal liquefaction residue, caking index, pyrolysis semi-coke, caking strength